DOE-HDBK-1129-2008, Tritium Handling and Safe Storage
Functional areas: Tritium Handling, Safe Storage
Tritium handling practices have evolved over several decades at Department of Energy (DOE) tritium facilities. The objective has been to accomplish required tritium work while minimizing and controlling the exposure of workers, the public, and the environment to tritium. This document provides guidance for the handling, storing, and shipping of tritium. Superseded by DOE-HDBK-1129-2015, dated 9-16-2015.
Project Number SAFT-0123
Supersedes:
DOE-HDBK-1129-2007, Tritium Handling and Safe Storage on Dec 30, 2008
Superseded By:
DOE-STD-1129-2015, Tritium Handling and Safe Storage on Sep 16, 2015
Version history and related documents
Superseded by
A newer version replaces this document.
- DOE-STD-1129-2015Tritium Handling and Safe Storage (Sep 16, 2015)
Supersedes
Earlier documents this one replaced.
- DOE-HDBK-1129-2007Tritium Handling and Safe Storage (Dec 30, 2008)
Document text
Text extracted from the attached file. Refer to the original document for the authoritative version.
Section 1
NOT MEASUREMENT
SENSITIVE
DOE-HDBK-1129-2008
December 2008
DOE HANDBOOK
TRITIUM HANDLING AND SAFE
STORAGE
U.S. Department of Energy AREA SAFT
Washington, D.C. 20585
DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited.
TS
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TABLE OF CONTENTS
SECTION PAGE
FOREWORD................................................................................................................................ ix
ACRONYMS ................................................................................................................................ xi
1.0 INTRODUCTION .................................................................................................................... 1
1.1 Purpose............................................................................................................................. 1
1.2 Scope................................................................................................................................ 1
1.3 Applicability ....................................................................................................................... 1
1.4 Key References................................................................................................................. 1
1.5 Resource Material for Further Information ........................................................................ 6
2.0 TRITIUM ................................................................................................................................. 9
2.1 Radioactive Properties .................................................................................................... 10
2.2 Physical Properties ......................................................................................................... 10
2.3 Chemical Properties........................................................................................................11
2.4 Biological Properties ....................................................................................................... 12
2.4.1 Gaseous Tritium and Tritiated Water ..................................................................... 12
2.4.2 Special Tritium Compounds ................................................................................... 12
2.5 Preferred Forms.............................................................................................................. 13
2.5.1 Characterization of Tritium Forms.......................................................................... 13
2.5.1.a Gaseous Tritium ............................................................................................ 13
2.5.1.b Metal Tritides................................................................................................. 14
2.5.1.c Tritiated Water ............................................................................................... 14
2.5.2 Identity of Common Forms..................................................................................... 15
2.5.2.a Gas................................................................................................................ 15
2.5.2.b Metal Tritides................................................................................................. 15
Section 2
2.5.2.b(1) Uranium .............................................................................................. 15
2.5.2.b(2) Palladium ............................................................................................ 18
2.5.2.b(3) Titanium .............................................................................................. 20
2.5.2.b(4) Zirconium ............................................................................................ 20
2.5.2.b(5) Societá Apparecchi Elettrici e Scientifici (SAES) Getters ................... 20
2.5.2.b(6) LaNi5-Based Alloys ............................................................................. 21
2.5.2.c Absorbed Water............................................................................................. 21
2.5.3 Summary................................................................................................................ 22
2.5.3.a Best for Storage Conditions .......................................................................... 22
2.5.3.b Best for Operations/Process ......................................................................... 22
2.5.3.c Best for Disposal Conditions ......................................................................... 23
3.0 BASIC TRITIUM REGULATORY INFORMATION................................................................ 23
3.1 Tritium Accountability and Environmental Considerations .............................................. 23
3.1.1 Radiological Materials Inventory ............................................................................ 23
3.1.2 Limits for Tritium in Drinking Water and the Environment. ..................................... 25
3.1.3 RCRA Applicability ................................................................................................. 26
3.2 Tritium Safeguards and Security..................................................................................... 28
3.3 Tritium Facility Safety Analysis and Regulatory Quantity Limits ..................................... 28
3.3.1 Safety Analysis....................................................................................................... 28
3.3.1.a Facility Requirements.................................................................................... 28
3.3.1.b Radiological Materials Inventory ................................................................... 29
3.3.1.c Material Release Assumptions ...................................................................... 30
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3.3.2 Integrated Safety Management.............................................................................. 31
3.3.3 Facility Segmentation............................................................................................. 32
3.4 Radiological Material Quantity Limits .............................................................................. 32
3.4.1 Tritium Shipping, Radioactive Material Inventory, Quantity Limits ......................... 32
3.4.2 Tritium Receiving Area, Shipping Area, Quantity Limits ........................................ 33
3.5 Tritium Unpackaging, Handling, and Packaging Areas, Quantity Limits ......................... 33
3.6 Tritium Waste Collection and Waste Packaging Area, Quantity Limits........................... 33
3.7 Tritium Radworker Training............................................................................................. 34
3.8 Tritium Focus Group (TFG)............................................................................................. 34
Section 3
4.0 FACILITY DESIGN ............................................................................................................... 34
4.1 Tritium System Philosophy.............................................................................................. 34
4.1.1 Tritium Capture, Contain, and Cleanup Process.................................................... 36
4.1.1.a Containment and Confinement Systems....................................................... 36
4.1.1.a(1) Primary Containers ............................................................................. 36
4.1.1.a(2) Secondary Containers......................................................................... 37
4.1.1.a(2)(a) High-Quality Secondary Containers ......................................... 37
4.1.1.a(2)(b) Medium-Quality Secondary Container...................................... 38
4.1.1.a(2)(c) Low-Quality Secondary Containers .......................................... 39
4.1.1.a(3) Primary and Secondary Containers .............................................. 39
4.1.2 Tritium Cleanup and Removal Systems................................................................. 40
4.1.3 Future Directions in Tritium Removal and Cleanup ............................................... 43
4.1.4 Inspection and Surveillance Requirements............................................................ 44
4.2 Building Ventilation System............................................................................................. 44
4.3 Chilled Water System...................................................................................................... 46
4.4 Seismic and Wind Design and Evaluation of Structures and Facilities ........................... 47
4.5 Other Design Considerations .......................................................................................... 49
4.6 Lessons Learned............................................................................................................. 50
4.6.1 SNLL Tritium Research Laboratory........................................................................ 50
4.6.2 SRS Old Tritium Extraction Facility ........................................................................ 52
5.0 DESIGN OF EQUIPMENT.................................................................................................... 53
5.1 Material Compatibility...................................................................................................... 53
5.1.1 System Design ....................................................................................................... 54
5.1.1.a Leak Testing.................................................................................................. 54
5.1.1.b Joining ........................................................................................................... 54
5.1.1.c Surface Coatings and Treatments ................................................................. 55
5.1.2 Structural Metals .................................................................................................... 55
5.1.2.a Austenitic Stainless Steels ............................................................................ 56
5.1.2.b Copper and Copper Alloys ............................................................................ 57
5.1.2.c Aluminum and Aluminum Alloys .................................................................... 57
5.1.2.d Materials to Avoid.......................................................................................... 57
Section 4
5.1.3 Polymers ................................................................................................................ 58
5.1.3.a Plastics .......................................................................................................... 58
5.1.3.b Elastomers .................................................................................................... 59
5.2 First Wall Design............................................................................................................. 59
5.2.1 High-Pressure Tritium ............................................................................................ 59
5.2.2 Low- and Medium-Pressure Tritium ....................................................................... 59
5.3 Secondary Wall Design................................................................................................... 60
5.3.1 High-Quality Secondary ......................................................................................... 60
5.3.2 Medium-Quality Secondary.................................................................................... 60
5.3.3 Low-Quality Secondary .......................................................................................... 60
5.4 Cleanup System Design.................................................................................................. 60
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5.5 Storage System Design .................................................................................................. 60
5.5.1 Short-Term Storage ............................................................................................... 60
5.5.2 Medium-Term Storage ........................................................................................... 61
5.5.3 Long-Term Storage ................................................................................................ 61
5.5.3.a Storage as a Gas .......................................................................................... 61
5.5.3.b Storage as a Metal Tritide ............................................................................. 61
5.6 Surveillance and Maintenance........................................................................................ 62
5.7 Seismic Considerations................................................................................................... 62
5.7.1 DOE Natural Phenomena Hazards Policy ............................................................. 62
5.7.2 Seismic Design and Evaluation of Equipment and Distribution Systems............... 63
5.8 Fire Scenarios ................................................................................................................. 67
5.9 Instrumentation ............................................................................................................... 67
5.9.1 Tritium Monitoring Systems.................................................................................... 67
5.9.2 Specialized Instrumentation ................................................................................... 70
5.9.2.a Remote Field Tritium Analysis System.......................................................... 70
5.9.2.b Surface Activity Monitor................................................................................. 71
5.9.3.c Breathalyzer .................................................................................................. 71
Section 5
6.0 TRITIUM RECEIVING AND STORAGE ............................................................................... 72
6.1 Shipping Packages ......................................................................................................... 72
6.1.1 Type A Shipping Packages .................................................................................... 72
6.1.2 Type B Shipping Packages .................................................................................... 73
6.2 Product Containers .........................................................................................................73
6.2.1 WSRC Product Vessel ........................................................................................... 73
6.2.2 WSRC Hydride Transport Vessel........................................................................... 73
6.2.3 Recommendations for Improvements for Product Containers ............................... 74
6.3 Valve Container Operations ............................................................................................ 75
6.3.1 Tritium Apparatus, Isolation Valves, and Purge Ports............................................ 77
6.4 Receiving Tritium ............................................................................................................ 79
6.5 Storage of Packaged Tritiated Materials ......................................................................... 80
6.6 Interim Storage of Tritiated Materials .............................................................................. 80
6.6.1 Background ............................................................................................................ 80
6.6.2 Requirements......................................................................................................... 81
6.6.3 Exclusions to the Packaging Requirements in DOE-HDBK-1129.......................... 81
6.6.4 Priority for Working off Tritium Containers ............................................................. 82
7.0 PACKAGING AND TRANSPORTATION.............................................................................. 83
7.1 General Administrative Packaging and Transport Requirements ................................... 83
7.2 Selection of Proper Packaging........................................................................................ 83
7.2.1 Form and Quantity of Tritium ................................................................................. 86
7.2.2 Evaluation of Approved Packaging ........................................................................ 87
7.2.3 Minimum Requirements for Packaging .................................................................. 87
7.2.4 Onsite versus Offsite Shipments............................................................................ 88
7.3 Package Loading and Preparation for Shipment ............................................................ 89
7.3.1 Disassembly and Inspection of the Package ......................................................... 89
7.3.2 Package Loading and Assembly Operations ......................................................... 90
7.3.3 Leak Testing........................................................................................................... 90
7.3.4 Preparation for Shipment ....................................................................................... 91
Section 6
7.4 Documentation and Records........................................................................................... 91
7.4.1 Package Documentation for Type A and B ............................................................ 91
7.4.2 Additional Type B Package Documentation........................................................... 92
7.5 Quality Assurance/Control Requirements ....................................................................... 92
7.5.1 DOT Quality Control Requirements ....................................................................... 92
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7.5.2 Quality Assurance Requirements for Type B Packages ........................................ 93
8.0 TRITIUM WASTE MANAGEMENT....................................................................................... 93
8.1 Approved Limits for the Release of Contaminated Materials and Property Containing
Residual Radioactive ...................................................................................................... 94
8.1.1 Release Limit Requirements for Surface-Contaminated Material .......................... 94
8.1.2 Removable Surface Contamination Measurement Process................................... 95
8.1.3 Environmental Discharge Requirements................................................................ 97
8.1.4 Tritium-Contaminated Wastewater......................................................................... 98
8.1.4.a Tritium-Contaminated Wastewater Generation ............................................. 98
8.1.4.b Tritium-Contaminated Waste Water Disposal ............................................... 99
8.1.4.b(1) Solidification on Clay........................................................................... 99
8.1.4.b(2) Solidification on Polymers ................................................................... 99
8.1.4.b(3) Evaporation to the Environment........................................................ 100
8.1.4.b(4) Release to the Sanitary Sewer.......................................................... 101
8.2 Waste Characterization................................................................................................. 101
8.2.1 Waste Knowledge ................................................................................................ 102
8.2.2 Tritium Disposition Options .................................................................................. 103
8.2.3 Economic Discard Limit for Tritiated Water .......................................................... 105
8.3 Waste Packaging .......................................................................................................... 106
8.4 Waste Shipping.............................................................................................................107
APPENDIX A: USEFUL NUMERICAL VALUES....................................................................... A-1
APPENDIX B: DEFINITIONS................................................................................................... B-1
APPENDIX C: ASSAY METHODS ........................................................................................... C-1
APPENDIX D: CONTAMINATION AND SURFACE ACTIVITY THRESHOLDS....................... D-1
APPENDIX E: RADIOLOGICAL CONTROL PROGRAMS FOR SPECIAL TRITIUM
COMPOUNDS .......................................................................................................................... E-1
APPENDIX F: RADIOLOGICAL TRAINING FOR TRITIUM FACILITIES ..................................F-1
APPENDIX G: GOOD PRACTICES ........................................................................................G-1
APPENDIX H: ENDNOTES ..................................................................................................... H-1
APPENDIX I: CHARTER OF THE TRITIUM FOCUS GROUP..................................................I-1
Section 7
DOE-HDBK-1129-2008
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FIGURES:
FIGURE 2-1. Rate of tritium decay of one mole of tritium...........................................................10
FIGURE 2-2. Pressure versus time in a container of tritium .......................................................11
FIGURE 2-3. Comparison of aqueous tritium levels found in the nuclear industry .....................15
FIGURE 2-4. Dissociation pressure for uranium, hydride, deuteride, and tritide ........................17
FIGURE 2-5. Plot of a good fit curve for the dissociation pressure of uranium hydride,
deuteride, and tritide............................................................................................17
FIGURE 2-6. Dissociation pressure of palladium hydride and deuteride....................................19
FIGURE 4-1. Tritium facility single-pass ventilation system........................................................35
FIGURE 4-2. Secondary containment ........................................................................................37
FIGURE 4-3. Secondary confinement ........................................................................................38
FIGURE 4-4.a. Building confinement system; and
FIGURE 4-4.b. Typical double-containment configuration..........................................................40
FIGURE 4-5. Typical gas-to-water tritium removal system flow schematic ................................40
FIGURE 4-6. Confinement volume cleanup rate as a function of system time constant, F/V,
assuming an exponential dilution rate .................................................................42
FIGURE 5-1. Development of the seismic equipment list ...........................................................65
FIGURE 5-2. Comparison of seismic capacity spectra to seismic demand spectra ...................66
FIGURE 6-1. Use of double valve container...............................................................................76
FIGURE 6-2. Purge ports and isolation valves ...........................................................................78
FIGURE 8-1. Ultimate disposition of tritiated material ..............................................................104
TABLES:
TABLE 2-1. Derived air concentrations for tritium and tritiated water .........................................12
TABLE 2-2. Dissociation pressure equation parameters for uranium hydride, deuteride,
and tritide................................................................................................................16
TABLE 2-3. Dissociation pressure equation parameters for palladium hydride and deuteride...19
TABLE 5-1. Representative equipment found in tritium facilities ................................................64
TABLE 5-2. SAM technical specifications...................................................................................72
TABLE 7-1. Allowable quantities of tritium per 49 CFR 173 .......................................................86
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FOREWORD
Tritium handling practices have evolved over several decades at Department of Energy
(DOE) tritium facilities. The objective has been to accomplish required tritium work while
minimizing and controlling the exposure of workers, the public, and the environment to
tritium. This document provides guidance for the handling, storing, and shipping of tritium.
Section 8
This Handbook is approved for use by all DOE elements and their contractors. There are no
requirements generated by this document, with the exception of satisfying interim storage
requirements as applicable to facilities under the auspices of the National Nuclear Security
Administration (NNSA) and the Offices of Environmental Management (EM) and Nuclear
Energy (NE), which is discussed in Section 6.6.
The principal authors of this revision to the Handbook—Bill Weaver of DOE-CNS, Joel
Rabovsky and Pete O’Connell of DOE-HSS—wish to acknowledge the contributions of Bill
Fortune and Andy Wallo of DOE-HSS, Bob Rabun of WSRC, Ron Hafner of LLNL, Mike
Rogers of LANL, and Paul Lamberger, independent consultant.
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ACRONYMS
AEA Atomic Energy Act of 1954
AI Alveolar-Interstitial region
ALARA As Low As Reasonably Achievable
ALI Annual Level of Intake
AMAD Activity median aerodynamic diameter
AMD Activity median diameter
APT Accelerator Production of Tritium
ASCE American Society of Civil Engineers
ASME American Society of Mechanical Engineers
ANSI American National Standards Institute
bb bronchiolar region
BB Bronchial region
Bq Becquerel
BS Bone surface
BZA Breathing zone air (sampler)
CERCLA Comprehensive Environmental Response, Compensation, and Liability Act
CFR Code of Federal Regulations
Ci Curie
CLWR Commercial Light Water Reactor
CMD Count median diameter
CoC Certificate of Compliance
CWA Clean Water Act
D&D Decontamination and Decommissioning
DAC Derived Air Concentration
DBA Design Basis Accident
DBE Design Basis Earthquake
DCF Dose Conversion Factor
DCFo Dose Conversion Factor based on observed activity
DCG Derived Concentration Guide
DNFSB Defense Nuclear Facilities Safety Board
DOE U.S. Department of Energy
DOT U.S. Department of Transportation
E50 Committed Effective Dose
EDL Economic Discard Limit
EPCRA Emergency Planning and Community Right-to-Know Act
EPDM Ethylene Propylene Diene Monomer
EPA Environmental Protection Agency
EH DOE Office of Environment, Safety and Health
EIS Environmental Impact Statement
ET Extrathoracic
f1 fraction of radionuclide absorbed from the GI tract
FCA Fire Control Area
FDTAS Field Deployable Tritium Analysis System
FY Fiscal Year
GI Gastrointestinal
HEPA High-Efficiency Particulate Air
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HDPE High-Density Polyethylene
HIVES Highly Invulnerable Encased Safe
HMR Hazardous Material Regulations
HSS DOE Office of Health, Safety and Security
HSV Hydride Storage Vessel
HSWA Hazardous and Solid Waste Amendments
HTV Hydride Transport Vessel
HVAC Heating, Ventilation, and Air Conditioning
IAEA International Atomic Energy Agency
IATA International Air Transport Association
ICRP International Commission on Radiological Protection
IMT Insoluble Metal Tritide
ISM Integrated Safety Management
ITP Insoluble Tritiated Particulate
keV Kiloelectron volt
LANL Los Alamos National Laboratory
LDPE Low-Density Polyethylene
LDR Land Disposal Restriction
LLD Lower Limit of Detection
LLI Lower Large Intestine
LLNL Lawrence Livermore National Laboratory
LN Lymph Node
LSA Low Specific Activity
LSC Liquid Scintillation Counting
LLW Low-level waste
mCi Millicurie
MCL Maximum Contaminant Level
MEI Maximally Exposed Individual
mm Millimeter
mrem Millirem
NFPA National Fire Protection Association
NP Nasal Passage Region
NPDWR National Primary Drinking Water Regulation
NPH Natural Phenomena Hazard
NRC U.S. Nuclear Regulatory Commission
NRPB National Radiological Protection Board
OBT Organically Bound Tritium
P Pulmonary Parenchyma Region
PC Performance Category
PCB Polychlorinated biphenyl
PMR Palladium Membrane Reactor
PPE Personal Protective Equipment
PPPL Princeton Plasma Physics Laboratory
psia pounds per square inch absolute
psig pounds per square inch gauge
PTFE Polytetrafluoroethylene
PVC Polyvinyl chloride
PV Product Vessel
RCRA Resource Conservation and Recovery Act
RCS Radiological Control Standard
RM Remainder Organ
Section 9
DOE-HDBK-1129-2008
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RMA Radioactive Materials Area
RTF Replacement Tritium Facility
RWP Radiological Work Permit
S Stomach or specific source organ (used with SEE)
SAES Societá Apparecchi Elettrici e Scientifici
SAF Self Absorption Factor
SAM Surface Activity Monitor
SAR Safety Analysis Report
SCO Surface Contaminated Object
SEE Specific Effective Energy
SEL Seismic Equipment List
SEM Scanning Electron Microscope
SEP Seismic Evaluation Procedure
SI Small Intestine
SMT Stable Metal Tritide
SNL Sandia National Laboratory
SNLL Sandia National Laboratory, Livermore
SNM Special Nuclear Material
SRS Savannah River Site
SSCs Structures, Systems, and Components
STC Special Tritium Compound
Sv Sievert
Sg Geometric Standard Deviation
T Tissue
TB Trachea and Bronchial Region
TFG Tritium Focus Group
TRL Tritium Research Laboratory, Sandia National Laboratory
TWD Technical Work Document
TSD Treatment, Storage, and Disposal
TSR Technical Safety Requirement
UB Urinary Bladder
UBC Uniform Building Code
UHMWPE Ultra-High-Molecular-Weight Polyethylene
ULI Upper Large Intestine
WETF Weapons Engineering Tritium Facility, Los Alamos National Laboratory
WSRC Washington Savannah River Company
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DOE-HDBK-1129-2008
1
1.0 INTRODUCTION
There are several tritium-handling publications, including International Atomic Energy
Agency (IAEA) Technical Report Series, Number 324, Safe Handling of Tritium, published in
1991; and U.S. Department of Energy (DOE) publications. Most of the tritium publications
are written from a radiological protection perspective. This Handbook provides more
extensive guidance and advice on the full range of tritium operations.
1.1 Purpose
This Handbook can be used by personnel involved in the full range of tritium handling, from
receipt to ultimate disposal. Compliance issues are addressed at each stage of handling.
This Handbook can also be used as a reference for those individuals involved in real-time
determination of bounding doses resulting from inadvertent tritium releases.
1.2 Scope
This Handbook provides useful information for establishing processes and procedures for
the receipt, storage, assay, handling, packaging, and shipping of tritium and tritiated wastes.
It includes discussions and advice on compliance-based issues and adds insight to those
areas in which DOE guidance is unclear. It is intended to be a “living document” that is
revised periodically. For example, planning for and implementing contamination control as
part of normal operation and maintenance activities are important functions in any tritium
facility. The best practices from around the DOE complex are planned for inclusion in the
next revision of this Handbook.
1.3 Applicability
DOE facilities range from small radiological facilities engaged in operations using a few
millicuries (mCi) up to 16,000 Ci of tritium to large-scale facilities referred to as nonreactor
nuclear facilities using more than 16,000 Ci of tritium. Guidance in this Handbook applies to
any scale of operations.
Some sections of this Handbook resulted from consensus agreement between members of
DOE’s Tritium Focus Group (TFG) and the authors, representing the views of the Offices of
Health, Safety and Security and the Chief of Nuclear Safety at DOE Headquarters. Other
sections are strictly the viewpoint of the Office of Nuclear and Facility Safety. This office
solicits comments and active discussion of the Handbook content in order to improve the
Handbook on its next revision.
Section 10
1.4 Key References
• DOE G 151.1-4, Response Elements
• DOE O 151.1C, Comprehensive Emergency Management System
• DOE M 231.1-2, Occurrence Reporting and Processing of Operations Information
• DOE O 231.1A, Change 1, Environment, Safety and Health Reporting
DOE-HDBK-1129-2008
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• DOE O 243.1, Records Management Program
• DOE O 420.1B, Facility Safety
• DOE G 420.1-1, Nonreactor Nuclear Safety Design Criteria and Explosive Safety Criteria
Guide for use with DOE O 420.1 Facility Safety
• DOE G 420.1-2, Guide for the Mitigation of Natural Phenomena Hazards for DOE
Nuclear Facilities and Nonnuclear Facilities
• DOE O 435.1, Chg 1, Radioactive Waste Management
• DOE M 441.1-1, Nuclear Material Packaging Manual
• DOE G 441.1-1C, Radiation Protection Programs Guide for Use with Title 10, Code of
Federal Regulations, Part 835, Occupational Radiation Protection
• DOE P 450.4, Safety Management System Policy
• DOE G 450.4-1B, Volume 1, Integrated Safety Management System Guide (Volume 1)
for use with Safety Management System Policies (DOE P 450.4, DOE P 450.5, and
DOE P 450.6); The Functions, Responsibilities, and Authorities Manual; and the DOE
Acquisition Regulation
• DOE O 460.1B, Packaging and Transportation Safety
• DOE G 460.2-1, Implementation Guide for Use with DOE O 460.2, Departmental
Materials Transportation and Packaging Management
• DOE O 460.2A, Departmental Materials Transportation and Packaging Management
• DOE M 470.4-6, Chg 1, Nuclear Material Control and Accountability
• DOE Order 5400.5 Chg 2, Radiation Protection of the Public and Environment
• DOE-HDBK-1001-96, Guide to Good Practices for Training and Qualification of
Instructors
• DOE-STD-1020-2002, Natural Phenomena Hazards Design and Evaluation Criteria for
Department of Energy Facilities
• DOE-STD-1021-93, Natural Phenomena Hazards Performance Categorization
Guidelines for Systems, Structures, and Components, reaffirmed April 2002
• DOE-STD-1022-94, Natural Phenomena Hazards Site Characterization Criteria,
reaffirmed April 2002
• DOE-STD-1023-95, Natural Phenomena Hazards Assessment Criteria, reaffirmed April
2002
• DOE-STD-1027-92, Hazard Categorization and Accident Analysis Techniques for
Compliance with DOE Order 5480.23, Nuclear Safety Analysis Reports, Change Notice
1, September 1997
• DOE-STD-1070-94, Guide for Evaluation of Nuclear Facility Training Programs
• DOE-STD-1098-2008, Radiological Control
• DOE-STD-1111-98, Laboratory Accreditation Program Administration
DOE-HDBK-1129-2008
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• DOE-STD-1120-2005, Volume 2, Integration of Environment, Safety, and Health into
Facility Disposition Activities
• DOE-STD-1121-2008, Internal Dosimetry
• DOE-STD-3009-94, Change Notice 3, Preparation Guide for U.S. Department of Energy
Nonreactor Nuclear Facility Safety Analyses
• DOE-HDBK-3010-94, Change Notice 1, Volumes 1 and 2, Airborne Release
Fraction/Rates and Respirable Fractions for Nonreactor Nuclear Facilities
• DOE/TIC-11268, A Manual for the Prediction of Blast and Fragment Loading of
Structures
• DOE/MLM-3719, Health Physics Manual of Good Practices for Tritium Facilities
• DOE Office of Nuclear and Facility Safety, Technical Notice 94-01, Guidelines for Valves
in Tritium Service
• DNFSB Recommendation 2005-1, Nuclear Material Packaging
• ANSI N13-1-1999, Guide to Sampling Airborne Radioactive Materials in Nuclear
Facilities
• ANSI N13.12-1999, Surface and Volume Radioactivity Standards for Clearance
Section 11
• ANS 14-1994, Internal Dosimetry Standards for Tritium
• ANSI N14.5-1997, Leakage Tests on Packages for Shipment
• ANSI Z88.2, Practices for Respiratory Protection
• ASCE 7-95, Minimum Design Loads for Buildings and Other Structures
• 10 CFR 20, Standards for protection against radiation
• 10 CFR 71, Packaging and transportation of radioactive material
• 10 CFR 830, Nuclear safety management
• 10 CFR 835, Occupational radiation protection
• 36 CFR, Chapter XII, National Archives And Records Administration
• 40 CFR 261, Identification and listing of hazardous waste
• 40 CFR 262, Standards applicable to generators of hazardous waste
• 40 CFR 302.4, Designation of hazardous substances
• 49 CFR 172, Hazardous materials table, special provisions, hazardous materials
communications, emergency response information, and training requirements
• 49 CFR 173, Shippers – general requirements for shipments and packagings
• 49 CFR 177, Carriage by public highway
• 49 CFR 178, Specifications for packagings
• 62 FR 62079, Joint NRC/EPA Guidance on Testing Requirements for Mixed Radioactive
and Hazardous Waste, November 20, 1997.
• Appendix of Chemistry and Physics, 54th Edition, CRC Press, 1973.
DOE-HDBK-1129-2008
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• EG&G Mound Applied Technologies, Health Physics Manual of Good Practices for
Tritium Facilities, MLM-3719, Draft, Miamisburg, Ohio, December 1991.
• IAEA, Technical Report Series #421, Management of Waste Containing Tritium and C14
(2004)
• IAEA Technical Report Series #324, Safe Handling of Tritium
• IAEA-SM-181/19, Estimates of Dry Deposition and Plume Depletion over Forests and
Grassland
• ICRP Publication 23, Reference Man: Anatomical Physiological and Metabolic
Characteristics, Pergamon Press, Oxford, 1975.
• ICRP Publication 26, Recommendations of the International Commission on
Radiological Protection, Annals of the ICRP 1 (2), 1977.
• ICRP Publication 30, Limits for Intakes of Radionuclides by Workers, Part 1, Annals of
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• ICRP Publication 60, Recommendations of the International Commission on
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• ICRP Publication 66, Human Respiratory Tract Model for Radiological Protection, Annals
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• ICRP Publication 67, Age Dependent Doses to Members of the Public From Intake of
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• ICRP Publication 71, Age Dependent Doses to Members of the Public From Intake of
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• ICRP-CD, ICRP Database of Dose Coefficients for Workers and Members of the
General Public, Version 1.0, 1998.
• ICRP Publication 78, Individual Monitoring for Internal Exposure of Workers, Annals of
the ICRP 27 (3-4), 1998.
• ISO 7503-2, Evaluation of Surface Contamination – Part 2: Tritium Surface
Contamination
• National Council on Radiation Protection and Measurements, Tritium Measurement
Techniques, NCRP 47, 1976.
• NCRP Report No. 62, Tritium in the Environment, National Council on Radiation
Protection and Measurements, Washington, D.C., 1979.
• National Radiological Protection Board of Great Britain, LuDEP Version 2.06, Personal
Computer Program for Calculating Internal Dose Using the ICRP Publication 66
Respiratory Tract Model, 1999.
• Mound Document MD-10516, Mound Technical Basis Document for Stable Tritiated
Particulate and Organically Bound Tritium, BWXT of Ohio, Inc., April 2000.
Section 12
• U.S. Nuclear Regulatory Commission Regulatory Guide 8.25, Air Sampling in the
Workplace, 1992.
• U.S. Nuclear Regulatory Commission NUREG-1400, Air Sampling in the Workplace,
1993.
DOE-HDBK-1129-2008
5
• OSWER 9928.4-03, Waste Analysis at Facilities that Generate, Treat, Store, and
Dispose of Hazardous Wastes: A Guidance Manual, April 1994
• Westinghouse Savannah River Company (WSRC), WSRC-TR-94-0596, Titanium for
Long Term Tritium Storage (U), December 1994.
• WSRC-RP-92-1161, SRS H1616 Hydride Transport Vessel Qualification Report (U),
Revision 5, 1998.
• J.E. Klein, WSRC-MS-2001-00247, A 1600 Liter Tritium Hydride Storage Vessel
• WSRC DPSPU 74-124-5, Safety Analysis Report – Packages, LP-50 Tritium Package,
Rev. 2, 4/88.
• Cheng, Y.S., Wang, Y., and Mulberry, W. Radiation Dosimetry and Guidelines for
Radiation Protection of Hafnium Tritide: Interim Report, Lovelace Respiratory Research
Institute, June 1, 1999.
• Personal Communication from Y.S. Cheng, Lovelace Respiratory Research Institute, to
C. Miles and J. Gill of Mound, July 1999.
• Cristy, M. and Eckerman, K.F., SEECAL: Program to Calculate Age-Dependent Specific
Effective Energies, ORNL/TM-12351, 1993.
• Cool, D. and Maillie, Dissolution of Tritiated Glass Microballoon Fragments: Implications
for Inhalation Exposure, Health Physics, 45, 1983, pp. 791-794.
• Dorrian, M.D. and Bailey, M.R., Particle Size Distributions of Radioactive Aerosols
Measured in Workplaces, Radiation Protection Dosimetry, 60, 1995, pp. 119-133.
• Hill, R.L., and Johnson, J.R., Metabolism and Dosimetry of Tritium, Health Physics, 65,
1993, pp. 628-647.
• Johnson, J.R., Lamothe, E.S., Jackson, J.S., McElroy, R.G.C., Metabolism and
Dosimetry of Tritium From Gas Contaminated Surfaces, Fusion Technology, Vol. 14,
September 1988, p. 1147.
• Killough, G.G., and Eckerman, K.F., A Conversational Eigenanalysis Program for
Solving Differential Equations, Proceedings of the Seventeenth Midyear Topical
Symposium of the Health Physics Society, 1984.
• Kropf, R.F., Wang, Y., and Cheng, Y.S., Self-Absorption of Tritium Betas in Metal Tritide
Particles, Health Physics, Vol. 75:4, October 1998, pp. 398-404.
• Newton, G.J., Hoover, M.D., Barr, E.B., Wong, B.A., and Ritter, P.D., Collection and
Characterization of Aerosols From Metal Cutting Techniques Typically Used in
Decommission Facilities, American Industrial Hygiene Association Journal, 48(11),
November 1987, pp. 922-932.
• Richardson, R.B. and Hong, A., Dose to Lung From Inhaled Tritiated Particulates, Chalk
River Laboratories Report, COG-98-262-I, April 1999.
• Rudran K., Radiation Doses to Lungs and Whole Body from Use of Tritium in Luminous
Paint. Radiation Protection Dosimetry, 25(2), 1988, pp. 117-125.
• Rogers, M., Process History/Technical Basis, Mound Report—Final Draft 2, BWXT of
Ohio, Inc. April 30, 1999.
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• Traub, R.J., Dosimetry of Metal Tritides, Pacific Northwest National Laboratory Report to
DOE/MEMP. May 1999.
• Trivedi, A., Percutaneous Absorption of Tritium-Gas-ContaminatedPump Oil. Health
Physics, 69. 1995. pp. 202-209.
• Watkins, R.A., Rhinehammer, T.B., Griffin, J.F., MLM-2523(OP), Shipping Container for
Tritiated Water. CONF-780506-35. January 1, 1978.
1.5 Resource Material for Further Information
Alvani, C., Ciavola, C., Casadio, S., Dibartolomeo, Chemical Aspects of the LiAlO2 Ceramic
for Tritium Breeding. High Temperatures, High Pressures. 20:397-402. 1991.
Section 13
Balonov, M.I., Dosimetry and Standardization of Tritium. Energoatomizdat. 1983.
Balonov, M.I., Likhtarev, I.A., Moskalev, Y.I. The Metabolism of 3He Compounds and Limits
for Intakes by Workers. Health Physics. 47:761-773. 1984.
Bard, S.T., Islam, M. A. Urine Bioassay Data for Two Individuals Following an Exposure to
Tritium Oxide and Titanium Tritide Aerosols during the Opening of a Shipment of Accelerator
Targets. Unpublished report. Bard, S.T.. POB 9537, Fort Collins, CO. 1992.
Barta, K., Turek, K. Size Spectrum of Titanium Tritide Particles. Jadema Energie. 18:347.
1972.
Beavis, L.C., Miglionico, C.J. Structural Behavior of Metal Tritide Films. Journal of Less-
Common Metals. 27:201-211. 1972.
Bellanger, G., Rameau, J.J. Influence of the Tritium in Type 316L Stainless Steel on
Corrosion. Fusion Technology. 24:145-149. 1993.
Biro, J., Feher, I. Tritium Incorporation Hazard Involved in the Use of Tritium Targets. IAEA.
Proceedings Series: Assessment of Airborne Radioactivity. pp. 501-519. 1967.
Carlson, R.S. Uranium-Tritium System: The Storage of Tritium. In Radiation Effects and
Tritium Technology for Fusion Reactors. Vol. IV. CONF-750989. pp. IV36-IV52. 1976.
Cheng, Y.S. Dissolution Rate and Radiation Dosimetry of Metal Tritides. Proceedings of
1993 DOE Radiation Workshop. CONF-9504128. p. K15-K28. 1995.
Cheng, Y.S., Dahl, A. R., Jow, H.N. Dissolution of Metal Tritides in a Simulated Lung Fluid.
Health Physics. 73:633-638. 1997.
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Health Physics. 68:S53. 1995.
Cheng, Y.S., Snipes, M.G., Wang, Y., Jow, H.N. Biokinetics and Dosimetry of Titanium
Tritide Particles in the Lung. Health Physics. 76. February 1999. pp. 120-128.
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Cool, D. A., Maillie, H. D. Tritium Distribution and Excretion Following Intrathecal Instillation
of Glass Microballoon Fragments in Rats. Health Phys. 46:599-606; 1984.
Corcoran, V.J., Campbell, C.A., Bothwell, P.B. Decontamination and Decommissioning of
UK Tritium Facilities. Fusion Technology. 21:727-732. 1992.
de Ras, E.M.M., Vaane, J.P., Van Suetendael, W. Investigation of the Nature of a
Contamination Caused by Tritium Targets Used for Neutron Production. In Radiation
Protection: Proceedings of the 5th Congress of the International Radiation Protection
Society. New York: Pergamon Press. Vol. 1. 1980. 48-51.
Dickson, R.S. Tritium Interactions with Steel and Construction Materials in Fusion Devises:
A Literature Review. AECL Report AECL-10208. 1990.
Duong, T., Trivedi, A. Measurement of Tritiated Species in Urine for Characterization of an
Exposure. Health Physics. 70:S82-S83; 1996.
Ebey, Peter S., LA-UR-01-1825, Conversion of Tritium Gas into Tritiated Water (HTO): A
Review with Recommendations for Use in the WETF SAR, Los Alamos National Laboratory.
Eidson, A.F., Griffith, W.C. Techniques for Yellowcake Dissolution Studies In Vitro and Their
Use in Bioassay Interpretation. Health Physics. 46:151-163. 1984.
Gildea, P. Operating Experience with the Sandia Tritium Facility Cleanup Systems. Fusion
Technology. 8:2507-2510. 1985.
Gill, J.T. Tritium on Metal Surfaces – A Quick Review: Also Why Tritiated Rust May be a
Hazard During D&D Operations. Personal communication. Workshop on Tritium Retention
and Removal. Princeton. 1994.
Hirabayashi, T., Saeki, M. Sorption of Gaseous Tritium on the Surface of Type 316L
Stainless Steel. Journal of Nuclear Materials. 120:309-315. 1984.
Section 14
Inkrett, W.C.T., Schillaci, M.E., Cheng, Y.S., Efurd, D.W., Little, T.T., Miller, G., Musgrave,
J.A., Wermer, J.R. Internal Dosimetry for Inhalation of Hafnium Tritide and Other Insoluble
Metal Tritide Aerosols. LANL. 1998.
International Atomic Energy Agency. Safe Handling of Tritium: Review of Data and
Experience. Technical Report Series 324. Vienna, Austria. 1991.
International Commission on Radiological Protection. ICRP Publication 72, Age-Dependent
Doses to Members of the Public From Intake of Radionuclides: Part 5, Compilation of
Ingestion and Inhalation Dose Coefficients. Oxford, England: Pergamon Press. 1996.
Jarvis, N.S., Birchall, A. LUDEP 1.0, A Personal Computer Program to Implement the New
ICRP Respiratory Tract Model. Radiation Protection Dosimetry. 53:191-193. 1994.
Kalwarf, D.R. Solubility Classification of Airborne Uranium Products Collected at the
Perimeter of the Allied Chemical Plant, Metropolis, Illinois. Richland, WA: Pacific Northwest
Laboratory. PNL-3288RE. 1980.
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Kamura, Y., Nishikawa, M. Adsorption/Desorption of Water on Ceramic Materials. Fusion
Technology. 27:25-38. 1995.
Kocol, H., McNelis, D.N., Moghissi, A.A. A Study of the Particulate and Gaseous Emissions
of Tritium from the Neutron Generator Targets. Health Physics. 31:73-76. 1976.
Lorenzen, W.A., Ring, J.P. The Management and Operation of a Large Scale Decay-In-
Storage Program, paper presented at 27th Mid-Year Topical Meeting of the Health Physics
Society, February 12-16, 1994. Albany, New York.
Loutfy, R.O., Moravsky, A.P., Wexler, E.M., Production and Characterization of Fullerene
Hydrides. Chapter in Encyclopaedia of Materials, Japan. 2001.
Matsuzuru, H., Moriyama, N., Ito, A. Leaching Behavior of Tritium from a Hardened Cement
Paste. Annals of Nuclear Energy. 6:417-423. 1979.
McConville, G.T., Menke, D.A. Removal of Surface Contamination with Tritium Gas. Storage
Science Meeting. 1993.
McConville, G.T., Menke, D,A,, West, D.S., Woods, C.M. Properties of Aged Metal Tritides.
DOE Research and Development Report MLM-3799, EG&G Mound. 1994.
McConville, G.T., Woods, C.M. Calculation of Tritium Dose from Insoluble Particulates. The
5th Tritium Symposium, Ispra, Italy. 1995. Fusion Technology. 28:905-909. 1995.
Mercer, T.T. On the Role of Particle Size in the Dissolution of Lung Burdens. Health
Physics. 13:1211-1221. 1967.
Miller, J.M., Bokwa, S.R. Leaching Behavior of High Specific Activity Titanium Tritide. Chalk
River Nuclear Laboratories. AECL-8770. 1985.
Miller, J. M. Leaching Behavior of Metal Hydrides Containing Immobilized Tritium. In
Conference Summaries of Radioactive Waste Management. Winnipeg, Canada: Canada
Nuclear Society. CONF-820933 54/NTIS, PC a15/MF A01. 1982. 192-198.
Mueller, W.M., Blackledge, J.P., Libowitz, G.G. Metal Hydrides. New York: Academic Press.
pp. 119-164. 1968.
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20:186-199. 1990.
Ortman, M.S., Heung, L.K., Nobile, A., Rabun, R.L. Tritium Processing at the Savannah
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Monsanto Research Corporation, Miamisburg Ohio, 1973.
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9
Richardson, R.B., Hong, A. Microdosimetry of Tritiated Particulates in Alveolar Sacs. In
Microdosimetry: An Interdisciplinary Approach (editors Goodhead, D.T., O’Neil, P., Mentzel,
H.G.) Cambridge, UK. The Royal Society of Chemistry. 1997.
Section 15
Richardson, R.B., Hong, A. Dose to Lung from Inhaled Tritiated Particles, Health Physics
Journal. September (2001).
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Paint Industry. Radiation Protection Dosimetry. 25:117-125. 1998.
Schober, T., Trinkaus, H., Lasser, R. A TEM Study of the Aging of Zr Tritides. Journal of
Nuclear Material. 141:453-457. 1986.
Sowell, C.V., Arent, L.J. Tritium Contamination Discovered at EG&G/EM in North Las
Vegas, Nevada. Health Physics. 70:S47; 1996.
Stevens, L., Phillips, M. Health Physics Lessons Learned from the DOE Moratorium on
Mixed Waste, 27th Mid-Year Topical Meeting of the Health Physics Society, February 12-16,
1994. Albany, New York.
Strom, D.J., Stewart, R.D., McDonald, J.C. Spectral Emissions and Dosiemtry of Metal
Tritide Particulates. Radiation Protection Dosimetry. 98:389-400. 2002.
Villagran, J.E., Whillans, D.W. Radiation Dose to Lung Cell Populations Resulting from
Inhalation of Titanium Tritide Particles. Chalk River Nuclear Laboratories, 1984.
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Titanium Tritide Particles in the Lung. Health Physics. 70:S82-S83. 1996.
Woehr, W.J., Gatami, A., Holodny, E. I. Radioactive Waste Volume Reduction in a
University/Hospital Setting, 27th Mid-Year Topical Meeting of the Health Physics Society,
February 12-16, 1994. Albany, New York.
2.0 TRITIUM
Isotopes are elements that have the same atomic number (same number of protons in the
nucleus) but of different atomic mass (i.e., the total of protons and neutrons in the nucleus).
There are three isotopes of hydrogen. Ordinary hydrogen, referred to as protium ( 1
1 H,
atomic mass of 1), is the most abundant element in the universe and has one proton in the
nucleus. Heavy hydrogen, referred to as deuterium ( H3
2 , or D, atomic mass of 2), makes up
about 0.015 percent of the hydrogen, and has one proton and one neutron in the nucleus.
Radioactive hydrogen, referred to as tritium ( 3
1 H or T, atomic mass of 3), has one proton and
two neutrons in the nucleus. Refer to Appendix G for basic information on tritium, its
properties, and compounds.
DOE-HDBK-1129-2008
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2.1 Radioactive Properties
Tritium is a beta emitter. It decays to 3He by emitting a beta particle (electron) and an
antineutrino from one of the neutrons in the nucleus. The energy of the beta particle varies
from 0 to 18.6 kiloelectron-volts (keV) with an average energy of 5.69 keV. For scientific
purposes, the generally accepted value for the half-life of tritium, as measured by Mound
Laboratories, is 12.323 ± 0.004 years (4500.88 ± 1.46 days). For DOE accountability
purposes, the half-life of tritium is 12.33 +/- 0.06 years. Figure 2-1 shows the rate of decay
of one mole of tritium over six half-lives.
FIGURE 2-1. Rate of tritium decay of one mole of tritium
2.2 Physical Properties
Tritium gas is colorless, odorless, tasteless, and radioactive. It decays to 3He, a monatomic
gas, by emitting an electron and antineutrino from the nucleus. Tritium has a high
coefficient of diffusion. It readily diffuses through porous substances such as rubber and
can also diffuse through metals.
As tritium decays in a container of constant volume at a constant temperature, the tritium
partial pressure decreases and the partial pressure of 3He increases. The pressure in the
container approaches twice that of the original container pressure. The rate of pressure
change over time is shown in Figure 2-2.
Section 16
Moles of T 2 and 3 He Versus Time, Per Mole of Tritium At the Start, In A Container Starting With Pure
Tritium At t=0
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
1.60
1.80
2.00
0.0
00 3.0
81 6.1
62 9.2
42
12.
32
3
15.
40
4
18.
48
5
21.
56
5
24.
64
6
27.
72
7
30.
80
8
33.
88
8
36.
96
9
40.
05
0
43.
13
1
46.
21
1
49.
29
2
52.
37
3
55.
45
4
58.
53
4
61.
61
5
64.
69
6
67.
77
7
70.
85
7
73.
93
8
Elapsed Time In Years In Increments Of 1/4 Half Life
Mo
les
Per
Mo
le
Of
Trit
iu
m
At
t=0
mHe3At-t
mT2At-t
mTotAt-t
m=moles
m (T2 at t y ears) = m (T2 in i tia l ) e {[tyears ) x ln 0.5]/12.323}
m (He3 a t t y ears ) = 2 m (T2 in i tial ) {1 - e{[t(years ) x ln 0.5]/12.323} }
m (T2 + H e3 at t y ears ) = m (T2 in i tial ) {2 - e {[t(y ears) x ln 0.5]/12.323} }
DOE-HDBK-1129-2008
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FIGURE 2-2. Pressure versus time in a container of tritium
Other properties of tritium are listed below. Additional characteristics are given in Appendix
A.
• Atomic Weight = 3.01605
• Gram Molecular Weight = 6.03210
• Diameter of a tritium atom (approximate) = 1.1 Angstroms
• Dissociation energy, T2 to 2T = 4.59 eV
• Ionization energy, T to T+ e- = 13.55 eV
• Half-Life = 12.323 +/- 0.004 years
In this Handbook, tritium in the form of the oxide (HTO, DTO, and T2O), unless otherwise
specified, is HTO. Likewise, tritium in its elemental form (HT, DT, and T2) is HT.
2.3 Chemical Properties
The electronic configuration of tritium is the same as protium and deuterium. The chemical
properties of the isotopes are also the same. The rates of reaction vary for the different
isotopes due to the difference in the atomic masses. Additionally, the energy provided by
the radioactive decay of tritium provides the activation energy required so that some
reactions will occur with tritium that will not occur with deuterium or hydrogen.
Hydrogen is present in almost all materials. If tritium is present in a material containing
hydrogen, the tritium atoms will exchange with hydrogen atoms to form a tritiated molecule
of the material.
0.0
0.5
1.0
1.5
2.0
0.000 12.323 24.646 36.969 49.292 61.615 73.938
Time in Years
Time Period Shown = 6 Half-Lifes
Pr
es
su
re
A
ny
U
ni
ts
T2 Partial Pressure
He3 Partial Pressure
T2 Partial Pressure + He3 Partial
Pressure
DOE-HDBK-1129-2008
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2.4 Biological Properties
2.4.1 Gaseous Tritium and Tritiated Water
The body does not readily absorb H2, HT, HD, D2, DT, or T2 from inhaled gases or through
the skin. If inhaled in elemental form, almost all tritium in the gas is exhaled. Only a very
small fraction is retained in the lungs.
Tritium in the form of water (HTO, DTO, and T2O) is absorbed through the skin and in the
lungs from inhaled gases. Tritium in water form is readily retained in the body and remains
with a biological half-life of approximately 10 days. Due to the body’s ready adsorption of
tritium in the form of tritiated water, exposure to tritiated water in air is on the order of 10,000
times more hazardous than exposure to gaseous tritium (HT, DT, and T2).
The Derived Air Concentration (DAC) for tritium is the airborne concentration that, if inhaled
over a one-year period, would produce approximately a 5-rem dose to the “average” worker.
The DAC is derived by the formula:
DAC = ALI/2400
where DAC = derived air concentration (µCi/ml)
ALI = annual limit of intake (µCi)
2400 = breathing volume for the average worker over 1 year in m3
= .02 m3/min x 60 min/hr x 40 hr/wk x 50 wk/yr
Section 17
The DACs for elemental tritium and tritiated water [1] are listed in Table 2-1.
TABLE 2-1. Derived air concentrations for tritium and tritiated water
µCi/ml Bq/m3
HT
HTO
2E-01
2E-05
9E9
7E05
2.4.2 Special Tritium Compounds
Special tritium compounds (STCs) are defined as any compound, except for H2O and H2,
that contains tritium, either intentionally (e.g., by synthesis) or inadvertently (e.g., by
contamination mechanisms). Examples of STCs are metal tritides and organically bound
tritium.
Special tritium compounds differ from the more common forms of tritium (elemental tritium
and tritium oxide) in a variety of characteristics, including particle sizes, chemical behavior,
and biological properties when ingested, absorbed, or inhaled into the human body. The
physical properties of special tritium compounds may make their detection, characterization,
and subsequent assessments of hazards and exposure effects (i.e., individual dose
assessments) difficult. As a result of these unique behaviors, specific guidance has been
developed (see Appendix E) to facilitate the development and implementation of appropriate
protective programs.
DOE-HDBK-1129-2008
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Although the DOE radiological protection community has been aware of STCs for many
years, to date their impact has been limited by the design features that are incorporated into
DOE facilities that handle significant quantities of tritium. These design features include
various forms of material containment and control, such as gloveboxes and high-efficiency
particulate air (HEPA)-filtered ventilation systems that effectively prevent significant releases
of STCs to occupied areas of the workplace or the environment. Recently, sensitivity to STC
contamination has been increased as a result of recent DOE activities involving
decontamination and decommissioning of older facilities. These activities may compromise
the effectiveness of the installed design features and allow releases of STC contamination
to the surrounding areas. Such releases may cause exposures to individuals in the area and
releases of STCs to the environment, both on- and off-site. In light of such experiences,
DOE suggests that individuals setting up programs for radiological control of STCs contact
sites that either work, with or have worked, with tritium to learn of their experiences with
STCs.
Appendix E (formerly DOE-HDBK-1184-2004) has been prepared by DOE to assist its
employees and contractors in developing and implementing radiation protection programs
that will provide adequate protection against the hazards presented by special tritium
compounds.
2.5 Preferred Forms
Most tritium in the DOE complex exists as a gas, in the form of tritiated water, or as a metal
tritide. The preferred form of tritium is dependent upon its use in a process, length of
storage, or its classification as a waste.
2.5.1 Characterization of Tritium Forms
2.5.1.a Gaseous Tritium
The use, transfer, storage, and shipment of gaseous tritium at or near atmospheric pressure
has a long history in the DOE complex and has been safely used for over thirty years.
Gaseous tritium at or near atmospheric pressure occupies 22.414 L/mole at 0° C, and
approximately 24.2 L/mole at room temperature, and requires approved packages for
shipment in either Type A or B quantities. If the containers are not properly designed or if
they are damaged, the gas can leak from the container into the environment.
Section 18
Gaseous tritium at ambient pressure is easily handled by most gas handling systems and is
a good source for general-purpose use. At low pressure and temperature, the tritium does
not penetrate deeply into the container wall. Helium and tritium embrittlement of the
container wall is not a significant issue at low pressures even after several years of
exposure. As tritium decays, the pressure in the container increases (see Figure 2-2) due to
the generation of the monatomic gas 3He. This pressure increase, at most, would only be
double the initial pressure. This factor should be considered during the initial design of the
vessel so it does not become an issue.
Gaseous tritium at high pressure takes up less space but is more difficult to contain in part
due to the potential for tritium and helium embrittlement of the vessel materials. This
embrittlement increases the probability of a tritium leak or catastrophic container failure.
DOE-HDBK-1129-2008
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Unloading high-pressure gas requires specifically designed systems and experienced,
skilled operators.
2.5.1.b Metal Tritides
Metal tritides reduce the overall volume of the stored tritium, but some of the finely divided
metals used are pyrophoric. Some metals form low-melting-point alloys with the materials
used in the construction of the metal tritide containers. Others require extremely high
temperatures in order to recover tritium from the material.
2.5.1.c Tritiated Water
Tritium in the form of T2O may be difficult to store for long periods due to its corrosive
properties. Experiments with T2O indicate that pure T2O is corrosive. This corrosiveness is
likely due to tritium oxide generating free radicals (OH−) from radiolytic decomposition of
water in addition to extra energy from beta decay impinging on surrounding molecules.
Additionally, pure T2O, like distilled H2O, will dissolve many materials. No data currently
exist that quantify the degree of corrosiveness; therefore, there is no basis to definitively
state that the U. S. Environmental Protection Agency (EPA) threshold of corrosivity (i.e., a
characteristic of hazardous waste), defined in Title 40 of the Code of Federal Regulations
(CFR), Section 261.22, is not exceeded. The authors believe, however, that only a high-
purity product, and not waste, would have a reasonable chance of exceeding this threshold.
A broader discussion of the relationship between tritiated water and hazardous wastes is
contained in Section 3.1.3.
Dilute tritiated water recovered from tritium removal systems has also proven to be corrosive
and difficult to contain. In a severe case, storage of tritiated water recovered from tritium
removal systems in liquid form at concentrations as low as a few curies per milliliter has
corroded through the weld area of stainless steel vessels after only a few days of exposure.
In this specific example, it is probable that the extreme corrosive nature of this dilute tritiated
water was due, in large measure, to chlorine contamination of the catalyst in the tritium
removal system. This corrosion is evidently inhibited by absorption of the tritiated water on
clay or in molecular sieve material.
Figure 2-3 provides a comparison of the various concentrations of tritiated water found
throughout the nuclear industry.
DOE-HDBK-1129-2008
15
FIGURE 2-3. Comparison of aqueous tritium levels found in the nuclear industry
2.5.2 Identity of Common Forms
Section 19
Tritium is usually supplied in gaseous or uranium tritide form. Other forms are also available
but are not in common use for bulk shipment.
2.5.2.a Gas
In gaseous form, tritium is usually supplied at a purity of 90 to 95 percent tritium (99 percent
in research applications) with deuterium and protium as the primary impurities.
2.5.2.b Metal Tritides
The use of metal tritide storage beds is one of the most convenient ways of handling tritium.
The metal tritide beds have different operating parameters and characteristics, and there are
advantages and disadvantages in use of the different materials.
2.5.2.b(1) Uranium
Uranium is currently the most useful material for general-purpose tritium storage beds. The
equation form for the dissociation pressure of uranium tritide, deuteride, and hydride for the
pressure in millimeters of mercury is, Pmm = 10 (-A/T +B), where A and B are parameters listed
in Table 2-3. Washington Savannah River Company (WSRC) has determined that in the
hydride transport vessel (HTV), for a uranium-to-tritium ratio of 1:2.9 in the HTV vessel, the
equation is
DOE-HDBK-1129-2008
16
Patm = 10(-4038.2/T + 6.074)
At room temperature, tritium in the presence of uranium powder forms uranium tritide. The
tritium partial pressure in the bed is very low. As a result, at room temperature the bed acts
as a vacuum pump that getters all of the hydrogen isotopes. The impurity gases that may
be present, such as 3He, N2, O2, or Ar, either remain in the overpressure gas in the bed or
react with uranium to form stable compounds. Inert gases, such as Ar, will remain in the
overpressure gas, and can be removed by pumping off with a vacuum pump after the
pressure has stabilized; however, 3He cannot be pumped off without first heating the bed.
N2 and O2 will react chemically with the uranium to form stable uranium compounds in the
bed, and, therefore, cannot be pumped off at all.
As the temperature of the bed is increased, the tritium partial pressure increases as a
function of temperature. Depending upon the U:T ratio, it can reach a pressure of around
500 pounds per square inch absolute (psia) at 600°C. The tritium may be transferred into
and out of manifolds, containers, etc., by heating the bed and then cooling it to room
temperature. The general form of the equation for the dissociation pressure, P, in
millimeters of mercury (mm) for uranium hydride, deuteride, and tritide is:
log Pmm = − A/T + B
or
Pmm = 10–(A/T(K)) + B
where
T = temperature (K)
The values for A and B for hydrogen, deuterium, and tritium, determined by several different
investigators, are listed in the following paragraphs, and the results are shown in Table 2-2
and plotted in Figure 2-4. Figure 2-5 is a plot of the general characteristics of uranium
hydride, deuteride, and tritide.
TABLE 2-2. Dissociation pressure equation parameters for uranium hydride, deuteride, and
tritide
Metal
Tritide Reference
Temperature
Range (oC)
Investigated
A
(/Kelvin) B
Temperature
(°C) required to
generate a
pressure of
1 atmosphere
UH3 Spedding, et al.
Destriau & Seriot
Wicke & Otto
Mogard & Cabane
Libowitz & Gibb
260 to 430
243 to 412
200 to 430
500 to 650
450 to 650
4500
4255
4450
4480
4410
9.28
9.08
9.20
9.20
9.14
430
415
434
435
432
UD3 Spedding, et al.
Destriau & Seriot
Wicke & Otto
unspecified
unspecified
unspecified
4500
4401
4500
9.43
9.01
9.40
414
445
417
UT3 Flotow & Abraham
WSRC
unspecified
unspecified
4471
4038.2
9.461
6.074
Section 20
408
unspecified
DOE-HDBK-1129-2008
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FIGURE 2-4. Dissociation pressure for uranium, hydride, deuteride, and tritide
FIGURE 2-5. Plot of a good fit curve for the dissociation pressure of uranium hydride,
deuteride, and tritide
Each time the tritium is cycled into the system manifolds, it picks up impurity gases. These
impurities collect in the bed overpressure gas and may be pumped off to remove them after
each heating/cooling cycle. Active impurity gases, such as oxygen and nitrogen, are
irreversibly removed by reaction with the uranium.
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
1500
1600
200 210 220 230 240 250 260 270 280 290 300 310 320 330 340 350 360 370 380 390 400 410 420 430 440
Temperature Degrees Centigrade
Di
ss
oc
ia
tio
n
Pr
es
su
re
in
to
rr
UT3-FlAb
UD3-Spd
UD3-DeSe
UD3-WiOt
UH3-Spd
UH3-DeSe
UH3-WiOt
UH3-LiGi)
UH3-MoCa
UD3
UT3
UH3
Dissociation Pressure of Uranium Tritide, Deuteride, and Hydride
0
10
20
30
40
50
60
20
0
22
0
24
0
26
0
28
0
30
0
32
0
34
0
36
0
38
0
40
0
42
0
44
0
46
0
48
0
50
0
52
0
54
0
56
0
58
0
60
0
62
0
64
0
66
0
Temperature in Degrees Centigrade
D
is
so
ci
at
io
n
Pr
es
su
re
in
A
tm
os
ph
er
es
UD3
UT3
UH3
Good fit equations for the dissociation pressure of uranium tritide, deuteride, and hydride in units of atmospheres. The data
from various experimenters was used to extend the range from 200 degrees Centigrade to 650 degrees Centigrade.
Patm UD3={10-(4 500/T deg K) +9.4 }/760 Pa tmUT3={10-(4471/T deg K) +9 .461 }/760 Patm UH3={10-(45 25/T deg K) +9.27 }/760
DOE-HDBK-1129-2008
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Disadvantages to using uranium tritide beds are: 1) uranium powder is pyrophoric; 2) the
generation of significant tritium pressure requires a high temperature that results in
permeation of tritium through the vessel wall; and 3) the capacity is also permanently
reduced by exposure to active impurity gases.
2.5.2.b(2) Palladium
Palladium is a metallic element of Group 8 in the Periodic Table. The symbol for palladium
is Pd, the atomic number is 46, the atomic weight is 106.42, and the melting point is
1554.9°C.
At room temperature, palladium absorbs up to 900 times its own volume in hydrogen. It
diffuses easily through heated palladium; this is one means of purifying the gas. Finely
divided Pd is a good catalyst, and is used for hydrogenation and dehydrogenation reactions.
Palladium powder is currently the second most-used material for general-purpose tritium
storage beds. Palladium can be obtained in powdered form and loaded directly into the
container used for the metal tritide bed. Palladium was used extensively at both Lawrence
Livermore National Laboratory (LLNL) and Sandia National Laboratory–Livermore (SNLL) in
the tritium storage beds.
When the tritium is exposed to the powder, it dissolves in the palladium powder with a
maximum Pd:T ratio of approximately 0.7. Palladium powder is not pyrophoric, but it has a
higher tritium partial pressure than uranium at room temperature.
At room temperature, tritium, deuterium, and protium dissolve in the palladium powder and
the tritium partial pressure in the gas over the powder is approximately 50 torr. The
overpressure increases as a function of temperature. As the temperature of the palladium is
increased by heating the bed, the tritium partial pressure increases as a function of the
temperature and reaches a pressure of around 750 psia at 350°C. The general form of the
equation for the dissociation pressure, P, in millimeters of mercury (mm) for palladium
hydride, deuteride, and tritide is:
Section 21
log Pmm = (−A/T + B)
or
Pmm = 10 (−A/T + B)
where
T= temperature (K)
The values for A and B for hydrogen and deuterium determined by different investigators are
given in Table 2-3, and the equations developed by the different experimenters over the
temperature range they investigated are plotted in Figure 2-6.
DOE-HDBK-1129-2008
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TABLE 2-3. Dissociation pressure equation parameters for palladium hydride and deuteride
Metal
Tritide Reference
Temperature
Range (oC)
Investigated A B
PdHx Gillespe & Hall
Gillespe & Hall
Ratchford & Castellan
Wicke & Nernst
0 to 180
200 to 300
unspecified
-78 to 175
1835.4
1877.82
2028.2
2039
7.3278
7.483
7.9776
7.65
PdDx Gillespe & Downs
Wicke & Nernst
to 300
unspecified
1696.11
1940
7.5138
8.00
The 3He generated as a result of decay of the tritium absorbed in the palladium is trapped in
the palladium and is not released until the bed is heated or until the T:3He ratio reaches a
particular value. 3He generated as a result of decay in the overpressure gas is not absorbed
in the palladium and remains in the overpressure gas. Most impurities do not react with,
and are not gettered by, the palladium powder. These impurities accumulate in the
overpressure gas as the bed is used to support operations.
FIGURE 2-6. Dissociation pressure of palladium hydride and deuteride
The generation of significant pressure at low temperature (750 psia at 350°C) is the primary
advantage of palladium. The primary disadvantage of palladium is the high partial pressure
of tritium over the powder at room temperature (50 torr at room temperature).
0
1000
2000
3000
4000
5000
6000
20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Temperature (C)
D
is
so
ci
at
io
n
Pr
es
su
re
(t
or
r)
log P mm =7.3278-1835.4/T
log P m =7.483-1877.82/T
log P mm =7.9776-2028.2/T
log P mm =7.65-2039/T
log P mm =7.5138-1696.11/T
log P mm =8-1940/T
log P mm =7.6-1900/T
log P mm =7.75-1810/T
Good Fit Line PdD
Good Fit Line PdH
DOE-HDBK-1129-2008
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2.5.2.b(3) Titanium
Titanium is a metallic element in Group 4 of the Periodic Table. The symbol is Ti, the atomic
number is 22, the atomic weight is 47.90, and the melting point is 1660°C. It is a low-cost
metal, and can absorb and store tritium in a compact solid form at a tritium pressure of
approximately 1E-7 torr.
Titanium hydride, TiH2, in powder form, is a black metallic dust that is less prone to
spontaneous ignition in air than the parent metal. Finely divided titanium hydride is reported
to ignite at 440°C and its dust is an explosion hazard, which dissociates above 288°C.
Titanium hydride is used in powder metallurgy, hydrogen production, foamed metals, glass
solder, and refractories, and as a gas getter in the electronics industry. Titanium tritide in
solid or massive form is stable in air for extended periods of time. Titanium retains the
decay helium up to a concentration of 0.3 He atom per Ti atom. Both SRS [2] and Ontario
Hydro [3-7] have selected titanium as their long-term storage medium. The SRS titanium
beds have an expected useful life of about 10 years, while the Ontario Hydro beds are
expected to be in operation for over 20 years. The Canadians are not space-restricted, and
therefore do not load their beds to the degree that SRS does. Additionally, longer times to
maximum helium retention ratio (0.3 He:Ti) can be achieved by diluting the tritium
concentration with deuterium or protium.
2.5.2.b(4) Zirconium
Section 22
Zirconium is a metallic element of Group 4 in the Periodic Table. The symbol for zirconium
is Zr, the atomic number is 40, and the atomic weight is 91.22. Zirconium is flammable as a
powder and melts at 1850°C. Zirconium is a hard, lustrous, grayish metal that is strong and
ductile, and is used in alloys, pyrotechnics, welding fluxes, and explosives.
Zirconium hydride ZrH2 is a flammable gray-black powder and is used in powder metallurgy,
nuclear moderators, and as a reducing agent. Finely divided zirconium hydride suspended
in air will ignite at 430°C. Zirconium hydride contains about twice as many hydrogen atoms
per unit of volume as liquid hydrogen. Massive zirconium hydride is stable in air for
extended periods of time at temperatures below 600°C.
Certain DOE radioactive zirconium fines (which are destined for disposal) are managed as
D001 mixed ignitable wastes. These radioactive zirconium fines are pyrophoric under 40
CFR 261.21(a)(2); i.e., they are capable of causing fire through friction. If zirconium used for
tritium storage beds is destined for disposal (i.e., constitutes a waste), the Resource
Conservation and Recovery Act (RCRA) hazardous waste characteristic of ignitability must
be analyzed. A broader discussion of RCRA hazardous waste is contained in Section 3.1.3.
2.5.2.b(5) Societá Apparecchi Elettrici e Scientifici (SAES) Getters
During the late 1990s, investigations were conducted concerning the use of SAES getters to
remove tritium from tritium-contaminated gaseous waste streams. These investigations
have concentrated on getters that cracked the gases containing tritium and removed the
resulting free tritium from the gas stream. The primary advantage of these getter systems is
that tritium is not converted by the tritium removal system to the more radiotoxic tritiated
water. Additionally, the tritium can be recovered in gaseous form from the getter, purified,
and reused.
DOE-HDBK-1129-2008
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The materials tested include those manufactured in the form of pressed pellets that can be
used in low–pressure, drop-packed bed reactors designed for the size required by the
application flow rate and lifetime requirements. The basic strategy implemented in prototype
systems was to crack the molecules on a hot getter and remove the nontritiated reactive
impurities that interfere with the performance of the hydrogen gettering alloys. Following
purification, the gas is passed through a hydrogen gettering bed to remove the hydrogen
isotopes from the gas stream. This philosophy worked well, and has gained acceptance for
use in inerted gloveboxes.
2.5.2.b(6) LaNi5-Based Alloys
The use of lanthanum-nickel hydrides has been a continuing topic of interest; promising
results for hydrogen storage have been reported1. Promising results were also reported in
the literature in 19882. Earlier research at Mound, however, in the 1970s and early 1980s
indicated that lanthanum-nickel-based alloys were not appropriate for tritium service due, in
part, to disproportionation. When cycled, the LaNi5 had a tendency to separate to form the
parent metals (La or Ni) or different alloys. The disproportionation tended to change the
pressure, concentration, and temperature properties of the metal/alloy mix and increase the
quantity of tritium bound in the heel that was not easily recoverable. However, research at
Savannah River National Lab (SRNL) has shown that “Substitution of aluminum for a portion
of the nickel in LaNi5 was found to lower the hydrogen plateau pressure and allow LaNiAI
alloys to be tailored to specific storage applications.” [8] SRNL found that the substitution of
aluminum in LaNi5 had the added benefit of stabilizing the alloy against disproportionation.
Decay of absorbed tritium to 3He does cause an “aging” effect, which limits the useful life of
LaNiAI alloy as a tritium storage material to less than about 10 years.
Section 23
2.5.2.c Absorbed Water
Molecular sieve material is used in tritium removal systems for removal of water
contaminated with tritium. Systems such as tritium removal systems, effluent recovery
systems, and cleanup systems remove tritium from a gas by cracking the tritium-containing
components on a heated precious metal catalyst. The free tritium then combines with
oxygen in the gas stream to form tritiated water. The gas stream is then cooled to room
temperature, and the water contained in the gas stream, including the tritiated water, is
removed by a molecular sieve trap.
A molecular sieve will hold about 18 percent water by weight, and the sieve may be
regenerated to remove the water so it can be reused. Tritiated water absorbed on molecular
sieve is not corrosive and may be stored in this way for long periods without damage to the
container wall.
Water contaminated with HTO is also stored on clay. The common method of solidification
of tritium-contaminated wastewater for disposal is to solidify the water on clay so that it can
1 “LaNi5 Intermetallic Hydride,” extracted from State-of-the-Art Review of Hydrogen Storage in
Reversible Metal Hydrides for Military Fuel Cell Applications, Gary Sandrock, Ph.D., for the
Department of the Navy, Office of Naval Research, N00014-97-M-0001, July 24, 1997.
2 “Hydrogen Isotope Sorption Properties of LaNi3Mn2 Alloy as a Candidate for the Tritium Storage
Material,” T. Ide et al., Sumitomo Heavy Industries, Ltd. and H. Yoshida et al., Japan Atomic
Research Institute, published in Fusion Technology, September 1988.
DOE-HDBK-1129-2008
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be classified as solid waste. Clay will hold approximately 60 percent water by volume.
Waste disposal sites generally require the use of 100 percent more clay than required to
solidify the water, and, as a result, the water is generally limited to 30 percent of the volume
of the clay for waste solidification purposes. Water absorbed on clay is not corrosive and
may be stored for long periods without damage to the container wall.
2.5.3 Summary
2.5.3.a Best for Storage Conditions
The decision on storage media is a function of the storage length and frequency of
unloadings. Media range from gas (short timeframe, many movements) to titanium (long
timeframe, few or no movements) with other media (e.g., uranium) in between. Although the
preferred form for storage is a metal tritide and the least desirable form is a liquid, there are
always exceptions to this rule. Factors to be considered include:
Solid (Metal Tritides): Unless already in solid form, tritium is not readily available as a solid
metal tritide and requires conversion before storage. Metal tritides can store large quantities
of tritium without occupying large volumes, but the storage containers are more complex
than gaseous storage containers. Depending upon the metallic tritide chosen for storage,
there are both advantages and disadvantages. Titanium tritide is very stable, even when
exposed to air, but it is more difficult to recover tritium from the titanium than from other
metals. Stored as uranium tritide, the tritium can be easily and quickly recovered and
provides for the removal of most impurities that might accumulate during storage. However,
uranium powder is also pyrophoric, and starts releasing 3He after a few months.
Section 24
Liquid (T2O): Tritium is not readily available in water form and requires conversion before
storage. Tritium is on the order of 15,000 to 25,000 times more hazardous in oxide form
than in elemental form. It takes very little space, but is difficult to store due to the corrosivity
of the water. The tritiated liquid can be solidified on clay, molecular sieves, or polymers prior
to disposal. In either case, the final decision should be based on the quantity of tritium and
the tritium concentration of the water to be stored.
Gas (T2): Tritium is readily available in gaseous form. A great deal of experience exists on
the design of gaseous tritium storage systems. As a gas it takes up more volume than as a
liquid or solid, but can be more easily released to the environment if the tritium container is
breached. Gas also presents a flammability vulnerability.
2.5.3.b Best for Operations/Process
Solid (Metal Tritides): When used as a gas in research where tritium is issued and
returned as a gas, there are advantages to the use of hydride beds for storage. The
heating/cooling cycle used to store and recover tritium from the bed results in routine
removal of the 3He and other impurities from the tritium supply. It can be reused in other
processes at reasonably high purity. Additionally, storage as a metal tritide allows the bed
to be used as a pressure generator and, in some cases, eliminates the need for mechanical
pumps.
Liquid (T2O): Unless the process itself uses tritium in the form of water, there are no
advantages to storage of tritium in liquid form for operations.
DOE-HDBK-1129-2008
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Gas (T2): Tritium is primarily used in gaseous form, purified in gaseous form, assayed in
gaseous form, and is more useful in this form than any other form. As a result, storage in
gaseous form for operations is appropriate.
2.5.3.c Best for Disposal Conditions
Disposing of tritium in the form of a liquid waste or gaseous waste is difficult. Generally
speaking, waste tritium is converted to solid form so that the material can be disposed of as
a solid low-level (radioactive) waste, assuming there is no RCRA hazardous component.
Solid (Metal Tritide): It is possible to dispose of gaseous tritium by converting it to a solid
metal tritide. However, the disposal site requires that the metal tritide not be pyrophoric. If it
is in particulate form, the metal tritide must be contained to meet disposal site requirements.
Liquid (T2O): If the waste is in gaseous form, the tritium is normally removed from the gas
mixture and reused. If the concentration of tritium in the waste gas is too low to make
recovery of the tritium economically worthwhile, the waste gas is sent to an effluent
processing system, where the tritium is removed before the gases are released to the
environment. The current effluent processing systems remove tritium from the waste gas by
converting it to water. The water is then solidified on molecular sieve, clay, mixtures of clay
and cement, or Stergo superabsorbent (discussed in Section 8.1.4.b(2)), and is then
packaged as solid waste and shipped to the disposal site.
Gas (T2): Waste disposal sites generally will not accept packages containing pressurized
gases or those in which a potential exists for generating 1.5 atmospheres (absolute) of
pressure over time.
3.0 BASIC TRITIUM REGULATORY INFORMATION
Section 25
Due to its more hazardous profile, most of the regulatory interest in tritium is concerned with
the oxide form. Figure 2-3 pictorially illustrates various concentrations and regulatory
setpoints. The radiological materials inventory for tritium accounting purposes may not
coincide with the radiological materials inventory for documented safety analysis (DSA)
purposes, which may not coincide with the radiological materials inventory for Environmental
Impact Statement (EIS) purposes. This is due to prescribed allowances for excluding
various portions of the inventory, as discussed in Sections 3.1 and 3.3. DOE regulations
concerning tritium (along with other radionuclides) can be found in 10 CFR 830, which
contains associated Quality Assurance (QA) Program requirements to be met.
3.1 Tritium Accountability and Environmental Considerations
3.1.1 Radiological Materials Inventory
The Atomic Energy Act (AEA) of 1954 describes three categories of materials: byproduct,
source, and special nuclear material (SNM). There are also three categories of nuclear
materials described in DOE M 470.4-6, Control and Accountability of Nuclear Materials:
SNM, source, and other. Table I-1 in the Manual identifies tritium as an “other” category
material that is accountable nuclear material.
DOE-HDBK-1129-2008
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Tritium is currently accountable for DOE down to 0.01 grams. Items that contain tritium
quantities of 0.005 grams or greater are rounded to the nearest 0.01 grams and become
accountable items. Items that contain less than 0.005 grams round to zero and are not
accountable items. For the purposes of accountability, the radiological materials inventory
of tritium is the sum of the tritium quantities contained in the accountable items. This sum
does not include any items that contain less than 0.005 grams of tritium or other items that
are not part of the facility accountable nuclear materials inventory. The accountability limit is
under consideration for revision, and personnel should always check the latest revision to
the Materials Control and Accountability (MC&A) Manual for the latest limits. Tritium
contained in water (H2O or D2O) used as a moderator in a nuclear reactor is not an
accountable material.
Quantities of tritium contained in waste may be part of the facility accountable nuclear
materials inventory until it is removed from the facility to a waste accumulation area for
storage or to a waste packaging area for packaging. Waste can also be put in a prescribed
form, as specified in DOE M 470.4-6. Individual waste items that contain at least 0.005
grams of tritium are accountable nuclear material items and become part of the facility
accountable nuclear materials inventory.
DOE requires that a tritium facility establish material control and accountability systems to
provide accurate nuclear materials inventory information. The facility tritium inventory and
scrap levels of tritium must be minimized consistent with the operational needs and
safeguards practices of the facility.
For each facility, a materials control and accountability program must be established for all
nuclear materials on inventory, including those designated as uneconomical to recover. The
facility materials control and accountability system should include the following:
Section 26
• Accounting System Database
• Account Structure
• Records and Reports
• Physical Inventories
• Periodic Physical Inventories
• Special Inventories
• Inventory Verification/Confirmation Measurements
• Measurements and Measurement Control
• Organization
• Selection and Qualification of Measurement Methods
• Training and Qualification of Measurement Personnel
• Measurement Systems
• Measurement Control
• Material Transfers
• External Transfers
• Internal Transfers
• Material Control Indicators
• Shipper/Receiver Difference Assessment
• Inventory Difference Evaluation
• Evaluation of Other Inventory Adjustments
DOE-HDBK-1129-2008
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• Documentation and Reporting Forms
• Procedures and Requirements
3.1.2 Limits for Tritium in Drinking Water and the Environment.
The current National Primary Drinking Water Regulation (NPDWR) for beta- and photon-
emitting radionuclides is 4 millirem (mrem) per year. The maximum contaminant level
(MCL) for tritium in drinking water systems, used to demonstrate compliance with the 4
mrem/year level regulatory criterion as determined by the EPA (40 CFR Part 141) is 20,000
pCi/L (740 Bq/L). Assuming that one drank 2 L, using the ICRP 30-based Derived
Concentration Guides (DCGs) from DOE Order 5400.5, a concentration of 80,000 pCi/L
(2,960 Bq/L) would produce a dose of 4 mrem per year. Other international standards are
based on 10 percent of the public dose limits as recommended by ICRP 60 and ICRP 103;
however, implementation varies by nation. Example recommendations include: the World
Health Organization, based on ICRP 60, 270,000 pCi/L (10,000 Bq/L); the Canada Nuclear
Safety Commission, 189,000 pCi/L (7,000 Bq/L); and the European Commission (EC), 2,700
pCi/L (100 Bq/L) screening value for tritium to determine if more detailed evaluations are
necessary and to determine if tritium in combination with other radionuclides may exceed
the 0.1 mSv/year (10 mrem/y) recommended dose criterion.
The EPA MCL of 20,000 pCi/L for tritium was promulgated in 1976 based on radiological
risk estimates from the Biological Effects of Ionizing Radiation I report (BEIR I), dose factors
from Handbook 69, Maximum Permissible Concentrations of Radionuclides in Air and Water
for Occupational Exposure, published by the National Bureau of Standards in 1959 and
amended in 1963, and various assumptions regarding drinking water exposures. In 1991,
as part of an effort to update and revise the drinking water standards contained in 40 CFR
Part 141, the EPA evaluated potential doses from 20,000 pCi/L using Federal Guidance
Report No. 11 dose factors based on ICRP 30, and determined that it would result in a
69,000 pCi/L limit; however, based on its policy for implementing the Safe Drinking Water
Act Amendments of 1996, the EPA left unmodified the 20,000 pCi/L limit, over DOE
objections.
Section 27
The NRC requires licensees to demonstrate compliance with NRC public dose limits by
calculating total effective dose equivalent to the individual likely to receive the highest dose
and demonstrate that it does not exceed public dose limits or demonstrate that annual
average concentration of effluents at the boundary of the unrestricted area does not exceed
values in 10 CFR Part 20, Appendix B, Table II. The values for liquid effluents are based on
an assumed ingestion of 2 L/day over the year and a dose constraint of 50 mrem/year. For
tritium, the value is 0.001 microcuries/ml (1,000,000 pCi/L). DOE Order 5400.5, Radiation
Protection of the Public and Environment, similarly requires DOE contractors to monitor
releases and calculate potential doses to members of the public to demonstrate that DOE
activities are being managed so that public dose is as far below the 100 mrem in a year
primary dose limit as is practical. The DOE Order includes tables of DCGs, which are
concentrations of radionuclides in water that would cause a 100 mrem in a year dose if an
individual drinks 730 L (2 L/day). The tritium DCG is 0.002 µCi/ml (2,000,000 pCi/L);
however, unlike NRC, DOE does not permit the use of concentration guidelines as a means
of compliance. Dose estimates are necessary to demonstrate compliance and the DCGs
are provided as a tool to assist in that evaluation. Although it is expected that discharges
would be significantly less than DCG values, exceeding the DCG does not necessarily
violate DOE Order 5400.5 if dose calculations demonstrate that public doses, as a result of
all pathways, are as low as reasonably achievable below the primary dose limit (this
DOE-HDBK-1129-2008
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includes all sources and pathways, and a 25 mrem/y constraint is usually applied to single
sources). DOE Order 5400.5 also requires that DOE facilities manage discharges so as not
to cause public drinking water systems downstream to exceed applicable drinking water
MCLs (20,000 pCi/L for tritium).
Under the Comprehensive Environmental Response, Compensation, and Liability Act
(CERCLA) process, EPA frequently employs drinking water standards as a goal for
protecting or cleaning groundwater (20,000 pCi/L for tritium), but also considers water
usability and other factors when establishing site-specific values. Neither DOE (DOE Order
5400.5) nor NRC (10 CFR Part 20, Subpart E) requirements for cleanup or clearance of real
property have specific concentrations or dose limits for tritium in groundwater. Tritium must
be considered along with all other radionuclides and pathways when demonstrating that the
dose to the public will be as far below 25 mrem/year as is reasonably achievable. However,
DOE’s requirement that DOE activities not cause existing public drinking water systems to
otherwise exceed drinking water standards also applies to cleanup and clearance.
Although rarely a health concern, the detection of tritium in groundwater is of interest to
many, and sometimes is a contentious issue. For example, the identification of an onsite
groundwater tritiated plume at Brookhaven National Laboratory contributed to the decision
to close the High Flux Beam Reactor (the source of the tritium in the plume), even though
the plume did not present a significant public risk and the spent fuel pool had a stainless
steel liner installed to prevent future leakage both within and outside the DOE complex.
Environment, Safety and Health Safety Advisory 2006-04, Stakeholder Sensitivity to Tritium
Releases [10], describes issues encountered at commercial nuclear power plants and non-
RCRA-regulated landfills that have found tritium in their leachate (e.g., the Pennsylvania
Department of Environmental Protection has identified tritium in the leachate of most of its
landfills). Both NRC and the Nuclear Energy Institute are sensitive to tritium groundwater
issues, as are the States. Effective monitoring programs and good outreach and
communication programs are key to preventing and mitigating actual and perceived
problems with tritium control.
Section 28
3.1.3 RCRA Applicability
Under the implementing regulations of RCRA, specifically at 40 CFR 261.4(a)(4), source,
SNM, and byproduct material, as defined by the AEA, is excluded from the definition of solid
waste, and thus from the RCRA hazardous waste management requirements. The AEA
definition of byproduct material includes “any radioactive material (except special nuclear
material) yielded in or made radioactive by exposure to the radiation incident to the process
of producing or utilizing special nuclear material.” Tritium produced in a U.S. reactor meets
the definition of byproduct material; therefore, the waste streams derived from U.S. reactor-
produced tritium are excluded from RCRA regulation (provided such waste streams do not
also contain a RCRA hazardous waste component in addition to the byproduct material
component).
Accelerator-produced tritium, on the other hand, did not qualify for this exclusion, since the
tritium is produced by a linear accelerator, and does not involve the production or utilization
of SNM or the extraction or concentration of source material. However, the AEA was
revised by the Energy Policy Act of 2005, which amended the definition of byproduct
material to include “any material that has been made radioactive by use of a particle
accelerator, and is produced, extracted, or converted after extraction, before, on or after the
date of enactment of [the Act] for use for a commercial, medical, or research activity.”
DOE-HDBK-1129-2008
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Therefore, only accelerator-produced tritium used for weapons production does not qualify
for the RCRA material exclusion, while other uses for the accelerator-produced tritium do
meet the RCRA exclusion. Additionally, tritium produced in the original Canada Deuterium
Uranium (CANDU) design, employing natural uranium as fuel, may not, in the opinion of
some DOE Headquarters groups (e.g., the Offices of General Counsel and Health, Safety
and Security (HSS)), meet the definition of byproduct material; therefore, it is prudent to
assume that it also does not qualify for RCRA exclusion.
Thus, for U.S. reactor-generated or accelerator nonweapons-production tritium waste to be
considered hazardous waste, the waste stream also would have to contain a RCRA-listed or
non-tritium-derived characteristic hazardous waste component. The waste stream from
CANDUs and weapons-related accelerator tritium would not be automatically be excluded
from RCRA, however, unless such tritium wastes exhibit one of the characteristics of RCRA
hazardous waste (ignitability, corrosivity, reactivity, or toxicity [40 CFR Sections 261.21
through 261.24]), the waste streams would not need to be managed as RCRA hazardous or
mixed waste. Pursuant to the RCRA regulations, it is the responsibility of the waste
generator to determine if that waste is subject to the hazardous waste requirements [40
CFR 262.11]. Categories of characteristic hazardous waste (and associated properties) that
appear to have some potential to apply to certain accelerator-produced tritium wastes are as
follows:
• Ignitability [40 CFR 261.21] – Ignitable wastes are solid wastes that exhibit any of the
following properties: liquids with a flashpoint of less than 60°C (140°F); solids that are
capable of causing fires through friction, absorption of moisture, or spontaneous
chemical changes; ignitable compressed gases, as defined in 49 CFR 173.300; or
oxidizers, as defined in 49 CFR 173.151.
Section 29
• Corrosivity [40 CFR 261.22] – Corrosive wastes are solid wastes that exhibit any of the
following properties: an aqueous material with pH <2 or >12.5; or a liquid that corrodes
steel at a rate greater than ¼ inch per year at a temperature of 55°C (130°F).
• Reactivity [40 CFR 261.23] – Reactive wastes are solid wastes that exhibit any of the
following properties: (1) they are normally unstable and readily undergo violent change
without detonating; (2) they react violently with water; (3) they form potentially explosive
mixtures with water; (4) when mixed with water, they generate toxic gases, vapors, or
fumes in a quantity sufficient to present a danger to human health or the environment;
(5) they are a cyanide- or sulfide-bearing waste which, when exposed to pH conditions
between 2 and 12.5, can generate toxic gases, vapors, or fumes in a quantity sufficient
to present a danger to human health or the environment; (6) they are capable of
detonation or explosive reaction if subjected to a strong initiating source or if heated
under confinement; (7) they are readily capable of detonation or explosive
decomposition or reaction at standard temperature and pressure; (8) they are a
forbidden explosive, as defined in 49 CFR 173.51, a Class A explosive, as defined in 49
CFR 173.53, or a Class B explosive, as defined in 49 CFR 173.88.
The discussion in Section 2.5.1.c provides a qualitative argument for the determination that
for tritiated waste, the characteristic of corrosivity typically are not generally exhibited.
However, little data are currently available to confirm whether or not the vapor space of
some tritium containers (e.g., tritium oxide adsorbed on molecular sieves) would exhibit the
hazardous characteristic of ignitability or reactivity over time due to radiolytic decay. As
explained above, the tritated waste stream that is not subject to the RCRA material
DOE-HDBK-1129-2008
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exclusion based on its being a byproduct material may still be excluded from the RCRA
hazardous waste regulations pursuant to 40 CFR 261.4(a)(4) if it does not contain a
hazardous waste component This may be the case even if sufficient quantities of both
hydrogen and oxygen are present to exhibit characteristics of ignitability or reactivity. This is
based on a regulatory policy that EPA has applied in certain cases whereby residuals
derived from the management of exempt or excluded waste retain the exemption or
exclusion. [11-15]. However, as indicated above, if a tritium waste (irrespective of its
source) also contains a distinct hazardous waste component, the waste stream should be
managed as a radioactive mixed waste under the AEA and RCRA.
The application of RCRA to certain tritium waste streams may be subject to regulatory
interpretation and enforcement discretion. With this in mind, it is recommended that
determinations as to whether or not certain tritium wastes constitute RCRA hazardous waste
be discussed and validated with the appropriate regulatory agency (e.g., the EPA Region or
RCRA-authorized State agency). Section 8.2.2 provides a flow diagram and expanded
discussion on this issue in addition to the definitions and options for tritium recovery and
disposal.
3.2 Tritium Safeguards and Security
Tritium is a nuclear material of strategic importance and must be safeguarded from theft or
diversion. Safeguard requirements are based on the category and attractiveness level of
the nuclear material, as specified in DOE M 470.4-6, Table I-4, “Graded Safeguards,”
Tritium is either a Category III or Category IV material depending upon the following:
Section 30
• Category III – Weapons or test components containing reportable quantities of tritium.
Deuterium-tritium mixtures or metal tritides that can be easily decomposed to tritium gas,
containing greater than 50 grams of tritium (isotope) with a tritium isotopic fraction of 20
percent or greater.
• Category IV – All other reportable quantities, isotopic fractions, types, and forms of
tritium.
3.3 Tritium Facility Safety Analysis and Regulatory Quantity Limits
A documented safety analysis is required by 10 CFR 830, Nuclear safety management, for
all Hazard Category 1, 2, and 3 nuclear facilities. Irrespective of these requirements, the
good practices associated with the implementation of Integrated Safety Management (ISM)
principles necessitate that hazards be identified and controlled, which is a major step in the
safety analysis process.
3.3.1 Safety Analysis
3.3.1.a Facility Requirements
There are a few fundamental assumptions normally made when performing safety analyses
on tritium facilities, which, if not satisfied, require more detailed analyses or development of
corrective actions. These include:
DOE-HDBK-1129-2008
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• The integrity of the primary container should be ensured for all normal operations,
anticipated operational occurrences, and for the design basis accidents (DBAs) it is
required to withstand.
• If the facility structure is not part of the secondary barrier, its failure as a result of severe
natural phenomena or other postulated DBAs should not prevent the primary container
or the secondary containment or confinement system from performing their necessary
safety functions.
• When secondary containers (secondaries) are used, a tritium effluent removal system to
handle tritium leakage from primary containers is recommended by this Handbook, but
not required by regulations.
3.3.1.b Radiological Materials Inventory
Attachment 1 to DOE-STD-1027-92, Change Notice 1, Hazard Categorization and Accident
Analysis Techniques for Compliance with DOE Order 5480.23, Nuclear Safety Analysis
Reports, states,
Additionally, material contained in Department of Transportation (DOT) Type B
shipping containers (with or without overpack) may be excluded from summation of a
facility’s radioactive inventory if the Certificates of Compliance are kept current and
the materials stored are authorized by the Certificate. However, Type B containers
(see Section 6.1) without an overpack should have heat protection provided by the
facility’s fire suppression system.
Further guidance from this Handbook expands this clarification to mean that if Type B
containers are currently certified to withstand the credible facility accidents in which they are
located, then their inventories could be excluded for the purpose of the Safety Analysis
Report (SAR). If the containers are not currently qualified (qualifications expire on a fixed
schedule), then their contents must be included in the summation of facility inventory and be
included in accident analyses, irrespective of accident conditions. If, however, the container
is currently certified, then a comparison of the conditions resulting from transportation and
facility accidents is performed. For example, consider a currently certified Type B container
that has been qualified to withstand fire and crush loads (i.e., Type B Hypothetical Accident
Crush Test loads) associated with a transportation accident. If these transportation accident
conditions are more severe than the associated credible facility accident conditions (e.g., fire
and seismic crush loads), the inventory in these containers can be excluded from the safety
analysis (irrespective of fire suppression system coverage). If the facility fire conditions
exceed the transportation fire conditions, the inventory is included. Note that credit for
safety-class or safety-significant fire suppression affects the selection of the credible facility
fire scenario, and therefore, the fire conditions for comparison with the transportation fire
conditions.
Section 31
If the transportation accident conditions are less severe than the facility accident conditions,
then the contents are included in the accident scenarios. For example, if the seismic crush
loads exceed the transportation crush loads, the contents cannot be excluded from the
facility seismic accident scenarios. They could, however, still be excluded from the facility
fire scenarios if the transportation fire conditions bound the facility fire conditions.
DOE-HDBK-1129-2008
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DOE-STD-1027-92, Change Notice 1 does not provide explicit exemption criteria for other
than Type B containers. General guidance for other than Type B containers would be to
include the tritium in the facility inventory. Specific guidance concerning the degree and
amount of residual tritium inventory to include in safety analyses based on facility-specific
configurations, can be obtained from HSS.
The Hazard Category of a nuclear facility is based on threshold quantities of radiological
material inventory. Gram quantities are rounded values based on the calculated number of
curies. [16, 17] The definitions for each Hazard Category are as follows:
• Hazard Category I (generally limited to nuclear reactors): Regardless of the quantity of
tritium in the inventory, a facility that handles only tritium is not classified, by tritium
quantity alone, as a Hazard Category I. The Program Secretarial Officer (PSO) may
designate a tritium facility as Category I if the potential for significant offsite
consequences exists. [16]
• Hazard Category II: To be classified as a Category II nuclear facility, the facility tritium
inventory must be > 30 grams. [16]
• Hazard Category III: To be classified as a Category III nuclear facility, the facility tritium
inventory must be > 1.6 and < 30 grams. [16]
• Less than Hazard Category III: Facilities that have less than 1.6 grams of tritium in the
facility radiological material inventory but more than a specified value (currently 100
curies for facilities for which the Offices of Environmental Management (EM) and
Defense Programs (DP) are PSO). [10 CFR 830]
• Nonradiological Facilities: Facilities that have less than 100 Ci of tritium are classified by
DP and EM as nonradiological facilities unless they contain other radionuclides above
reportable quantities. [16,17]
3.3.1.c Material Release Assumptions
Once the total inventory available for release is known, the appropriate source term can be
calculated. The components of the source term, as described in DOE-HDBK-3010-94,
Airborne Release Fraction/Rates and Respirable Fractions for Nonreactor Nuclear Facilities,
are material at risk, damage ratio, airborne release fraction, respirable fraction, and leakpath
factor. The factors for airborne release and respirable fractions are normally assumed to be
1.0 for elemental tritium and oxide. The other factors are facility-specific. For fire scenarios,
the fraction of the release assumed to be oxide is normally 100 percent. Typical scenarios
to review for inclusion in safety analyses are area fires (single and multiple Fire Control
Areas (FCAs)), full facility fire, leaks or spills, hydrogen explosions, and Natural Phenomena
Hazards (NPH) events (the design basis earthquake (DBE) may have a seismic-induced
fire, which usually results in the bounding accident). DOE-STD-3009-94, Change Notice 3,
Preparation Guide for U.S. DOE Nonreactor Nuclear Facility Safety Analysis Reports,
provides detailed guidance for performing accident analyses.
Section 32
Several dose methodologies have been used for safety analysis throughout the DOE
complex. One example from Savannah River [18] describes the resulting dose from several
SRS facilities using the differing methodologies, including UFOTRI (Unfallfolgenmodell für
DOE-HDBK-1129-2008
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Tritiumfreisetzungen) [19], which models both vapor and gas species of tritium. However,
with the implementation of DOE G 414.1-4, Safety Software Guide for Use with 10 CFR 830,
Subpart A, Quality Assurance Requirements, and DOE O 414.1C, Quality Assurance, some
computer modeling methodologies, such as Hotspot, are designated as toolbox codes for
safety analysis, while others, such as UFOTRI, are not. Safety analysts must check the
current DOE Safety Software Control Registry before using a specific program for safety
analysis calculations.
Several Federal environmental laws (e.g., CERCLA, Emergency Planning and Community
Right-to-Know Act (EPCRA), and the Clean Water Act (CWA) require that releases of
hazardous substances above reportable quantities (for tritium, this is 100 curies in 24 hours)
be reported to the National Response Center. In many cases, the curie levels are
backcalculated from offsite dose receptor requirements. DOE O 231.1A, DOE M 231.1-2,
DOE O 151.1C, and DOE G 151.1-4 make distinctions between “normal” or “routine”
releases and “abnormal” or “accidental” releases, and suggest reporting abnormal or
accidental releases, even if they are below Federally permitted levels.
3.3.2 Integrated Safety Management
All tritium-related operations and activities, including design, construction, system
acceptance and turnover, operations, shutdown, deactivation, and decommission for Hazard
Category 2 and 3 nuclear facilities (and Category 1, if ever applicable), should follow
commitments identified in DOE ISM directives of the 450.4 series, which were an outgrowth
from the Defense Nuclear Facilities Safety Board (DNFSB) 95-2 Implementation Plan. The
commitments for ISM follow the seven Guiding Principles:
1. Line Management Responsibility for Safety
2. Clearly Defined Roles and Responsibilities
3. Personnel Competence Commensurate with Responsibilities
4. Balanced Priorities
5. Identification of Safety Standards and Requirements
6. Hazard Controls Tailored to the Work Being Performed
7. Operations Authorization
The process for planning and conducting pre-work hazards analysis for all work operations
at tritium facilities should be consistent with the Guiding Principles listed above and should
follow a structured approach commensurate with the risks and hazards involved. Several
methods for enhanced work planning and related work planning strategies used throughout
the DOE complex follow five steps:
1) Define the Scope of Work,
2) Analyze the Hazards,
3) Develop and Implement Hazard Controls,
4) Perform Work within Controls, and
5) Provide Feedback and Continuous Improvement.
This sequence is one of many ways to ensure a structured approach in work planning with a
focus on worker safety and reduced environmental risks.
DOE-HDBK-1129-2008
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3.3.3 Facility Segmentation
Facility segmentation is discussed in DOE-STD-1027-92. Activities conducted in the same
facility may be separated into different areas for analysis purposes, but only if independence
(in accident space) can be shown. Potential areas for segmentation include:
Section 33
• Receiving area,
• Receiving storage area,
• Shipping area,
• Shipping storage area,
• Tritium unpackaging, handling, and packaging operations,
• Low-level waste accumulation area,
• Low-level waste packaging area, and
• Packaged low-level waste storage area.
The independence of the segments, however, is not easily demonstrated. Common piping
and heating, ventilation, and air conditioning (HVAC) cannot exist to use this segmentation
process. Additionally, common-cause initiating events (e.g., fire, seismic) affect multiple
segments, thereby placing an additional burden of proof on the analyst to demonstrate
independence. A successful segmentation analysis, however, would not affect the
applicability of Price-Anderson enforcement of the Nuclear Safety Rules to the facility.
3.4 Radiological Material Quantity Limits
3.4.1 Tritium Shipping, Radioactive Material Inventory, Quantity Limits
Once an item has met the DOE and DOT requirements for shipment (e.g., properly
packaged, radioactively surveyed, properly marked, properly completed shipping papers),
the item inside the approved shipping package can be shipped to a new location.
During shipment, the item inside the approved shipping package is expected to be subject to
the normal activities associated with its movement from one location to another; for
example, loading and unloading the package from vehicles, transport to a shipping area,
storage in the shipping area prior to transport, loading and unloading the package onto
trucks/trains/airplanes, and storage in the receiving area after arrival at the new destination.
The packaging required by DOT and NRC regulations is designed to protect the workers,
the public, and the environment from the radioactive material during normal package
handling, transport, and shipping/receiving storage.
The applicable requirements for various quantities of tritium for transportation and storage
are roughly as follows:
• Limited Quantity (< 21.6 Ci for gas; see Table 7-1 for solids, liquids, and applicable
49 CFR 173 requirements): Limited quantities of tritium can be packaged and shipped in
strong, tight containers (paper boxes, paint cans) with proper markings.
• Type A Quantity (21.6 to < 1100 Ci): Type A quantities of tritium use DOT Specification
7A containers, properly marked and surveyed prior to shipment. A number of different
DOE-HDBK-1129-2008
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packages are available from small cans, 55- and 85-gallon drums, 4 x 4 x 7-foot steel
boxes, up to and including oversized, specially designed containers. These containers
are relatively inexpensive.
• Type B Quantity (> 1100 Ci): Type B quantities of tritium must be shipped in a certified
DOT Type B package. There is only a limited number of these expensive Type B
packages available for tritium shipment (e.g., UC-609), and special routing (i.e.,
prescribed routes employing highway route control such as using major highways or
bypassing cities) is required.
• Type B-Quantity, Low-Level Radioactive Waste: For the purposes of storage at the
waste site, Type B-quantity solid waste can be stored in Type A containers.
At the waste generation location, items containing greater than 1100 Ci of tritium are
normally stored in Type A containers. These Type A containers containing over 1100 Ci
must then be placed into Type B containers for shipping to DOE waste sites. At the DOE
waste site, the Type A containers can be removed from the Type B package and stored in
the Type A package. This allows the expensive Type B package to be returned to the
shipper and reused for another Type B shipment. A radiological materials inventory must
still meet the requirements as discussed in Section 3.3.1.b.
Section 34
3.4.2 Tritium Receiving Area, Shipping Area, Quantity Limits
There are no limits (other than local administrative limits) on the inventory of approved
containers that can be stored in a properly marked shipping area, receiving area, shipping
storage area, and receiving storage area. There are, however, site-wide limits that may be
imposed in the EIS that could restrict the total inventory quantities.
These areas must be inside an area posted as a Controlled Area. The Controlled Area
encloses an area posted as a Radioactive Materials Area (RMA). The Controlled Area and
the RMA can be the same area. The RMA must be periodically surveyed and appropriately
marked to indicate the nuclear hazard associated with the area. These areas may have
more than one incoming or outgoing certified package containing Type A or B packages
waiting for transport.
3.5 Tritium Unpackaging, Handling, and Packaging Areas, Quantity Limits
The tritium is removed from the specification package/certified package in unpackaging,
handling, and packaging areas, and, as such, these areas should be designated as
radiological areas or Hazard Category 2 or 3 nuclear facilities, depending upon the quantity
of tritium in the inventory.
3.6 Tritium Waste Collection and Waste Packaging Area, Quantity Limits
The waste collection/packaging area will have, in process, the collection and packaging of
low-level waste. The waste collection/packaging area should be designated as a
radiological facility or nuclear facility as defined by the quantity of tritium.
DOE-HDBK-1129-2008
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3.7 Tritium Radworker Training
10 CFR 835, Occupational radiation protection, Subpart J, requires that individuals complete
radiation safety training commensurate with the hazards in the area. DOE-STD-1098-2008,
Radiological Control, recommends that the content of Appendix F, “Radiological Training for
Tritium Facilities,” be considered in addition to DOE’s core training material for radiological
workers at tritium facilities. This Appendix provides a recommended implementation
process for conducting the radiation safety training at tritium facilities as required by 10 CFR
835 and as recommended in DOE-STD-1098-2008.
3.8 Tritium Focus Group (TFG)
The TFG comprises both DOE Federal and contractor personnel associated with tritium
operations. It was formed in 1991 in response to the Secretary of Energy’s Task Group on
tritium operations, and has expanded in scope and stature since that time. Its charter is
contained in Appendix I.
4.0 FACILITY DESIGN
DOE tritium facilities, as a subset of DOE nonreactor nuclear facilities, must conform to the
design requirements contained in DOE O 420.1B, Facility Safety. Implementation guidance
for this Order can be found in DOE G 420.1-1 and DOE G 420.1-2.
4.1 Tritium System Philosophy
Tritium-related construction projects in the past have been designed and managed by
personnel who are qualified to design standard industrial buildings and equipment but lack
experience with tritium operations. During the design and construction phase, limited use
had been made of tritium expertise, and, after building completion, the staff had to adapt the
facility for tritium operations. It is more desirable to have tritium construction projects
managed by a team that includes tritium expertise on staff. The building/systems would be
designed to meet the needs of the user, and costly retrofits after completion could be
avoided.
Section 35
During the first 25 years of tritium technology, the handling techniques in use were designed
to protect the worker from exposure to tritium. Worker protection was provided primarily by
the use of single-pass ventilation systems designed to rapidly remove any tritium released in
the breathing space from the area occupied by the workers. The ventilation gases were
released through an elevated stack at high velocity to massively dilute the gases before they
could reach ground level. Single-pass ventilation systems and high-velocity hoods were
used extensively and quite successfully for worker protection during these early years.
These high-velocity ventilation, high-velocity air hood, and elevated release techniques are
still used for worker protection, but generally as a supplement to improved barriers that
better protect the environment.
In those early years, the room or building enclosing the tritium activity was equipped with a
single-pass ventilation system (Figure 4-1) that did not recirculate the air back into the
facility. Outside air was brought in by the ventilation fans, conditioned for comfort, passed
through the building spaces one time, and was then released to the environment through an
DOE-HDBK-1129-2008
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elevated stack. The room air exchange rate generally accepted to be adequate for worker
protection was 6 to 10 room air changes per hour.
FIGURE 4-1. Tritium facility single-pass ventilation system
The tritium apparatus was enclosed in a high-velocity air hood, and the worker worked
through gloves in the doors or reached in through hood openings to operate the equipment.
The high-velocity air hoods were maintained at a pressure negative to the room spaces, and
the natural air flow was from the room through the hood opening and then out the ventilation
duct work and up the stack to the environment.
Tritium releases that occurred due to normal operations, component failure, and worker
error were inside the hood. The high-velocity air flowing through the hood swept any
released tritium away from the worker and out the stack to the environment where the tritium
was massively diluted in concentration. These techniques protected the worker; however,
tritium was released to the environment.
As concern for the environment increased, tritium technologists first attempted to control
releases by increasing design and material selection requirements, adding and enforcing
regulations, and increasing worker training and awareness. Time would prove that these
techniques, although helpful, were not completely successful. The tritium workers were
already operating at a high performance level and the tritium releases associated with
equipment design and material selection were not measurably decreasing as a result of the
more stringent design requirements and reviews. Tritium releases continued to occur. The
expectation of faultless materials and errorless workers was unrealistic. By the late 1960s
and early 1970s, another philosophy, one of capture, containment, and cleanup evolved.
Air Intake
Hood Exhaust
Pressure zone control used to move air from
lower contamination areas to higher
contamination areas, and then out the stack High-velocity air hood
Typical face velocity of
150 lineal ft/min
DOE-HDBK-1129-2008
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4.1.1 Tritium Capture, Contain, and Cleanup Process
Section 36
The capture, contain, and cleanup process encloses the primary or first wall tritium container
inside a secondary container such as a double-walled container, glovebox, room, or building
so that any tritium escaping from the primary container is captured in the secondary
container. A tritium removal system associated with the secondary container then removes
the tritium from the secondary by circulating the captured gases through a cleanup system.
4.1.1.a Containment and Confinement Systems
There are many different technical descriptions of the terms containment and confinement.
The simple dictionary definitions are: containment – being contained, which in turn is to hold
or enclose; and confinement – being confined, which in turn is to restrict, to keep within
limits. It is beneficial to define how these words are used in the tritium field. In some
facilities and applications, the terms are used interchangeably. The TFG definitions are
defined in Appendix B, Definitions. This Handbook, as noted in the Definitions, makes a
distinction between these terms as follows:
Containment system – A collection of passive barriers that can satisfy a specified leak
criterion without operation of any ancillary equipment. An example of a containment system
is a series of piping and vessels enclosing tritium gas operations. An example of a simple
double containment system is a container within another container with each container
acting as a separate and independent containment system; more intricate double
containment systems have the capability to monitor the volume between the containers for
leak detection of the inner container.
Confinement system – A collection of barriers that can satisfy a specified leak criterion
contingent upon operation of its ancillary (active) system. Examples of confinement systems
include: a glovebox and its associated cleanup system, and a room with its associated
cleanup system.
Note that in the context of these definitions, a glovebox with an associated glovebox cleanup
system is a confinement system. A glovebox structure itself is a containment system if, and
only if, the specified leak criterion can be met by the structure itself.
4.1.1.a(1) Primary Containers
Operations are conducted with tritium enclosed inside leak tight primary containers
consisting of parts such as valves, tubing, pipe, components, transducers, pumps, and
vessels. The leak rate of these primary or first wall containers, at operating pressure, is
generally certified to be less than 10-6 to 10-7 cm3 of helium per second (cm3 He/sec). The
quantity of tritium released during all normal operations is extremely small and can be
estimated from the engineering specifications. Many primary tritium systems are designed
with pressure relief protection. These devices should not relieve directly into the
environment, but rather into holding tanks designed with sufficient capacity to retain the
entire contents of the primary system.
DOE-HDBK-1129-2008
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4.1.1.a(2) Secondary Containers
In modern tritium operations, the primary container is enclosed inside a secondary barrier
such as a glovebox. The secondary system is only exposed to tritium, if it is released from
the primary barrier.
Secondary containers in the DOE complex vary in size, shape, leak rate, and quality
depending upon the age, projected use, and the quantity of tritium at risk. Figure 4-2
illustrates an example of secondary containment.
FIGURE 4-2. Secondary containment
Section 37
4.1.1.a(2)(a) High-Quality Secondary Containers
Some operations are equipped with high quality, double-walled pressure vessels. The outer
pressure vessel is the secondary containment system, and the inner container is the primary
container. This type of secondary containment system is generally used for storage of large
quantities of tritium of very high quality, and is certified at operating pressure to leak rates of
less than 10-6 to 10-7 cm3 He/s.
These high-quality secondary containment systems safely store any tritium released from
the primary container for several days or weeks without a significant release to its
environment. The maximum quantity of tritium released from these high-quality systems
during a significant primary container leak can be accurately estimated from the secondary
containment system engineering specifications.
The space between the primary vessel and the secondary container in these systems is
usually evacuated during service. If tritium is released into these spaces, there are no
dilution gases present, and the gas leaking from the secondary container is in the same
form as the gas in the primary container. If the gas released into this high-quality secondary
DOE-HDBK-1129-2008
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is 90 percent tritium, less than 1 Ci of tritium will be released to the surrounding area for
each four to 40 storage days.
Following a release into a high-quality secondary container, the tritium can be recovered by
pumping it from the secondary container into another primary container. Several days can
elapse during the recovery process without a significant release of tritium to the
environment.
4.1.1.a(2)(b) Medium-Quality Secondary Container
It is not practical or possible to enclose all primary tritium containers inside high-quality, non-
diluting, evacuated secondary containers. Gloveboxes, as discussed in 4.1.1.a, can be
utilized in both secondary containment and secondary confinement systems. Figure 4-3
illustrates one example.
FIGURE 4-3. Secondary confinement
Most primary containers can be enclosed in gloveboxes. The box gives access to the
primary containers for ease of operation and maintenance. The leak rate of a glovebox can
generally be certified to be no more than 10-3 to 10-4 cm3 He/s. Tritium permeation and
diffusion through the elastomeric seals and gloves is reasonably well known, and the tritium
released from the glovebox during a primary container leak can be accurately estimated.
If tritium is released into the glovebox, the gases in the glovebox are mixed with and dilute
the tritium. The gases leaking from the glovebox are then in the form of tritium mixed with
the glovebox gases. Assuming a glovebox with a volume of 1 m3 and a release of 10 grams
of tritium, the glovebox concentration following the release will be 0.1 Ci/cm3. Even at the
relatively high leak rates of 10-3 to 10-4 cm3 He/s, approximately 0.1 Ci of tritium will be
released for every 1,000 to 10,000 seconds of elapsed time. This is a release of
approximately 1 Ci from the facility stack for every 3 to 30 storage hours, which generally
does not pose a significant health risk.
DOE-HDBK-1129-2008
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Following a release into a glovebox, the tritium is recovered in a tritium removal system.
This low-level waste is in the form of water contaminated with tritium. Several hours can
elapse during the recovery process without a significant release of tritium to the
environment.
4.1.1.a(2)(c) Low-Quality Secondary Containers
Section 38
Other facilities are equipped with lower-quality systems such as rooms or buildings. It is
difficult to determine the leak rate of these low-quality systems and, therefore, it is difficult to
estimate the quantity of tritium that will be released to the environment during a primary
container leak.
If the secondary container is a room or building, the ventilation system could be shut off to
reduce the release of the tritium to the environment through the building stack when a
release occurs. In this case the released tritium contaminates the building. If a tritium
cleanup system is available, (in a room or a building), the ventilation system is switched over
to the recirculation mode to reduce the amount of contamination. If a cleanup system is not
available then a choice is made (ahead of time so it is proceduralized and personnel are
trained) whether to stack or contain the release.
For example, if there is no cleanup system and the ventilation sytem is shut off, assuming a
100 m3 (20 x 18 x 10 feet) building and a 1-gram release to the building, the tritium
concentration in the building gases will be 0.0001 Ci/cm3. If the building is the containment
barrier, it will leak approximately 5 percent of its volume to the environment per hour;
therefore, an environmental tritium release of 500 Ci/hr will result. Cleanup of the building
also is required in this scenario.
Even with a room or building cleanup system, a substantial fraction of the tritium released
from the primary containment system will be released to the environment before recovery is
accomplished due to the high leak rate of these low quality secondary systems. However,
these low-quality systems still have a place in the tritium containment strategy. These room-
or building-type systems, equipped with high flow rate tritium removal systems, are used in
facilities where there are no other feasible alternatives due to the large size of the
equipment being enclosed.
4.1.1.a(3) Primary and Secondary Containers
The container-within-a-container concept introduced above is applied in the tritium
community in various configurations. Figure 4-4.a shows a building confinement system.
Figure 4-4.b shows an arrangement consisting of a higher-quality primary container with a
lower-quality secondary container with indication or sampling capability from the annulus
area to help detect whether the primary is leaking. Before opening the secondary, the
annulus area should be sampled and if a leaking primary is suspected from the sample or
from the pressure indicator, then the container is moved to within a glovebox or
compensatory measures taken prior to opening. Depending on the application and quality of
the primary container, the secondary may not need to be a containment barrier itself. The
secondaries for high quality primary containers are most often employed as a physical
protection barrier for the primary container. For example, the LP-50 SARP [20] states…“no
credit is taken for the seal on the shell in the safety analysis and no test of its seal tightness
is made. The secondary vessel is a mechanical protection barrier. For primary containers
of questionable or low quality, the secondary should provide a containment function as the
DOE-HDBK-1129-2008
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probability of primary container failure is higher.” Section 6.6 discusses the container
requirements for interim storage of tritium/tritiated materials.
FIGURE 4-4.a. Building confinement system FIGURE 4-4.b. Typical double-
containment configuration
Section 39
4.1.2 Tritium Cleanup and Removal Systems
Current designs employ tritium removal systems. When tritium is released into a secondary,
the associated cleanup system starts, and the gases containing tritium are circulated
through the cleanup system, and the tritium is removed. See Figure 4-5 for a diagram of a
typical gas-to-water conversion tritium removal system.
FIGURE 4-5. Typical gas-to-water tritium removal system flow schematic
If the cleanup system is associated with a high-quality barrier (leak rate of less than 1 Ci of
tritium in a period of 4 to 40 days), tritium transfer to another container can take several
days to complete without a significant release of tritium to the environment. If the cleanup
DOE-HDBK-1129-2008
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system is associated with a medium quality barrier (leak rate of less than 1 Ci in 3 to 30
hours), the cleanup system flow rate needs to be high enough to remove tritium within a few
hours in order to prevent a significant release of tritium to the environment. If the cleanup
system is associated with a low-quality barrier, (leak rate of 8 Ci or more per minute), the
cleanup system flow rate needs to be very high so that tritium is removed from the gas
before it is released to the environment.
The captured tritium is generally removed by circulating the gas through a system that
removes tritium down to the part-per-billion level. Typical present-day cleanup systems
remove tritium by cracking the molecules on a hot catalyst. The free hydrogen atoms
combine in the catalytic reactor with the oxygen present to form water. The tritiated water is
then removed from the gas by molecular sieve traps. Depending upon the tritium species,
the concentration reduction of these systems can be from one million to one hundred million
in a single pass.
The tritium released to the environment during this process is a function of the quantity of
tritium released, the volume, and leak rate of the container, and the cleanup rate of the
tritium removal system.
There are several considerations in determining the adequacy of the tritium removal system.
First is the volume: the larger the volume, the longer it will take to remove tritium from the
gases. Second is the tritium removal system flow rate. This rate affects the time required to
remove tritium from the gases. The lower the flow rate, the longer it will take to remove
tritium from the volume.
Third is the cleanup rate of the tritium removal system. This system is typically operated in a
recirculating mode, but may also be operated in a single-pass mode. The tritium-
contaminated gases are pumped through the tritium removal system, and the cleaned gases
are either returned to the volume or released to the environment.
In a large complex system filled with equipment, it is difficult to know exactly how the
returned or make-up gases will mix with gas in the system. The gas exit port should be
spaced several feet away from the return port. It could be assumed that gas flows through
in a slug, like a piston, and that only a single pass would be required to remove all of the
tritium from the gases. Slug or piston displacement flow, however, is unlikely, and a more
common assumption is to assume that the incoming tritium free gases exponentially dilute
the gases.
Employing the standard assumption of exponential dilution (which has been experimentally
verified in the DOE complex [21]), the quantity of tritium in the system Qt is expressed by
Qt = Qi e−t(F/V)
Section 40
Where Qi = initial quantity of tritium released
t = time after starting the tritium removal system
F = flow rate of the tritium removal system
V = volume of the system
DOE-HDBK-1129-2008
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A simple way of using the equation is to calculate the time it will take to reduce the system
tritium concentration by a factor of 10. That is:
Qt/Qi = 1/10 = e−t(F/V)
This implies:
−t(F/V) = ln 1/10 = -2.3
or
t = 2.3 x (F/V)
Therefore, assuming exponential dilution, the tritium concentration of the gas will be reduced
by a factor of 10 for every 2.3 time constants determined by F/V. Similar calculations show
that the concentration will be reduced by a factor of 100 and 1000 for every 4.6 and 6.9 time
constants, respectively. Figure 4-6 is the plot of the relationship between the percent of
tritium remaining in the volume with time.
FIGURE 4-6. Confinement volume cleanup rate as a function of system time constant, F/V,
assuming an exponential dilution rate
The fourth consideration is the system leak rate. While the tritium removal system is in
operation, some of the gases will leak out of the system to the environment. The barrier
0
10
20
30
40
50
60
70
80
90
100
0.00 0.30 0.60 0.90 1.20 1.50 1.80 2.10 2.40 2.70 3.00 3.30 3.60 3.90 4.20 4.50 4.80 5.10 5.40 5.70 6.00
t/(V/F) = Number of System Time Constants (F/V)
Q
(i)
/Q
(t
) x
1
00
=
P
er
ce
nt
o
f Q
(i
) r
em
in
in
g
in
th
e
co
nf
in
em
en
t v
o
lu
m
e
Note that the quantity of tritium remaining in the
confinement volume decreases by a factor of 10
for each 2.3 time constants, i.e. when t=2.3 x F/V
Q(t)=Q(i) e-t/(F/V)
DOE-HDBK-1129-2008
43
must be leak-tight enough to prevent a significant release of tritium to the environment while
the tritium is being removed. A high flow rate tritium removal system can be used to help
offset a leaky system, but will significantly increase the cost of the removal system.
The quantity of tritium released to the environment due to the leak rate can be calculated.
Assuming exponential dilution, the concentration of tritium in the gas CT2(t) is
CT2(t) = CT2(i)e -t/(F/V)
where CT2(i) = initial concentration of tritium in the system
t = time
V = volume of the system
F = flow rate of the tritium removal system
Note, CT2(i) = QT2/V where QT2 is the quantity of tritium released.
Therefore, the rate of tritium released from the system, d C
d t
T 2 , at any time, t, is
d C
d t
T 2 = LCT2(t) = LCT2(i)e -t(F/V)
where L = leak rate of the system
The tritium release from the system due to leakage T2(rel) over any time period from 0 to t, is
T2(rel) = ∫LCT2(i)e -t(F/V) dt
= (V/F) LCT2(i)e -t(F/V) |t0
= (V/F) LCT2(i)e -t(F/V)
The calculated leak rate that will result in a tritium release, T2(rel), of 1 Ci due to an initial
tritium release, CT2(i), of 1 g (10,000 Ci) into a glovebox with a volume, V, of 1m3 and a flow
rate, F, of 1 m3/min is
L = T
2(rel)/(V/F) CT2(i)e -t(F/V)
= 1/ (1 x 10000 x 1)
= .0001 m3/min
= 1.667 cm3/s
Therefore, a glovebox leak rate of 1.667 cm3/s will result in the release of 1 Ci of tritium from
a 1 m3 volume glovebox during the time it takes a tritium removal system operating at a flow
rate of 1 m3/min to clean up the glovebox following a tritium release.
4.1.3 Future Directions in Tritium Removal and Cleanup
Future tritium facilities should analyze the applicability of confinement systems in their
facilities. For example, DOE O 420.1B states,
Section 41
For a specific nuclear facility, the number and arrangement of confinement barriers
and their required characteristics shall be determined on a case-by-case basis.
DOE-HDBK-1129-2008
44
Factors that shall be considered in confinement system design shall include type,
quantity, form, and conditions for dispersing the material. Engineering evaluations,
trade-offs, and experience shall be used to develop practical designs that achieve
confinement system objectives. The adequacy of confinement systems to effectively
perform the required functions shall be documented and accepted through the Safety
Analysis Report.
As regulatory release criteria and As Low as Reasonably Achievable (ALARA) concerns are
strengthened, the desirability of barriers increases. Many past confinement systems were of
the glovebox and room or building design. One disadvantage of these systems is that
tritium is converted to oxide, which must eventually be handled and disposed (with the
attendant risks). Room- or building-type confinement systems were used in some tritium
facilities such as in the T-building at Mound, in TFTR at Princeton Plasma Physics
Laboratory (PPPL), and in TSTA and Weapons Engineering Tritium Facility (WETF) at Los
Alamos. If the system is not very close to 100 percent efficient, the released oxide (which is
about 10,000 times more toxic than the gas) could give an overall detriment (e.g., if 10,000
Ci of gas are collected, but only one Ci of oxide is released by the system, the whole
operation is just a draw). Some current designs, notably the cleanup systems at 233-H at
SRS, make use of gettering without oxidation. The primary advantage of these getter
systems is that tritium is removed and stored in elemental form and is not converted by the
tritium removal system to the more radiotoxic tritiated water. The application for glovebox
atmospheres is good; however, severe challenges for removing tritium from room
atmospheres with the required flow rates, while not fouling the getters, appear less
promising. Research into other than metal (e.g., fullerene) gettering material has been
sponsored by HSS in the past; subsequently, fullerenes have been examined for hydrogen
storage for the Hydrogen Economy [22]. Results indicate that stored tritium is stable for
almost 10 years. The Loutfy et al. reference in section 1.5 presents an excellent overview
on fullerenes.
It is possible that advances in design will make room or building-type confinement systems
desirable, or it may turn out that these cleanup systems in general are found not to be cost-
effective, and that a better use of resources to decrease environmental releases could be
made by upgrading the existing primary and secondary systems. Additionally, there may be
future glovebox decisions in which the oxidation process is still chosen over the gettering
process due to programmatic reasons. There is no compelling agreement at this time to use
room or building cleanup systems.
4.1.4 Inspection and Surveillance Requirements
Instrumentation should be provided to monitor the leak-tight integrity of process piping,
tanks, and other equipment. The surveillance measurements may include those of pressure
differentials or flow rates and should relate to the design leak rate. Radiation monitoring
instrumentation may be used to qualitatively assess changes in leak rate.
4.2 Building Ventilation System
Section 42
If tritium does penetrate its barriers, it can be released into the worker breathing space. In
this scenario, the ventilation system should be designed to meet the following objectives.
• Move released tritium from the worker breathing space as soon as possible.
DOE-HDBK-1129-2008
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• Minimize the contamination of other areas while moving released tritium.
• Release the tritium-contaminated gases at an elevation and velocity that will result in
massive dilution and mixing with outside air before the tritium reaches ground level.
The ventilation system should be designed using the following guidelines:
• The ventilation system should be a single-pass ventilation system. Outside air is
brought in through a supply fan, conditioned for the comfort of the workers, passes
through the ductwork to the ventilated spaces one time, goes through the exhaust
ductwork to an exhaust fan, and is released to the environment through the facility stack.
• The air supply and exhaust systems should be designed to eliminate dead air spaces
where tritium-contaminated gases may accumulate.
• The ventilation system ductwork should not be shared with non-tritium operations.
• To minimize cross-contamination from one room to another, the exhaust gas from each
room should dump into a central exhaust duct. Exhaust gases from several rooms
should not be combined before being dumped into the central exhaust duct.
• To minimize cross-contamination from one ventilation function to another, the gases for
each type of function, such as room ventilation, high velocity air hood ventilation, and
glovebox ventilation, from a single room should not be combined until they reach the
central exhaust duct.
• To ensure good mixing and dilution by outside air, the exhaust gases should be released
to the environment through an elevated stack at high velocity.
• The ventilation system should be designed to use pressure zone control to minimize
cross-contamination. The ventilation control system is designed to hold the spaces
occupied by the tritium operations at a negative pressure relative to the spaces
surrounding the facility. If the whole building is a tritium facility, then the building is at a
slightly negative pressure relative to the environment. If the tritium is in a single room in
a building, the room is at a negative pressure relative to the adjacent rooms. Air
continuously leaks into the tritium operating areas from the surrounding environment.
The ventilation zones of tritium processing areas should be maintained under controlled
temperature and humidity conditions at all times to reduce the in-leakage of moisture to
inert atmosphere gloveboxes. (Further reductions of inleakage of moisture into inert
gloveboxes can be achieved by selecting a glove material that has a low permeation rate
for moisture and by reducing the exposure time (e.g., glove port covers) and/or total
glove surface area).
• The walls separating adjacent rooms must be reasonably sealed to minimize tritium
released from contaminating an adjacent room. Administrative controls need to be in
place to require caulking and sealing around wall penetrations such as conduit and
piping.
DOE-HDBK-1129-2008
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• For the ventilation system to work as designed, the inside and outside doors and airlocks
need to be used properly. Propping an outside or inside door open will upset the
pressure zone control system. An outside door bypasses the stack and provides a path
for a ground level tritium release. The doors should be equipped with automatic door
closures, and all personnel should be instructed on the proper use of doors.
Section 43
• For facilities handling gram quantities of tritium, a rule of thumb is 6 to 10 air changes
per hour as the standard of performance.
The ventilation rate should be based on analysis of the hazards of the operations. A
facility that has the potential to release only a few curies of gaseous tritium into the
breathing space does not need to operate at the same ventilation rate as a facility that
has the potential to release tritium into the breathing space.
• Single-pass ventilation systems are expensive to operate because all air must be
conditioned to make its single pass through the facility, and this conditioned air is not
reused. Additionally, a high flow rate is desired in order to remove any released tritium
from the facility as soon as possible to protect the workers.
• Special precautions such as Personnel Protective Equipment, including respiratory
protection and passing exhaust through particulate filters, are needed when working with
SMTs. D&D work with SMTs should occur within a confined airspace, if possible.
It is feasible to design future ventilation systems to operate at a variable flow rate that is
a function of the time of day and the measured tritium concentration in the rooms. This
would entail a higher initial cost, but would decrease the long-term operating costs
without significant impact on the facility safety.
4.3 Chilled Water System
The chilled water system that is used to cool the tritium-related activities in a facility must be
carefully designed to minimize the volume and tritium concentration of the contaminated
water generated. The use of single-wall, water-to-gas heat exchangers in tritium removal
systems and vacuum furnaces for example, will result in tritium contamination of the chilled
water system. In some facilities, the same chilled water system is used to cool non-tritium
activities in the same building, and, at some sites, the same chilled water system is also
used in non-tritium related activities in adjacent buildings. As a result, tritium-contaminated
wastewater is generated, and tritium contamination is spread from one piece of equipment
to another, from one room to another, and from one building to another through the chilled
water supply. This can lead to loss of control of a radioactive material and use of duct
systems should be minimized.
The chilled water system should be designed to minimize the volume of water that can be
contaminated with tritium. One technique is to use water-to-water heat exchangers or
double-walled, gas-flushed water-to-gas heat exchangers to isolate the high volume central
system from the tritium-related activities. The volume of water in the secondary loop is
much smaller than that in the primary loop.
The primary reason for using chilled water for cooling equipment is cost. The systems are
reliable, low in cost, small in size, readily available in many different sizes from many
DOE-HDBK-1129-2008
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different manufacturers, and easy to maintain. Air-to-air heat exchangers can, in some
cases, be substituted for chilled water cooling, but are larger in size and will not work in
some applications. Refrigerated cooling systems are more expensive, but operationally
eliminate the need for disposing of tritium-contaminated water generated by the chilled
water systems.
4.4 Seismic and Wind Design and Evaluation of Structures and Facilities
Section 44
A discussion of the DOE Natural Phenomena Hazards Policy is included in Section 5.7.1.
This policy is also applicable to structures and the complete facility. Section 5.7.2 and its
references should be reviewed as part of the overall seismic and wind design for evaluation
of a tritium facility.
An understanding of the types of loading produced by earthquakes and windstorms is useful
in planning mitigating approaches. An earthquake produces shaking, which will affect the
entire facility and its contents. Attention to anchorage and connection details to all
structures, systems, and components is essential. Earthquakes may also cause ground
rupture if the facility is near a fault. Loss of ground stability may also occur due to
settlement or liquefaction and will depend on soil types and location of the ground water
table.
Windstorms generally affect the structural shell and systems and components outside of the
structure. Windstorms will produce direct pressure and suction on walls and roofs with
increased loading at corners, eaves, and ridges. Extreme windstorms can produce missiles
from debris near the facility or from nearby facilities. These missiles can strike walls and
roofs and their effects should be evaluated. During tornadoes, in addition to pressure
effects and windborne missiles, there will be an atmospheric pressure change or a pressure
drop below ambient pressure as the tornado passes over a facility. This can affect wall and
roof openings and ventilation system filters.
An approach used at SRS is to store resources in a Highly Invulnerable Encased Safe
(HIVES). HIVESs are metal cabinets designed to store tritium reservoirs and Hydride
Storage Vessels (HSVs). The HIVES is designed to be capable of protecting the pressure
boundary integrity of stored reservoirs or HSVs against impact of structural elements
freefalling from the collapse of Building 234-H and the adjacent 296-H stack caused by
credible NPH DBAs. A HIVES is constructed of hardened T-1 steel, primarily from 1-inch
plate. The overall dimensions are approximately 22” W x 39” D x 68” H, which includes both
a cabinet and a matching bonnet assembly bolted to the cabinet top plate. This bonnet
contains an aluminum hexagonal cell honeycomb material designed to absorb the impact
loading stated above.
The following should be considered when designing or evaluating structures or facilities for
earthquakes and windstorms:
• The Performance Category (PC) of the structure or facility should be determined. It is
not necessary for the entire facility to have the same PC; that is, different parts of a
facility could be in different performance categories. For example the office portion of a
tritium handling facility may be PC-1, while the laboratory portion may be PC-3.
DOE-HDBK-1129-2008
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• Judgment should be exercised to ensure that various parts of the facility have been
categorized in a rational manner. For example, a PC-1 facility does not physically
support a PC-3 facility.
• In addition to the vertical load carrying system, a lateral force resisting system should
carry the seismic and wind loads. This may be a frame or shear wall system or separate
bracing system. Attention to connection details is very important in ensuring adequate
structural integrity to resist the limited energy input motion produced by earthquakes and
the longer duration wind loading.
• An understanding of the type of loading that earthquakes and extreme winds produce on
Section 45
the overall structure is essential during the design and evaluation process.
• An adequate load path must be ensured throughout the structure
– Roof and wall connection details to structural system
– Overall roof-to-wall connections
– Wall-to-foundation connections
– Foundation adequacy
• Innovative technologies, such as base isolation and passive energy dissipation devices,
should be considered during design of new facilities and for upgrading of existing
facilities to reduce seismic loads to systems and equipment within the structure. These
approaches have been used in many projects throughout the world since 1990.
• Avoid the type of details and structural features that have performed poorly during past
earthquakes. Some examples follow:
Structural Systems
– Unreinforced masonry construction
– Non-ductile concrete construction
– “Soft” story construction
– Incomplete lateral force resisting systems
– Welded steel connections
– Irregularities, eccentricities, and discontinuities in both weight and geometry
– Pounding or impact with nearby facilities
Details
– Inadequate hoop reinforcement in concrete columns
– Reinforcing steel connections
– Connection details
– Accommodation of differential motion
• Ensure foundation adequacy by avoiding the following:
– Ground failures
– Landslides
– Liquefaction
– Excessive or differential settlement
DOE-HDBK-1129-2008
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• Ensure that lifelines are not damaged.
– Provide flexibility in lifeline connections to the facility.
– Identify important lifeline functions such as power, water, sewer, gas, and
communications that will be needed immediately after an earthquake or windstorm.
– Examine the vulnerability of lifelines onsite as well as offsite.
– Plan for alternative lifeline support.
• Examine and prepare for the possibility of a fire following the earthquake.
Employing mitigation efforts before earthquakes or windstorms occur is a very cost-effective
means to provide life safety, to minimize damage and losses, and to reduce the impact on
the facility and operations. It is extremely important to pay attention to all details because
natural phenomena will find the weak links and cause damage.
4.5 Other Design Considerations
The following items should be considered in the design of a facility with tritium operations.
• Designated safety-class systems should employ the concepts of redundancy,
separation, and diversity. Some designs in the past, notably at Building 233-H at SRS
(i.e., RTF), employed redundant signals to a single actuation device. An improvement to
this design concept would be to provide these redundant signals to two independent,
separate (by distance) actuation devices.
• A design requirement should be included to prevent the formation of explosive mixtures
during the handling, processing, and storage of tritium gas and other hydrogen isotopes.
• Calibrated tanks and associated piping that are used for pressure-volume-temperature
measurements should have surface treatment of their interiors (e.g., electropolished and
passivated) to allow accurate volume measurements.
• Tritium process and handling systems should use, wherever possible, nonflammable
hydraulic, lubricating, and cooling fluids.
• The designer should consider not using hydrogenous fluids where they might become
contaminated with tritium.
• The designer should consider providing for the retention of firewater with subsequent
monitoring prior to disposal for all buildings where there is tritium.
Section 46
• Barriers should be provided to prevent damage to equipment and injury to personnel
while performing testing operations that could produce missiles or blast pressures.
These barriers should be designed using conservative and proven design principles,
such as those of DOE/TIC 11268, A Manual for the Prediction of Blast and Fragment
Loading of Structures.
• An independent air system should be provided for breathing air. It should have
dedicated, oil-free compressors or pressurized cylinders of breathing air, and provide
breathing air in all areas of the tritium facility where it may be needed for maintenance
DOE-HDBK-1129-2008
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operations and/or personnel safety. Contamination of the air supply (e.g., from
refrigerant leaks or air intakes) should be detectable at levels low enough so as not to
pose health concerns.
• The design considerations of the Fire Protection System should include the following:
– determining safety classification of structures, systems, and components (SSCs) of
both fire detection and fire suppression systems;
– consideration of unique fire sources (e.g., uranium beds used for tritium storage);
– compatibility of fire extinguishing agents with the fire sources in a tritium facility; and
– containing and handling requirements for expended fire fighting agents (including
water inventory) that may become contaminated with tritium.
4.6 Lessons Learned
Buildings 232-H, 233-H, and 234-H at SRS, the WETF, located at Los Alamos National
Laboratory (LANL), and the Tritium Research Laboratory (TRL) at SNLL are examples of
facilities that were initially designed to perform tritium handling. Most other facilities in use
were originally designed to do other work and have been retrofitted to perform tritium
handling.
One of the major problems with the facility retrofit process is that the existing utilities such as
ventilation, floor drains, gas supplies, and chilled water systems are shared with the
adjacent non-tritium areas. The same ductwork, which is used to sweep released tritium
from tritium operating areas, is used to provide ventilation for offices and non-tritium areas,
and, as a result, tritium back diffuses into the non-tritium areas through the shared ductwork.
The same chilled water system used to cool the tritium-related equipment is used to cool the
non-tritiated office spaces, and leaks of tritium-contaminated chilled water result in
contamination of clean areas. The floor drains from the non-contaminated areas drain into
the same system as the floor drains from the tritiated areas, and, through the drains, gases
flow from one area to another.
Tritium facility utilities such as chilled water, compressed air, gas supplies, ventilation, floor
drains, sink drains, storm drains, and stacks should not be shared with other non-tritium
areas. Sharing these systems spreads tritium contamination to other areas, complicates
day-to-day management of the facility, and impacts the transition process if the facility is
transitioned to other use. The use of hazardous materials should be reduced or eliminated
in the initial design stages of the facility, as it will likely lead to the generation of mixed
wastes and increased decontamination and decommissioning (D&D) costs.
4.6.1 SNLL Tritium Research Laboratory
Section 47
Tritium operations have been terminated at the TRL, and the facility has been transitioned to
other use. The problems encountered during transition of the TRL should serve as an
example for facility designers of the future. The TRL was designed beginning in 1972
specifically to handle tritium, and a few changes to the initial design would have resulted in
significant cost and timesaving during the transition process.
• The tritium removal system in the central glovebox had a supply and return manifold
fabricated of six-inch diameter stainless steel pipe. The associated vacuum pump
DOE-HDBK-1129-2008
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effluent manifold consisted of an all welded two-inch diameter pipe. These manifolds
were approximately 200 feet long and extended down the central corridor of the building.
The manifolds extended into each room from the corridor and were of all welded
construction. During the transition process, special tooling had to be purchased to cut
the six-inch and two-inch diameter pipe into sections small enough to be disposed of as
solid waste.
Designing the system to include flanges and isolation valves at specific locations would
have resulted in some cost savings during facility dismantlement and transition.
However, since too many valves and flanges can increase the potential for leaks during
operation, the installation points should be placed only at strategic locations.
• The floor covering installed in the TRL consisted of 12-inch tiles glued to the concrete
floor. Both the floor tile and the adhesive contained asbestos that had to be removed
during transition of the facility. Additionally, tritium-contaminated liquids were spilled on
the floor during operation and leaked through the tile into the concrete below. The use
of adhesives made of non-hazardous materials would have resulted in significant cost
savings.
PPPL has suggested that sealing the concrete with a thick, hard finish epoxy paint prior
to installation of any floor covering would mitigate the impact of tritiated liquid spills,
although even epoxy will experience tritium permeation.
• The TRL was equipped with a recirculating chilled water system. The water-to-gas heat
exchangers used the chilled water to cool the glovebox and vacuum effluent tritium
removal system gases, vacuum furnace heat exchangers, glovebox temperature control
systems, and in a variety of other tritium-related tasks. After a few months of operation,
tritium contamination was found in the chilled water. In order to control the buildup of
tritium in this system, the contaminated water was periodically drained from the system
and replaced with uncontaminated water.
If the initial design had used water-to-water heat exchangers as barriers, the volume of
contaminated water would have been minimized. If double-walled, gas-flushed, water-
to-gas heat exchangers had been used, the contamination would have been significantly
lower.
• The TRL used approximately 100 oil-type vacuum pumps. Oil-free vacuum pumps were
not as common when the TRL was designed. The vacuum pump oil becomes
contaminated with tritium during use. At some DOE locations, tritium-contaminated oil is
regulated as a mixed waste. Handling the tritium-contaminated oil is a significant safety
hazard to operating personnel and should be eliminated where practical.
If oil-free vacuum pumps had been used, the generation of mixed waste in the form of
tritium-contaminated vacuum pump oil would have been eliminated as would the hazard
associated with changing vacuum pump oil.
Section 48
• The TRL was equipped with a ten-air-change-per-hour, single-pass, pressure-zone-
controlled ventilation system. Some of the ductwork became contaminated and was
removed and disposed of as solid low-level (radioactive) waste during the transition
process.
DOE-HDBK-1129-2008
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Experience from Sandia has suggested that if the ventilation ductwork for room air
ventilation had been separated from the ductwork used for high velocity air hood and
glovebox ventilation, the contamination would have been easier to control during the
transition process.
• The presence of hazardous materials in the form of asbestos and oil complicated the
transition process. The materials used in fabrication and during facility operation should
be reviewed, and, if possible, all hazardous materials should be eliminated.
• The initial design of the TRL included collection of wastewater from floor drains and
sinks in two underground holding tanks so that the water could be checked for
contamination before it was sent for disposal. The holding tanks were buried and could
not be inspected. The wastewater drain system consisted of several hundred feet of
buried drainpipe, which drained into the holding tanks. After a few years of operation,
the underground tanks were replaced with holding tanks enclosed in a below-ground-
level open concrete pit. If the tanks leaked, the concrete pit would contain the leak. This
design also provided for inspection of the tanks for leaks. The buried, underground drain
lines remained in place throughout the life of the facility.
Wastewater holding tanks and collection systems should be designed so that potential
leaks can be contained and the holding tanks and drain system can be inspected
periodically.
4.6.2 SRS Old Tritium Extraction Facility
Between 1995 and 1997, a team of specialists performed D&D work on the Old Tritium
Extraction Facility (232-F) at the SRS [23]. The work was conducted in six phases. Each
phase presented challenges regarding the behavior of tritium, particularly tritium in
equipment and structures of metal and concrete. A description of each phase is as follows:
• Phase I, Pre-Characterization/Isolation, was designed to identify the specific buildings,
ancillary equipment, structures and premises to be cleaned, and isolate them in a way
that avoided inadvertent contamination elsewhere in the complex.
• Phase II, Detailed Facility Characterization, included determination of the type and
amount of actual contaminants and determined the location and type of disposal
operations required. This phase was the most complex in terms of characterizing tritium
contamination.
• Phase III, Decontamination and Dismantlement, involved removing hazardous materials
such as PCBs, mercury, and lead, as well as radioactive constituents such as tritium and
fission products. It also involved dismantling equipment and some structures.
• Phase IV, Demolition with Explosives, involved the removal and destruction of the facility
and stack.
• Phase V, Waste Management, was a continuing process throughout all six phases. It
involved the determination of how much of each contaminant was present at the site and
where the various site contaminants would be disposed.
DOE-HDBK-1129-2008
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• Phase VI, Green Grass Restoration, restored the site to a usable, visually aesthetic
entity.
Section 49
Detailed characterization was one of the most challenging phases in dealing with tritium,
and required an expert understanding of the behavior of tritium in porous and nonporous
materials. For example, because tritium migrates to the subsurface of porous materials,
volumetric characterization required core boring. This was not well understood initially and
early characterization activities, which involved smear and scabbling techniques or wiping
and scraping the surface of concrete, gave false (low) tritium contamination levels. In some
instances, areas that were smeared clean began to reveal elevated readings following rain
inleakage. In addition, destructive testing for nonporous material, such as metals, was
required to fully characterize volumetric tritium contamination.
DOE-STD-1120-05, Integration of Environment, Safety, and Health into Facility Disposition
Activities, provides guidance for integrating and enhancing worker, public, and
environmental protection during facility disposition activities.
5.0 DESIGN OF EQUIPMENT
The design requirements for tritium are a function of the tritium form, quantity, concentration,
pressure, and period of storage. High concentrations of tritium gas stored at high pressure
(> 2,000 psia) are difficult to contain due to tritium and helium embrittlement of the container
materials. Design of these systems requires careful selection of the materials of
construction and must be designed using expertise in high-pressure tritium containment.
Low concentrations of tritium in gaseous form mixed with other gases at low (< 600 psia) to
medium (600 to 2,000 psia) pressure, regardless of the quantity, do not significantly impact
the strength of the materials they are stored in. As a result, standard designs can be used.
Tritiated water in the form of T2O is somewhat corrosive unless properly stored with an
overpressure of T2 gas. This is due to the suppression of the formation of oxygen in the
cover gas and peroxides in solution [24]. Tritium systems should be designed by persons
with tritium experience.
Low concentrations of HTO (mCi/mL to Ci/mL) recovered from tritium removal systems have
proven to be corrosive when stored in liquid form in metallic containers and have resulted in
the development of significant leaks in containers within days or weeks. Storage of this
same water solidified on clay or on molecular sieve material, regardless of the quantity, is
stable and noncorrosive and may be stored for many years in the container.
5.1 Material Compatibility
Proper materials selection and rigorous design have led to tritium-handling systems that are
extremely safe for long periods of time. Materials exposed to tritium under certain conditions
can be susceptible to hydrogen embrittlement. The chances of embrittlement are
significantly reduced by proper material selection. No additional thickness of components,
such as the “corrosion allowance” used to mitigate uniform corrosion, is added to
components to reduce or eliminate the chance of hydrogen-induced cracking and
subsequent failure as material degradation effects are not uniform.
DOE-HDBK-1129-2008
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Section 50
Tritium can permeate vessel barriers, especially in components operating at elevated
temperature. Currently available tritium permeation data are normally sufficient to estimate
the order of magnitude of tritium permeation through barriers. These estimates can be used
during system design or to determine whether additional purging and stripping systems are
required to “clean up” permeated tritium or whether other design changes (such as wall
thickness, material, or coating) are required to reduce permeation. Tritium permeation can
lead not only to contamination outside the barrier, but it can also result in significant
quantities of tritium being dissolved in parts, which can lead to hydrogen embrittlement.
Over time, this tritium decays to 3He, which has been found to accentuate hydrogen
embrittlement and to cause weld cracking (see below).
5.1.1 System Design
High quality tritium primary containers must have a low leak rate and probability of failure or
leaking (see section 6.6 for leak rates associated with packaging requirements) The
consequences of tritium leaks can include personnel uptake, release to the environment,
ignition (if mixed with oxygen), and violation of operating permits. Pressure and vacuum
vessels used in tritium systems are generally designed and constructed using codes and
standards applicable to boiler and pressure vessels. In the United States, use of the
American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code is
recommended but not required. Pressure and vacuum vessels constructed using this code
have an accepted rigor in design, construction, and inspection that facilitates approval and
acceptance by regulators. The ASME Boiler and Pressure Vessel Code primarily covers the
design of vessels, and does not cover all of the aspects of a tritium system design. Other
design standards, such as resistance to seismic events, also must be followed, depending
on the location and regulators of the facility. See Sections 4.4 and 5.7 for more discussion
on seismic design.
5.1.1.a Leak Testing
After fabrication, thoroughly leak testing tritium systems is extremely important. Normally,
leak testing employs commercial helium-mass-spectrometer-based systems and is
performed after any other required proof, pressure, or vacuum performance tests. Other
leak detection methods, such as rate-of-rise, can also be employed in addition to helium
mass spectrometry. A dilute solution of tritium in an inert gas can also be used to detect
small leaks. Tritium is a highly effective leak detection species, since it travels rapidly
through cracks and can be easily detected at very low levels.
5.1.1.b Joining
Components of tritium systems are commonly joined by welding. Welds are normally
designed so they can be non-destructively inspected by a suitable method such as
radiography or ultrasonic testing. Also, the weld design should minimize so-called “virtual
leaks” on the interior of tritium containing volumes. Examples of weld practices to minimize
virtual leaks include 1) using full penetration welds where possible, and 2) welding feed-
throughs to the interior wall surface (not on the outside, which would leave a gap on the
inside around the feed-through that is difficult to outgas). Standard weld rod filler materials
are chosen, depending on the base alloy. Every effort should be made to reduce or
eliminate residual welding stresses.
DOE-HDBK-1129-2008
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Section 51
There is less experience using other joining methods such as brazing or high temperature
soldering in tritium systems. Dissimilar materials may have to be joined by a transition
junction, using an intermediate material to enable proper welding and accommodate
differences in thermal expansion and other properties.
Tritium gas permeates austenitic stainless steels, and, over time, 3He is created by beta
decay of tritium in solution in the material. Welding stainless steel containing solute helium
is difficult because intergranular cracking can occur. During welding, the solute helium
agglomerates at grain boundaries and forms both intergranular cracks in the heat-affected
zone and pores in the fusion zone. Low-heat-input weld techniques have been shown to
mitigate this problem to some degree; however, weld repair of helium-containing stainless
steel is normally difficult to perform without some cracking.
All-metal mechanical joints are also a sound way to join components in tritium systems.
Typically, copper, silver-plated nickel, or silver-plated stainless steel have been used as
gaskets. Commercial high- and ultrahigh- vacuum fittings are normally compatible with
tritium.
5.1.1.c Surface Coatings and Treatments
Aluminum and aluminide coatings have been successfully employed on stainless steel to
reduce permeation into and through the steel. These coatings can be applied on large items
using a proprietary fluidized bed furnace, having a controlled atmosphere (in the so-called
“calorization” process). Gold has also been used as a permeation barrier in some
applications and is often applied over a thin nickel buffer layer (“strike”) that has been
applied to the bulk metal (e.g., stainless steel) after proper surface preparation.
Several companies treat stainless steel surfaces using various proprietary electrochemical
processes to “passivate” the surface. These processes probably enrich the chrome content
of the surface oxide, polish the surface (thereby reducing the effective surface area), and
remove carbon and hydrogen from near the surface. All of these microstructural changes
may be desirable for tritium systems in which the process gas must remain at high purity.
Capillary lines that route gas to mass spectrometers are commonly passivated, to reduce
changes of gas composition by isotope exchange, while the gas flows from the sample
location to the mass spectrometer. Passivated surfaces reduce the rate of isotope
exchange in hydrogen isotope mixtures, probably by reducing the catalytic effect of the
surface decomposing hydrogen isotope molecules to atoms, which enables isotope
exchange. Vacuum systems having surfaces treated in this way evacuate faster. This type
of surface passivation can be expensive, so many parts of tritium systems are not
passivated; normally only parts requiring the special properties of passivated surfaces are
treated.
5.1.2 Structural Metals
Exposure of metals to high pressure (> 2,000 psia) hydrogen, deuterium, or tritium will result
in hydrogen embrittlement of the material. This could eventually result in material failure.
The time until failure is a function of the container material, the pressure, and temperature.
Additionally, materials exposed to high-pressure tritium are also subject to helium
embrittlement. Tritium at high pressure enters the metal and decays to 3He. The buildup of
helium in the metal results in helium embrittlement, which, depending upon the pressure,
temperature, and type of material, will eventually result in failure of the material. Exposure
Section 52
DOE-HDBK-1129-2008
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of metals to low to medium pressure tritium at normal temperatures does not generally result
in material failure within any reasonable period of time.
Some metals are more resistant to embrittlement than others and, therefore, are more
compatible with tritium. Depending upon the specific application, 304L and 316L stainless
steel are generally considered to be the most hydrogen compatible and readily available
stainless steels for tritium service. High-pressure vessels, valves, and tubing designed of
these materials when used at their rated pressure and temperature will provide many years
of service without material failure. When equipment is designed for tritium operations, a
materials expert should be consulted to ensure that the materials selected are compatible
with their intended service.
5.1.2.a Austenitic Stainless Steels
The recommended materials of construction for tritium-handling systems are from the class
of wrought 3XX series of austenitic (face-centered-cubic) stainless steels, including Types
304L, 316L, and 347. Types 304L and 316L are most often used in tritium processing
systems. These steels provide good strength, weldability and resistance to hydrogen
embrittlement. Components fabricated from these materials are procured routinely. Many
commercially available vacuum system components that are used in tritium systems, such
as valves, piping, pumps, and analytical instrument sensors, are fabricated from these types
of austenitic stainless steel. Wrought materials are preferred to cast because wrought
materials normally have a more homogenous microstructure. In the past, tritium has leaked
through parts having poorly oriented stringers and inclusions. The forging direction of some
wrought components has been specified so that the orientation of inclusions is not in a
direction that could result in a tritium leak path. Low carbon grades (such as 304L and
316L) are preferred to avoid weld sensitization and to reduce the number of inclusions
(impurity particles such as oxides and carbides). Modern vacuum-arc-remelted steels are a
good choice because they have lower impurity levels, thereby resulting in fewer inclusions
that could aid hydrogen-induced cracking or provide leak paths. Typically, tritium system
components employ seamless pipe and tube where practical.
Stabilized grades, such as Type 347, have been employed in applications where post-weld
heat treatment is not possible. This usually occurs when a process vessel contains a
working material (such as hydride or getter) that will degrade when exposed to the post-weld
heat treatment, which is typically performed at about 1,100°C for austenitic stainless steels.
High carbon grades, such as Type 347H or Type 316H (having 0.04 percent carbon
minimum), have been successfully employed for tritium service if high temperature strength
is required. Type 347H is employed in the Hydride Transport Vessel (see section 6.2.2),
and Type 316H was employed for the SRS Building 232-H Extraction Furnace retorts. Type
310 stainless steel has good oxidation resistance and can be considered for elevated
temperature applications if oxidation is a concern. Type 316 stainless has superior creep
resistance but inferior oxidation resistance to Type 310.
Section 53
Some types of higher-strength austenitic stainless steels not generally employed for tritium
service may be required for fasteners (such as nuts and bolts) in mechanical joints in high-
temperature regions. This may be acceptable if the bolts are exposed to only residual
amounts of tritium. These materials also may be used to contact 3XX stainless steels to
avoid galling of mating screw contact surfaces. Typical materials used in these applications
DOE-HDBK-1129-2008
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include Nitronic 60, Nitronic 50 (also called 21-13-9) and Nitronic 40 (also called 21-6-9);
these are all nitrogen-strengthened austenitic stainless steels.
5.1.2.b Copper and Copper Alloys
In principle, copper should be a suitable material in tritium systems. Copper has several
tritium-compatible properties. Tritium has a low permeability in copper, and copper is a
ductile, stable, face-centered cubic metal and so is resistant to hydrogen embrittlement.
The high thermal conductivity of copper is a desirable property for process vessels requiring
heat flow or constant temperature. Copper can be easily joined in a number of ways (e.g.,
soldering, brazing, welding). In spite of these advantageous properties, copper and copper
alloys are not commonly used in tritium systems. Several factors may account for this. The
ASME allowable design strength of copper falls rapidly at temperatures above 200°C,
making it difficult to use copper at elevated temperature. Also, hydrogen isotopes can react
at elevated temperature with oxygen in copper, whether the oxygen is in solid solution or in
copper oxide precipitates. In either case, water is formed, and over time water vapor
agglomerates at grain boundaries, which eventually results in intergranular cavitation,
cracking, and failure. This failure mechanism is sometimes termed “steam embrittlement.”
Also, a transition junction (normally nickel) is required to join copper and the stainless steel
components of the remainder of the system.
5.1.2.c Aluminum and Aluminum Alloys
Aluminum has properties making it potentially desirable for tritium systems. It has a low
density and a high thermal conductivity. Hydrogen isotope permeability is very low in
aluminum compared to stainless steel. Aluminum is used in applications where light weight
is important, such as in containers that must be lifted by personnel in gloveboxes. Aluminum
can be used for the construction of medium-quality static containment vessels. However,
aluminum is not commonly used in tritium systems. Stainless steel has much higher
strength, at room and elevated temperature. Welding aluminum requires more precautions
because aluminum reacts with atmospheric water vapor, which can cause porosity due to
hydrogen in the weld fusion zone.
5.1.2.d Materials to Avoid
Plain carbon steels and alloy steels must not be used for tritium service. These steels have
high strength and (normally) a body-centered-cubic crystal structure, both of which make the
material less ductile and much more susceptible to hydrogen embrittlement. Ferritic
stainless steels (such as Type 430), martensitic stainless steels (both quench-and-tempered
(such as Type 410) and precipitation hardening (such as 17-4 PH and PH 13-8 MO)) and
precipitation hardened austenitic stainless steels (such as AM-350) should not be used for
general tritium service; they are all more susceptible to hydrogen embrittlement than the
austenitic stainless steels. Additionally, free-machining grades of austenitic stainless steel
(such as Type 303) should not be used.
Section 54
Other materials that must not be used for tritium service are any material that forms hydride
near room temperature and atmospheric pressure. Examples include zirconium, tantalum,
niobium, and many alloys of these materials.
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5.1.3 Polymers
All polymers degrade when exposed to radiation. Both tritium and tritiated water permeate
all polymers, and permeated tritium deposits the beta decay energy throughout the polymer
bulk. (Although the tritium beta energy is very low and has a small penetration depth in
matter, permeation allows tritium atoms to be near enough to polymer chains throughout the
bulk to cause changes in the polymer by radiation.) Types of radiation-induced changes in
polymer properties include softening (degradation) or hardening, ductility loss, color change,
dimensional change, and gas evolution. Because of these effects, polymers should only be
used in tritium systems where no metal alternatives exist. Normally, only polymers that
harden during radiation exposure are employed, and are replaced before they begin to
deteriorate. In addition to polymer breakdown itself, products of degradation can form
corrosive liquids or acids such as HF and HCl. Polymer parts must be easily replaceable as
a part of normal operations, and a program of regular inspection and replacement should be
established. The system should be designed to expose any polymers to as little tritium as
possible. Typical uses of polymers in gas-handling systems include gaskets, O-rings,
electrical cable insulation and valve parts, including seats, stem tips, and packing.
Polymers relatively resistant to radiation can typically withstand up to about 1 million rad
(1 rad = 100 erg energy deposited per gram of material). By knowing the solubility of tritium
in a polymer at a given temperature and tritium partial pressure and the decay rate of tritium,
the approximate dose can be calculated, assuming the tritium concentration has reached
equilibrium.
Many effects of radiation on polymers are accentuated by oxygen. Protecting polymers from
oxygen or air will likely lengthen the lifetime of polymers exposed to tritium. Also,
temperatures above about 120°C accelerate radiation effects in polymers, so the
temperature of any polymer parts should be kept as low as possible. Inert additives such as
glass or graphite generally enhance the resistance of polymers to radiation. Addition of
antioxidants may also enhance radiation resistance.
5.1.3.a Plastics
VespelTM, a polyamide, has been successfully used for valve stem tips in some tritium
laboratories. Ultra-High-Molecular-Weight Polyethylene (UHMWPE) and High-Density
Polyethylene (HDPE) have been used for valve stem tips in automatic valves at SRS.
Although the latter two materials were designed by Dupont specifically for tritium service at
SRS, their performance has not reached its desired level. Use of HDPE has been
discontinued, while valves that use UHMWPE are transitioned into Vespel as the need
arises to repair or replace. EH Technical Notice 94-01, Guidelines for Valves in Tritium
Service, describes in detail differing materials and actuators for varying applications.
Section 55
Low-Density Polyethylene (LDPE) is very permeable by tritium and tritiated water and
should not be considered for use in tritium systems. Polytetrafluoroethylene (PTFE), which
trade name is TeflonTM) degrades and decomposes in tritium, resulting in the formation of
HF. In humid air, HCl and HF are formed, which are both highly corrosive. Generally,
chlorofluorocarbon polymers should not be used in tritium service. Polyvinyl chloride (PVC)
and vinylidene chloride (Saran) are among several polymers used in tritium protective
clothing, but should not be used for process equipment because they contain chlorine.
DOE-HDBK-1129-2008
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5.1.3.b Elastomers
Tritium readily permeates into and diffuses through elastomeric materials and, depending
upon thickness, begins appearing on the outside of the elastomeric seal within hours after
exposure to tritium. Elastomers are subject to radiation damage. They harden and lose
their sealing ability due to exposure to high concentrations of tritium.
Ethylene propylene diene monomer (EPDM) elastomers are employed for low-pressure
process flange gaskets because of EPDM’s relatively good performance in tritium service.
In some cases, Buna-N process flange gaskets are being replaced by EPDM when the
gaskets are changed; however, in other applications, Buna-N remains in use. VitonTM, a
common O-ring material, is used, but can embrittle in months in tritium service. Butyl rubber
has low permeation for both tritium and tritiated water, but is not as resistant to radiation
damage as EPDM. Butyl rubber is used for glovebox gloves. Silicon rubber can be used in
glovebox construction and has found to be effective at Mound and other sites. Water vapor
in the air outside gloveboxes permeates gloves and can lead to a significant portion of the
residual tritiated water vapor in tritium gloveboxes.
Kel-FTM and its successor Neoflon™, are common chlorofluorocarbon polymers
(Polychlorotrifluoroethylene (PCTFE)) and are incompatible with tritium. They, like TeflonTM,
degrade in tritium gas and should not be used.
5.2 First Wall Design
5.2.1 High-Pressure Tritium
For high-pressure tritium, it is generally recommended that the first wall be of all metal
construction and hydrogen compatible materials including valves, valve seats, and tubing.
The use of non-hydrogen-compatible materials results in material failure and the release of
the contained tritium. Elastomers are not tritium-compatible, and, as a result, elastomeric
seals and valve seats are not recommended for use in the containment of high-pressure
tritium. There are exceptions to this general case, and other criteria may be used when
justified by analysis.
5.2.2 Low- and Medium-Pressure Tritium
For the containment of low- and medium-pressure tritium, it is generally recommended that
the first containment wall be of all metal construction of hydrogen-compatible materials
where possible, including valves, valve seats, and tubing. Hydrogen and helium
embrittlement of the materials of construction is not usually significant at low and medium
pressures. As a result, non-hydrogen-compatible materials may be used if required by the
design or if the required component is not available in other materials.
Section 56
It is difficult to design a vacuum system, which, in some cases is the first wall, without
including some non-hydrogen-compatible materials and elastomers. However,
embrittlement of the materials is not an issue because the tritium exposure is transient and
the pressure is low. Under these conditions, the elastomers are not exposed to tritium
continuously, and most can be used in tritium operations under this condition. Surveillance
and/or preventive maintenance schedules should be selected in order to maintain elastomer
functionality.
DOE-HDBK-1129-2008
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5.3 Secondary Wall Design
5.3.1 High-Quality Secondary
The design requirements for a high-quality secondary wall are the same as the primary wall.
If the secondary wall is required to provide long-term containment of high concentrations of
tritium, it should meet the same requirements as the primary or first-wall container.
5.3.2 Medium-Quality Secondary
If the secondary wall is a glovebox and only contains tritium that has been diluted by the
glovebox gases for a short duration (e.g., a few hours) while the glovebox is cleaned up by
the tritium removal system, the requirements can be relaxed. Although the quantity of tritium
contained may be quite large, the low pressure and concentration of tritium will not result in
material failure due to tritium exposure.
5.3.3 Low-Quality Secondary
If the secondary wall is a room or building and only contains tritium that has been diluted by
the air contained in the room or building while the room or building is cleaned up by the
tritium removal system, the construction requirements can be relaxed. Although the quantity
of tritium contained may be quite large, the low pressure and concentration of tritium will not
result in material failure.
5.4 Cleanup System Design
Most of the components of the tritium removal and cleanup system are only exposed to
tritium at low concentrations and pressure for short time periods. The only long-term
exposure is in the water collection system where the water is collected at low pressure on a
molecular sieve. All-metal construction is recommended, but the materials of construction
are not required to be hydrogen-compatible materials. Where appropriate, elastomeric
sealing materials have been used successfully in these systems for many years without
significant problems. When possible, metal seals should be used because they are more
durable and reliable and require less maintenance than elastomeric seals.
To minimize the potential for the generation of mixed waste and to decrease radiation
exposure of the workers, oil-free pumps should be used where possible.
5.5 Storage System Design
Storage systems must consider the total cost of the storage cycle and the purpose for the
storage. Storage techniques that increase the complexity of the handling process without
adding beneficial features should not be used. The barrier concept discussed in Sections
4.1.1 through 4.1.3, in addition to the wall design considerations discussed above, should be
incorporated into all storage system designs.
5.5.1 Short-Term Storage
Tritium used to support the day-to-day activities in a facility must be readily available to the
facility customers. If the facility uses tritium in gaseous form and its decay to helium does
DOE-HDBK-1129-2008
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not impact the process, then, to simplify the operation and the equipment, the tritium can be
stored in gaseous form. The storage container should be fabricated of all metal, hydrogen-
compatible materials including valves, valve seats, and seals.
Section 57
5.5.2 Medium-Term Storage
If tritium is only used in periods of two years or less, the requirements do not change
significantly from those of short-term storage. Experience has shown that tritium can be
stored safely at near atmospheric pressure for long periods of time. If the buildup of helium
in the supply does not impact the use, then storage as a gas is an acceptable alternative.
There are, however, advantages of tritide bed storage for medium-term use. Impurities such
as nitrogen and oxygen form uranium nitride and uranium oxide and are removed from the
gas stream as the bed is heated and cooled. Helium, which accumulates due to the decay
of tritium, and any other impurities remain in the overpressure gas above the bed and may
be pumped off after the bed had been cooled down and the tritium has been gettered by the
uranium. As a result, the uranium bed not only provides for tritium storage but also provides
a means of maintaining a reasonably pure and stable tritium supply.
5.5.3 Long-Term Storage
Due to its short half-life, storing tritium for several years implies that it is not readily needed.
It should be placed in a safe and stable condition while it decays.
5.5.3.a Storage as a Gas
Metal tritides have the advantage of significantly decreasing the volume required to store
tritium without increasing the pressure of the gas during storage. Compared to the
fabrication and preparation of metallic storage beds, regardless of what metal is used, the
cost of storage of tritium as a gas at near atmospheric pressure is economical. ASME code-
designed stainless steel tanks are available or can be designed and fabricated at a
reasonable cost. A tank at atmospheric pressure would have a final pressure of 15 pounds
per square inch after all of the tritium had decayed, so embrittlement is not an issue. The
long-term storage of hydrogen and tritium in containers is well understood in comparison to
the understanding of long-term storage of metal tritides.
5.5.3.b Storage as a Metal Tritide
Uranium beds designed at Sandia in the late 1970s for laboratory use were about the size of
two one-gallon paint cans. This included the secondary containment system and electric
heaters used to drive off the tritium during removal. These beds were designed to store 50
grams of tritium as uranium tritide that was easily recoverable in a matter of less than an
hour. Long-term storage in this type of container is expensive, but the tritium can be easily
and quickly recovered for use. Additionally, large uranium beds capable of storing 1,000
liters of hydrogen were used at Mound. Also, impurities such as nitrogen and oxygen form
uranium nitride and uranium oxide, and are removed from the gas stream as the bed is
heated and cooled. Helium, which accumulates due to the decay of tritium, and other
nonreacting impurities remain in the overpressure gas above the bed.
To help resolve unknowns regarding consequences of air-ingress accidents in uranium
beds, a series of air-ingress experiments was conducted at Ontario Hydro Research
Division, with the participation of PPPL and the Idaho National Environmental and
DOE-HDBK-1129-2008
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Engineering Laboratory. The experiments indicated that the resulting reaction was
restrained with only modest temperature excursions. This leads to the conclusion that the
hazards associated with an air-ingress accident involving a uranium bed is smaller than
previously anticipated. Additionally, tests conducted by WSRC indicate that, except for
catastrophic container failure, the tritium release due to air inleakage into a uranium tritide
bed is limited by diffusion.
Section 58
Titanium hydride is not pyrophoric at room temperatures, is a stable material, and has been
studied for use in the long-term storage of tritium. It is reported to be less prone to
spontaneous ignition in air than the parent metal. Following the hydriding process, if the
titanium hydride is exposed to air under controlled conditions, a small quantity of hydrogen
is released from the material as the oxide layer forms on the surface of the material.
Following formation of the oxide layer, titanium hydride is stable in air. Hydrogen will not be
released unless the material temperature is significantly increased.
Palladium tritide is not pyrophoric at room temperature, is a stable material, and the
overpressure of tritium over the bed at room temperature is approximately 50 torr.
Metal tritides have the advantage of significantly decreasing the volume required to store
tritium without increasing the pressure of the gas during storage.
5.6 Surveillance and Maintenance
The level of equipment surveillance (including radiological monitoring) and maintenance
required is based on the hazard class of a facility; i.e., Hazard Category 1 through 3 or
Radiological. The specific requirements for the different classes of facility equipment are a
function of the safety issues associated with the equipment. These are specified in the
facility safety analysis report or other facility safety documentation and in the facility
maintenance plan.
5.7 Seismic Considerations
This section describes 1) DOE NPH Policy, which defines the requirements for protection
against natural phenomena such as earthquakes, and 2) seismic design and evaluation of
equipment and distribution systems. Seismic and wind design and evaluation of structures
and facilities are discussed in Section 4.4.
5.7.1 DOE Natural Phenomena Hazards Policy
DOE has developed a policy for the mitigation of natural phenomena (such as earthquakes,
extreme winds, and floods) on its facilities. This policy is in the form of an Order, an
Implementation Guide, and a series of Standards. DOE O 420.1B and its Implementation
Guides provide the overall requirements for mitigation of the effects of natural phenomena.
The Standards lay out the basic performance requirements for SSCs subjected to loads
caused by earthquakes, extreme winds, and floods.
The approach in the DOE policy consists of placing each SSC into a PC based on its
function, its importance to safety, and the quantity and type of material involved, if any.
DOE-STD-1021-93, Change Notice 1, Natural Phenomena Hazards Performance
Categorization Guidelines for Structures, Systems, and Components, provides guidance for
DOE-HDBK-1129-2008
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categorizing SSCs. Background material used in the development of DOE-STD-1021-93
can be found in UCRL-ID-112612. The Standard provides useful dose information for
radiological materials and toxic chemicals. Additional information that is useful in
determining categorization results from accident analyses, information from a SAR, and
information in support of DOE-STD-3009-94 CHG 3. An equipment list will be developed
with the PC for each SSC identified.
DOE policy invokes DOE-STD-1022-94, Natural Phenomena Hazards Characterization
Criteria, and DOE-STD-1023-95, Change Notice 1, Natural Phenomena Hazards
Assessment Criteria, if any SSC is categorized as a PC-3 or PC-4. These Standards define
acceptable procedures for determining the NPH levels at the site for use in design or
evaluation. If only PC-2 or lower SSCs exist at the site, Uniform Building Code (UBC)
design values are acceptable. However, site-specific values are always preferable if they
are available.
Section 59
Design and evaluation criteria are provided in DOE-STD-1020-2002, Natural Phenomena
Hazards Design and Evaluation Criteria for Department of Energy Facilities. This Standard
provides an acceptable approach for the design and evaluation of SSCs in PCs 1, 2, 3,
and 4. The DBE and wind can be developed from the available NPH description, either site-
specific or from the UBC. A table of representative seismic and wind design values for most
DOE sites is contained in DOE-STD-1020-2002; however, the use of the values in this
Standard must be justified for the site. DOE-STD-1020-2002 also discusses the 5 percent
damped in-structure response spectra, which are used for the design and evaluation of
equipment. These spectra must be developed from the description of the ground motion
and the facility characteristics.
The user should review these Standards, the appendices in the Standards, and the
references listed below and be aware of the type of information provided therein. DOE has
conducted training on the use of the design and evaluation Standard since 1989, and copies
of the training material are also available.
5.7.2 Seismic Design and Evaluation of Equipment and Distribution Systems
In the event of an earthquake, DOE facilities need to have adequate measures for the
protection of the public, workers, environment, and investment. Due to the evolutionary
nature of design and operating requirements as well as developments in engineering
technology, existing DOE facilities embody a broad spectrum of design features for
earthquake resistance. These features depend on factors such as vintage of the facility
design and construction and hardware supplier practices at the time of design and
construction. The earliest vintage facilities often have the least design consideration for
seismic-induced forces and displacements and exhibit the greatest difference between their
design basis and current requirements for seismic design criteria for new facilities. DOE has
developed a Seismic Evaluation Procedure (SEP)3 to summarize a technical approach and
provide generic procedures and documentation requirements, which can be used at DOE
facilities to evaluate the seismic adequacy of equipment and distribution systems.
The SEP is intended to provide DOE facility managers, safety professionals, and engineers
with a practical procedure for evaluating the seismic adequacy of equipment. Often the
3 DOE/EH-0545, Seismic Evaluation Procedure for Equipment in DOE Facilities, March 1997.
DOE-HDBK-1129-2008
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approach used to review the seismic capacity of equipment in facilities is to conduct
sophisticated evaluations, which can be very time-consuming, complex, and costly. Much of
the available funding and time can be spent on analysis rather than on the real objective of
increasing the seismic capacity of the equipment. The SEP is designed to be an extremely
cost-effective method of enhancing the seismic safety of facilities and reducing the potential
for major economic loss that can result from equipment damaged by an earthquake.
The following is a suggested list of topics to consider in the design of new systems and
equipment or the evaluation of existing systems and equipment. Representative equipment
that may be found in tritium facilities is listed in Table 5-1.
TABLE 5-1. Representative equipment found in tritium facilities
Section 60
ELECTRICAL EQUIPMENT MECHANICAL EQUIPMENT
Batteries on Racks Fluid-Operated / Air-Operated Valves
Motor Control Centers Motor/Solenoid-Operated Valves
Low- and Medium-Voltage Switchgear Horizontal Pumps
Distribution Panels Vertical Pumps
Transformers Chillers
Battery Chargers and Inverters Air Compressors
Instrumentation and Control Panels Motor-Generators
Instruments on Racks Engine-Generators
Temperature Sensors Air Handlers
Computer Data / Storage Systems Fans
Alarm Instrumentation HEPA Filters
Communications Equipment Gloveboxes
Miscellaneous Machinery
PIPING AND RACEWAY SYSTEMS ARCHITECTURAL FEATURES
Cable and Conduit Raceway Systems Unreinforced Masonry (URM) Walls
Piping Hollow Clay Tile Walls
HVAC Ducts Suspended Ceilings
Underground Piping Raised Floors
Underground Raceways Storage Racks
Stacks Cranes
Conveyors of Material Elevators
TANKS SWITCHYARD AND SUBSTATION EQUIPMENT
Vertical Tanks Power Transformers
Horizontal Tanks and Heat Exchangers Miscellaneous Equipment
Underground Tanks
Canisters and Gas Cylinders
Miscellaneous Tanks
The PC for each system or component to be reviewed must be defined (PC 1, 2, 3, or 4) in
the Seismic Equipment List (SEL). The methodology and procedures for evaluating the
seismic adequacy of equipment described in the SEP are based on the observed
performance, failure, and response of various types of SSCs during and after they were
subjected to either actual or simulated earthquake motion. An SSC in a DOE facility can be
evaluated for seismic adequacy provided that the associated guidelines, limitations,
requirements, and caveats described in the SEP are satisfied.
The general approach for the development of the SEL is envisioned to be a three-step
process as depicted in Figure 5-1. After a SEL Team is selected, the first step of the
process is the development of the preliminary SEL from a list of the facility SSCs. The SEL
DOE-HDBK-1129-2008
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Team consists primarily of safety professionals and systems engineers with assistance from
seismic engineers and facility operators. Only a portion of the facility SSCs will be contained
in the SEL and, in many cases, the SEL will contain only safety-related SSCs that must
function during or after a seismic event. The selection of the SSCs belonging on the SEL
should be based on the results of accident analyses. These accident analyses should
consider the appropriate facility hazards as required by DOE Orders and Standards.
FIGURE 5-1. Development of the seismic equipment list
For the DOE facility being seismically evaluated, accident analyses and their results are
typically provided in a SAR. The preliminary SEL should be based on information provided
in this SAR. For a nonreactor nuclear facility, DOE-STD-3009-94 Change Notice 3 provides
guidance on the preparation of a SAR. Using the guidance in DOE-STD-3009-94 Change
Notice 3 and the appropriate accident analyses in the SAR, SSCs can be differentiated into
Safety-Class or Safety-Significant, and the preliminary SEL can focus on those facility
SSCs. For facilities without a SAR, accident analyses comparable to those required for a
SAR should be performed.
Section 61
Additional guidance for the development of the preliminary SEL is provided in DOE-STD-
1021-93. This Standard considers the results of facility hazard classification, SSC safety
classification, and performance categorization. With these considerations, the facility SSCs
are assigned to the appropriate performance category. The preliminary SEL focuses on
those SSCs that are classified above a specified PC. In addition to selecting SSCs based
on a SAR or on DOE-STD-1021-93, there are system safety considerations and seismic
vulnerability considerations that should be addressed when developing the preliminary SEL.
Next, the location of equipment items in the facility and in-structure response spectra for this
level or location is determined. The in-structure response spectra represent the modification
of the ground response spectra by the facility. There may be amplification or attenuation of
the motion at various frequencies at different locations within the facility. As discussed in
DOE-STD-1020-2002, the 5 percent damped in-structure response spectra are used for
design or evaluation of equipment at a specific location. Guidance for determining in-
structure response spectra is provided in the Standard. To evaluate equipment and
distribution systems, the following items should be considered:
DOE-HDBK-1129-2008
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• Functionality Requirements
– Does the item need to function during the earthquake?
– Does it need to function only after the earthquake?
– Can it be placed back into service by operator actions?
• Does the item have sufficient capacity to meet the earthquake demand specified for its
PC? An example of a comparison of capacity to demand is shown in Figure 5-2.
FIGURE 5-2. Comparison of seismic capacity spectra to seismic demand spectra
• Is the item adequately anchored or braced? There are special considerations for base-
isolated or vibration-isolated items since they have behaved poorly during earthquakes.
• Does an adequate “Load Path” exist to transfer all seismic loads in addition to operating
loads? A load path is a continuous path, which carries load from the top of a structure or
component down through an element and finally into the foundation. Loads produced by
the earthquake must be combined with normal operating loads such as weight, pressure,
temperature, and any temporary loads that may exist.
• Are there system interaction issues?
– Can something fall and cause the item not to function?
• Can the item impact with nearby items?
– Is there differential motion between the item and the structure?
– Is there a water spray or flood issue?
– Is there a fire issue?
Each new system or new component must be designed to meet the DOE seismic criteria
specified in DOE Natural Phenomena Policy as specified in Section 4.4. Adequate
documentation to support its design must be maintained by the facility management.
Adequate inspection should be conducted to make sure the system or component was
fabricated and installed as specified in the design documents. Documentation must be
maintained current throughout the life of the item.
DOE-HDBK-1129-2008
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Section 62
Evaluation of existing systems or components must be conducted based on the “Actual”
condition of the item. This may be different than the design or “As-Built” condition due to
field modifications or deterioration of the item during its service. An examination of the item,
its installation, and current condition should be made during a walkdown by seismic
engineers as defined in the SEP. Existing systems and components may also be evaluated
by use of experience data. This is an alternative approach that can be used if the systems
or components are installed in an acceptable manner and meet the rules specified in the
SEP to ensure that the item is similar to items in the experience database. DOE has
developed references for the evaluation of existing systems and components, has
conducted training on their application, and has implemented the seismic evaluation
guidelines for systems and components at DOE facilities.
5.8 Fire Scenarios
There have been investigations that point to the conclusion that fire scenarios are the
dominant risk at most tritium facilities. These fire scenarios are not restricted to seismic-
induced fires, but include fires from all sources. These analyses show that the slower
burning fires are limiting, and that in these cases, fires result in oxidation rates that are high
(in excess of 90 percent). Additionally, compliance with National Fire Protection Association
(NFPA) requirements, while limiting the potential for fire spread, does not ensure that a full-
facility fire scenario need not be analyzed. Reference [25] describes the oxidation rates that
are used in safety analysis at LANL. It should be noted that the bounding value given a fire
is 100 percent oxidation.
It is possible that fires of sufficient magnitude and frequency may occur at some tritium
facilities so as to warrant safety system classifications of both the fire suppression and fire
detection systems. This importance that HSS places on fire protection at tritium facilities
was highlighted as early as September 1991 during a review of the then-under-construction
RTF. The exemption request from some requirements of DOE Orders 5480.7 and 6430.1A
for RTF was not approved by HSS/NS until physical modifications were made to the tritium
facility [26]. The definition of tritium that was Material at Risk in selected fire (and seismic)
scenarios was also developed prior to startup at RTF, which eventually led to decisions on
upgraded selected storage containers and inventory limits. [27]
5.9 Instrumentation
This section provides information on several instruments used to detect and monitor tritium.
The references are provided for information only. DOE does not certify that a particular
product is superior to any other product from another vendor. References in this Handbook
do not imply endorsement by DOE.
5.9.1 Tritium Monitoring Systems
Several different types of instruments may be used to detect and measure tritium in the
operation of a facility. Examples and a discussion of such instrumentation follow:
• Ionization Chambers — Tritium decays to 3He by the ejection of a beta particle. The
beta particle generated by the decay of tritium ionizes the surrounding gas. The number
of ions produced due to the loss of energy of the beta particle is a function of the type of
gas. A sample of gas is collected in the ionization chamber and the ionization current is
DOE-HDBK-1129-2008
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Section 63
measured. The resulting chamber ionization current is proportional to the quantity of
tritium in the gas. The larger the measuring chamber volume, the higher the output
current and the easier it is to measure. However, as the volume of the chamber
increases, the longer it will take to get an accurate measurement. Modern electronic
systems have solved most of the problems associated with measuring small ionization
currents in small volumes and as a result, the volume of the ionization chambers has
been reduced over the years from 50 L down to 1 or 2 L. Most tritium measuring
instruments have an ionization chamber.
• Proportional Counters — Gas proportional counters are also used to measure the
amount of tritium contained in a gas. A sample of the gas to be monitored is mixed with
a counting gas and passed through a proportional counter tube where the pulses caused
by the decay of tritium are counted. Proportional counter monitors can be used for most
gas monitoring applications and are also available to measure surface contamination.
• Scintillation Crystal Detectors — Scintillation detector systems are used to measure the
total mole percent of tritium in a sample of gas independent of the chemical composition
of the tritium in the gas (HT, DT, T2, and CHxTy). A sample of the gas is introduced into
a measurement chamber at low pressure, generally less than a few torr. The chamber
contains a scintillation crystal, which is exposed to the tritium as it decays. The light
pulse produced in the scintillation crystal is either counted or is used to produce a
current, which is proportional to the mole percent tritium contained in the gas sample.
Crystal scintillation detection is generally used to measure the mole percent of tritium in
gases containing high concentrations of tritium.
• Mass Spectrometer — Magnetic sector, quadrupole, and drift tube mass spectrometers
are used as analytical tools to measure the individual components that make up the gas
being measured. Mass spectrometers are generally used for the purposes of assay and
accountability or for scientific purposes. A sample of the gas to be measured is
introduced at low pressure (a few microns) into a chamber and ionized. The ions
produced are then measured by a means that discriminates on mass. The number of
ions produced at each mass is measured and is proportional to the partial pressure of
the component in the gas sample.
The sophistication of the measurement systems varies greatly from facility to facility
through out DOE. Light isotope, drift tube, mass spectrometers require a large capital
investment and require a skilled staff to operate, and, in some cases, may not be cost-
effective. All DOE tritium facilities do not require a light isotope drift tube mass
spectrometer. Quadrupole mass spectrometers and crystal scintillation detectors are
much less expensive, but still require operation by knowledgeable well-trained
personnel. The DOE assay and accountability requirements and regulations do not
currently reflect this difference in sophistication and cost and currently place the same
requirements on small as well as large-scale operations.
• Liquid Scintillation Counters — Due to the need to measure the removable tritium on
surfaces and in the body water of workers, almost all tritium facilities are equipped with
or have access to a liquid scintillation counter. If the scintillation counter is not available
on site the service can generally be purchased from a local firm. Liquid scintillation
counters are used to measure the quantity of tritium on surfaces, in liquids, and in
dissolved samples. For removable surface contamination measurements, a wipe of the
Section 64
DOE-HDBK-1129-2008
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surface to be measured is taken using dry paper or a Q-Tip. The filter paper or Q-Tip is
then placed in a scintillation cocktail, and the quantity of tritium is measured by counting
the light flashes that occur in the scintillation cocktail as the tritium decays. The surface
contamination is then calculated in units of dpm/100 cm2.
For liquid measurement, a sample of the liquid to be measured is placed in the liquid
scintillation cocktail and measured. The tritium concentration of the liquid is calculated in
Ci/mL. For solid measurement, a known weight of a material is dissolved to produce a
liquid and then the liquid is sampled and measured in the scintillation counter. The
quantity of tritium is then calculated in units of Ci/g of the original solid.
• Gas Samplers — Many different types of gas samplers have been developed and used
for measuring very small quantities of tritium in very large volumes of gas. These
samplers are used to measure quantities of tritium released through a facility stack and
for environmental monitoring at a site. Stack exhaust gas monitoring systems generally
use an ionization chamber to measure the tritium in the stack gases and a gas sampler
to measure the extremely low levels of tritium that cannot be measured by an ionization
chamber.
Most of the stack gas samplers are patterned after the ethylene glycol sampling system
developed at Mound Laboratories. A commercial version of this system is now
available. In this system, a sample of gas from the stack is circulated through six
ethylene glycol bubblers in series. The first three bubblers remove tritium in the form of
HTO, DTO, and T2O. The gas stream is passed through a heated catalytic reactor
where tritium in the form of HT, DT, T2, and CHxTy, is cracked and oxidized to form
water. This sample is then passed through three more ethylene glycol bubblers to
remove the tritium gas, which is now in the form of water. After a period from a few
hours to days, a sample of the ethylene glycol from each bubbler is removed and
counted using a scintillation counter to determine the quantity of tritium in each bubbler.
Tritium recovered from the first three bubblers is proportional to the tritium in oxide form
contained in the stack gases and the tritium recovered in the last three bubblers is
proportional to the quantity of tritium in elemental form contained in the exhaust gases.
Due to the extremely small quantity of tritium contained in the atmospheric gases
surrounding a tritium facility, the environmental gas samplers use higher flow rate
sampler systems than those required for stack monitoring, and, in general, collect the
water on molecular sieve traps. The water collected on the molecular sieve traps is then
recovered from the trap and the tritium concentration of the gas passing through the trap
is calculated from the tritium concentration of the collected water, the gas flow rate
through the trap, and the sampling time.
• Portable Room Air Monitors — There are several handheld portable room air monitors
on the market, and their capabilities and ranges vary as a function of the different
manufacturer and the purpose for which they were designed. It is convenient in some
activities to have the capability to connect a small hose to the monitor so that it may be
used to detect tritium leaks around equipment.
• Fixed Station Room Air Monitors — Fixed station monitors are designed to be installed
Section 65
in fixed locations and to be used to monitor the room air tritium concentrations.
DOE-HDBK-1129-2008
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Depending upon the manufacturer they may have several ranges and are equipped with
one or two alarm set points and audible as well as visual alarms.
• Glovebox Atmosphere Monitors — Glovebox monitors may be open mesh or closed
ionization chambers and are designed to monitor the higher levels of tritium inside the
glovebox containment systems.
• Hood and Exhaust Duct, Air Monitors — Hood and exhaust duct air monitors are similar
to fixed station monitors in range and characteristics.
• Exhaust Stacks, Air Monitors — Exhaust stack monitors are similar to fixed station air
monitors except that they generally have larger ionization chambers to increase the
sensitivity of the monitor.
• Personnel Friskers and Breath Analyzers — There has been some interest in
instruments which can be used to frisk personnel as they enter and exit tritium
contaminated areas. One DOE facility implemented a process of personnel frisking
consisting of the use of skin surface wipes counted in a liquid scintillation counter upon
entry and exit from tritium contaminated areas. In another facility, a hand station based
on counting the associated gas flow across the hands was used. To date, the
development work required to relate measurements made by these techniques to dose
or worker exposure has not been completed. It is expected that differences in the body
chemistry of personnel and differences in the time delay between tritium exposure and
equilibration of tritium in the body will continue to make the results of skin surface
contamination measurement and breath analysis monitoring inconsistent. The impact of
false alarms and inconsistent results on worker confidence will probably continue to
make these systems unsatisfactory for worker monitoring.
5.9.2 Specialized Instrumentation
There are many other types of specialized devices and/or instrumentation vendors, and
some may be superior to those discussed here. No endorsement of these devices should
be inferred by the reader.
5.9.2.a Remote Field Tritium Analysis System
A system for the remote, in-situ analysis of tritium in surface and ground waters has been
developed at SRS. Using automated liquid scintillation counting techniques, the Field
Deployable Tritium Analysis System (FDTAS) has been shown to have sufficient sensitivity
to measure tritium in water samples at environmental levels (10 becquerels (Bq)/L [~270
pCi/L] for a 100-minute count) on a near-real-time basis.
The FDTAS consists of several major components: a multi-port, fixed-volume sampler, an
on-line water purification system using single-use “tritium columns,” a tritium detector
employing liquid scintillation counting techniques, and the serial communications devices.
The sampling and water purification system, referred to as the “autosampler,” is controlled
by a Programmed Logic Controller pre-programmed to perform a well-defined sampling,
purification, and flushing protocol. The tritium analyzer contains custom software in the local
computer for controlling the mixing of the purified sample with liquid scintillation cocktail,
counting, and flushing the cell. An external standard is used to verify system performance
DOE-HDBK-1129-2008
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and for quench correction. All operations are initiated and monitored at the remote
computer through standard telephone line modem communications. [28] This system has
been commercially licensed by SRS to a firm that has a line of other sampling monitors.
Section 66
5.9.2.b Surface Activity Monitor
A surface activity monitor (SAM) for measuring tritium on metal (electrically conducting) and
nonmetal (electrically nonconducting) surfaces has been developed at Ontario Hydro
Technologies. [29-31]
The monitor detects tritium on the surface and in the near-surface regions by virtue of
primary ionization in air due to the outward electron flux from the contaminated surface. The
resulting ion pairs are measured by imposing an electric field between the contaminated
surface and a collector plate. A simple theoretical model relates the total tritium
concentration on a surface to the measured current.
Experiments benchmarking the application of the surface activity monitor on metal surfaces
against independent measurement techniques of aqueous dissolution and thermal
desorption show equivalence in the total tritium activities measured. Comparison of surface
activity monitor measurements with the dry polystyrene smear protocol has shown that the
two methods are complementary. Smearing measures the activity removed by the smear
action, which can be used to infer the total activity on the surface. Surface activity monitor
measurements determine the total activity on the surface, which can be used to infer
removable activity. Ontario Hydro has stated that this device is the only surface monitor for
tritium that provides an absolute measurement of the total activity on metallic surfaces.
Experiments demonstrating the application of the surface activity monitor on a variety of
non-conducting surfaces have been conducted. Some of the non-conducting surfaces
examined include paper, concrete, granite, and wood. Experiments are underway to extend
the database of nonconducting materials measured by SAM and catalogue the associated
collection efficiencies.
Currently, the SAM is commercially available in two models, QP100 and QP200, which have
measurement ranges of 0 – 200 nCi/cm2 and 0 – 200 µCi/cm2, respectively. A summary of
the technical specifications of the instrument is given in Table 5-2.
5.9.3.c Breathalyzer
A device undergoing development in Canada is the Scintrex Tritium-in-Breath Monitor. It is
an automatic monitor dedicated towards health physics and radiation biology applications.
The Tritium-in-Breath Monitor measures levels of exhaled tritium within 5 minutes of
sampling, thus saving considerable time and effort in the monitoring process. This rapid
assessment has a sensitivity level of 5 µCi/L-urine equivalent, which may be sufficient for
alarming the cautionary levels of in-body tritium. Preliminary development of this equipment
has been done at the Atomic Energy of Canada Ltd. research laboratory in Chalk River,
Canada.
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TABLE 5-2. SAM technical specifications
Model QP 100 Model QP 200
Detection Sensitivity 740 Bq/100 cm2
(0.2 nCi/cm2)
(440 dpm/cm2)
740 kBq/100 cm2
(0.2 µCi/cm2)
(440 kdpm/cm2)
Ranges 0-74 kBq/100cm2
(0-200 nCi/cm2)
0-74 MBq/100cm2
(0-200 µCi/cm2)
Measurement Area 9 cm2
Signal Display 3½ digit LCD
Instrument Response Time Less than 15 seconds
Operating Time 500 hours continuous service
Operating Temperature 15 – 60ºC
Air Pressure 600 – 120 kPa
Humidity 5 – 65 percent RH
Change in Offset 0.04 nCi/cm2/ºC over 5ºC to 30ºC
Dimensions: Footprint
Height
5.8 cm diameter
14.2 cm
Weight 575 g
Accessories Calibration surface activity sources
Verification surface activity source
Reusable boots to eliminate cross contamination
Battery pack
Section 67
6.0 TRITIUM RECEIVING AND STORAGE
In the past, DOE has been a commercial supplier of tritium to industry. DOE ceased
commercial sale of tritium at the end of fiscal year (FY) 1995 and now only supplies tritium to
DOE-operated facilities. There is no charge to DOE facilities for the tritium. Costs may be
incurred for the shipping container, the loading and shipping of the container, and any other
incidental costs associated with shipping tritium from the supplying facility to the user. While
it is advantageous to transport tritium in a metal hydride vessel, the receiving sites must be
equipped with appropriate furnace capability.
6.1 Shipping Packages
The packages for shipment of tritium must meet regulatory requirements based on the
amount of tritium being transported. The design requirements for radioactive materials
shipping packages are specified in 10 CFR 71.43 and 49 CFR 173.410. See Section 7.2.3,
Minimum Requirements for Packaging, for the basic shipping container design
requirements.
6.1.1 Type A Shipping Packages
Type A quantities (< 1,100 curies) of tritium may be shipped in DOT 7A Type A shipping
packages. Several commercial manufacturers will design packages that meet these
radioactive materials shipping criteria. There are no comparable requirements, as discussed
in section 7.3.3., for leak testing Type A packages as there are for Type B packages.
DOE-HDBK-1129-2008
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6.1.2 Type B Shipping Packages
Tritium in Type B quantities (less than or equal to 1,100 curies) is shipped in the form of
uranium tritide in the WSRC-developed HTV or if the tritium is in gaseous form, it is shipped
in the WSRC-developed Product Vessel (PV). The package can be transported as non-
exclusive (i.e., with other than radioactive cargo) use by highway, rail, water, or air. LP50
containers are no longer used for shipping off-site. The HTV and PV can be packaged for
shipment in the Type B, UC-609 shipping package. Primary containers other than the HTV
and PV can also be shipped in the UC-609. However, if tritium is ordered from or is to be
returned to a DOE facility, it is generally shipped in an HTV or PV if packaged inside the UC-
609. Caution should be exercised when shipping “empty” HTVs, as the residual heel may
contain > 1100 curies, thereby requiring a Type B shipment for the “empty” HTV. For design
and analysis purposes, the storage vessel receives no credit for tritium containment. As
discussed in section 3.3.1.b, tritium contained in a certified Type B packages are certified to
withstand the credible facility accidents can be excluded from the inventory of a facility for
DSA purposes.
Type B quantities may also be transported from one DOE site to another in the Sandia-
designed H1616 shipping package. DOE authorization is required before using the H1616
package. The primary tritium container enclosed inside the H1616 must meet the Sandia
National Laboratory (SNL) specification SS393217. The HTV is qualified for shipment in the
H1616 packaging and meets the SNL specification. Of the two H1616 variations, H1616-1
and H1616-2, qualification for transport in the H1616-1 automatically includes qualification
for transport in the H1616-2.
6.2 Product Containers
6.2.1 WSRC Product Vessel
The WSRC PV is designed for use with the UC-609 to ship up to 10 grams of gaseous
tritium in a single valve, 21L-volume container at pressures up to 1,200 torr. The PV is
designed to meet the requirements of the ASME Boiler and Pressure Vessel Code, Section
VIII, Division 1, 1991 Addenda, Lethal Service, Full Vacuum to 8.5 psig (1,200 torr) at 77oF.
Section 68
Although the PV is designed to meet ASME code requirements, the PV is not ASME code
stamped. The vessel is equipped with a single valve, Nupro® SS-4HS-TW valve, 316 SS
body and is closed with a male Cajon® SS-4-VCR-4 nut and a Cajon® SS-4-VCR-CP cap.
6.2.2 WSRC Hydride Transport Vessel
The HTV [32] can be loaded with a maximum of 3 moles (18 grams) of tritium as uranium
tritide. The main body of the HTV is fabricated from two four-inch Schedule 40 pipe caps,
welded together and contains a free volume of approximately 690 cubic centimeters. The
HTV weighs 9.3 pounds, has a maximum outside diameter of 4.560 inches, and is 9.980
inches high. The HTV is equipped with two ports with a single Nupro® SS-4HS-TW closure
valve on each port. Both ports are equipped with 2-micron nominal pore size, cup-shaped,
porous stainless steel filters welded on the end of the port tube inside the vessel. The
purpose of the filters is to confine the uranium powder. One filter is positioned in the volume
above the uranium and is connected through a valve to the female port with a Cajon® SS-4-
DOE-HDBK-1129-2008
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VCR-1 female nut. The second filter, connected through the valve to the male port, is
positioned below the level of the uranium powder in the bottom of the vessel and is
connected through the valve to the male port with a Cajon® SS-4-VCR-4 male nut. Both
ports are used when the bed is used in a flowthrough mode of operation.
The maximum normal unloading temperature is 450°C, and the maximum unloading
pressure at temperature is 2.9 psia. Exceeding the 2.9 psia pressure at temperature will
impact the vessel service life.
When uranium is loaded to full stoichiometry with tritium to form UT3, it retains the decay
helium in the solid for about 300 days until the concentration of helium reaches
approximately 0.134 He:U, after which some of the helium will be released from the solid.
The helium release rate increases over a period of about 600 days, until it equalizes with the
helium generation rate.
The HTV Dissociation Pressure [32], P is
log Patm = -(4038.2/T) + 6.074
where T = temperature (K)
which implies
Patm = 10−(4038.2/T) + 6.074
The second equation for the HTV Dissociation Pressure is
log P psia = −(4038.2/T) + 7.2413
which implies
Ppsia = 10 −(4038.2/T) + 7.2413
WSRC conducted several tests on the HTV to determine the impact of an air ingress
incident. The results indicate that in the dehydride state the uranium reacted with both
oxygen and nitrogen in the air. The reaction stopped when the accumulation of argon and
moisture in the vessel reached atmospheric pressure and prevented additional air from
entering the vessel. The maximum temperature was approximately 200°C. If air is drawn
through the uranium continuously, a temperature higher than 1,000°C can be reached, and
damage to the vessel may occur.
6.2.3 Recommendations for Improvements for Product Containers
Both the PV and HTV containers are single-valve designs (although the HTV actually has
two valves; one for filling and one for evacuating), employing an SS-4HS-TW valve.
Selection of this valve was based in part on the favorable rating it received against valves of
similar size. It is rated at 315°C and 1000 psig. Additionally, the valve stem tip is Stellite™
spherical design, a desirable tip configuration. Although the leak rate is verified annually at
SRS, the employment of a single H-type valve close to the heat zone is not an optimal
design, as described in EH Technical Notice 94-01, Guidelines for Valves in Tritium Service,
and users should be prepared for potential leaks across the valve seat in addition to bellows
leaks.
Section 69
DOE-HDBK-1129-2008
75
Modifications to existing designs could be incorporated into future revisions. In addition to
valve overtorque protection and/or hardware upgrades, the HTV use of thin-walled SS 348
may lead to more than desired outgassing as the number of cycles accumulates. The
upgrading of material or jacketed design are potential options. Other design improvements
could include internal baffling and different (types, sizes, and locations) filters. An
operational practice of tracking and segregating containers that are used for high-purity
shipments and those used for other shipments (e.g., scrap shipments) would be beneficial in
ensuring the capability to ship War Reserve gas by not contaminating the U bed with mixed
isotopes.
6.3 Valve Container Operations
The use of two valves in series on containers filled with tritium that are to be disconnected
from the tritium apparatus on a routine basis has been in common use for several years.
When the failure of a single valve seat can result in the release of significant quantities of
tritium, two valves in series should be used. If the seat of a single valve develops a leak
during storage and the container port is uncapped, the tritium will be released into the
containment system through the failed valve seat.
Valve seat failure is often associated with damage to the seat caused by long exposure to
tritium or by misalignment resulting from improper operation or maintenance practices.
Double valves are recommended in all cases where the container valve seat is exposed to
tritium for long periods of time or is susceptible to misalignments. Additional guidance for
tritium valve selection, operation and maintenance is contained in the Office of Nuclear and
Facility Safety’s Technical Notice 94-01 and discussed in [33]. This document describes
desirable features and material for various tritium applications and lists recommended
practices.
It is assumed by experienced tritium handlers that valve seats can fail, and, therefore, the
basic strategy in double-valve use is depicted in Figure 6-1 and described as follows:
• The container is connected, leak tested, and filled with the required quantity of tritium,
and the second container valve is closed.
• The tritium between the second valve and the tritium supply is pumped away, and the
section is isolated and monitored for pressure rise.
• If a pressure rise indicates that the second valve seat is leaking, then the container is
emptied while connected to the manifold, and the valve seat is repaired.
• If no leak is detected, then the first valve is closed and the second valve is opened, and
the tritium trapped between the first valve and the second valve is pumped away. This
section is isolated and monitored for a pressure rise.
• If this test indicates that the first valve seat is leaking, the container is emptied, and the
valve seat is repaired.
• If no leak is detected, then the second valve is closed, the container is disconnected,
and the container port is capped and sealed.
• The container is transported to a new location or placed in storage as appropriate to the
task.
DOE-HDBK-1129-2008
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FIGURE 6-1. Use of double valve container
This leaves the container in the following condition:
• The tritium is trapped inside the container by the first valve, and the valve seat of the first
valve is exposed to tritium during storage or transport.
• The space between the first valve and the second valve has been evacuated and
Section 70
contains no significant quantity of tritium or other gases. The second valve seat is not
exposed to tritium during the storage or transport cycle.
• The space between the second valve and the container port cap contains glovebox gas
or air sealed into the void space by the port closure seal.
To make a reconnection to a manifold, the following steps apply:
• Before the container is reconnected to a manifold, the two valves are checked by hand
to make sure they are closed.
• The port is uncapped and connected to the manifold.
• The gas trapped in the space between the port and the manifold is pumped out, and the
connection is leak checked using a helium leak detector calibrated to detect a leak of
< 10-6 cc He/second.
• If the port connection is leaking, the leak is repaired, and the leak test is rerun.
After filling the container with
tritium, close V2, open V3,
and evacuate the port to the
tritium storage system.
Close V2 and V3 and
monitor for seat leak
across V2
V1 V2 V3
Monitor for V2 seat leak
Close V1
Close V2 and V3 and
remove tritium container and
cap tritium container and
port
Open V2 and monitor for
seat leak across V1
Open V3 and evacuate
port to tritium storage
V1 V2 V3
Monitor for V1 seat leak
V1 V2 V3
Container filled
with tritium
V1 V2 V3
V1 V2 V3
V1 V2 V3
DOE-HDBK-1129-2008
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• The first hand valve is opened and then closed to allow tritium from the container to
enter the void space between the two valves.
• The second hand valve is opened and then closed to allow the trapped tritium to expand
into the port volume.
• The outside of the port connection area can be sniffed with a tritium monitor. The
containment system tritium monitor may be observed for an increase in tritium
concentration to detect a tritium leak from the port connection into the containment
volume.
• If no leak is detected, then the two series valves may be opened, and the reconnection
is complete.
6.3.1 Tritium Apparatus, Isolation Valves, and Purge Ports
A “purge port” is a capped, sealed port connected through a valve to a potentially tritium-
contaminated volume. The purpose of a purge port is to provide a path, which can be used
to remove tritium-contaminated gases from the isolation volume prior to making a line break
at the component flanges to remove a component. If the tritium-contaminated gases are not
removed from the isolation volume, they will be released into the containment system when
the flange is unsealed. The released gases and outgassing from the isolation volume
surfaces will contaminate the containment volume gases. Following removal and
replacement of a component, the port is used to leak test the new component and flange
seals prior to placing the component in service.
Figure 6-2 is an illustration of two purge ports installed to allow evacuation of the volume
and leak testing of the flanges between two sets of valves, thus allowing isolation and
removal of a tritium-contaminated component. Note that the purge ports are part of the
permanently installed system, and are not part of the component.
The component is isolated with two valves on each side of the component, and a purge port
has been installed between each set of valves. The purge port allows evacuation of the
volume between the two valves to remove the tritium-contaminated gases from the isolation
volume prior to removal of the component.
Section 71
In operation, the two sets of valves are closed to isolate the component from the rest of the
tritium manifold. A vacuum pump is connected to the two purge ports. The purge port
valves are opened and the gases trapped between the isolation valves are evacuated to
remove the tritium-contaminated gases. In most applications, air is allowed to enter the
purged volume, and the evacuation operation is repeated. Other gases, such as argon and
nitrogen, may be used; however, air is usually more effective at decontaminating the
surfaces. Ambient air entering the purged volume contains several thousand parts per
million of normal water along with the nitrogen and oxygen. Some of the tritium and HTO on
the internal surfaces of the purged volume exchange with the hydrogen and water in the
ambient air and are pumped out during the purge cycle. This purge/backfill cycle is
repeated 3 to 6 times to remove as much of the tritium as possible before disconnecting the
component. Performance of three ambient air purge backfill cycles is typical, and, in
practice, more than 6 purge backfill cycles has not proven to be beneficial.
DOE-HDBK-1129-2008
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Isolation Valves
Component to be
removed/repaired
Isolation Valves
Connected
to the rest of
the T2
system
Evacuate
port volume;
check for
leaks
Purge Ports
Component to be
removed/repaired
Evacuate
isolation
valve
volume
Component flanges
Component to be
removed/repaired
Backfill with
air; repeat
evacuate
backfill cycle
as
necessary
Purge
with
air
Air
purge
valve
FIGURE 6-2. Purge ports and isolation valves
After the component has been removed and replaced, the new component is leak-tested
through the purge port before the isolation valves are opened. The sequence of operations
is as follows:
• The four component isolation valves are closed.
• The purge ports are uncapped and connected to a vacuum pumping system.
• The port volume is evacuated and leak checked.
• If no leaks are found, the purge port valves are opened, and the gases in the volume
between the isolation valves are evacuated to a tritium-contaminated waste gas
collection and removal system.
• The evacuation valve is closed, and air is allowed to enter the isolation volume through a
valve mounted on the maintenance manifold.
• The air inlet valve is closed. The ambient air is allowed to sit in the isolation volume for
a few minutes to allow the exchange of hydrogen and tritium to take place.
• The evacuation valve is opened, and the volume is again pumped out to the cleanup
system.
• This evacuation and/or backfill sequence can be repeated several times.
• The component is disconnected at the maintenance flanges and removed. The new
component is installed.
• To control outgassing from the removed component, blind flanges with installed purge
ports may be installed over the open end of the removed component.
• The new flange connections are leak tested through the purge ports. If the new flange
connections are not leak tight, they are repaired or replaced and retested.
DOE-HDBK-1129-2008
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• When the component and flanges are leak tight, the purge valves are closed,
disconnected from the leak test system, and capped.
• The component isolation valves are opened, and the new component is placed in
service.
Section 72
As is always the case when dealing with process quantities of tritium, adherence to
procedures is particularly important. If a large source (e.g., container) of tritium is connected
via valving to the piping used in evacuating, an inadvertent valve operation could result in a
significant loss. One such incident occurred at Mound, in which a valve was inadvertently
opened, resulting in a loss of approximately 10 grams of tritium to the cleanup system via
the evacuation header.
6.4 Receiving Tritium
Tritiated material may be delivered to a receiving area, a receiving storage area, or directly
to the tritium-handling facility. A brief description of the DOE regulatory requirement is as
follows:
• The Receiving Area and/or Receiving Storage Area must be inside a posted Controlled
Area.
• The Receiving Area and/or Receiving Storage Area must be inside a posted RMA.
• The Receiving Area and/or Receiving Storage Area must be posted to reflect the
radiological hazard that exists due to the quantity and types of nuclear material received
and/or stored.
• The boundary of the Controlled Area and the RMA can be the same boundary.
The area where the tritiated material is being kept while waiting to be transported from the
Receiving Area must be posted as a Controlled Area and an RMA while the tritiated material
is present. When the tritiated material is moved to a Storage Area, the signs can be
removed. While in the Receiving Area and/or Storage Area, the material must remain in the
certified shipping container. No tritiated material handling or unpacking can take place in
this area.
As long as the material remains packaged in the approved container (includes certification),
the quantities are not a facility issue during the receiving process. However, the total site
quantities, including the packaged material, cannot exceed limits specified in the site’s EIS.
Site and facility management may have internal requirements and limits associated with the
receipt and storage of nuclear materials. In general, as long as the material remains in the
approved shipping package it can be received, stored, and transported per requirements.
The container should be radiologically surveyed to determine radiological posting needs and
to ensure it is safe for storage. When the material is removed from the receiving area, the
RMA, and Controlled Area, and radiological sign may be removed.
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6.5 Storage of Packaged Tritiated Materials
The packaged tritiated materials may be transported to an approved storage area while
awaiting transport to a tritium-handling operations area or shipment. While in the Storage
Area, the same rules apply as those in the Receiving Area.
• The Storage Area must be inside a posted Controlled Area.
• The Storage Area must be posted to reflect the radiological hazard that exists due to the
quantity and types of nuclear material stored.
• Periodic surveys must be performed and be sufficiently detailed to determine that
surface contamination levels are not exceeded, airborne releases are not occurring, and
packages are not leaking.
6.6 Interim Storage of Tritiated Materials
6.6.1 Background
Tritiated material pending further handling, whether processing, recovery, repackaging, or
shipping, is stored in various locations and configurations. This section delineates the
container configurations for packaging requirements applied to interim storage. Interim
storage is on-site storage of tritium/tritiated materials outside of an approved engineered
contamination barrier.
Section 73
The DOE response, in conjunction with DNFSB staff concurrence, to DNFSB
Recommendation 2005-1 on packaging of nuclear materials in interim storage, exempted
tritium from inclusion in the scope of DOE M 441.1-1 and instead committed to address
interim storage requirements in DOE-HDBK-1129-2007. These requirements, in section
6.6.2., are the only requirements contained in DOE-HDBK-1129-2007. These requirements
apply only to DOE tritium facilities under NNSA, EM, and NE cognizance for implementation
of DNFSB Recommendation 2005-1 and not to other organizations using this Handbook as
a guide.
The primary intent of Recommendation 2005-1 is the protection of workers from dose
exposure from deterioration of packaging or handling mishaps from nuclear material that are
in interim storage. Due in part to the physical, chemical, and radiological differences
between tritium and the actinides (which both the DNFSB Recommendation and DOE M
441.1-1 address), interim storage repackaging requirements for tritium consistent with the
underlying philosophy, but not necessarily identical to the Manual, are described in section
6.6.2. Additionally, since historical data indicate that worker exposures from tritium have
occurred as a result of inappropriate opening of containers, especially those containing
legacy waste, operational restrictions were also considered in the development of the tritium
requirements which exceed the span of DOE M 441.1-1 Although not a requirement, a
double-valve design, as discussed in section 6.2.3, is recommended for inclusion in the next
generation of product vessel designs; this will allow the use of preferred container
loading/unloading practices discussed in section 6.3.
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6.6.2 Requirements
The requirements of this section are compatible with the containment philosophy discussed
in detail in Sections 4.1, 5.2, and in the Definitions section. The primary focus of the
following requirements is the protection of workers from unintended doses due to releases
from containers. As such, in addition to mechanical-related failures of the containers,
additional release mechanisms (such as opening gas containers in an unprotected area and
handling mishaps such as knocking over and spilling tritides from hydride-bearing
containers) were considered in formulating the following two requirements in this section.
1) Opening of primary tritium containers, especially those containing legacy material,
should be done in a fume hood or glovebox. Other radiological controls can also be
used if approved by the cognizant site radiological organization. These controls may
include the use of tents, glove bags, elephant trunks, or supplied-air PPE.
2) Tritiated material residing in containers or locations not specifically listed in the
“Exclusions to DOE-HDBK-1129 packaging requirements” section below must be
packaged to meet interim storage requirements. The function of the interim storage
package is to retain the nuclear material during storage. The interim storage package is
defined as an assembly of one or more containers that meets a DOE directive or
Standard. The package can consist of a single container or be a double-container
configuration with primary and secondary containers. Containers should be constructed
consistent with the general design parameters of Chapter 5 of this Handbook and must
not violate the material compatibility principles. The package must meet both of the
following two leak rates to satisfy interim storage requirements:
Section 74
a) prior to the drop test, the leak rate on the package as measured by a method
comparable to those described in ANSI-N14.5-1977 must be equal to or less than
1 x 10-7 ref cm3/sec, and
b) leak no more than 6.5 Ci per hour after dropping the package, as a unit, from the
working height (for the subject package) at the facility or four feet, at a minimum.
6.6.3 Exclusions to the Packaging Requirements in DOE-HDBK-1129
1. Tritium that is located within engineered contamination barriers as defined in DOE M
441.1 1 (e.g., within gloveboxes, or fume hoods (laminar flow)). Normally ventilated
rooms, however, are not considered contamination barriers. Additionally, rooms or
buildings serviced by an active tritium cleanup system are not considered contamination
barriers for the worker. Engineered contamination barriers are on occasion defeated for
operational reasons or maintenance acts. Due to the relatively short time frame involved,
(compared to interim storage) no compensatory measures are required for the tritium
residing within the affected contamination barrier during these periods.
2. Tritium that is located within certified4 shipping containers (e.g., H1616 and UC-609 (and
Bulk Tritium Shipping Package (BTSP), which is the UC-609 replacement upon
certification) or in a PV container.
4 Certified means currently valid, and does not include those shipping containers whose certification
period has lapsed.
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3. Packaged tritiated material that has been declared waste per the local site procedure
and that has been packaged to meet DOT or Waste Acceptance Criteria.
4. Tritium in containers known to possess less than A2 (1,100 Ci) releasable quantities.
Container heels and tritium absorbed onto metal storage beds are not normally
releasable and therefore are not included when determining whether A2 quantities are
involved.
5. Tritium in any form contained in weapons and prototypical designed weapons
components.
Tritium packaging that is being handled under radiological (protective) control (e.g.,
containers that are in the process of connecting/disconnecting to a gloveport, such as tritium
in a LP-50 connecting to a gloveport for unloading or for containers undergoing
decontamination) are excluded from the packaging requirements for the period of the
handling evolution itself. Handling is also inclusive of movement between engineered
contamination barriers.
6.6.4 Priority for Working off Tritium Containers
Safe handling and storage of nuclear material at DOE facilities relies on the use of adequate
containers to prevent worker contamination and uptake of radioactive material. The
combinations of material and container configurations that were adequate for the originally
anticipated period of storage or for a particular use, may no longer be adequate. Facilities
should prioritize the current inventory of tritiated material non-conforming containers (that do
not meet any of the packaging exclusions above) based on the inventory and hazards of the
material taking cognizance of the relevant physical, reactive, and radiological properties as
well as the interactions with the existing and projected container conditions. Particular
attention should be directed toward the condition of the container penetration including the
weld, fittings and valve(s). Containers that cannot be verified to contain tritium compatible
sealing surface material (see Section 5.1) in penetration fittings and valves should be
dispositioned first. LP-50s containing substantial inventory would also be high priority
containers to be worked followed by other non-conforming containers including molecular
sieves. LP-50s and AL-M1-5s must have compensatory measures in place while awaiting
repackaging, unloading or waste disposition, including:
Section 75
a) associated secondaries/caps are in place and functioning and
b) the stored containers are under an approved surveillance program (the
secondaries/caps can be removed during surveillance checks) whose objective is the
identification of early indication of container degradation. Leak rate testing (normally
employing a sniff test method) must be an integral part of the surveillance program.
Site plans are to be developed that implement a schedule based on risk for dispositioning
tritium residing in non-conforming containers not meeting any of the five exclusions to the
packaging requirements.
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7.0 PACKAGING AND TRANSPORTATION
7.1 General Administrative Packaging and Transport Requirements
As a hazardous material, tritium is subject to the DOT Hazardous Materials Regulations
(HMRs) in 49 CFR Parts 106 through 180. These regulations specify the shipping paper,
marking, labeling, placarding, and packaging requirements for hazardous material. The
safety requirements for packaging are dependent on the type, form, and quantity of tritium,
per DOE O 460.1B, Packaging and Transportation Safety. Additional packaging and
transportation regulations for radioactive material are found in 10 CFR 71 and in DOE O
461.1A, Packaging and Transfer or Transportation of Materials of National Security Interest.
However, tritium in concentrations less than 1E+06 Bq/g (2.7E-05 Ci/g) and no more than
1E+09 Bq (2.7 E-02 Ci) in a consignment is considered an exempt quantity and not subject
to DOT regulations.
Tritium may also meet the definition of other hazard classes in 49 CFR 173; e.g., tritium gas,
in certain conditions, may meet the definition of a flammable gas. Tritium-contaminated
hazardous waste will be subject to the requirements for hazardous waste shipments.
Organizational responsibility for the packaging and transport of hazardous materials such as
tritium needs to be clearly defined. Written procedures must be developed for the
operations that package and ship tritium. DOT hazardous materials regulations
(49 CFR 172.704) require initial and recurrent general awareness/familiarization, safety-
related, and function-specific training for hazardous materials workers.
There are also pre-transport requirements applicable to hazardous/mixed wastes that
address packaging, labeling, marking, placarding, and accumulation time provisions which
can be found in 40 CFR 262.30 – 34.
The guidance provided in this Handbook assumes that tritium is the only radioactive material
in the packages. If another radionuclide is present, additional requirements may apply to
the packaging and transport of the combination of radioactive materials.
7.2 Selection of Proper Packaging
The package types for radioactive material are limited-quantity excepted package, low-
specific-activity (LSA), surface-contaminated object (SCO), Type A, and Type B. The
definitions of the package types are listed in order of increasing allowable radioactivity
material limits. The Type A values related to these packages are found in the table of 49
CFR 173.435.
• Limited-Quantity Excepted Package: The requirements for a limited-quantity package of
tritium are as follows:
– The radiation level at any point on the external surface of the package does not
exceed 0.005 milliSievert (mSv)/hr (0.5 mrem/hr).
– The amount of radioactive material is no more than the limit in 49 CFR 173.425 (see
Table 7-1).
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Section 76
– The package meets the general design requirements for radioactive materials
packaging from 49 CFR 173.410 (see Section 7.2.3).
– The nonfixed (removable) contamination on the external surface of the package does
not exceed the limits in 49 CFR 173.443 (a) (0.41 Bq/cm2 or 22 dpm/cm2 for tritium).
– The outside of the inner or outer packaging is marked “Radioactive.”
– The outside of each package must be marked with the applicable four digit UN
identification number for the material preceded by the letters UN.
– The outside package be labeled with the designated International Air Transport
Association (IATA) “Radioactive Material, Excepted Package” handling label.
The advantage to using the limited-quantity excepted packaging is that it is excepted
from specification packaging, marking, labeling, and, if not a hazardous substance or
hazardous waste, it is also excepted from the shipping paper and certification
requirements of the HMR.
• LSA is a quantity of Class 7 (radioactive) material with limited specific activity. Shielding
materials surrounding the LSA material may not be considered in determining the
estimated average specific activity of the package contents. The definition for LSA was
revised into three groups: LSA-I, LSA-II, and LSA-III. The definitions for these groups
are provided below.
– LSA-I is defined as contaminated earth, concrete, rubble, other debris, and activated
material in which the radioactive material is essentially uniformly distributed and the
average specific activity does not exceed 10-6A2/g. For tritium, the maximum
allowable specific activity in these materials for LSA-I is 4 x 10-5 TBq/g (0.001 Ci/g, 1
Ci/kg, or 2.2 lb/Ci).
– LSA-II is defined as either water with tritium concentration up to 0.8 TBq/L (20.0 Ci/L)
or material in which Class 7 (radioactive) material is essentially uniformly distributed
and the average specific activity does not exceed 10-4A2/g for solids and gases and
10-5A2/g for liquids. For tritium-contaminated solids or gases, the maximum
allowable specific activity is 0.004 TBq/g (0.1 Ci/g, 100 Ci/kg). The resulting limit for
tritium-contaminated liquid (other than tritiated water) is 4 x 10-4 TBq/g (0.01 Ci/g).
– LSA-III is defined as solids such as consolidated wastes or activated materials that
meet the testing requirements of 49 CFR 173.468 (water leach test) and the
following requirements:
The Class 7 (radioactive) material is essentially uniformly distributed throughout
a solid or a collection of solid objects or essentially uniformly distributed in a solid
compact binding agent (such as concrete, bitumen, or ceramic).
The Class 7 (radioactive) material is relatively insoluble, or is intrinsically
contained in a relatively insoluble material, so that, even under loss of packaging,
the loss of Class 7 (radioactive) material per package by leaching when placed in
water for seven days would not exceed 0.1 A2. The resulting limit for tritium is 4
TBq (110 Ci).
The average specific activity of the solid does not exceed 2 x 10-3A2/g. The
resulting limit for tritium is 0.08 TBq/g (2.16 Ci/g).
The advantage to transporting material as LSA is that, for domestic transportation of an
exclusive use shipment that is less than an A2 quantity, bulk packagings may be used. Also
these shipments are excepted from the marking and labeling requirements of 49 CFR 173
DOE-HDBK-1129-2008
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Subpart I. However, the exterior of each package of radioactive materials must be stenciled
or otherwise marked “RADIOACTIVE—LSA.”
Section 77
• SCO is similar to LSA but is limited to a solid object that is not itself radioactive but has
Class 7 (radioactive) material distributed on any of its surfaces. SCO is divided into two
groups, SCO-I and SCO-II. The definitions are provided below.
— SCO-I is defined as a solid object that meets all of the following requirements:
The nonfixed contamination on the accessible surface averaged over 300 cm2 (or
the area of the surface if less than 300 cm2) does not exceed 4 Bq/cm2
(104 µCi/cm2) for beta emitters such as tritium.
The fixed contamination on the accessible surface averaged over 300 cm2 (or the
area of the surface if less than 300 cm2) does not exceed 4 x 104 Bq/cm2
(1 µCi/cm2) for beta emitters such as tritium.
The nonfixed plus the fixed contamination on the inaccessible surface averaged
over 300 cm2 (or the area of the surface if less than 300 cm2) does not exceed
4 x 104 Bq/cm2 (1 µCi/cm2) for beta emitters such as tritium.
— SCO-II is defined as a solid object on which the limits for SCO-I are exceeded and
meets all of the following requirements:
The nonfixed contamination on the accessible surface averaged over 300 cm2 (or
the area of the surface if less than 300 cm2) does not exceed 400 Bq/cm2
(10-2 µCi/cm2) for beta emitters such as tritium.
The fixed contamination on the accessible surface averaged over 300 cm2 (or the
area of the surface if less than 300 cm2) does not exceed 8 x 105 Bq/cm2
(20 µCi/cm2) for beta emitters such as tritium.
The nonfixed plus the fixed contamination on the inaccessible surface averaged
over 300 cm2 (or the area of the surface if less than 300 cm2) does not exceed
8 x 105 Bq/cm2 (20 µCi/cm2) for beta emitters such as tritium.
Also, as with bulk LSA, for domestic transportation of an exclusive use shipment of SCO that
is less than an A2 quantity, bulk packagings may be used. And these shipments are
excepted from the marking and labeling requirements of 49 CFR 173 Subpart I. However,
the exterior of each package must be stenciled or otherwise marked “RADIOACTIVE—
SCO.”
• Type A packages are limited to an A2 quantity of radioactivity. The A2 limit for tritium is
40 TBq (1,100 Ci) per package. The physical form of the package contents must be
within the envelope of the contents used during testing of the package. Type A
packages are significantly less expensive and much easier to obtain than Type B
packages.
• Type B packages provide the highest level of safety features of all types of radioactive
material packaging. The contents are limited by the requirements of the Certificate of
Compliance (CoC) for the package. The CoC is issued by the agency that certifies that
the package meets the Type B requirements.
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7.2.1 Form and Quantity of Tritium
The form of the tritium affects the quantity of tritium that may be shipped in one package and
the design and testing requirements for the packaging. Table 7-1 is a comparison of the
allowable quantities of tritium in various package types. Quantities based on A1 values for
“Special Form” certified packages.
TABLE 7-1. Allowable quantities of tritium per 49 CFR 173
Form
Shipping
Package
Type
Maximum Quantity/
Specific Activity of
Tritium per Package
Comments
All
physical
forms
None • Activity concentration
for exempt material of
10-6 TBq and
• Activity limit for
exempt consignment
of 10-3 TBq (0.027 Ci)
Both conditions must be satisfied.
Solid Limited
quantity
0.04 TBq (1.1 Ci)
Section 78
LSA-I 4 x 10-5 TBq/g (0.001Ci/g)
LSA-II 0.004 TBq/g (0.1 Ci/g) The conveyance limit* for combustible solids is 4,000
TBq (1.1 x 105 Ci)
LSA-III 0.08 TBq/g (2.16 Ci/g)
SCO-I Limit based on surface
contamination
The maximum nonfixed contamination on accessible
surfaces is 4 Bq/cm2 (10-4 µCi/cm2). The maximum
fixed contamination on accessible surfaces is 4 x 104
Bq/cm2 (1 µCi/cm2). The total surface contamination
on the inaccessible surfaces is limited to 104 Bq/cm2
(1 µCi/cm2). The conveyance limit* is 4,000 TBq (1.08
x 105 Ci)
SCO-II Limit based on surface
contamination
The maximum nonfixed contamination on accessible
surfaces is 400 Bq/cm2 (10-2 µCi/cm2). The maximum
fixed contamination on accessible surfaces is 8 x 105
Bq/cm2 (20 µCi/cm2). The total surface contamination
on the inaccessible surfaces is limited to 8 x 105
Bq/cm2 (20 µ Ci/cm2). The conveyance limit* is 4,000
TBq (1.08 x 105 Ci)
Type A 40 TBq (1100 Ci)
Type B Limited by CoC for the
package
The Type B UC-609 package is limited to 150 g of
tritium
Liquid Limited
quantity
(tritiated
water)
37 TBq (1000 Ci)
3.7 TBq (100 Ci)
0.037 TBq (1 Ci)
< 0.0037 TBq/L (0.1 Ci/L)0.0037 to 0.037 TBq/L(0.1 to
1.0 Ci/L) >0.037 TBq/L (1.0 Ci/L)
Limited
quantity
(other
liquids)
0.004 TBq (0.108 Ci)
LSA-II 4 x 10-4TBq/g (0.01 Ci/g) The conveyance limit* is 4,000 TBq (1.1 x 105 Ci)
Type A 40 TBq(1100 Ci)
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Note that the 10/01/05 edition of 49 CFR 173 changed the A2 quantity for tritium from 1,080 to 1,100 Ci
*The conveyance limit is the limit per trailer if highway transportation is used.
7.2.2 Evaluation of Approved Packaging
Tritium-contaminated solid waste is typically packaged in DOT Type A, Specification 7A
open head 55-gallon drums or Type A metal boxes. The maximum amount of tritium that
may be shipped in a Type A package is 40 TBq (1,100 curies).
Packages containing over 40 TBq of tritium must meet the Type B container requirements.
These containers are few in number, and, compared to Type A packages, expensive to
manufacture and use. If Type B packages are to be considered for shipments, the CoC
should be reviewed carefully against the form and quantity of tritium to be shipped.
The UC-609 and TRUPACT-II are the currently approved Type B containers for tritium and
tritium-containing materials. The UC-609 is a drum type container with a limited volume
containment vessel. The containment vessel is authorized for containers of tritium gas,
tritiated water, or tritium-containing solids and is limited to 150 grams of tritium. The
TRUPACT-II is authorized for fourteen DOT Type A, Specification 7A 55-gallon drums or
two Standard Waste Boxes. The authorized waste forms for the TRUPACT-II are solids or
solidified liquids.
Tritium waste that meets the definition of LSA or SCO may be shipped domestically in
industrial packagings or DOT Type A, Specification 7A packagings.
7.2.3 Minimum Requirements for Packaging
The design requirements for a radioactive materials package are located in
49 CFR 173.410. These requirements include the following:
• The package can be easily handled and properly secured in or on a conveyance during
transport.
• The materials of construction of the packaging and any components or structure will be
physically and chemically compatible with each other and with the package contents.
The behavior of the packaging and the package contents under irradiation will be taken
into account. Irradiation of materials is not a concern for tritium however material
compatability as discussed in Section 5 must be considered.
Section 79
• All valves through which the package contents could escape will be protected against
unauthorized operation.
• Each lifting attachment that is a part of the package must be designed with a minimum
safety factor of five, based upon breaking strength, when used to lift the package in the
Type B Limited by CoC for the
package
The Type B UC-609 package is limited to 150 g of
tritium
Gas Limited
Quantity
0.8 TBq (21.6 Ci)
LSA-II 0.004 TBq/g (0.1 Ci/g The conveyance limit* is 4,000 TBq (1.1 x 105 Ci)
Type A 40 TBq (1100 Ci)
Type B Limited by CoC for the
package
The Type B UC-609 package is limited to 150 g of
tritium
DOE-HDBK-1129-2008
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intended manner, and it must be designed so that failure of any lifting attachment under
excessive load would not impair the ability of the package to meet other requirements of
49 CFR Subpart I. Any other structural part of the package, which could be used to lift
the package, must be capable of being rendered inoperable for lifting the package during
transport or must be designed with strength equivalent to that required for lifting
attachments.
• The external surfaces, as far as practicable, will be free from protruding features and will
be easily decontaminated.
• The outer layer of packaging will avoid, as far as practicable, pockets or crevices where
water might collect.
• Each feature that is added to the package will not reduce the safety of the package.
• The package will be capable of withstanding the effects of any acceleration, vibration, or
vibration resonance that may arise under normal conditions of transport without any
deterioration in the effectiveness of the closing devices on the various receptacles or in
the integrity of the package as a whole and without releasing the nuts, bolts, or other
securing devices even after repeated use.
For transport by air, the following requirements apply:
• The integrity of containment will not be impaired if the package is exposed to ambient
temperatures ranging from -40°C (-40°F) to 55°C (131°F).
• The temperature of the accessible surfaces of the package will not exceed 50°C (122°F)
at an ambient temperature of 38°C (100°F) with no account taken for insulation;
• The surface temperature of packages is limited to 38°C (100°F) for nonexclusive
shipments and 50°C (122°F) for exclusive shipments. This requirement should not be
an issue with tritium shipments based on the low decay heat for tritium.
• Packages containing liquids will be capable of withstanding, without leakage, an internal
pressure that produces a pressure differential of not less than 95 kPa (13.8 lb./square
inch).
The requirements for Type A packages include the ability to withstand the following tests
specified in 49 CFR 173.465:
• Water spray–simulation of 2 inches of rainfall per hour for at least one hour.
• Free drop–a drop of 1 to 4 feet, depending on the package mass, onto a hard surface.
• Stacking–compressive load of five times the package mass for a minimum of 24 hours.
• Penetration–this test is performed by dropping a 6 kilogram, 3.2 centimeter steel bar
onto the weakest point of the package from a minimum height of one meter.
Packages designed for liquids and gases are required to pass a more rigorous free drop and
penetration test than solids.
7.2.4 Onsite versus Offsite Shipments
Offsite shipments of hazardous materials or any shipment that meets the requirements of
“transportation in commerce” must comply with the HMR. DOT provided a clarification of
transportation in commerce in a 1991 letter to DOE. The following is excerpted from the
letter:
Section 80
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Transportation on (across or along) roads outside of Government properties
generally is transportation in commerce. Transportation on government properties
requires close analysis to determine whether it is in commerce. If a road is used by
members of the general public (including dependents of Government employees)
without their having to gain access through a controlled access point, transportation
on (across or along) that road is in commerce. On the other hand, if access to a
road is controlled at all times through the use of gates and guards, transportation on
that road is not in commerce.
One other means of preventing hazardous materials transportation on Government
property from being in commerce is to temporarily block access to the section of the
road being crossed or used for that transportation. The road would have to be
blocked by persons having the legal authority to do so and public access to the
involved section of road would have to be effectively precluded.
Attachment 1 to DOE O 460.2A, Departmental Materials Transportation and Packaging
Management, requires that contractors comply with the HMR for onsite materials transfers
or comply with an approved site- or facility specific Transportation Safety Document that
describes the methodology and compliance process to meet equivalent safety for any
deviation from the HMRs.
7.3 Package Loading and Preparation for Shipment
7.3.1 Disassembly and Inspection of the Package
DOE O 460.2A requires that DOE contractors inspect incoming hazardous materials
shipments for damage or loss and evidence of leakage. Radioactive material shipments
shall be inspected for external surface contamination and dose rate.
Additionally, pursuant to 49 CFR 173.474, prior to the first use of any radioactive materials
packaging, the offerer must determine the following:
• The packaging meets the quality of design and construction requirements as specified in
49 CFR Subpart I.
• The effectiveness of the shielding, containment, and, when required, the heat transfer
characteristics of the package, are within the limits specified for the package design.
Finally, for Type B packages pursuant to10 CFR 71.85 the following preliminary
determinations prior to first use of any packaging are required:
• Ascertain that there are no cracks, pinholes, uncontrolled voids, or other defects that
could significantly reduce the effectiveness of the packaging.
• Where the maximum normal operating pressure will exceed 35 kPa (5 lb/in2) gauge, the
package user shall test the containment system at an internal pressure at least 50
percent higher than the maximum normal operating pressure to verify the capability of
that system to maintain its structural integrity at that pressure.
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7.3.2 Package Loading and Assembly Operations
49 CFR 173.475 requires routine determinations during the loading of a radioactive
materials package. Before each shipment of any Class 7 (radioactive) material, the offerer
must ensure, by examination or appropriate tests, the following:
• The packaging is proper for the contents to be shipped.
• The packaging is in unimpaired physical condition, except for superficial marks.
• Each closure device of the packaging, including any required gasket, is properly
installed, secured, and free of defects.
• Each special instruction for filling, closing, and preparation of the packaging for shipment
Section 81
has been followed.
• Each closure, valve, or other opening of the containment system through which
radioactive material might escape is properly closed and sealed.
• The internal pressure of the containment system will not exceed the design pressure
during transportation.
• For fissile material, each moderator and neutron absorber, if required, is present and in
proper condition
Additionally, for Type B packagings,
• Any system for containing liquid is adequately sealed and has adequate space or other
specified provision for expansion of the liquid.
• Any pressure relief device is operable and set in accordance with written procedures.
• Any structural part of the package that could be used to lift or tie down the package
during transport is rendered inoperable for that purpose, unless it satisfies the design
requirements of 10 CFR 71.45. (See Section 7.2.3.)
• Accessible package surface temperatures will not exceed the limits in 10 CFR 71.43 at
any time during transportation. (See Section 7.2.3.)
7.3.3 Leak Testing
Leak testing (normally a helium leak test) is required for radioactive materials shipments in
Type B packages. The package must be leak-tight (1 x 10-7 reference cm 3/s with a test
sensitivity of ≤ 5 x 10-8 reference cm3/s) as defined by American National Standards Institute
(ANSI) N14.5. There is no longer a requirement for a total integrated leakage test on Type B
package containment vessels provided that the non-removable parts of the contaminated
vessel, i.e., the seals, have not been modified or disturbed per the current version of the
ANSI standard. Assembly verification and maintenance verification leak testing
requirements will be noted in the CoC for the Type B package. Packages that contain liquid
in excess of the A2 quantity for tritium (40 TBq or 1,100 Ci) and intended for air shipment
must be tested to show that they will not leak under an ambient atmospheric pressure of not
more than 25 kPa, absolute (3.6 psia). The test must be conducted to determine
compliance with this requirement on the entire containment system or on any receptacle or
vessel within the containment system.
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7.3.4 Preparation for Shipment
For each shipment of more than 40 TBq (1,100 Ci) of radioactive material, DOE O 460.2A
requires the contractor to notify the shipment consignee of the dates of the shipment, the
expected date of arrival, and any special loading or unloading instructions. Placarding for
tritium shipments is required if the packages are labeled with Radioactive Yellow III labels or
for exclusive use shipments of low specific activity tritium and surface contaminated objects
with tritium transported in accordance with 49 CFR173.427(b)(4) and (5) or (c). Marking,
labeling, placarding and shipping paper requirements from 49 CFR 172 need to be
evaluated for each shipment of hazardous materials.
7.4 Documentation and Records
The record may be the original or a reproduced copy. A microform may be used provided
that authorized personnel authenticate the copy. The record may also be stored in
electronic media with the capability for producing legible, accurate, and complete records
during the required retention period. Each record must be legible throughout the retention
period specified by regulation. Records such as letters, drawings, and specifications must
include all pertinent information such as stamps, initials, and signatures. The contractor
shall maintain adequate safeguards against tampering with and loss of records. DOE O
414.1C contains more detail on records and documentation.
Section 82
The documents and records requirements of 10 CFR 830.120 state that “Documents shall
be prepared, reviewed, approved, issued, used and revised to prescribe processes, specify
requirements, or establish design. Records shall be specified, prepared, reviewed,
approved and maintained.”
7.4.1 Package Documentation for Type A and B
Each contractor who transports licensed material outside of the confines of its plant or other
place of use, or who delivers licensed material to a carrier for transport, shall comply with
the applicable requirements of the regulations appropriate to the mode of transport of DOT
in 49 CFR Parts 170 through 189.
• The contractor should particularly note DOT regulations in the following areas:
– Packaging - 49 CFR 173, Subparts A and B and paragraphs 173.401 through
173.478.
– Marking and labeling - 49 CFR 172, Subpart D and paragraphs 172.400 through
172.407; 172.436 through 172.440.
– Placarding - 49 CFR 172.500 through 172.519, 172.556 and Appendices B and C.
– Monitoring - 49 CFR 172, Subpart C.
– Accident reporting - 49 CFR 171.15 and 171.16.
– Shipping papers - 49 CFR 172, Subpart C.
• The contractor should also note DOT regulations pertaining to the following modes of
transportation:
– Rail - 49 CFR 174, Subparts A-D and K.
– Air - 49 CFR 176, Subparts A-D and M.
– Vessel - 49 CFR 176, Subparts A-D and M.
DOE-HDBK-1129-2008
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– Public Highway - 49 CFR 177.
7.4.2 Additional Type B Package Documentation
In addition to Type A package requirements, Type B packages have documentation
requirements defined in 49 CFR 173.
49 CFR 173.403 – Definitions
• Type B (U) package means a Type B packaging that, together with its radioactive
contents, for international shipments requires unilateral approval only of the package
design and of any stowage provisions that may be necessary for heat dissipation.
• Type B (M) packaging means a Type B packaging, together with its radioactive
contents, that for international shipments requires multilateral approval of the
package design, and may require approval of the conditions of shipment. Type B
(M) packages are those Type B package designs which have a maximum normal
operating pressure of more than 700 kilopascals per square centimeter (100 psi
gauge) or a relief device which would allow the release of Class 7 (radioactive)
material to the environment under the hypothetical accident conditions specified in
10 CFR Part 71.
49 CFR 173.473 – Requirements for foreign-made packages.
• In addition to other applicable requirements of this subchapter, each shipper of a foreign-
made Type B, Type B (U), Type B (M), or fissile material package for which a competent
authority certificate is required by the IAEA Regulations for the Safe Transport of
Radioactive Materials, Safety Series No. 6 should also comply with the requirements in
49 CFR 173.473.
7.5 Quality Assurance/Control Requirements
7.5.1 DOT Quality Control Requirements
Quality control requirements for packaging and transportation are defined in 49 CFR 173.
49 CFR 173.474 – Quality control for construction of packaging
• Prior to the first use of any packaging for the shipment of radioactive material, the
shipper shall determine that
– The packaging meets the quality of design and construction requirements as
specified in this subchapter; and
– The effectiveness of the shielding, containment, and, when required, the heat
transfer characteristics of the package, are within the limits specified for the package
design.
Section 83
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49 CFR 173.475 – Quality control requirements prior to each shipment of radioactive
materials.
• Before each shipment of any radioactive materials package, the shipper shall ensure by
examination or appropriate tests, that
– The package is proper for the contents to be shipped;
– The package is in unimpaired physical condition, except for superficial marks;
– Each closure device of the packaging, including any required gasket, is properly
installed, secured, and free of defects;
– Each special instruction for filling, closing and preparation of the packaging for
shipment has been followed;
– Each closure, valve, or other opening of the containment system through which the
radioactive content might escape is properly closed and sealed;
– Each packaging containing liquid in excess of an A2 quantity and intended for air
shipment has been tested to show that it will not leak under an ambient atmospheric
pressure of not more than 0.25 atmosphere, absolute, (0.25 kilograms per square
centimeter or 3.6 psia). The test must be conducted on the entire containment
system, or on any receptacle or vessel within the containment system, to determine
compliance with this requirement.
– The internal pressure of the containment system will not exceed the design pressure
during transportation; and
– External radiation and contamination levels are within the allowable limits specified in
this subchapter.
7.5.2 Quality Assurance Requirements for Type B Packages
Quality assurance requirements for the use and maintenance of Type B packages are
defined in 49 CFR 173.
8.0 TRITIUM WASTE MANAGEMENT
The regulations governing waste are complex. It is important to understand the basic
concept of “waste” and the difference between waste, low-level (radioactive) waste, sanitary
land fill waste, reusable equipment, usable materials, and scrap. The following provides a
guideline for defining waste. It should be noted that tritium-containing materials, whether or
not they are defined as waste, must be managed in accordance with applicable
requirements, as discussed in Chapter 3.0.
• All materials, whether inside or outside a radiological or nuclear facility, which are of
negligible or no economic value, considering the cost of recovery, are waste.
• Low-level radioactive waste is radioactive waste that is not high-level radioactive waste,
spent nuclear fuel, transuranic waste, byproduct material (as defined in section 11e.(2)
of the AEA, as amended), or naturally occurring radioactive material, and that has
residual radioactive material concentrations above the approved DOE authorized
release limit (DOE Order 5400.5 Chg 2).
DOE-HDBK-1129-2008
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• Sanitary landfill waste, which has no value and is below the unrestricted release limit, is
waste and may be disposed of in a DOE sanitary landfill. Disposal of this waste at a
non-DOE sanitary landfill may be done after notifying the appropriate state agency of the
DOE authorized limits for this activity.
• Reusable equipment, such as computers, tools, electrical instruments, and drill presses,
which can be used if released without restriction from the facility and has value, is not
waste. If the equipment is contaminated above the unrestricted release limit and can be
transferred and used at another radiological or nuclear facility, it is not waste.
• Usable materials, such as nails, bolts, nuts, sheetrock, plywood, plastic sheeting,
Section 84
barrels, decorative rock, sand, gravel, brick, and unused chemicals, which can be used if
released without restriction from the facility and have value, are not waste. If the
material is contaminated above the unrestricted release limit and can be transferred and
used at another radiological or nuclear facility, it is not waste.
• Scrap, such as scrap nonprecious metal, scrap precious metal, scrap wood, and scrap
chemicals, which can be sold as scrap if released without restriction from the facility and
has value, is not waste.
8.1 Approved Limits for the Release of Contaminated Materials and Property
Containing Residual Radioactive
For release and disposal, materials that exhibit radioactive surface contamination less than
the values in the revised Figure IV-1 of DOE Order 5400.5 Chg 2 fall into three categories.
• Category 1 Disposal in a DOE or non-DOE sanitary landfill
• Category 2 Disposal and/or treatment in a DOE or non-DOE RCRA treatment, storage,
and disposal facility
• Category 3 Transfer of ownership (either by sale or other means) to members of the
public
The Category 1 materials may be released or disposed of without further regard to residual
radioactivity if they are at or below the values specified in the revised Figure IV-1 of DOE
Order 5400.5 Chg 2. Site policies and procedures should clearly describe the use of these
values and how other requirements of the Order (such as ALARA, survey measurement
recordkeeping, and compliance with the specific requirements of the disposal facility) are
met. Disposal at a non-DOE sanitary landfill must meet the same requirements as waste
disposed at a DOE sanitary landfill, and the appropriate state agency must be notified of the
DOE-authorized limits for this activity.
Category 3 material must meet similar requirements as Category 1 material, and the
appropriate coordination with the state agency and/or NRC Region must be carried out.
8.1.1 Release Limit Requirements for Surface-Contaminated Material
There are two directives that cover the control limits and methods of removable surface
contamination measurement: 10 CFR 835, Occupational radiation protection, and DOE
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Order 5400.5 Chg 2. Additional guidance is contained in a DOE memorandum from A.
Lawrence to Distribution, dated May 1, 2002, which includes the draft DOE G 441.1 as an
enclosure. The values specified for tritium are consistent with 10 CFR 835.
Appendix D to 10 CFR 835 specifies surface contamination value for use in determining
whether a location needs to be posted as a contamination or high-contamination area
(Subpart G), and if an item is considered to be contaminated and cannot be released from a
contamination or high-contamination area to a controlled area (Subpart L). 10 CFR 835
does not permit unrestricted release of contaminated items. The surface contamination
value for removable tritium is 10,000 dpm/100 cm2. In addition, Footnote 6 to Appendix D
provides a requirement to consider the migration of tritium from the interior of an item to the
surface when applying the surface contamination value for tritium. Per Appendix E,
“Radiological Control Programs for Special Tritium Compounds” is considered to apply to
special tritium compounds, including metal tritides.
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The second regulation concerns the release of materials per the requirements of DOE Order
5400.5 Chg 2. This document provides requirements for unrestricted release of objects with
residual radioactivity. This requirement is described in the document Response to
Questions and Clarification of Requirements and Processes: DOE 5400.5 Chg 2, Section
II.5 and Chapter IV Implementation (Requirements Relating to Residual Radioactive
Materials). [34] This document recommends the use of 10,000 dpm/100 cm2 as an interim
guideline for removable tritium. This limit is also specified in Table 1, “Surface Activity
Guidelines” (see Appendix D). This value is considered acceptable for special tritium
compounds, including metal tritides.
ANSI/HPS Standard N13.12-1999, Surface and Volume Radioactivity Standards for
Clearance, gives the screening level for unrestricted used items with residual levels of tritium
on the surface of 600,000 dpm/100 cm, of which no more than 20% or 120,000 dpm/100 cm
should be removable (volume screening value of 3,000 pCi/g). These values are currently
not endorsed by DOE.
Although not specifically addressed in the regulations, users should be cautioned that, in
some cases, the initial, relatively clean concrete surface measurements did not accurately
characterize the bulk tritium contents (see 4.6.2).
8.1.2 Removable Surface Contamination Measurement Process
The regulatory requirements are not specific as to how the removable surface contamination
wipe is to be done or whether or not it is to be wet or dry. Footnote 4 of Appendix D to
10 CFR 835 states that a dry wipe may not be appropriate for tritium, but does not provide
an explanation as to what may be appropriate. As a result, it would seem that either a wet
or dry wipe can be used and still meet the requirements of 10 CFR 835. The requirements
stated in Response to Questions and Clarification of Requirements and Processes… [34]
include: “The measurement should be conducted by a standard smear measurement but
using a wet swipe or piece of Styrofoam,” although in Table 1 of this document, a dry wipe
(i.e., a dry filter or soft absorbent paper) is specified. The “should” included in this sentence
and the use of Styrofoam would seem to allow for the use of either dry or wet wipes.
The use of a wet or dry wipe to determine removable surface contamination levels is
noteworthy due to possible differences in measured levels between the two techniques.
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Appendix E, Radiological Control Programs for Special Tritium Compounds, provides
guidance on monitoring surfaces for the presence of special tritium compounds.
The measurement of removable surface contamination has not been standardized by the
technical disciplines, and, as a result, it is difficult to compare readings between facilities.
Reasons for variations between facilities may be due to the following:
• Instrumentation: The instruments used for counting wipes are of different manufacturers
and models providing varying accuracy and precision. The methodologies used are not
standardized or cross-checked against each other to determine if results are similar.
• Units: The measurement units used at the different sites are either dpm/100 cm2 or
dpm/cm2 with the former being the more common. Comparing results from one facility to
another requires careful checking to make sure that the dpm values discussed are for
the same area of surface.
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• Wipe Material: The wipe materials most commonly used are dry filter paper, Styrofoam,
and Q-Tips. There is no standardization of materials across facilities.
• Wipe Preparation: Dry wipes and wet wipes are used at the facilities. The wet wipes
are prepared by soaking the Q-Tip or the filter paper in water, counting solution, or other
liquids.
• Wipe Technique: The technique used to determine the area wiped and pressure applied
when using the different materials varies from site to site.
• Dry versus wet wipes: Recent comparative tests performed at the LLNL Tritium Facility
show that there are differences in the results obtained between a dry and a wet wipe of
the same surface. In some cases, the dry wipe resulted in measured values higher than
those measured by a wet wipe, while in other cases the wet wipe was higher. These
tests, using de-ionized water as the wetting agent, indicate that the difference between a
dry or wet wipe is a function of the type of surface and the level of contamination.
Generally, the levels measured by wet and dry wipes of the same surface are within a
factor of 3.
Good practices in this area for consideration include:
• When the surface of the object is less than 100 cm2, the activity per 100 cm2 should be
calculated based on the area wiped, and the entire object should be wiped.
• Records should be kept in units of dpm/100cm2.
• Either dry or wet wipes can be used to satisfy regulatory requirements. The
requirements do not identify a wetting agent, nor do they specifically require a wet wipe.
Some facilities use wet wipes in the belief that this is a more conservative approach. In
fact, depending on the specific surface conditions, either method may produce
somewhat higher measured values. Given the high intrinsic variability of the wet swipe
process and the fact that the dry method is less complex and can be standardized and
performed more consistently, the dry process is the preferred method of this Handbook.
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• The methods used to measure removable surface contamination are not presently
standardized and are not the same at all facilities. The following discussion describes a
Generic Wipe Survey Technique that could be used at any DOE facility.
– The amount of removable material should be determined by wiping an area of 100
cm2 on the object using dry filter paper or a dry Q-Tip, applying moderate pressure,
and measuring the amount of radioactive material on the dry wipe.
– Dry Filter Paper: The wiping technique, using dry filter paper, should consist of
wiping a total path length of 16 inches using a single 16-inch lazy-S path or multiple
shorter lazy-S paths that total 16 inches (tests show an average wipe width of 1 inch
for dry filter paper).
– Q-Tip: The wiping techniques, using a dry Q-Tip, should consist of wiping a total
path length of 80 lineal inches of Q-Tip path (tests show an average wipe width of
0.2 inches for a Q-Tip).
• The Generic Wipe Survey Technique can be used for most applications; however, items
with hidden surfaces or inaccessible areas require special consideration. For items that
possess inaccessible areas that do not normally contact tritium, use of the Generic Wipe
Survey Technique on the accessible surface area is sufficient in that these areas
become contaminated only as a result of contamination on the surface area. However,
for inaccessible areas such as pipes, tubes, drains, ductwork, valves, pumps, vessels, or
transducers that potentially contact tritium, a two-step process is recommended:
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– First Wipe Survey: The accessible surfaces of the item should be wipe-surveyed
using the Generic Wipe Survey Technique.
– Second Wipe Survey: A second wipe survey should be made of the entry points into
the item inaccessible areas (such as fittings, valve throats, ends of tubes, cracks,
doors, and louvers). The second wipe survey should be made with a Q-Tip inserted
as far as reasonably possible into the openings of the items. The total area of wipe
should be estimated and the results corrected to dpm per 100 cm2.
8.1.3 Environmental Discharge Requirements
DOE Order 5400.5 Chg 2 makes use of a “best available technology” selection process to
reduce effluent discharges; however, this process is not applicable to tritium. DOE Order
5400.5 Chg 2 relies on the ALARA philosophy in tritium operations to reduce effluent levels.
The restriction on liquid surface discharge is that the concentration be maintained less than
the DCG value of 2.0 E-3 µCi/ml. The NRC release limit for 10 CFR 20, is 1.0 E-3 µCi/ml.
For airborne effluents, the annual discharge to the air (as stated in 40 CFR 61, National
Emission Standards for Hazardous Air Pollutants) for all radionuclides on site must be such
that the offsite boundary dose is less than 10 mrem. Therefore, stacking and evaporation
are methods that could be considered if this contribution and all others result in a dose
under 10 mrem. Agreements with local regulators, however, may preclude or significantly
reduce the release values allowed by these regulations, as could ALARA concerns.
All discharges to the environment that may contain tritiated wastes should be provided with
monitoring systems. Future designs will likely incorporate real-time attributes to annunciate
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when the discharge concentration exceeds the specified limits. Soil column discharge is
highly discouraged.
8.1.4 Tritium-Contaminated Wastewater
The generation of tritium-contaminated water is an inherent part of any tritium-handling
operation. Any water used in a facility that handles tritium has the potential of being
contaminated. To ensure that wastewater exiting such a facility does not exceed regulatory
limits, the facility must measure the tritium content of the wastewater generated, and control
its disposal.
8.1.4.a Tritium-Contaminated Wastewater Generation
The wastewater from a tritium facility falls into three categories:
• Sinks and Floor Drains: The least contaminated water is that water that runs into the
facility sinks and floor drains. Unless water use is controlled, the volume of this water is
typically in the tens of thousands of gallons per year. This water can generally be
released to the sanitary sewer after the tritium content is measured to ensure that it is
within regulatory limits.
• Wash and Decontamination Water: In a tritium handling area, contaminated wastewater
is generated by routine activities such as mopping floors and decontamination of tools.
Unless water use is controlled, the volume of water generated by these activities is
typically in the hundreds to thousands of gallons per year. The tritium content of water
from these activities is low, but is above background and is easily measured. Control
and disposal of this low-level tritium-contaminated water is not industry standardized
and, at present, is a function of the individual facility.
• Tritium Removal System Wastewater: Usually, the water collected by a facility Tritium
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Removal System will be the highest tritium concentration water collected at the facility.
The volume of water generated by the tritium removal system is typically in the tens to
hundreds of liters per year.
There are several potential methods for collection of the removal system wastewater. If
possible, the system should be designed to collect water directly on a removable molecular
sieve trap in less than 1,000 Ci quantities per trap. These traps can be disposed of as solid,
low-level radioactive waste without further tritium handling if they are taken out of service
(e.g., the date based on operational estimates of loading) prior to reaching 1,100 Ci. The
molecular sieve trap can be valved-off, certified to contain no pressure exceeding 1.5
atmospheres absolute at 20°C and no free liquids, and can be disconnected from the
apparatus and placed directly into a DOT 7A package for shipment to the disposal site.
Type B quantities (> 1,100 curies/trap) may also be disposed of following this same
technique except for overpacking the package in a Type B container for shipment to the
disposal site. Due to radiolysis of the water, consideration must be given to the increase of
hydrogen and oxygen pressure in the shipping package. Additionally, the pressure buildup
in the container, due to decay of the tritium and radiolysis, has the potential to increase the
pressure in the container above 1.5 atmospheres absolute.
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The details of the packaging, stabilization of the waste item in the package, hydrogen
generation in the package, and pressure buildup, and possible backfill of the void space with
clay, should be explored with DOE waste site personnel before the first shipment is
required. The DOE waste site criteria are subject to interpretation, and packaging details
need to be discussed with DOE waste site personnel to make sure that the package meets
their interpretation of the criteria.
8.1.4.b Tritium-Contaminated Waste Water Disposal
8.1.4.b(1) Solidification on Clay
Tritiated wastewater can be solidified on clay or Stergo superabsorbent (discussed in
Section 8.1.4.b(2)), and disposed of as solid, low-level (radioactive) waste.
• Type A Quantities (< 1,100 curies)
The waste site should be asked to approve solidification of Type A quantities of tritium in
the form of water solidified directly on clay in DOT 7A, 55-gallon drums. Following the
waste site guidance, which typically requires that 100 percent more clay be used to
solidify the water than required, the following packaging method should meet the criteria.
Clay will hold from 60 to 70 percent water by volume without any free liquid. The actual
quantity that can be held is dependent upon the type of clay. Superfine® clay will hold 73
percent water by volume without any free liquid. Floroco® clay will hold approximately 65
percent by volume. Based upon this, a DOT 7A, 55-gallon drum filled with Superfine®
clay will hold approximately 40 gallons of water. Following the typical guidance, which
requires that 100 percent more adsorbent be used than required, a 55-gallon drum could
be used to solidify 20 gallons of water.
Other methods and techniques of wastewater solidification are available, such as clay-
filled primary containers overpacked inside Type A containers. Mixtures of cement, clay,
and other materials have been used with success. Unfortunately, most of the more
complex solidification methods require the use of some type of aggressive mixing
method, such as barrel mixers, which results in spreadable contamination problems and
the resulting increased personnel exposures.
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• Type B Quantities ( > 1,100 curies)
Type B quantities of tritium in the form of water may also be solidified and packaged at
the generation site in Type A containers for the purpose of storage at the waste site.
However, Type B quantity waste, packaged in Type A containers, must be placed in a
Type B shipping package during transport and shipping to the waste site.
The Trupact II shipping package is approved for shipment of solidified, tritium-contaminated
water.
8.1.4.b(2) Solidification on Polymers
PPPL shipped tritium to Hanford for burial and performed studies of solidification in various
polymers. Three polymers are approved for absorption of radioactive liquids for land burial
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at the Hanford site. In order for these polymers to absorb the liquids, and, therefore, exhibit
the properties of a solid, they must be used in accordance with EPA test method 9096,
Liquid Release Test, so that they pass a pressure test of 20 psi (this is a specific Hanford
burial requirement; for example, Nevada Test Site (NTS) does not require a 20 psi test, but
instead relies on vibration testing to simulate transport conditions in accordance with NTS
waste acceptance requirements. This testing is performed for each solidification medium
and associated liquid). These polymers provide significant advantages over clay-based
absorbents in that they do not require mixing, and that they exhibit less than 1% expansion
by volume.
PPPL performed independent evaluations and testing of these polymers to verify the ratios
and absorption capability. Stergo (Corpex Technologies) passed the 20 psi test at a ratio of
20:1 water:polymer; additionally, Stergo and SP-400 (Waterworks).passed the test at a
pressure of 50 psi (the normal test pressure), using ratios of 10:1.
Users may want to perform their own additional independent testing to determine the correct
ratio(s) for their product (if different from the aforementioned) and/or for their specific liquid
characteristics. The PPPL testing was performed on tap water with a neutral pH.
8.1.4.b(3) Evaporation to the Environment
It is possible but expensive to solidify several thousand gallons of water containing only tens
of curies of tritium. When properly permitted by State and Federal regulations, tritiated
wastewater can be evaporated to the environment. An example of an evaporator, which
was permitted by EPA, is the evaporator used at the now closed TRL facility at SNL. This
tritium-contaminated wastewater evaporator was permitted to evaporate up to 100 Ci/yr to
the environment. Over several years this system evaporated tens of thousands of gallons of
extremely low-level tritium-contaminated water.
Evaporation may not be a reasonable or feasible method of wastewater disposal at every
site; however, it was the preferred disposal option at Three Mile Island. Over 2.2 million
gallons of tritiated water were collected for storage and treatment at the TMI site after the
1979 accident. This waste water, with tritium concentrations ranging from 1.6E-1 µCi/mL to
2.4E-2 µCi/mL, resulted from many sources including the primary coolant, spent fuel pool,
submerged demineralized system, and the EPICOR I and II ion-exchange processing
systems. Lesser sources included wastewater from the decontamination of systems and
components including steam generators and flushing of auxiliary systems. The principal
constituents of this processed water were boric acid and tritium. The water was
accumulated in large Process Water Storage Tanks (about 600,000 gallons) and processed
through a vacuum evaporator system. The majority of the tritiated water was released to the
environment. The boric acid and residual radioactive contamination was concentrated into a
powder form and disposed of at a LLW disposal facility in Barnwell, SC. In the past, these
low-level concentrations of tritiated water were diluted to meet the 10 CFR 20 Appendix B
limit of < 1.0E-3 µCi/mL and released. However, in this case, the estimated 1,000 Ci of
tritiated water was released to the environment by evaporation. Refer to Figure 2-3 for
comparison of the TMI accident-generated tritiated water concentrations with those found
throughout the tritium complex.
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8.1.4.b(4) Release to the Sanitary Sewer
Very-low-level tritium-contaminated water, which is generated by hand washing, showering,
and normal facility water use, may be stored and analyzed to see that it meets state and
Federal release criteria. If the water meets the regulations, it may be released to the local
sanitary sewer. The NRC release limit for tritium as defined in 10 CFR 20 Appendix B,
Table 3, for release to sanitary sewers is 1.0 E-2 µCi/mL. This release limit is based on the
monthly average (total quantity of tritium divided by the average monthly volume of water
released to the sanitary sewer). If more than one radionuclide is released, the sum of the
fractions rule applies. Also, draft 10 CFR 834 specifies less than a 5 Ci annual tritium
release to sanitary sewers.
Regulations regarding the packaging for disposal and disposal of tritium-contaminated water
are complex. The available choices for disposal are dependent on the tritium content of the
water and the equipment available. Facility planning must include provisions for disposal of
tritium-contaminated water at all levels of contamination down to a level that may be
released to the local sanitary sewer system.
8.2 Waste Characterization
The purpose of hazardous waste characterization is to determine the applicability of the
RCRA hazardous waste management requirements and to demonstrate compliance with
these requirements (in accordance with 40 CFR Parts 261 through 268). Radioactive waste
characterization must satisfy the requirements in DOE O 435.1 Chg 1. Mixed waste
characterization must satisfy both. Waste characterization is the process used to determine
the physical, chemical, and radiological properties of the LLW. As a general rule, if a
hazardous waste component is reasonably expected to be present in a radioactive waste
stream, it is advisable to manage the waste as mixed waste until the waste is characterized
by chemical analysis or process knowledge to document that the waste contains no
hazardous wastes as identified in 40 CFR 261.
Waste characterization is the process of identifying, assessing, and documenting the
physical, chemical, and radiological properties of process wastes and wastes generated
from cleanup and removal activities. The waste profile created during characterization is the
foundation for waste segregation, management, and certification operations.
Characterization programs must be developed to address waste certification requirements
dictated by the waste management, disposal, or treatment option selected for each waste
stream, in addition to the applicable regulatory requirements. The primary characterization
determinations to be considered for tritium-contaminated waste are the low-level and
hazardous waste determinations.
Defining process waste streams is one of the most overlooked aspects of waste
characterization. Many generators believe characterization involves the assessment of
inventory containers. Effective waste management must begin at the point of waste
generation. The generator must first identify all of the waste-generating processes.
Information such as process inputs, sub processes, equipment, and chemical use must be
reviewed to generate an adequate profile for each waste stream.
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Section 91
Documenting the waste stream assessments is also an important part of the
characterization process. It is critical that the personnel generating waste be provided with
the information required to properly manage waste generated in their area. Additionally, an
auditable record must be created that allows for review of the characterization process and
determinations. Waste-generating processes must be reviewed periodically to identify
changes that could result in the addition of new streams or changes to existing streams. In
addition, the regulations must be monitored to address promulgated and proposed changes
that affect current or future characterization programs.
RCRA, an amendment to the Solid Waste Disposal Act, was enacted in 1976 to address the
management of municipal and industrial wastes. RCRA includes a number of subtitles.
Subtitle C of RCRA directs the management of hazardous waste. This subtitle imposes
administrative provisions to ensure accountability for hazardous waste management, as well
as substantive requirements designed to protect human health and the environment from
the effects of improper management of hazardous waste. Under the RCRA implementing
regulations, hazardous waste is defined as any solid waste exhibiting one or more of the
characteristics of hazardous waste: ignitability, corrosivity, reactivity, and metal or organic
compound toxicity [40 CFR 261.20 - .24]; or is included on one of three lists of hazardous
wastes [40 CFR 261.30 - .33]. These lists include hazardous wastes generated by
nonspecific (F-listed wastes) and specific sources (K-listed wastes), in addition to
commercial chemical products (P- and U-listed wastes). RCRA was amended significantly
in 1984 by the Hazardous and Solid Waste Amendments (HSWA), which expanded the
scope and requirements of RCRA. Among other things, HSWA required EPA to evaluate all
listed and characteristic hazardous wastes, and to develop requirements (i.e., treatment
standards) that must be achieved prior to land disposal of these wastes. The implementing
regulations for accomplishing this statutory requirement are established within the Land
Disposal Restrictions (LDR) program [40 CFR 268].
In conjunction with the hazardous waste and LDR-related waste determinations, additional
physical and chemical information may be required depending on the treatment or disposal
options being considered. These parameters may include, but are not limited to, the
assessment of the waste for free liquids, headspace gases, chelating agents,
anions/cations, PCBs, particulate, explosives, pyrophorics, and waste matrix composition.
8.2.1 Waste Knowledge
Waste knowledge or acceptable knowledge refers to information used to support waste
characterization activities. In recent regulatory preambles and guidance, EPA uses the
terms “waste knowledge” or “acceptable knowledge” in place of the term “process
knowledge.” The terms “waste knowledge” or “acceptable knowledge” are broader terms
that include process knowledge, waste analysis data obtained from generators, and existing
records of analysis, or a combination of this information supplemented with chemical
analysis. Process knowledge is the common terminology for the RCRA regulatory language
“applying knowledge of the hazard characteristic of the waste in light of the materials or the
processes used” [40 CFR 262.11(c)(2)]. EPA has defined process knowledge to include
detailed information on the wastes obtained from existing published or documented waste
analysis data or studies conducted on hazardous wastes generated by similar processes
[see Joint NRC/EPA Guidance on Testing Requirements for Mixed Radioactive and
Hazardous Waste, November 20, 1997 (62 FR 62079); and Waste Analysis at Facilities that
Generate, Treat, Store, and Dispose of Hazardous Wastes: A Guidance Manual, OSWER
9938.4-03, April 1994]. Process knowledge includes any documentation that describes or
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verifies a facility’s history, mission, and operations, in addition to waste stream-specific
information used to define generating process, matrix, contaminants, and physical
properties. Waste-generating facilities should maintain and utilize waste knowledge to
characterize waste streams (i.e., in lieu of sampling and analyzing the waste), whenever
possible, to avoid unnecessary exposures to radioactivity and eliminate needless or
redundant waste testing. This requires the generator to maintain auditable records that
document the composition of the waste, including waste matrix and contaminants.
The documentation should be constructed in such a way that independent review would
result in consistent characterization conclusions. The collection, review, management, and
dissemination of the information should be standardized and documented to ensure data
integrity and that the information is defensible during future assessments.
The use of waste knowledge to characterize wastes may be applicable in a number of
situations, including:
• Waste stream is difficult to sample because of the physical form.
• Sampling analysis would result in unacceptable risks of radiation exposure.
• Waste is too heterogeneous in composition.
• Waste sampling and analysis is not feasible or necessary.
• Waste stream results from well-documented specific processes, such as with standard
laboratory operations.
8.2.2 Tritium Disposition Options
Tritium exists in various concentrations and forms throughout the complex. The tritium
contained in waste streams could be stored, released to the environment (i.e., in compliance
with applicable regulatory limits or permitted levels), or recovered for reuse. This section
provides an overview of a process to help make an informed decision on tritium disposition.
The diagram depicted in Figure 8-1 provides a simplified flow path for ultimate disposition of
tritiated material. The first fork is associated with the production source of the tritium. As
discussed in Section 3.1.3, the RCRA regulations include an exclusion from the hazardous
waste management requirements for source, special nuclear and byproduct material as
defined by the AEA [40 CFR 261.4(a)(4)]. U.S. reactor and non-weapons production
accelerator produced tritium wastes meet this definition of “byproduct” material, and, as
such, are excluded from the RCRA requirements applicable to solid waste and hazardous
waste. Additionally, EPA has applied a regulatory policy in certain cases [5 – 9] by which
residuals, derived from the management of RCRA exempt or excluded waste, retain the
exemption or exclusion (even if they subsequently exhibit hazardous characteristics). These
considerations provide the basis for not including a hazardous waste determination step,
relative to assessing the tritium itself, in the reactor-produced tritium fork presented in Figure
8-1.
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FIGURE 8-1. Ultimate disposition of tritiated material
1 This pathway appears unlikely to exist in DOE; however, final determinations are always subject to
local regulatory authority and interpretation.
NOTE: Naturally-occurring and accelerator-produced radioactive material (NARM) mixed
with hazardous is treated the same as radioactive material mixed with source, SNM, or
byproduct material, per DOE O 435.1, Chg 1, even though the Federal Facility Compliance
Act of 1992 may not require this treatment.
Section 93
CANDU and accelerator-produced weapons production tritium waste do not qualify for the
RCRA source, special nuclear, and byproduct material exclusion. As such, the tritium waste
stream that exhibits one or more of the characteristics of hazardous waste (e.g., ignitability,
corrosivity) would be subject to the RCRA hazardous waste provisions. For this reason, the
left fork in Figure 8-1 includes a determination of whether the material (i.e., the tritium waste
itself) is hazardous. The authors believe that it is unlikely that forms of tritiated materials in
the container configurations used in the DOE complex would exhibit any of the four
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characteristics of hazardous waste. This pathway, while unlikely to exist, is still possible
(e.g., compressed tritium gas in a container configuration satisfies the characteristic of
ignitability) and is illustrated in Figure 8-1.
Both forks of the figure include a mixed waste determination. Specifically, this determination
step considers whether the tritiated material also contains a RCRA hazardous waste
component (i.e., in addition to the tritium/radioactive component). If a tritium waste stream
also contains a hazardous waste component, the waste stream would need to be managed
as a radioactive mixed waste in accordance with the AEA and RCRA. The determination
that a mixed waste exists will result in the more stringent disposition option depicted. Note
that even though naturally-occurring and accelerator-produced radioactive materials do not
constitute a source, special nuclear or byproduct material, (except for accelerator produced
tritium meeting the commercial, medical or research uses is now byproduct) all DOE waste
containing naturally-occurring and accelerator-produced radioactive materials mixed with a
hazardous component must be managed as hazardous waste under RCRA [pursuant to
DOE O 435.1 Chg 1]. The disposition options for non-hazardous, non-mixed tritium from
both forks are similar, with the biggest difference resulting from the storage requirements for
RCRA solid material. These disposition options are a function of the form (solid, liquid, or
gas).
8.2.3 Economic Discard Limit for Tritiated Water
EPA uses the economic discard limit (EDL) to evaluate whether a hazardous material or
residue should be classified as a waste. If it has sufficiently high economic value, the
material should be considered for recovery and reuse. The intent is not to allow facility
(government-owned and commercially-owned) operations to define material as not being
waste and thereby not be required to meet the current Federal statutes on permitting of
hazardous waste material for treatment, storage, and disposal (TSD).
In a simplistic form, the EDL is the threshold value in determining when a materials
economic value ($/unit weight or volume) exceeds the associated cost for the materials
TSD. If the economic value, based on current market value or replacement value, is
determined to be of greater value than the cost of TSD, the material can be considered non-
waste. The governing statues and requirements for non-waste are less extensive, and the
disposition times are less severe.
Section 94
There are many ways to determine the economic value of a material; the most common is
market price. The current market price is, in large measure, established by Canadian
commercial sales, and is approximately $3.50 Canadian dollars per Ci. ($3.27 US/Ci) at the
exchange rate of 1 USD = 1.0678 CAD. Historically, this value has been fairly constant in
U.S. dollar terms; for example, in 1999, it was $3.15 USD/Ci ($4.61 CAD/Ci) at 1 USD=
1.4653 CAD. The Canadian price is somewhat arbitrary, and is based on selling only about
100 g/yr, with its supply of over 2,500 g/yr. The Canadian marginal cost is estimated to be
about $3.25/Ci (CAD dollars) [34]. The quantity of tritium transacted also affects the price.
In 2007, PNNL obtained quotes from three sources for a 1,000-Ci purchase. The Canadian
price was 3.50 CAD/Ci for greater than Type A quantities, adding a 4,000-CAD fixed fee for
any purchase less than Type A, resulting in a cost of 7.5 CAD/Ci. Private firm cost was
quoted at 10 USD/Ci, and the DOE cost was “free” for the tritium, but the associated costs of
labor, safeguards and security, and overhead costs factored in the resulting value of 15
USD/Ci [35]. These data suggest a value of about 10 USD/Ci for smaller quantities of
tritium.
DOE-HDBK-1129-2008
106
It appears that the value of the recovered tritium (i.e., from waste streams; high-Ci-content
process streams are more economical) is overstated in many proposals to recover tritium,
and that recovery options, even the most cost-effective such as the PMR, are difficult to
justify on economics alone. Any recovery argument should also have an environmental
impact component as well.
In the absence of a Department-wide policy on tritium recovery, DOE sites with tritium oxide
and tritiated water inventories should consider their EDLs based on their site-specific
conditions and needs. The implication of the preceding discussion is that once tritium goes
into the oxide form, it is difficult to justify on an economic basis alone using any recovery
method. The fact that economic recovery of tritium from oxide form is not easily justified
should be a factor in the local DOE Site Office determination of waste classifications.
8.3 Waste Packaging
DOE, DOT, and NRC requirements for radioactive waste packaging are presented in
Chapter 7.
Barriers, in addition to the outer packaging, should be considered to inhibit tritium migration
from waste packages. The only significant difference associated with packaging of waste
for shipment versus packaging of any other quantity of nuclear material for shipment is that
Type B quantities of waste may be packaged in Type A containers at the waste generation
site and shipped to the waste site overpacked in Type B containers such as the Trupact II.
During shipment, the waste package must meet the current DOE and DOT regulations for
shipment of the form and quantity of radioactive material; i.e., Limited Quantity, Type A
Quantity, Type B Quantity. After receipt at the waste disposal site, the type A package
containing the Type B quantity of low-level (radioactive) waste is removed from the Type B
package. The Type B package is then returned to the shipper for reuse, and the Type A
package containing the Type B quantity of tritium is stored at the waste disposal site along
with the other low-level waste.
The waste acceptance requirements are a little different at each waste disposal site. The
following is a list of things to be considered before waste is packaged.
Section 95
• Free Liquids: Waste should contain as little free liquid as reasonably achievable, but
under no conditions shall the free liquid volume exceed 0.5 percent by volume of the
external container.
• Absorbent: If absorbent material is used to solidify liquid in the waste, the quantity of
absorbent material added to the waste must be sufficient to absorb a minimum of twice
the volume of the liquid.
• Particulate: Waste in particulate form should be immobilized, and, if immobilization is
impractical, other acceptable waste packaging shall be used, such as overpacking: drum
containing particulate enclosed in another drum; and wooden or steel box with
particulate enclosed in a 6-mil sealed plastic liner inside the box.
• Gases: Pressure in the waste box shall not exceed 1.5 atmospheres absolute at 20oC.
Compressed gases as defined by 49 CFR 173.300 are generally not accepted for
disposal unless the valve mechanism has been removed or it is obvious that the
container has been punctured.
DOE-HDBK-1129-2008
107
• Containers, Vessels, Manifolds: Containers, vessels, and manifolds that have been
exposed to tritium and should remain sealed, must be certified to contain no pressure
greater than 1.5 atmospheres* absolute prior to packaging as waste.
• Stabilization: Where practical, waste should be treated to provide a more structurally
and chemically stable waste form.
• Etiologic Agents: LLW containing pathogens, infectious wastes, or other etiologic agents
as defined in 49 CFR 173.386 are generally not accepted.
• Chelating Agents: Chelating or complexing agents at concentrations greater than 1
percent by weight of the waste form are generally not accepted.
• Polychlorinated Biphenyls: Polychlorinated Biphenyls contaminated LLW is generally not
accepted unless the Polychlorinated Biphenyls concentration is less than 50 ppm
• Explosives and Pyrophorics: Material in a form that may explode spontaneously or
combust if the container is breached is generally not accepted for disposal.
8.4 Waste Shipping
The shipping requirements for Class 7 (radioactive) material can be found in Section 6.1. If
the tritium waste is mixed with RCRA constituents, a hazardous waste manifest and Land
Disposal Restriction notification is required for offsite shipments. See Section 7.1 for RCRA
pre-transport requirements associated with mixed waste. In addition, any containers less
than 110 gallons in capacity must be marked as hazardous waste in accordance with
40 CFR 262.32.
During shipment, the waste package must meet the current DOE and DOT regulations for
shipment of the form and quantity of radioactive material; i.e. Limited Quantity, Type A
Quantity, and Type B Quantity.
* DOE Order 5820.2A, from which the 1.5 atmospheres requirement is taken, has been superceded
by DOE O 435.1, but in the revised Order the 1.5 atmosphere requirement only applies to initial
gaseous forms (“Low-level waste in a gaseous form must be packaged such that the pressure does
not exceed 1.5 atmospheres absolute at 20°C.”) Another requirement from DOE O 435.1 states,
“When waste is packaged, vents or other measures should be provided if the potential exists for
pressurizing containers or generating flammable or explosive concentrations of gases within the
waste package.
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DOE-HDBK-1129-2008
A-1
APPENDIX A: USEFUL NUMERICAL VALUES
A.1 General Data
Section 96
• 1 becquerel (Bq) = 1 disintegration/second = 2.7 x 10-11 Ci
• 1 Ci = 3.7 x 1010 disintegrations/second = 3.7 x 1010 Bq = 37 GBq
• Avogadro's Number = 6.023 x 1023 molecules/mole
• STP conditions: 760 Torr, and 0oC (1 atm and 273K)
• 1 mole of ideal gas at STP = 22.414 L at 0° C, and approximately 24.2 L/mole at
room temperature
• 1 Sievert (Sv) = 83.8 roentgens = 100 rem
• A1 quantity-special form
• A2 quantity –other than special form or normal form
A.2 General Tritium Data
• Tritium decays to 3He + beta + neutrino
• Half-life of tritium (Scientific purposes) = 12.323 ± 0.004 years (4500.88 ± 1.46 days)
Half-life of tritium (Accountability purposes) = 12.33 +/- 0.06 years (DOE M 474.1-2,
Figure IV-2)
• Tritium decay factor = 0.99984601/day
• Maximum beta energy of decay (E max.) = 18.6 keV
• Mean beta energy of decay (E mean) = 5.69 keV
• Volume of 1 Ci of tritium (T2) at STP = 0.386 mL
• Tritium (T2) gas = 9619 Ci/g
• T2 gas contains 58023 Ci/mole
• 2.589 Ci/cm3 of T2 at STP
• Diameter of a tritium atom (approximate) = 1.1 Angstroms
• Dissociation energy, T2 to 2T = 4.59 eV
• Ionization energy, T to T+ + e- = 13.55 eV
• Atomic weight = 3.01605
• Gram molecular weight of tritium = 6.0321 g
• Grams tritium/liter at STP = 0.269122 g/L
• Liters/gram of tritium at STP = 3.71579 L/g
• Boiling point of tritium at 1 atmosphere = 25.0 K
• T2 gas, at 1 atmosphere pressure and 25oC = 2.372 Ci/cm3
• Tritiated water, T2O = 3200 Ci/cm3
A.3 Regulatory Quantities
• Type B Quantity = > 1100 Ci
• Type A Quantity = > 0.11 to <1100 Ci depending on form
• Limited Quantity = < 21.6 Ci of tritium in gaseous form
< 1.1 Ci of tritium in solid form
< 1 Ci of tritium at a concentration of > 1 Ci/L liquid
< 100 Ci at a concentration of > 0.1 to < 1 Ci/L liquid
< 1000 Ci at a concentration of < 0.1 Ci/L liquid
• A2 Quantity = 40 TBq (1100 Ci)
• Limited Quantity Excepted Package Requirement for tritium
− Radiation level < 0.005 mSv/hr (0.5 mrem/hr)
− Quantity of radioactive material < limit in 49 CFR 173.425
DOE-HDBK-1129-2008
A-2
− Package meets general design requirements for radioactive material packaging
from 49 CFR 173.410
− Nonfixed/removable contamination on the external surface of the package is <
limit in 49 CFR 173.443 (0.41 Bq of tritium/cm2 or 22 disintegrations/min
(dpm)/cm2 for tritium)
− Outside of inner or outer packaging is marked “Radioactive”
• Low Specific Activity (LSA) A quantity of Class 7 (radioactive) material with limited
specific activity
− LSA-I
Earth, concrete, rubble or other debris = 4 x 105 TBq of tritium/g (0.001 Ci of
tritium/g, 1 Ci of tritium/kg or 2.2 lb/Ci of tritium)
− LSA-II
Tritium-Contaminated Water up to: 0.8 TBq of tritium/L (20.0 Ci/L)
Solids and Gases up to 0.004 TBq of tritium/g (0.1 Ci/g, 100 Ci/kg)
Liquids 4 x 104 TBq of tritium/g (0.01 Ci/g, 10 Ci/kg)
− LSA-III
Solids, consolidated wastes, or activated material that meet 49 CFR 173.468
water leach test; and
Uniformly distributed in a collection of solid objects or uniformly distributed in
solid compact binding agent; i.e., concrete, bitumen, ceramic, etc.
Relatively insoluble or intrinsically contained in relatively insoluble material
such that, under loss of packaging and placed in water for seven days, would
not exceed 4 TBq of tritium (110 Ci of tritium)
The average specific activity of the solid does not exceed 0.08 TBq of
tritium/g (2.16 Ci/g)
• SCO (Surface Contaminated Object) Non-radioactive solid objects with Class 7
(radioactive) materials distributed on the surfaces
− SCO-I
Section 97
Nonfixed contamination on accessible surface averaged over 300 cm2 is < 4
Bq of tritium/cm2 (104 µCi/cm2 )
Fixed contamination on the accessible surface averaged over 300 cm2 is < 4
x 104 Bq of tritium/cm2 (1 µCi/cm2 )
Nonfixed plus fixed contamination on the inaccessible surface averaged over
300 cm2 is < 8 x 105 Bq of tritium/cm2 (20 µCi/cm2)
− SCO-II
Solid object on which limit for SCO-I is exceeded and meets the following:
Nonfixed contamination of accessible surface averaged over 300 cm2 is < 400
Bq of tritium/cm2 (10-2 µCi/cm2).
Fixed contamination of accessible surface averaged over 300 cm2 is < 8 x 105
Bq of tritium/cm2 (20 µCi/cm2).
Nonfixed plus fixed contamination of accessible surface averaged over 300
cm2 is < 8 x 105 Bq of tritium/cm2 (20 µCi/cm2).
• Type A Packages limited to 40 TBq of tritium (< 1100 Ci) per package
• Type B Packages for quantities > 40 TBq of tritium (> 1100 Ci) per package
• Graded Safeguards Program
− Category III: Weapons or test components, containing reportable quantities > 50
g T2 with isotopic fraction T2 > 20 percent
− Category IV: All other reportable quantities
DOE-HDBK-1129-2008
-— Package meets general design requirements for radioactive material packaging
from 49 CFR 173.410
— Nonfixed/removable contamination on the external surface of the package is <
limit in 49 CFR 173.443 (0.41 Bg of tritium/cm? or 22 disintegrations/min
(dpm)/cm* for tritium)
Outside of inner or outer packaging is marked “Radioactive”
Low Specific Activity (LSA) A quantity of Class 7 (radioactive) material with limited
specific activity
- LSA-I
= Earth, concrete, rubble or other debris = 4 x 10° TBg of tritium/g (0.001 Ci of
tritium/g, 1 Ci of tritium/kg or 2.2 Ib/Ci of tritium)
— LSACII
« Tritium-Contaminated Water up to: 0.8 TBgq of tritium/L (20.0 Ci/L)
« Solids and Gases up to 0.004 TBq of tritium/g (0.1 Ci/g, 100 Ci/kg)
= Liquids 4 x 10* TBq of tritium/g (0.01 Ci/g, 10 Ci/kg)
- LSALCIII
= Solids, consolidated wastes, or activated material that meet 49 CFR 173.468
water leach test; and
« Uniformly distributed in a collection of solid objects or uniformly distributed in
solid compact binding agent; i.e., concrete, bitumen, ceramic, etc.
« Relatively insoluble or intrinsically contained in relatively insoluble material
such that, under loss of packaging and placed in water for seven days, would
not exceed 4 TBgq of tritium (110 Ci of tritium)
«" The average specific activity of the solid does not exceed 0.08 TBq of
tritium/g (2.16 Ci/g)
SCO (Surface Contaminated Object) Non-radioactive solid objects with Class 7
(radioactive) materials distributed on the surfaces
- SCO-l
= Nonfixed contamination on accessible surface averaged over 300 cm’ is < 4
Bq of tritium/cm? (10* uCi/cm? )
= Fixed contamination on the accessible surface averaged over 300 cm’ is < 4
x 10* Bg of tritium/cm? (1 wCi/cm” )
« Nonfixed plus fixed contamination on the inaccessible surface averaged over
300 cm’ is < 8 x 10°Bq of tritium/cm? (20 uCi/cm?)
- SCO-II
Solid object on which limit for SCO-I is exceeded and meets the following:
= Nonfixed contamination of accessible surface averaged over 300 cm7is < 400
Bq of tritium/cm? (10° uCi/cm’).
= Fixed contamination of accessible surface averaged over 300 cm’ is < 8 x 10°
Bq of tritium/cm? (20 uCi/cm’).
« Nonfixed plus fixed contamination of accessible surface averaged over 300
cm’is < 8 x 10°Bq of tritium/cm? (20 uCi/cm’).
Section 98
Type A Packages limited to 40 TBq of tritium (< 1100 Ci) per package
Type B Packages for quantities > 40 TBq of tritium (> 1100 Ci) per package
Graded Safeguards Program
— Category Ill: Weapons or test components, containing reportable quantities > 50
g T2 with isotopic fraction T2 > 20 percent
— Category IV: All other reportable quantities
DOE-HDBK-1129-2008
A-3
• Facility Categories
− Hazard Category 1: Category A reactors and facilities designated by PSO.
− Hazard Category 2: > 30 g of tritium
− Hazard Category 3: > 1.6 but < 30 g of tritium
− Radiological Facility:< 1.6 g of tritium
A.4 Tritium Dose and Exposure Data
• Biological half-life = 8 to 12 days (oxide); biological half-life of tritides is currently
being researched
• Derived Air Concentration (DAC)
− DAC for HTO = 21.6 µCi/m3 = 2 x 10-5 µCi/mL = 7 x 105 Bq/m3
− DAC for HT = 200,000 µCi/m3 = 2 x 10-1 µCi/mL = 9 x 109 Bq/m3
− DACs for STCs –see Appendix E
• Dose Conversion Factor (DCF)
− DCF = 0.063 mrem/µCi (inhalation)
− DCF = 0.095 mrem/µCi (inhalation plus 50 percent allowance for skin absorption)
• Annual Limit of Intake (ALI)
− ALI for HTO = 80,000 µCi
− An initial exposure equilibrium urine count of 1 µCi/L equates to approximately a
3-mrem dose.
− A urine count of 50 µCi/L for a year equates to approximately a 5,000-mrem
dose.
− Breathing 21.6 µCi/m3 HTO in air for 8 hours/day, 50 week/year will result in a
dose of approximately 5,000 mrem.
− Tritiated water is approximately 25,000 times more hazardous than tritium gas
because of rapid uptake mechanisms.
• Tritium Beta Particles
− Range in Air = 4.5 to 6 mm
− Range in Water = 0.0005 cm
− Range in Tissue = 0.0007 cm
− Radiation, 1 mCi in man (70 kg) = 0.0044 rem/day
− Maximum Penetration = 0.6 mg/cm3
A.5 Tritium Container Data
• WSRC Hydride Transport Vessel (HTV)
− Reusable container for transporting up to 18 grams of tritium
− Shipped in UC-609
− Dual port, flow through capable
− One female, one male port, Cajon® SS-4-VCR
− Tritium stored as uranium tritide
− Contains 493 g depleted uranium
− Stoichiometry Maximum 1:2.9
− Weight 9.3 lb
− Height 9.995 in
− Diameter 4.6 in
− Volume 690 cm3
− Maximum normal operating temperature = 450oC
− Pressure Limit at Maximum normal operating temperature = 2.9 psia
− Tritium vapor pressure as a function of temperature at U:T = 1:2.9
− Dissociation Equations
DOE-HDBK-1129-2008
A-4
− Log Patm = -4038.2/T + 6.074, Patm = 10-4038.2/T +6.074
Log Ppsia = -4038.2/T + 7.2413, Ppsia = 10-4038.2/T+7.2413
− Maximum specified tritium leak rate in std cc = <1.26 x 10-7 std cc/s.
• WSRC Product Vessel (PV)
− Reusable container for transporting 10 g of tritium in gas form
− Shipped in UC-609
− Volume 21 L
− Maximum pressure 1,200 torr
− Height 30.5 in
− Diameter 9.875 in
− Weight 44 lb
− Single valve, Nupro® SS-4-HS-TW
− Male Nut, Cajon® SS-4-VCR-4
− Female Cap Cajon® SS-4-VCR-CP
− Maximum helium leak rate = 1 x 10-7 STP cc/s He with 8.5 psig helium internal
pressure by belljar method
• WSRC Hydride Storage Vessel (HSV)
− Container for storing up to 1600 STP liters of hydrogen isotopes
− Capable of being shipped in UC-609
− Dual port, flow through capable
− One female, one male port, Cajon® SS-4-VCR
− Tritium stored as titanium tritide
− Contains 4400 g titanium (Ergenics HY-STOR 106)
− Weight 45 lb
− Height 16.3 in
− Diameter 6.6 in
− Maximum normal operations temperature = 760°C
− Pressure Range at normal operating temperature = 192 psig to Full Vacuum
− Pressure Limit at 120°C = 1000 psig
− Maximum helium leak rate = 1x 10-7 STP cc/s He with 30 psig helium internal
Section 99
pressure by belljar method
• WSRC LP-50 (No longer certified for shipping).
− Container for storing tritium in gas form
− Volume 50 L
− Aluminum shell for containment control and valve protection
− Maximum initial pressure at loading 1,200 torr
− Height 28.3 in
− Diameter 13.2 in
− Product Container Weight 32 lb
− Aluminum Shell Weight 43 lb
− Full Package Weight including drum 260 lb
− Single valve, Hoke Model 4213X2 packless valve
− Male Nut, Cajon® SS-4-VCR-4
− Female Cap Cajon® SS-4-VCR-1-BL
− Maximum helium leak rate = 7 x 10-8 STP cc/s He with 22.7 psia helium internal
pressure by belljar method
• Mound AL-M1-5
− Up to 100,000 Ci absorbed on molecular sieve, silica gel or commercial clay
DOE-HDBK-1129-2008
A-5
− Used for storage and shipment of absorbed tritiated water.
− Cylindrical vessel 6 5/8 in O.D. by 23 7/8 height
− 316 Stainless Steel
− Cap which is screwed onto threaded center post of container containing two self-
sealing quick disconnect fittings used for connection to tritium monitors to check
for tritium leak from container
− Cap has two functions; physical protection of valves, fittings and pressure
transducer at top of container and also secondary containment. The cap is
sealed with four O rings; one face seal at the bottom circumference of the
cover, another near the top of the center post and two sealing the quick
disconnect fittings in their wells at the top of the cap.
− Organic compounds should be limited to 1% or less of the water content of the
container.
− Halogen compounds are to be avoided
A.6 Other Data
• Calorimeter Factor
− 3.0657 +/- 0.009 g of tritium per Watt
− 0.3240 +/- 0.0009 Watts/g of tritium
• ANSI N14.5-87 Leakage Test
− < 1 x 10-7 cm3 /s /He
DOE-HDBK-1129-2008
A-6
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DOE-HDBK-1129-2008
B-1
APPENDIX B: DEFINITIONS
Actual Activity – The total quantity of radioactive material within a particulate. Sometimes
referred to as true activity.
Airborne radioactivity area – Any area where the measured concentration of airborne
radioactivity, above natural background, exceeds or is likely to exceed the derived air
concentration (DAC) values listed in Appendix A or Appendix C of 10 CFR 835, or where an
individual present in the area without respiratory protection could receive an intake
exceeding 12 DAC-hrs in a week (DOE 10 CFR 835).
As low as reasonably achievable (ALARA) – A phrase (acronym) used to describe an
approach to radiation protection to control or manage exposures (both individual and
collective to the work force and the general public) and releases of radioactive material to
the environment as low as social, technical, economic, practical, and public policy
considerations permit (DOE 5400.5 Chg 2).
Below regulatory concern – A definable amount of low-level waste that can be
deregulated with minimal risk to the public (DOE O 435.1 Chg 1).
Best available technology for radioactive effluent control (BAT) – The preferred effluent
treatment technology, selected after taking into account factors related to technology,
economics, public policy, and other parameters. As used in this Handbook, the BAT is not a
specific level of treatment, but is the conclusion of a selection process in which several
alternative effluent treatment technologies are evaluated. This process, however, is not
applied to tritium (Draft DOE 834).
Biokinetic Model – A mathematical model that describes in quantitative terms the retention
and transport of a material in the body. The biokinetic model used in ICRP 78 is
recommended to evaluate intakes of STCs.
Section 100
Breathing Zone Air Sampler (BZA) – An air sampler that draws air from the area close
enough to the nose so the sample can be considered representative of the air a person
breathes (ANSI Z88.2-1992). An example of a breathing zone air sampler is a lapel monitor.
Buffer zone – The smallest region beyond the disposal unit that is required as controlled
space for monitoring and for taking mitigative measures, as may be required (DOE O 435.1
Chg 1).
Byproduct material – (1) any radioactive material (except special nuclear material) yielded
in or made radioactive by exposure to the radiation incident to the process of producing or
utilizing special nuclear material, and (2) the tailings or wastes produced by the extraction or
concentration of uranium or thorium from any ore processed primarily for its source material
DOE-HDBK-1129-2008
B-2
content (Atomic Energy Act of 1954, 42 USC 2011). The Energy Policy Act of 2005 revised
this definition as follows: The term ‘‘byproduct material’’ means –
(1) any radioactive material (except special nuclear material) yielded in or made radioactive
by exposure to the radiation incident to the process of producing or utilizing special
nuclear material;
(2) the tailings or wastes produced by the extraction or concentration of uranium or thorium
from any ore processed primarily for its source material content;
(3)
(A) any discrete source of radium-226 that is produced, extracted, or converted after
extraction, before, on, or after the date of enactment of this paragraph for use for a
commercial, medical, or research activity; or
(B) any material that –
(i) has been made radioactive by use of a particle accelerator; and
(ii) is produced, extracted, or converted after extraction, before, on, or after the
date of enactment of this paragraph for use for a commercial, medical, or
research activity; and
(4) any discrete source of naturally occurring radioactive material, other than source
material, that –
(A) the Commission, in consultation with the Administrator of the Environmental
Protection Agency, the Secretary of Energy, the Secretary of Homeland Security,
and the head of any other appropriate Federal agency, determines would pose a
threat similar to the threat posed by a discrete source of radium-226 to the public
health and safety or the common defense and security; and
(B) before, on, or after the date of enactment of this paragraph is extracted or converted
after extraction for use in commercial, medical, or research activity.
Certified waste – Waste that has been confirmed to comply with disposal site waste
acceptance criteria (e.g., the Waste Isolation Pilot Plant-Waste Acceptance Criteria for
transuranic waste, the DOE/NVO-325 criteria) under an approved certification program.
(DOE O 435.1 Chg 1)
Confinement system –
Any equipment, structure, or system, which limits the release and/or dispersion of a
hazardous/radioactive material within a facility. Examples are fume hoods, air locks,
ventilation systems, and may include containment and recovery systems. Confinement
systems may consist of multiple techniques and barriers depending upon the quantity of
tritium involved and the consequences of an uncontrolled release (U.S. DOE Tritium Focus
Group).
Section 101
A collection of barriers that can satisfy a specified leak criterion contingent upon operation of
its ancillary (active) system. Examples of confinement systems include: a glovebox and its
associated cleanup system, and a room with its associated cleanup system. Note that in the
context of this definition, a glovebox with an associated glovebox cleanup system is a
confinement system. A glovebox structure itself is a containment system if, and only if, the
specified leak criterion can be met by the structure itself (DOE-HDBK-1129-99).
An area having structures or systems from which releases of hazardous materials are
controlled. Primary confinement systems are process enclosures (gloveboxes, conveyors,
transfer boxes, and other spaces normally containing hazardous materials). Secondary
DOE-HDBK-1129-2008
B-3
confinement areas surround one or more primary confinement systems (operating area
compartments) (DOE O 435.1 Chg 1).
Containment system –
Any equipment, structure, or systems that serve as an integral and essentially leak tight
barrier against the uncontrolled release of hazardous/radioactive material to the
environment and other areas within the facility. Examples include process piping, sealed
containers, tanks, gloveboxes, and any other closed loop system, which holds the material
for possible recovery of tritium (U.S. DOE Tritium Focus Group).
A collection of passive barriers that can satisfy a specified leak criterion without operation of
any ancillary equipment. An example of a containment system is a series of piping and
vessels enclosing tritium gas operations. An example of a simple double containment
system is a container within another container with each container acting as a separate and
independent containment system; more intricate double containment systems have the
capability to monitor the volume between the containers for leak detection of the inner
container (DOE-HDBK-1129-99).
The assembly of components of the packaging intended to retain the radioactive material
during transport (10 CFR Part 71).
Controlled Area – Any area to which access is managed by or for DOE to protect
individuals from exposure to radiation and/or radioactive material (10 CFR 835).
Derived Air Concentration (DAC) – For the radionuclides listed in Appendix A of
10 CFR 835, the airborne concentration that equals the Annual Limit of Intake (ALI) divided
by the volume of air breathed by an average worker for a working year of 2,000 hours
(assuming a breathing volume of 2,400 m3) (DOE 10 CFR 835).
Derived Concentration Guide (DCG) – The concentration of a radio nuclide in air or water
that, under conditions of continuous exposure for one year by one exposure mode (i.e.,
ingestion of water, submersion in air, or inhalation), would result in an effective dose
equivalent of 100 mrem (1 mSv). DCGs do not consider decay products when the parent
radionuclide is the cause of the exposure (DOE Order 5400.5 Chg 2).
DOE/DOT Type A, approved shipping package – For the purpose of this text, these are
packages that can be used for the transport of Type A quantities of radioactive materials.
The two typical packages used for solids are metal 55-gallon drums with full removable lids
and metal boxes 4 feet wide by 4 feet high and 7 feet long with removable lids. DOT 7A
packages may be fabricated in almost any size to fit special needs like packaging of
gloveboxes.
Section 102
Documented Safety Analysis (DSA) – Documented safety analysis means a documented
analysis of the extent to which a nuclear facility can be operated safely with respect to
workers, the public, and the environment, including a description of the conditions, safe
boundaries, and hazard controls that provide the basis for ensuring safety (10 CFR 830).
Successor to the Safety Analysis.
DOE-HDBK-1129-2008
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Dose Assessment – Process of determining radiation dose and uncertainty included in the
dose estimate, through the use of exposure scenarios, bioassay results, monitoring data,
source term information and pathway analysis.
Dose Conversion Factor (DCF) – Dose per unit intake.
Dosimetric Model – A mathematical model that prescribes how to use the biokinetic and
radiation transport models to quantify the dose to specific organs and tissues and how to
calculate effective dose. The dosimetric models for STC are described primarily in ICRP
publications 67 and 71.
Facility segmentation – The concept of independent facility segments should be applied
where facility features preclude bringing material together or causing harmful interaction
from a common severe phenomenon. Therefore, the standard permits the concept of facility
segmentation provided the hazardous material in one segment could not interact with
hazardous materials in other segments. For example, independence of HVAC and piping
must exist in order to demonstrate independence for facility segmentation purposes. This
independence must be demonstrated and places the “burden of proof” on the analyst.
Additionally, material contained in DOT Type B shipping containers (with or without
overpack) may also be excluded from summation of a facility’s radioactive inventory if the
Certificates of Compliance are kept current and the materials stored are authorized by the
Certificate. However, Type B containers without overpack should have heat protection
provided by the facility’s fire suppression system (DOE-STD-1027-92, Chg 1, Rev. 1).
Free liquids – Liquids that readily separate from the solid portion of a waste under ambient
temperature and pressure. (DOE O 435.1 Chg 1)
Gastrointestinal (GI) Tract Model – A mathematical representation of the behavior of
radionuclides in the contents of the human gastrointestinal tract.
Hazard Category 1 – A facility in which the hazard analysis shows the potential for
significant off-site consequences. Category A reactors and facilities designated by PSO.
Regardless of the quantity of tritium, a facility that handles only tritium is not a Hazard
Category 1 facility unless it is designated so by the PSO (DOE-STD-1027-92, Chg 1,
Rev. 1).
Hazard Category 2 – A facility in which the hazard analysis shows the potential for
significant on-site consequences. Facilities with the potential for nuclear criticality events or
with sufficient quantities of hazardous material and energy, which would require on-site
emergency planning activities. The threshold tritium inventory for a tritium facility to be
designated as a Hazard Category 2 facility is 30 grams or 300,000 Ci (DOE-STD-1027-92,
Chg 1, Rev. 1).
Hazard Category 3 – A facility in which the hazard analysis shows the potential for only
significant localized consequences. Facilities included are those with quantities of
hazardous radioactive materials that meet or exceed values in Table A.1 of DOE-STD-1027-
97. The threshold for tritium is specified as 1.6 grams or 16,000 Ci (DOE-STD-1027-92,
Chg 1, Rev. 1).
Section 103
Hazardous materials – Those materials that are toxic, explosive, flammable, corrosive, or
otherwise physically or biologically health-threatening (DOE-STD-3009).
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B-5
Hazardous wastes – Those wastes that are designated hazardous by EPA regulations
(40 CFR 261) (DOE O 435.1 Chg 1).
Insoluble Metal Tritide (IMT) – A type of insoluble special tritium compound in which tritium
has formed a chemical bond to a metal.
Insoluble Special Tritium Compound – A special tritium compound, for which the tritium
cannot be rapidly taken up by the systemic compartment of the body.
Insoluble Tritiated Particle (ITP) – Any tritiated particle from which the tritium is not readily
released in air or aqueous solutions during the time interval over which the sample is
collected and initially analyzed. This time interval may vary significantly, typically ranging
from minutes to days.
Leak-tight – A leakage rate, which, “in a practical sense, precludes any significant release
of radioactive materials. This degree of containment is achieved by demonstration of a
leakage rate that is ≤ to 1 x 10-7 ref cm3/s of air, at an upstream pressure of 1 atmosphere
(atm) absolute, and a downstream pressure of 0.01 atm abs, or less. Note: A leakage rate
of 1 x 10-7 ref cm3/s is equal to 4.09E-12 gram-moles of dry air or helium, and is equivalent
to a helium leakage rate, under the same conditions, of approximately 2 x 10-7 cm3/s.” (ANSI
N14.5-1997))
Less than Hazard Category 3 Nuclear Facilities –
Facilities that do not meet or exceed Category 3 threshold criteria specified in DOE STD-
1027-92, Rev. 1, Table A.1, but still possess some amount of radioactive material may still
be considered Nuclear Facilities. The Category 3 threshold quantity of tritium is 16,000
curies. Less than Hazard Category 3 Nuclear Facilities are exempt from some requirements
such as development and maintenance of DSAs but are not exempt from other safety
requirements (DOE-STD-1027-92, Chg 1, Rev. 1).
Less than Hazard Category 3 Nuclear Facilities are those with an inventory of radiological
materials below the levels as defined in DOE-STD-1027-92, Chg 1, (currently 16,000 curies)
but above the reportable quantity value (currently 100 curies) listed in Appendix B to Table
302.4 (per 40 CFR 302). This lower limit of 100 curies is applicable to EM and DP facilities
(DOE-EM-STD-5502-94).
Low-level waste – Waste that contains radioactivity and is not classified as high-level
waste, transuranic waste, or spent nuclear fuel or 11e(2) byproduct material as defined by
this Order (DOE O 435.1 Chg 1). Test specimens of fissionable material irradiated for
research and development only, and not for the production of power or plutonium, may be
classified as low-level waste, provided the concentration of transuranic is less than 100
nCi/g. (DOE O 435.1 Chg 1).
Mixed waste – Waste containing both radioactive and hazardous components as defined by
the Atomic Energy Act and the Resource Conservation and Recovery Act, respectively
(DOE O 435.1 Chg 1).
Nonreactor nuclear facility – those facilities, activities or operations that involve, or will
involve, radioactive and/or fissionable materials in such form and quantity that a nuclear or a
DOE-HDBK-1129-2008
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nuclear explosive hazard potentially exists to workers, the public, or the environment, but
does not include accelerators and their operations and does not include activities involving
only incidental use and generation of radioactive materials or radiation such as check and
calibration sources, use of radioactive sources in research and experimental activities,
electron microscopes, and X-ray machines (10 CFR 830).
Section 104
Nuclear facility – means a reactor or a nonreactor nuclear facility where an activity is
conducted for or on behalf of DOE and includes any related area, structure, facility, or
activity to the extent necessary to ensure proper implementation of the requirements
established by this Part. (10 CFR 830) DOE-STD-1027-92, Chg 1 defines tritium inventory
thresholds for nuclear facilities.
Observed Activity – The apparent quantity of radioactive material within a particulate as
determined by liquid scintillation counting - without attempting to correct for beta particle
self-absorption, bremsstrahlung, or the emissions from HT or HTO.
Organically Bound Tritium (OBT) – A type of tritiated material in which the tritium has
formed a chemical bond with an organic material – typically via a carbon-tritium bond.
Primary containment – The first barrier to an uncontrolled release of hazardous/radioactive
material to the environment and/or other areas in the facility. The barrier may/may not serve
for containment of the radioactive material (U.S. DOE Tritium Focus Group).
Protective Action Guides (PAGs) – Projected numerical dose values established by EPA,
DOE, or States for individuals in the population. These values may trigger protective actions
that would reduce or avoid the projected dose.
Radioactive waste – Solid, liquid, or gaseous material that contains radionuclides regulated
under the Atomic Energy Act of 1954, as amended, and of negligible economic value
considering costs of recovery (DOE O 435.1 Chg 1).
Radiological area – Any area within a controlled area which must be posted as a “radiation
area,” “high radiation area,” “very high radiation area,” “contamination area,” “high
contamination area,” or “airborne radioactivity area” in accordance with 835.603
(10 CFR 835) (DOE 10 CFR 835).
Receiving and/or shipping area – An area or two different areas that have been
designated as radioactive materials Receiving and/or Shipping Areas and have been posted
for the receipt and shipment of packaged radioactive materials.
Receiving and/or Shipping, Storage Area – An area or two different areas that have been
designated as the Receiving and/or Shipping Area, Storage Area and have been posted for
the storage of packaged incoming and outgoing shipments of radioactive materials.
Reference man – A hypothetical aggregation of human (male and female) physical and
physiological characteristics arrived at by international consensus (ICRP Publication 23).
These characteristics may be used by researchers and public health workers to standardize
results of experiments and to relate biological insult from ionizing radiation to a common
base. The “reference man” is assumed to inhale 8,400 cubic meters of air in a year and to
ingest 730 liters of water in a year (DOE Order 5400.5 Chg 2).
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Release of property – As used in DOE Order 5400.5 Chg 2, it is the exercising of DOE’s
authority to release property from its control after confirming that residual radioactive
material (over which DOE has authority) on the property has been determined to meet the
guidelines for residual radioactive material in Chapter IV of DOE Order 5400.5 Chg 2 or any
other applicable radiological requirements. There may be instances in which DOE or other
authority will impose restrictions on the management and/or use of the property if the
residual radioactive material guidelines of Chapter IV of DOE Order 5400.5 Chg 2 are not
met or if other applicable Federal, state, or local requirements cause the imposition of such
restrictions (DOE Order 5400.5 Chg 2).
Section 105
Safety analysis – A documented process that:
• Provides systematic identification of hazards within a given DOE operation
• Describes and analyzes the adequacy of the measures taken to eliminate, control, or
mitigate identified hazards
• Analyzes and evaluates potential accidents and their associated risks (DOE Order
5400.5 Chg 2)
Safety-class structures, systems, and components (safety-class SSCs) – The term
safety-class structures, systems, and components means the structures, systems, or
components, including portions of process systems, whose preventive or mitigative function
is necessary to limit radioactive hazardous material exposure to the public, as determined
from safety analyses (10 CFR 830).
Safety-significant structures, systems, and components (safety-significant SSCs) –
the structures, systems, and components which are not designated as safety-class
structures, systems, and components, but whose preventive or mitigative function is a major
contributor to defense in depth and/or worker safety as determined from safety analyses (10
CFR 830).
Secondary containment – The second barrier to an uncontrolled release of hazardous or
radioactive materials to the environment and/or other areas in the facility. The barrier
may/may not serve for containment of the radioactive material (U.S. DOE Tritium Focus
Group).
Self-Absorption Factor for Beta Particles (SAFβ) – The fraction of beta particles emitted
from within a particulate that escapes the particulate.
Self-Absorption Factor for Energy (SAFe) – The fraction of energy emitted from within a
particulate that escapes the particulate.
Soil column – A system that incorporates an in-situ volume of soil through which liquid
waste percolates from ponds, cribs, seepage basins, or trenches with the primary purpose
being to retain suspended or dissolved radioactive material by absorption, ion exchange, or
physical entrainment. Unless used specifically for radionuclide disposal, areas such as
drain fields and natural ground surfaces or stream beds that may become contaminated as
a result of incidental exposure are not soil columns (Draft 10 CFR 834).
Soluble Tritiated Particle – Any tritiated particle from which the tritium is readily released in
air or aqueous solutions during the time interval over which the sample is collected and
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initially analyzed. This time interval may vary significantly, typically ranging from minutes to
days.
Source material – (1) uranium, thorium, or any other material which is determined by the
commission pursuant to the provisions of section 61 (42 USC 2091) to be source material;
or (2) ores containing one or more of the foregoing materials in such concentration as the
Commission may by regulation determine from time to time (Atomic Energy Act of 1954, 42
USC 2011).
Special nuclear material – (1) plutonium, uranium enriched in the isotope 233 or in the
isotope 235, and any other material which the Commission, pursuant to the provisions of
section 51 (42 USC 2017) determines to be special nuclear material, but does not include
source material; or (2) any material artificially enriched by any of the foregoing, but does not
include source material (Atomic Energy Act of 1954, 42 USC 2011).
Special Tritium Compound (STC) – Any compound, except for H2O, that contains tritium,
either intentionally (e.g., by synthesis) or inadvertently (e.g., by contamination mechanisms)
(10 CFR 835). Also referred to as tritiated material.
Section 106
Stochastic effects – Biological effects, the probability, rather than the severity, of which is a
function of the magnitude of the radiation dose without threshold; i.e., stochastic effects are
random in nature. Nonstochastic effects are biological effects, the severity of which, in
affected individuals, varies with the magnitude of the dose above a threshold value (DOE
Order 5400.5 Chg 2 Chg 2).
Technical safety requirements (TSRs) –Technical safety requirements (TSRs) means the
limits, controls, and related actions that establish the specific parameters and requisite
actions for the safe operation of a nuclear facility and include, as appropriate for the work
and the hazards identified in the documented safety analysis for the facility: Safety limits,
operating limits, surveillance requirements, administrative and management controls, use
and application provisions, and design features, as well as a bases appendix (10 CFR 830).
Tritiated Material – Any material containing at least an accountable amount of tritium.
Tertiary containment – The third barrier to an uncontrolled release of hazardous or
radioactive materials to the environment and/or other areas in the facility. The barrier
may/may not serve for containment of the radioactive material (U.S. DOE Tritium Focus
Group).
Treatment – Any method, technique, or process designed to change the physical or
chemical character of waste to render it less hazardous, safer to transport, store or dispose
of, or reduced in volume (DOE O 435.1 Chg 1).
Uptake – For STCs, the process by which the tritium atoms in STCs are taken into the
systemic compartment of the body. This process includes the uptake of tritium that has
been dissociated from the host molecule as well as the uptake of an entire STC molecule.
Waste container – A receptacle for waste, including any liner or shielding material that is
intended to accompany the waste in disposal (DOE O 435.1 Chg 1).
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Waste package – The waste, waste container, and any absorbent that are intended for
disposal as a unit. In the case of surface contaminated, damaged, leaking, or breached
waste packages, any overpack shall be considered the waste container, and the original
container shall be considered part of the waste (DOE O 435.1 Chg 1).
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APPENDIX C: ASSAY METHODS
There are a number of different assay methods used at the DOE tritium facilities. Most
facilities need assay equipment capable of measuring tritium in gaseous, solid, and liquid
form.
• Gas Analysis: For assay of gaseous tritium, most facilities use some form of mass
spectrometer ranging from quadrapole to large sophisticated light isotope drift tube
systems. Gas analysis equipment; especially gas analysis equipment which will
measure the low molecular weight gases like H2, HD, HT, D2, DT and T2 accurately; is
very expensive and requires a high degree of expertise to operate. These systems can
cost from fifty to several hundred thousand dollars.
• Solid (Metal Tritide): Tritium stored in solid form such as a metal tritide must either be
Section 107
decomposed to return it to the gas form for analysis, or the heat output of the solid
caused by the decay of tritium can be measured in a constant heat flow calorimeter. In
order to use calorimetry to measure the tritium quantity, it must be known that the item
being assayed does not contain any other radioactive component and that no chemical
reactions are taking place in the container. Constant heat flow calorimeters vary in
chamber size from a few cubic centimeters up to a few liters, and the item to be assayed
must be small enough to fit inside the calorimeter chamber. The constant heat flow
assay process is the most accurate assay method available if the chamber size and item
to be assayed are well matched.
• Liquid (HTO, DTO, T2O): Tritium at high concentrations in liquid form is generally
measured using calorimetry. Low concentrations of tritium in liquid form are generally
measured by using a scintillation counter. A sample of the liquid is mixed in a
scintillation cocktail, and the quantity of tritium in the sample is measured.
C.1 Measurement Accuracy and Safeguards and Security
The DOE Order in Nuclear Material Control and Accountability, DOE O 470.4-6 [36]
requires that tritium be accounted for to the hundredth of a gram (470.4-6) [36]. However,
most of the equipment and the techniques used cannot accurately determine the tritium
quantity to a hundredth of a gram once the quantity assayed exceeds about one half gram.
Sophisticated equipment is justified mostly for special process needs. Even sophisticated
equipment does not measure the quantity of tritium accurately to a hundredth of a gram
once the quantity exceeds about five grams. The assay technique to be used in an
operation or facility should be discussed with DOE safeguards and security to make sure
that it will meet the DOE needs for the facility safeguards and security category and the
activities performed in the facility.
C.2 Tritium Assay Analysis by PVT Mass Spectrometer
The most common method of assaying tritium in gaseous form, i.e., T2, HT, and DT, mixed
with other gases such as Ar, N2,, O2, and 3He, is referred to as “PVT mass spec.” The total
number of moles of gas, n, in a container is calculated using the equation
n = PV/zRT
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C-2
where P = pressure in the container in torr
V = volume of the container in liters
z = compressibility factor (See Table C.1)
R = constant = 62.3631 (See below)
T = temperature ( K)
In the formula, the container volume (V) is determined ahead of time by measurement using
a volume measuring system, or, if no other means is available, it may be calculated from the
physical dimension of the container. The gas pressure (P) and temperature (T) are
determined by measurement with available instruments at the time of the mass spec
sampling. R is a constant, which is a function of the units of pressure and volume used in
the equation and is equal to 62.3631 for pressure in torr and volume in liters.
The compressibility factor (z) is a function of gas type, pressure, and temperature and is
either determined from a compressibility table for tritium or estimated using a standard
equation such as
z(T2) = 1 + [(P (torr) x 0.000832)/1000]
This equation is for a temperature of 295 K.
Most operating facilities have established methods for determining the compressibility factor.
For those facilities that do not already have these methods established, Table C-1, Table of
Tritium Compressibility Factors, may be helpful.
Section 108
As an example, for a container with a volume of 22.414 L at a pressure of 760 torr and a
temperature of 273.15 K (Standard Temperature and Pressure (STP) conditions) the
number of moles is calculated as follows:
N = PV/zRT
= (760 x 22.414)/(1.000 x 62.3631 x 273.15)
= 1.0000 mole
Note: z(T2) at 273.15 K = 1.000.
The total moles of gas in the container at any time, t, is the sum of the moles of the
individual gases present in the mixture at that time or in equation form:
PV/zRT = n(Moles Total) = n(T2)+n(HT)+n(DT)+n(CT4)+n(qTw)+n(He-3)+n(N2)+ n(O2)+n(Ar)+n(etc.)
The n(qTw) represents a generic tritium-containing component. The “q” in, n(qTw), represents
any other element which may be present, and the “w” represents the number of tritium
atoms in the molecule. The n(etc.), represents any generic, non-radioactive, non-tritium
component.
From this equation, it follows that
PV/zRT = n(Moles Total) = n(Total Moles of Tritium Containing Gases) + n(Total Moles of Non-tritium Gases)
where
n(Total Moles of Tritium Containing Gases) = n(T2) + n(HT) + n(DT) + n(CT4) + n(qTw) + etc.
and
n(Total Moles of Non-Tritium Gases) = n(He-3) + n(N2) + n(O2) + n(Ar) + n(etc.) + etc.
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C-3
The number of moles of tritium in the container is the sum of the number of moles of tritium
in each tritium component. The number of moles of tritium in each tritium component is
equal to the number of moles of the component multiplied by the moles of tritium per mole of
component. The moles of tritium per mole of component is defined as the ratio of the
number of tritium atoms in the component chemical formula to the number of tritium atoms in
T2, i.e., 2.
n(Total Moles of Tritium)= 2n(T2) + 1n(HT) + 1n(DT) + 4CT4 + w n(qTw) + etc.
TABLE C-1. Table of tritium compressibility factors at 295 K
Z(T2) = 1 + {[(Patm x 760) x 0.000832]/1000}
P
(atm)
z(T2) P
(atm)
z(T2) P
(atm)
z(T2) P
(atm)
z(T2) P
(atm)
z(T2) P
(atm)
z(T2)
0.0 1.0000 3.0 1.0019 6.0 1.0038 9.0 1.0057 12.0 1.0076 15.0 1.0095
0.1 1.0001 3.1 1.0020 6.1 1.0039 9.1 1.0058 12.1 1.0077 15.1 1.0095
0.2 1.0001 3.2 1.0020 6.2 1.0039 9.2 1.0058 12.2 1.0077 15.2 1.0096
0.3 1.0002 3.3 1.0021 6.3 1.0040 9.3 1.0059 12.3 1.0078 15.3 1.0097
0.4 1.0003 3.4 1.0021 6.4 1.0040 9.4 1.0059 12.4 1.0078 15.4 1.0097
0.5 1.0003 3.5 1.0022 6.5 1.0041 9.5 1.0060 12.5 1.0079 15.5 1.0098
0.6 1.0004 3.6 1.0023 6.6 1.0042 9.6 1.0061 12.6 1.0080 15.6 1.0099
0.7 1.0004 3.7 1.0023 6.7 1.0042 9.7 1.0061 12.7 1.0080 15.7 1.0099
0.8 1.0005 3.8 1.0024 6.8 1.0043 9.8 1.0062 12.8 1.0081 15.8 1.0100
0.9 1.0006 3.9 1.0025 6.9 1.0044 9.9 1.0063 12.9 1.0082 15.9 1.0101
1.0 1.0006 4.0 1.0025 7.0 1.0044 10.0 1.0063 13.0 1.0082 16.0 1.0101
1.1 1.0007 4.1 1.0026 7.1 1.0045 10.1 1.0064 13.1 1.0083 16.1 1.0102
1.2 1.0008 4.2 1.0027 7.2 1.0046 10.2 1.0064 13.2 1.0083 16.2 1.0102
0.1 1.0001 4.3 1.0027 7.3 1.0046 10.3 1.0065 13.3 1.0084 16.3 1.0103
1.4 1.0009 4.4 1.0028 7.4 1.0047 10.4 1.0066 13.4 1.0085 16.4 1.0104
1.5 1.0009 4.5 1.0028 7.5 1.0047 10.5 1.0066 13.5 1.0085 16.5 1.0104
1.6 1.0010 4.6 1.0029 7.6 1.0048 10.6 1.0067 13.6 1.0086 16.6 1.0105
1.6 1.0010 4.7 1.0030 7.7 1.0049 10.7 1.0068 13.7 1.0087 16.7 1.0106
1.8 1.0011 4.8 1.0030 7.8 1.0049 10.8 1.0068 13.8 1.0087 16.8 1.0106
1.9 1.0012 4.9 1.0031 7.9 1.0050 10.9 1.0069 13.9 1.0088 16.9 1.0107
2.0 1.0013 5.0 1.0032 8.0 1.0051 11.0 1.0070 14.0 1.0089 17.0 1.0107
2.1 1.0013 5.1 1.0032 8.1 1.0051 11.1 1.0070 14.1 1.0089 17.1 1.0108
2.2 1.0014 5.2 1.0033 8.2 1.0052 11.2 1.0071 14.2 1.0090 17.2 1.0109
2.3 1.0015 5.3 1.0034 8.3 1.0052 11.3 1.0071 14.3 1.0090 17.3 1.0109
2.4 1.0015 5.4 1.0034 8.4 1.0053 11.4 1.0072 14.4 1.0091 17.4 1.0110
2.5 1.0016 5.5 1.0035 8.5 1.0054 11.5 1.0073 14.5 1.0092 17.5 1.0111
2.6 1.0016 5.6 1.0035 8.6 1.0054 11.6 1.0073 14.6 1.0092 17.6 1.0111
2.7 1.0017 5.7 1.0036 8.7 1.0055 11.7 1.0074 14.7 1.0093 17.7 1.0112
2.8 1.0018 5.8 1.0037 8.8 1.0056 11.8 1.0075 14.8 1.0094 17.8 1.0113
2.9 1.0018 5.9 1.0037 8.9 1.0056 11.9 1.0075 14.9 1.0094 17.9 1.0113
3.0 1.0019 6.0 1.0038 9.0 1.0057 12.0 1.0076 15.0 1.0095 18.0 1.0114
Section 109
DOE-HDBK-1129-2008
C-4
Table C-1. Table of Tritium Compressibility Factors at 295 K (continued)
Z(T2) = 1 + {[(Patm x 760) x 0.000832]/1000}
P
(atm)
z(T2) P
(atm)
z(T2) P
(atm)
z(T2) P
(atm)
z(T2) P
(atm)
z(T2) P (atm) z(T2)
18.0 1.0114 21.0 1.0133 24.0 1.0152 27.0 1.0171 30.0 1.0190 33.0 1.0209
18.1 1.0114 21.1 1.0133 24.1 1.0152 27.1 1.0171 30.1 1.0190 33.1 1.0209
18.2 1.0115 21.2 1.0134 24.2 1.0153 27.2 1.0172 30.2 1.0191 33.2 1.0210
18.3 1.0116 21.3 1.0135 24.3 1.0154 27.3 1.0173 30.3 1.0192 33.3 1.0211
18.4 1.0116 21.4 1.0135 24.4 1.0154 27.4 1.0173 30.4 1.0192 33.4 1.0211
18.5 1.0117 21.5 1.0136 24.5 1.0155 27.5 1.0174 30.5 1.0193 33.5 1.0212
18.6 1.0118 21.6 1.0137 24.6 1.0156 27.6 1.0175 30.6 1.0193 33.6 1.0212
18.7 1.0118 21.7 1.0137 24.7 1.0156 27.7 1.0175 30.7 1.0194 33.7 1.0213
18.8 1.0119 21.8 1.0138 24.8 1.0157 27.8 1.0176 30.8 1.0195 33.8 1.0214
18.9 1.0120 21.9 1.0138 24.9 1.0157 27.9 1.0176 30.9 1.0195 33.9 1.0214
19.0 1.0120 22.0 1.0139 25.0 1.0158 28.0 1.0177 31.0 1.0196 34.0 1.0215
19.1 1.0121 22.1 1.0140 25.1 1.0159 28.1 1.0178 31.1 1.0197 34.1 1.0216
19.2 1.0121 22.2 1.0140 25.2 1.0159 28.2 1.0178 31.2 1.0197 34.2 1.0216
19.3 1.0122 22.3 1.0141 25.3 1.0160 28.3 1.0179 31.3 1.0198 34.3 1.0217
19.4 1.0123 22.4 1.0142 25.4 1.0161 28.4 1.0180 31.4 1.0199 34.4 1.0218
19.5 1.0123 22.5 1.0142 25.5 1.0161 28.5 1.0180 31.5 1.0199 34.5 1.0218
19.6 1.0124 22.6 1.0143 25.6 1.0162 28.6 1.0181 31.6 1.0200 34.6 1.0219
19.7 1.0125 22.7 1.0144 25.7 1.0163 28.7 1.0181 31.7 1.0200 34.7 1.0219
19.8 1.0125 22.8 1.0144 25.8 1.0163 28.8 1.0182 31.8 1.0201 34.8 1.0220
19.9 1.0126 22.9 1.0145 25.9 1.0164 28.9 1.0183 31.9 1.0202 34.9 1.0221
20.0 1.0126 23.0 1.0145 26.0 1.0164 29.0 1.0183 32.0 1.0202 35.0 1.0221
20.1 1.0127 23.1 1.0146 26.1 1.0165 29.1 1.0184 32.1 1.0203 35.1 1.0222
20.2 1.0128 23.2 1.0147 26.2 1.0166 29.2 1.0185 32.2 1.0204 35.2 1.0223
20.3 1.0128 23.3 1.0147 26.3 1.0166 29.3 1.0185 32.3 1.0204 35.3 1.0223
20.4 1.0129 23.4 1.0148 26.4 1.0167 29.4 1.0186 32.4 1.0205 35.4 1.0224
20.5 1.0130 23.5 1.0149 26.5 1.0168 29.5 1.0187 32.5 1.0206 35.5 1.0224
20.6 1.0130 23.6 1.0149 26.6 1.0168 29.6 1.0187 32.6 1.0206 35.6 1.0225
20.7 1.0131 23.7 1.0150 26.7 1.0169 29.7 1.0188 32.7 1.0207 35.7 1.0226
20.8 1.0132 23.8 1.0150 26.8 1.0169 29.8 1.0188 32.8 1.0207 35.8 1.0226
20.9 1.0132 23.9 1.0151 26.9 1.0170 29.9 1.0189 32.9 1.0208 35.9 1.0227
21.0 1.0133 24.0 1.0152 27.0 1.0171 30.0 1.0190 33.0 1.0209 36.0 1.0228
To determine the component in the gas and the number of moles of each component in the
gas, a sample of the container gas is analyzed, and the mole percent of each gas is
determined. This gas analysis results in a number for each component in the mixture, which
represents the mole percent of each gas at the time of the analysis. The mole percent (m%)
is calculated by
m%(component) = (Moles of a component/Moles Total) x 100
Therefore, the Mole Percent Total (m%(Total)) is
m%(Total) = 100 = m%(T2)+ m%(HT)+ m%(DT)+ m%(CT4)+ m%(qTw) + m%(He-3)+ m%(N2)+ m%(O2) + m%
(etc.)
The number of moles of each gas component in the container is calculated by
n(Moles of Component) = (m%(component) /100) x n(Total Moles)
DOE-HDBK-1129-2008
C-5
The grams of each component can then be calculated using the formula
Grams of Component = (m%(component)/100) x (n(Total Moles)) x (Gram Molecular Weight of
Component)
The following is the process used to determine the number of moles and grams of tritium in
the HT component in a container.
Section 110
1. Calculate the total moles of material in the container.
2. Analyze the sample using a mass spectrometer to determine the mole percent of HT.
3. Calculate the number of moles of HT in the container.
4. Calculate the number of grams of HT in the container.
5. Multiply the moles of HT by ½ to determine the moles of T2 in the HT component.
6. Multiply the moles of HT by ½ and by the gram molecular weight of tritium to determine
the grams of tritium in the HT component.
In steps 5 and 6, the ½ is used because it is the ratio of the number of tritium atoms in HT to
the number of tritium atoms in T2 (HT/T2 = 1/2).
The percent tritium in the container is the sum of the mole percent of each tritium
component multiplied by the number of moles of tritium per mole of the tritium component.
The moles of tritium per mole of component is equal to the ratio of the number of tritium
atoms in the component chemical formula to the number of tritium atoms in T2; i.e., 2. This
can be expressed as the following formula:
m%(Tritium Per Mole Total)= 2 m%(T2)+ 1 m%(HT) +1 m%(DT)+ 4m%(CT4)+ 2w m%(qTw)+ etc.
The moles of tritium in the container are the sum of the moles of tritium contained in each
component in the container. This is calculated using the following equation, which is the
ratio of the tritium atoms in the component chemical formula to the tritium atoms in T2; i.e., 2.
In the formula qTw/T2 this would be w/2, or in HT/T2 this would be1/2.
Moles of Tritium = [(m%(T2)/100) x (T2/T2) x n(Moles Total)] + [(m%(HT)/100) x (HT/T2) x n(Moles
Total)] + [(m%(DT)/100) x (DT/T2) x n(Moles Total)] + [(m%(CT4)/100) x
(CT4/T2) x n(Moles Total)] + [(m%(qTw)/100) x (qTw/T2) x n(Moles Total)] + …
where x/T2 is the number of moles of tritium per mole of the tritium component.
Factoring out n(Moles Total)/100 and rearranging, the equation becomes
(Moles of tritium x 100)/(n(Moles Total)) = (m%(T2)+ m%(HT)x 1/2 + m%(DT) x 1/2 + m%(CT4) x 2 +
m%(qTw) x w/2 + etc.)
= m%(Tritium Per Mole Total)
Rearranging the equation becomes
Moles of tritium = (n(Moles Total) x m%(Tritium Per Mole Total))/100
The amount of tritium in grams is obtained by multiplying the moles of tritium obtained in the
last equation by the gram molecular weight of tritium (6.0321g).
DOE-HDBK-1129-2008
C-6
As an example, the grams of tritium in a shipment of research grade tritium are determined
using the following process.
An analysis of a shipment of research grade gaseous tritium shows the following:
Component Percent
T2
D2
DT
HT
HD
3He
Ar
N2
H2
99.704
0.115
0.079
0.050
0.023
0.016
0.012
0.010
0.005
The container pressure is 742 mm, temperature is 20oC, and volume is 49.348 liters. This
gives a compressibility factor (z(T2)) of 1.0006 and the constant, R, i+s 62.3631.
Calculating the percent tritium is as follows:
m%(Tritium Per Mole Total) = m%(T2) + m%(HT) x 1/2 + m%(DT) x 1/2
= 99.704 + (0.050 x 1/2) + (0.079 x 1/2)
= 99.704 + 0.025 + 0.0395
= 99.7685 percent
The number of moles of gas in the container is calculated by
n(Moles Total) = PV/zRT
= (742 x 49.348)/(1.0006 x 62.3631 x 293.15)
= 2.002 moles total
The amount of tritium in grams is
Grams of Tritium = (n(Moles Total) x m%(Tritium Per Mole Total) x 6.0321)/100
= (2.002 x 6.0321 x 99.7685)/100
= 12.046 grams tritium
Section 111
The determination of the amount of tritium is only for the point in time that the sample was
analyzed as a result of the decay of tritium. Over time, the number of moles of the gases
containing tritium decreases. The pressure and number of moles of non-tritiated gases
increase with time due to the 3He produced and the molecules formed by the atoms of other
materials released when the tritium decays. Therefore, the mole percent and number of
moles of gas in the container and in the sample change with time. Figure C-1 shows an
example of the changing moles in a gas mixture.
DOE-HDBK-1129-2008
C-7
0
5
10
15
20
25
30
35
40
45
0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300
Elapsed Time In Days
M
ol
e
Pe
rc
en
t O
f E
ac
h
C
om
po
ne
nt
A
t T
im
e
t
M%He3At-t
M%T2At-t
M%ArAt-t
m% Ar
m% T2
m% He3
FIGURE C-1. Change in mole percent with time in a mixture of 40% T2, 40% 3He and 20%
Ar
The total number of moles in the container is known at the time of the sampling but not at
the time of the analysis. If the gas analysis is performed on the same day as the sampling,
then, since the half-life of tritium is 4500.88 days, the error caused by the decay is small (<
0.015 percent for 1 day, approximately 1 percent in 67 days). Some facilities are equipped
to perform the sample analysis within a few minutes or on the same day as the sampling.
Others facilities must depend upon collecting a gas sample, on the sampling date, for
analysis at a later date.
The following equations include three significant dates. The Sample Date is the day the gas
sample for analysis is collected, and the pressure, volume, and temperature of the container
are measured and recorded to determine the total moles of gas. The Analysis Date is the
date the gas sample is analyzed to determine the mole percent of tritium per mole in the
sample. The Book Value Date is a date on which the quantity of tritium in the container is
known from a previous assay. Additionally, it assumes a gaseous mixture at the start of
100% tritium and other stable gases; i.e., it does not contain HT, DT, HTO, or other
radioactive or non-inert gases.
The process steps are as follows:
1. Calculating the number of moles of gas in the container on the Sampling Date.
2. Determining the percent of tritium in the collected sample on the Analysis Date by gas
analysis.
DOE-HDBK-1129-2008
C-8
3. Using the two values in steps 1 and 2, the time period, in days, between the two dates
and the half-life of tritium, calculating the number of grams of tritium in the container on
the Sampling Date.
Once the quantity of tritium in the container on the Sampling Date is known, the quantity of
tritium in the container for any other date, including the Book Value Date can be calculated.
The number of moles of gas in the container on the Sampling Date (n(TotCSmplDa)) is the sum
of the number of moles of the non-tritiated gases present in the container, which do not
change with time due to decay, (n(Non-tritium)), plus the number of moles of tritium in the
container at the time of the sampling (n(T2CSmplDa)). In equation form
PV/zRT = n(TotCSmplDa)
= n(Non-tritium) + n(T2CSmplDa)
Rearranging the equation it becomes
n(Non-tritium) = n(TotCSmplDa) - n(T2CSmplDa) {1}
The total number of moles of material in the container on the Analysis Date, (n(TotCAnlDa)) is
n(TotCAnlDa) = n(Non-tritium) + n(T2CSmplDa) x e((t ln(0.5))/4500.88) + 2 x (n(T2CSmplDa) - n(T2CSmplDa)
e((t x ln(0.5))/4500.88))
Section 112
where n(Non-tritium) = sum of the moles of the other gases
(n(T2CSmplDa) (e((t ln(0.5))/4500.88)) = number of moles of T2 decayed
2 x (n(T2CSmplDa) - n(T2CSmplDa) e((t ln(0.5))/4500.88)) = number of moles of 3He created
t = time between the Sampling Date and Analysis Date in days
Factoring, the equation becomes
n(TotCAnlDa) = n(Non-tritium) + n(T2CSmplDa) x (2 - e((t x ln(0.5))/4500.88)) {2}
On the day the gas analysis is performed, the mole percent of tritium (m%(T2MAnlDa)) is
determined by gas analysis. The equation is
m%(T2MAnlDa) is equal to the number of moles of tritium on the sampling date decayed to the
analysis date; i.e., (n(T2CSmplDa) x e((t x ln(0.5))/4500.88)) divided by the number of moles in the
sampled container on the analysis date; i.e., (n(TotCAnlDa)) multiplied by 100 to convert it to
percent.
m%(T2MAnlDa)={(n(T2CSmplDa)e((txln(0.5))/4500.88))/n(TotCAnlDa)} x 100
where (n(T2CSmplDa) x e((t x ln(0.5))/4500.88)) = number of decayed moles of T
(n(TotCAnlDa)) = number of moles in the sample on the Analysis Date
t = time between the Sampling Date and Analysis Date in days
Rearranging the equation, it becomes
n(TotCAnlDa) = {(n(T2CSmplDa) e ((t x ln(0.5))/4500.88))/m%(T2MAnlDa)} x 100 {3}
DOE-HDBK-1129-2008
C-9
Substituting Equation {1} into Equation {2}, we have
n(TotCAnlDa) = n(TotCSmplDa) - n(T2CSmplDa) + n(T2CSmplDa) x (2 - e((t x ln(0.5))/4500.88))
Rearranging the equation, it becomes
n(TotCAnlDa) = n(TotCSmplDa) + n(T2CSmplDa) x (1 - e((t x ln(0.5))/4500.88)) {4}
Substituting Equation {3} into Equation {4}, we have
100 (n(T2CSmplDa) e ((t x ln(0.5))/4500.88))/ m%(T2MAnlDa)= n(TotCSmplDa) + n(T2CSmplDa) (1- e ((t
xln(0.5))/4500.88))
Multiplying through by m%(T2MAnlDa), it becomes
100 (n(T2CSmplDa) e ((t x ln(0.5))/4500.88))= m%(T2MAnlDa) n(TotCSmplDa) + m%(T2MAnlDa) n(T2CSmplDa) (1- e
((t x ln(0.5))/4500.88))
Rearranging and factoring, we have
n(T2CSmplDa) = (n(TotCSmplDa) x m%(T2MAnlDa))/((e((t x ln(0.5))/4500.88) x (100 + m%(T2MAnlDa))) -
m%(T2MAnlDa))
The quantity of tritium in grams is then the number of moles of tritium on the Sampling Date,
n(T2CSmplDa),,multiplied by the gram molecular weight of tritium (6.03210 g) or
Grams T2 On Sampling Date = 6.0321 x (PV/zRT) x (m%(T2MAnlDa))
[e((t x ln(0.5))/4500.88) x (100 + m%(T2MAnlDa))] - m%(T2MAnlDa)
If a container has pure tritium mixed with other non-decaying and non-chemically reacting
gases on the Book Value Date, sampled on the Sample Date and analyzed on the Analysis
Date, then the gram of tritium in the container on the Sample Date can be calculated using
the derived formula, the PV/zRT data and the m%(T2MAnlDa) data measured on the Analysis
Date.
Figure C-2 is a graph of the changes in the moles of material taking place in a container of
pure T2 versus time over a period of six tritium half-lifes. The graph shows the moles of
tritium decreasing from 1.0 and approaching 0.0, the 3He increasing from 0.0 and
approaching 2.0, and the total moles increasing from 1.0 and approaching 2.0.
DOE-HDBK-1129-2008
C-10
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
1.60
1.80
2.00
0.0
00
3.0
81
6.1
62
9.2
42
12.
32
3
15.
40
4
18.
48
5
21.
56
5
24.
64
6
27.
72
7
30.
80
8
33.
88
8
36.
96
9
40.
05
0
43.
13
1
46.
21
1
49.
29
2
52.
37
3
55.
45
4
58.
53
4
61.
61
5
64.
69
6
67.
77
7
70.
85
7
73.
93
8
Elapsed Time In Years In Increments Of 1/4 Half Life
Section 113
M
ol
es
P
er
M
ol
e
O
f T
rit
iu
m
A
t t
=0
MHe3At-t
MT2At-t
MTotAt-t
FIGURE C-2. Moles of T2 and 3He versus time
Similar formulas can be derived for other two-component gases, such as HT mixed with
other non-tritiated gases and DT mixed with other non-tritiated gases. See Figures C-3 to
C-6 for other examples.
0.00
0.25
0.50
0.75
1.00
1.25
1.50
0.0
00
3.0
81
6.1
62
9.2
42
12.
32
3
15.
40
4
18.
48
5
21.
56
5
24.
64
6
27.
72
7
30.
80
8
33.
88
8
36.
96
9
40.
05
0
43.
13
1
46.
21
1
49.
29
2
52.
37
3
55.
45
4
58.
53
4
61.
61
5
64.
69
6
67.
77
7
70.
85
7
73.
93
8
Elapsed Time In Years In 1/4 Half Life Increments
M
ol
es
O
F
Ea
ch
C
om
po
ne
nt
P
er
M
ol
e
O
f D
T
At
t=
0
MHe3At-t
MDTAt-t
MD2At-t
MT2asDTAt-t
MTotAt-t
3He
D 2
DT
Moles Total
Moles T2
as DT
DOE-HDBK-1129-2008
C-11
FIGURE C-3. Moles of DT, 3He, and D2 versus time
0
10
20
30
40
50
60
70
80
90
100
0.000 6.162 12.323 18.485 24.646 30.808 36.969 43.131 49.292 55.454 61.615 67.777 73.938
Elapsed Time In Years In 1/4 Half Life Increments
M
ol
e
Pe
rc
en
t O
f E
ac
h
C
om
po
ne
nt
A
t T
im
e
t
M%He3At-t
M%DTAt-t
M%D2At-t
M%T2/MtotAt-t
DT
He3
T2
D2
FIGURE C-4. Mole percent of T2, D2, DT, and 3He versus time
0.00
10.00
20.00
30.00
40.00
50.00
60.00
70.00
80.00
90.00
0.0
00
3.0
81
6.1
62
9.2
42
12.
32
3
15.
40
4
18.
48
5
21.
56
5
24.
64
6
27.
72
7
30.
80
8
33.
88
8
36.
96
9
40.
05
0
43.
13
1
46.
21
1
49.
29
2
52.
37
3
55.
45
4
58.
53
4
61.
61
5
64.
69
6
67.
77
7
70.
85
7
73.
93
8
Elapsed Time In Years In 1/4 Half Life Increments
M
ol
e
Pe
rc
en
t O
f E
ac
h
C
om
po
ne
nt
A
t T
im
e
t
M%He3At-t
M%T2At-t
M%ArAt-t
3He
T2
Ar
DOE-HDBK-1129-2008
C-12
FIGURE C-5.40% T2, 40% 3He, and 20% Ar - Changes in mole percent
of components versus time
0.00
10.00
20.00
30.00
40.00
50.00
60.00
70.00
0.000 6.162 12.323 18.485 24.646 30.808 36.969 43.131 49.292 55.454 61.615 67.777 73.938
Elapsed Time In Increments Of 1/4 Half Life
M
ol
e
Pe
rc
en
t O
f C
om
po
ne
nt
A
t T
im
e
t
M%He3At-t
M%DTAt-t
M%D2At-t
M%ArAt-t
m% He3
m% DT
m% AR
m% D2
FIGURE C-6. 40% DT, 40% 3He, and 20% Ar, Change in mole percent
of each component versus time
C.3 Calorimetry Assay
Calorimetry is the quantitative measurement of heat. A calorimeter is an apparatus for
measuring heat quantities generated in or emitted by materials in processes such as
chemical reaction, changes of state, and formation of solutions. Heat is generally measured
in calories or joules. A calorie is a unit of heat energy equal to the heat energy required to
raise the temperature of a gram of water from 14.5 to 15.5oC, at a constant pressure of 1
atmosphere. A calorie is equal to 4.186 joules.
A calorimeter designed to be used in processes that continually generate heat (power
sources) and measures power instead of heat is called a Constant Heat Flow (CHF)
calorimeter. A CHF calorimeter measures the power (joules/second) of a source not the
heat output (joules) of a source. The power is usually measured in Watts, which is a unit of
power equal to 1 joule/second.
A radioactive material is a power source, which deposits the energy due to decay in the
radioactive material itself and in the materials surrounding the radioactive material. The
power generated by the decay of tritium has been measured and is equal to 0.3240 ±
0.0009 Watts/gram of tritium.
Section 114
Mound Laboratory has been the leader in the design, fabrication, calibration, and operation
of CHF calorimeters for many years. Mound has specialized in the development of CHF
DOE-HDBK-1129-2008
C-13
calorimeters to be used in the measurement of radioactive material quantities by measuring
their power output. CHF calorimeters are generally designed to meet the specific needs of
the items to be assayed and are limited in application by the following:
• Physical size of the calorimeter measurement chamber,
• Wattage range of the measurement system,
• Precision and accuracy of the measurement for the size and wattage range of the item
to be measured,
• Throughput or number of samples to be measured per day.
CHF calorimeters have been designed in many different configurations, such as over/under,
and twin. Most CHF systems in use today use digital control systems operated by a stored
program and are easy to operate. The steps in making a CHF measurement are generally
as follows:
• Install a dummy mass in the calorimeter container, pack steel or copper wool around the
dummy mass, and install it in the measurement chamber.
• Make a zero baseline run at a wattage level (Wzbl), which is at a wattage level greater
than the unknown wattage level of the sample to be measured.
• During the baseline run, the digital control system establishes a calorimeter bridge
voltage value for a known (Wzbl) wattage input.
• Remove the calorimeter container from the measurement chamber, remove the dummy
sample from the container, replace it with the sample to be measured, place it back in
the measurement chamber, and make an unknown sample run.
• During the unknown sample run, the digital control system decreases the power in the
calorimeter until the bridge voltage is the same as that measured in the zero baseline
run.
• The power input to the calorimeter during this unknown sample run (Wusr) is measured.
• The power of the sample being measured (Ws) is calculated by subtracting the wattage
value measured during the zero baseline run from the wattage measured during the
unknown sample run to find the wattage of the sample. In equation form:
Ws = Wzbl - Wusr
The calorimeter factor for tritium used at most DOE sites for the purposes of reporting
accountable quantities of tritium to DOE is 0.3240 +/- 0.0009 Watts/g of tritium.
CHF calorimetry can be used to measure tritium in solid form. CHF is the most accurate
method available for the measurement of tritium quantities if the chamber size and wattage
level of the item to be measured are well matched to the specifications of the CHF system
being used. CHF systems, however
• Do not provide any information about the different gases present in a container (e.g., HT,
DT, H2, D2, 3He),
• Only measure the quantity of tritium in the container,
• Are not currently available for items larger than 11 inches in diameter and 16 inches
long, and
• Take several hours to complete a single measurement.
DOE-HDBK-1129-2008
C-14
This page is intentionally blank.
DOE-HDBK-1129-2008
D-1
APPENDIX D: CONTAMINATION AND SURFACE
ACTIVITY THRESHOLDS
D.1 Appendix D to Part 835 - Surface Radioactivity Values
The data presented in Appendix D are to be used in identifying contamination and high
contamination areas as defined in Sec. 835.2(a), identifying the need for surface
contamination monitoring and control in accordance with Sec. 835.404, identifying the need
for radioactive material controls in accordance with Sec. 835.1101.
Section 115
Surface Radioactivity Values {1}
[In dpm/100 cm2]
Radionuclide
Removable
{2}, {4}
Total (fixed +
removable) {2},
{3}
U-nat, U-235, U-238, and associated decay products 1,000{7} 5,000
Transuranics, Ra-226, Ra-228, Th-230, Th-228, Pa-231, Ac-227,
I-125, I-129
20 500
Th-nat, Th-232, Sr-90, Ra-223, Ra-224, U-232, I-126, I-131, I-133 200 1,000
Beta-gamma emitters (nuclides with decay modes other than
alpha emission or spontaneous fission) except Sr-90 and others
noted above {5}
1,000 5,000
Tritium and tritiated compounds {6} 10,000 See footnote 6
{1} The values in this Appendix, with the exception noted in footnote 6, apply to radioactive contamination
deposited on, but not incorporated into the interior of, the contaminated item. Where surface contamination by
both alpha- and beta-gamma-emitting nuclides exists, the limits established for alpha- and beta-gamma-emitting
nuclides apply independently.
{2} As used in this table, dpm (disintegrations per minute) means the rate of emission by radioactive material as
determined by correcting the counts per minute observed by an appropriate detector for background, efficiency,
and geometric factors associated with the instrumentation.
{3} The levels may be averaged over one square meter provided the maximum surface activity in any area of 100
cm2 is less than three times the value specified. For purposes of averaging, any square meter of surface should
be considered to be above the surface radioactivity value if (1) from measurements of a representative number
of sections it is determined that the average contamination level exceeds the applicable value; or (2) it is
determined that the sum of the activity of all isolated spots or particles in any 100 cm2 area exceeds three times
the applicable value.
{4} The amount of removable radioactive material per 100 cm2 of surface area should be determined by swiping
the area with dry filter or soft absorbent paper, applying moderate pressure, and then assessing the amount of
radioactive material on the swipe with an appropriate instrument of known efficiency. (Note—The use of dry
material may not be appropriate for tritium.) When removable contamination on objects of surface area less than
100 cm2 is determined, the activity per unit area should be based on the actual area, and the entire surface
should be wiped. It is not necessary to use swiping techniques to measure removable contamination levels if
direct scan surveys indicate that the total residual surface contamination levels are within the limits for removable
contamination.
{5} This category of radionuclides includes mixed fission products, including the Sr-90 which is present in them.
It does not apply to Sr-90 which has been separated from the other fission products or mixtures where the Sr-90
has been enriched.
{6} Tritium contamination may diffuse into the volume or matrix of materials. Evaluation of surface contamination
shall consider the extent to which such contamination may migrate to the surface in order to ensure the surface
DOE-HDBK-1129-2008
D-2
contamination value provided in this appendix is not exceeded. Once this contamination migrates to the surface,
it may be removable, not fixed; therefore, a "Total" value does not apply. In certain cases, a "Total" value of
10,000 dpm/100 cm2 may be applicable either to metals of the types from which insoluble special tritium
compounds are formed, that have been exposed to tritium, or to bulk materials to which insoluble special tritium
compound particles are fixed to a surface.
Section 116
{7} These limits apply only to the alpha emitters within the respective decay series.
D.2 Response to Questions and Clarification of Requirements and Processes: DOE
Order 5400.5 Chg 2, Section II.5 and Chapter IV Implementation (Requirements
Relating to Residual Radioactive Materials), DOE Office of Assistant Secretary for
Environment, Safety and Health, dated November 17, 1995
TABLE 1 SURFACE ACTIVITY GUIDELINES
Allowable Total Residual Surface Activity (dpm/100 cm2)4
Radionuclides5 Average6/7 Maximum9/
8
Removable9
Group 1 – Transuranics, I-125, I-129, Ac-227, Ra-226,
Ra-228, Th-228, Th-230, Pa-231
100 300 20
Group 2 – Th-natural, Sr-90, I-126, I-131, I-133,
Ra-223, Ra-224, U-232, Th-232
1,000 3,000 200
Group 3 – U-natural, U-235, U-238, and associated
decay products, alpha emitters
5,000 15,000 1,000
Group 4 – Beta-gamma emitters (radionuclides with
decay modes other than alpha emission or
spontaneous10 fission) except Sr-90 and others noted
above7
5,000 15,000 1,000
Tritium (applicable to surface and subsurface)11 N/A N/A 10,000
4 As used in this table, dpm (disintegrations per minute) means the rate of emission by radioactive
material as determined by counts per minute measured by an appropriate detector for
background, efficiency, and geometric factors associated with the instrumentation.
5 Where surface contamination by both alpha- and beta-gamma-emitting radionuclides exists, the
limits established for alpha- and beta-gamma-emitting radionuclides should apply independently.
6 Measurements of average contamination should not be averaged over an area of more than
1 m2. For objects of smaller surface area, the average should be derived for each such object.
7 The average and maximum dose rates associated with surface contamination resulting from beta-
gamma emitters should not exceed 0.2 mrad/h and 1.0 mrad/h, respectively, at 1 cm.
8 The maximum contamination level applies to an area of not more than 100 cm2.
9 The amount of removable material per 100 cm2 of surface area should be determined by wiping
an area of that size with dry filter or soft absorbent paper, applying moderate pressure, and
measuring the amount of radioactive material on the wiping with an appropriate instrument of
known efficiency. When removable contamination on objects of surface area less than 100 cm2
is determined, the activity per unit area should be based on the actual area, and the entire
surface should be wiped. It is not necessary to use wiping techniques to measure removable
contamination levels if direct scan surveys indicate that the total residual surface contamination
levels are within the limits for removable contamination.
DOE-HDBK-1129-2008
D-3
10 This category of radionuclides includes mixed fission products, including the Sr-90 that is present
in them. It does not apply to Sr-90 that has been separated from the other fission products or
mixtures where the Sr-90 has been enriched.
11 Property recently exposed or decontaminated should have measurements (smears) at regular
time intervals to ensure that there is not a build-up of contamination over time. Because tritium
typically penetrates material it contacts, the surface guidelines in Group 4 are not applicable to
tritium. The Department has reviewed the analysis conducted by the DOE Tritium Surface
Contamination Limits Committee (“Recommended Tritium Surface Contamination Release
Guides,” February 1991), and has assessed potential doses associated with the release of
property containing residual tritium. The Department recommends the use of the stated guideline
as an interim value for removable tritium. Measurements demonstrating compliance of the
removable fraction of tritium on surfaces with this guideline are acceptable to ensure that non-
removable fractions and residual tritium in mass will not cause exposures that exceed DOE dose
limits and constraints.
Section 117
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E-1
APPENDIX E: RADIOLOGICAL CONTROL PROGRAMS
FOR SPECIAL TRITIUM COMPOUNDS
DOE-HDBK-1129-2008
E-2
TABLE OF CONTENTS
PARAGRAPH PAGE
FIGURES .................................................................................................................................. E-2
TABLES .................................................................................................................................... E-3
E.1 – INTRODUCTION ............................................................................................................. E-4
E.1.1 Special Tritium Compounds .................................................................................... E-5
E.1.2 Prevalence of STCs in the DOE Complex............................................................... E-6
E.1.3 Appendix Overview ................................................................................................. E-7
E.2 – NATURE OF SPECIAL TRITIUM COMPOUNDS ........................................................... E-7
E.2.1 General.................................................................................................................... E-7
E.2.2 STC Host Materials ................................................................................................. E-8
E.2.3 STC Categorization ................................................................................................. E-8
E.2.4 Sources of STCs ................................................................................................... E-10
E.2.5 Hazards Associated with STCs ............................................................................. E-10
E.2.6 Challenges to Radiological Control Programs....................................................... E-11
E.3 – WORKPLACE MONITORING FOR STCS .................................................................... E-12
E.3.1 Observed Versus Actual Activity ........................................................................... E-12
E.3.2 Area Monitoring ..................................................................................................... E-13
E.3.3 Individual and Workplace Controls for STC-Contaminated Areas ........................ E-16
E.4 – INDIVIDUAL MONITORING .......................................................................................... E-17
E.4.1 Identifying Individuals to be Monitored .................................................................. E-17
E.4.2 Air Monitoring for STCs ......................................................................................... E-18
E.4.3 Radiobioassay....................................................................................................... E-19
E.4.4 Organically Bound Tritium (OBT) .......................................................................... E-19
E.5 – INTAKE AND DOSE ASSESSMENT ............................................................................ E-21
E.5.1 Biokinetic and Dosimetric Models ......................................................................... E-21
E.5.2 Internal Dose Determination.................................................................................. E-30
E.6 – WORKPLACE CONTROLS........................................................................................... E-45
E.6.1 Design/Engineered Controls ................................................................................. E-45
E.6.2 Administrative Controls ......................................................................................... E-46
Section 118
ANNEX A – VALUES OF SIGNIFICANT DOSIMETRIC PROPERTIES OF STCS................ E-56
ANNEX B – INSOLUBLE METAL TRITIDE BENCHMARK .................................................... E-57
ANNEX C – MATHCAD DEFINITIONS AND SUBROUTINES............................................... E-60
ANNEX D – PARAMETERS FOR DISSOLUTION OF INSOLUBLE TRITIATED
PARTICULATE MATERIALS ............................................................................. E-68
FIGURES Page
Figure E.5-1 Simplified Overview of How the Major Components of the ICRP 78 Biokinetic
Model for Insoluble Metal Tritides are Connected
E-22
Figure E.5-2 Systemic Biokinetic Model for Tritiated Water Coupled to the GI Tract Model E-23
Figure E.5-3 Deposition of Aerosols in the Respiratory Tract and Their Subsequent
Mechanical Clearance
E-26
Figure E.5-4 Two-stage Dissolution of STC Particles in the Respiratory Tract E-26
Figure E.5-5 GI Tract Biokinetic Model E-27
DOE-HDBK-1129-2008
E-3
TABLES
Table Page
Table E.1-1 Ratio of DCF for Selected STC to DCF for Selected Radioactive Isotope or
Compound
E-5
Table E.1-2 Examples of Processes and Locations Where STCs Could Exist E-6
Table E.2-1 Categorization of Special Tritium Compounds E-8
Table E.5-1. Compartments of the Respiratory Tract Model E-25
Table E.5-2. Deposition Fractions for Different Compartments of the Respiratory Tract as
a Function of Particle AMAD
E-25
Table E.5-3. Organs and Tissues with Explicit ICRP 60 Tissue Weighting Factors E-28
Table E.5-4. Dosimetric Source Organs for Intakes of STC E-29
Table E.5-5. Dosimetric Target Organs E-29
Table E.5-6. Physical Diameter Versus AMAD for Monodisperse Particle Distribution (σg =
1)
E-35
Table E.5-7 Default Assumptions for Insoluble Tritiated Particulate Intakes E-36
Table E.5-8. Constants for Calculating SAFs for Various Monodisperse ( σg = 1) ITPs E-37
Table E.5-9. SAFe for Various ITP Materials and Polydisperse ( σg = 2.5) Particle Size
Distributions (in AMAD)
E-38
Table E.5-10. SAFβ for Various ITP Materials and Polydisperse ( σg = 2.5)
Particle Size Distributions (in AMAD)
E-38
Table E.5-11. Committed Equivalent Dose DCFs (Sv/Bq) for Various ITPs and Particle
Sizes (AMAD, σg = 2.5), Absorption Type S Assumed
E-39
Table E.5-12. DCF (Sv/Bq), E50, for Various ITPs and Particle Sizes (AMAD, σg = 2.5),
Absorption Type S Assumed
E-39
Table E.5-13. DCF (Sv/Bq), E50, for Various ITPs and Particle Sizes (AMAD, σg = 2.5),
Absorption Type S Assumed, with SAFe Corrections Applied to the Lung
Dose Component
E-40
Table E.5-14. DCFo (Sv/observed Bq), E50, for Various ITPs and Particle Sizes (AMAD, σg
= 2.5), Absorption Type S Assumed
E-41
Table E.5-15. Fractional Uptake and Biological Halftime for Soluble OBT and HTO (ICRP
78, 1997)
E-44
DOE-HDBK-1129-2008
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E.1 - INTRODUCTION
Over the past several decades, DOE and its predecessor agencies have undertaken a
variety of missions related to basic scientific research and national defense. A number of
these missions have involved development, processing, storage, and disposal of a wide
variety of exotic and/or hazardous materials, requiring comprehensive health and safety
programs to ensure protection of affected workers, the public, and the environment. DOE’s
programs for protection of individuals from exposure to these materials have evolved over
the years in response to changes in scientific knowledge and societal perceptions and
impacts. In some cases, the physical and hazardous properties of the materials were not
well known at the time of their development or use. In other cases, the hazards were fairly
well known and characterized, but changes in scientific knowledge and public risk
perceptions have required improvements in associated protection programs.
Section 119
E.1.1 Special Tritium Compounds
The detection and control of tritium are complicated when it is produced, used, and stored in
some chemical and physical forms. Hydrogen atoms tend to migrate through surfaces with
which they come into contact, and form chemical bonds with the host material. The
hydrogen atoms may be released at a later time (commonly referred to as “outgassing”).
While this property of hydrogen atoms may complicate measures implemented to contain
tritium, it has been well characterized, and appropriate materials can be specified to
minimize adverse effects. This property can also be used to practical advantage, as
hydrogen atoms (including tritium) can be diffused through other materials, particularly
metals, such as uranium, and stored within the matrix for subsequent extraction and use.
Tritium atoms may also diffuse into, and form chemical bonds with, organic materials with
which they come into contact. The most common of these host materials are lubricating oils,
solvents, and plastics.
The term “special tritium compound” (STC) is used to describe these compounds of tritium
with host metals and organic materials.
The diffusion of tritium atoms into host metals and organic materials can complicate efforts
to detect, and quantify levels of, tritium contamination in the workplace, environment, and
individuals. These complications generally fall into three categories:
• Detection – Once the tritium atom has migrated into the matrix of the host material,
some fraction of its emissions may not be able to escape that matrix.
• Physical and Chemical Behavior – If a tritiated material exists in a particulate state, or is
subjected to any forces (e.g., heat, abrasion, cutting) that reduce it into a particulate
state, the tritiated particles will behave physically and chemically like the host material
particles, not like hydrogen. Therefore, the characteristics that are important variables in
the internal dose assessment process (e.g., particle size, solubility, disassociation, inter-
compartment transport, etc.) differ from those of tritium in elemental or oxide form.
• Emitted Radiation – Although only a small percentage of the beta particles emitted by the
decaying tritium atoms may be detected, they may interact with surrounding host material
DOE-HDBK-1129-2008
E-5
atoms, resulting in emission of bremsstrahlung radiation and internal bremsstrahlung from the
nucleus.
The behavior of STCs can present a variety of challenges to a facility’s radiation protection
program. For example:
• It may be difficult to differentiate between STCs and the more common forms of tritium using
routine workplace monitoring techniques.
• The physical and chemical behavior of STCs may render commonly used tritium bioassay and
available internal dose models ineffective.
• Difficulties in identifying and quantifying STC contamination can cause significant delays
between performance of workplace monitoring and completion of analyses.
In the absence of effective detection methods, workplace hazards cannot be accurately assessed.
Without accurate hazard assessments, associated activities such as area posting, material
labeling, job planning, access control, and material release, are made difficult.
Section 120
The risk associated with STCs can be put into perspective by comparing the effective dose
equivalent per unit uptake (DCF) of various STCs with the effective dose equivalent per unit
uptake of other representative radionuclides. As shown in Table E.1-1, the DCF for Hf-T, a very
insoluble tritiated particle is about 24 times that of HTO, while it is one twentieth that of 137Cs, and
one 270,000th that of 239Pu. Thus, while the risk associated with STC that results in the greatest
dose per unit uptake is greater that that from tritium oxide, it is less than the risk associated from
fission products and actinides. Note that when assessing the hazard from STCs and other forms
of radioactive material, it is necessary to know the quantities of material available for uptake, as
well as the opportunities for uptake in addition to the inherent risk associated with the radioactive
material.
Table E.1-1 Ratio of DCF for Selected STC to DCF for Selected Radioactive Isotope or
Compound
STC/Isotope
Ratio of DCF for selected
STC to DCF for selected
radioactive isotope or
compound
HTO
TH f −
24
HTO
OBT
2
Cs
TH f
137
−
1/20
U
TH f
235
−
1/77,000
Pu
TH f
239
−
1/270,000
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E.1.2 Prevalence of STCs in the DOE Complex
STCs typically occur in much smaller quantities than other more common types of
radioactive materials such as plutonium, uranium and HTO. However, STCs are found at
many DOE sites as a result of past and present DOE operations. Table E.1.1 lists examples
of the types of processes involving the production or handling of STCs as well as various
types of structures that could contain or be contaminated with STCs. The important
consideration is that there is a wide variety of processes and locations where STCs may
exist. Accordingly, it is prudent to consider the need for radiological protection measures
specific to STCs when planning work in areas where any form of tritium has been handled or
stored.
Table E.1-2 Examples of Processes and Locations where STCs Could Exist
Processes Locations
Tritium targets for neutron generators
Reactor operations
Fusion Experiments
Extrication of tritium from fuel elements
Isotope separation
Storage of tritium
Stripping tritium from non-hydrogen gas streams
Operations involving tritium labeled compounds
Operations producing tritium contaminated oils
and solvents
Waste treatment and storage
D&D Operations
Weapons testing
Gloveboxes
Fumehoods
Ventilation systems
Waste containers
Sampling equipment
Ground water
Uranium beds
Spent fuel
Alcohol wash systems
Weapons components
Molecular sieves and getters
Kiln piping
Be reflector blocks
Neutron Generators
Heavy water purification evaporators
Fuel storage basins
Although the DOE radiological protection community has been aware of STCs for many
years, to date their impact has been limited by the design features that are incorporated into
DOE facilities that handle significant quantities of tritium. These design features include
various forms of material containment and control, such as gloveboxes and HEPA-filtered
ventilation systems that effectively prevented significant releases of STCs to occupied areas
of the workplace or the environment. Sensitivity to STC contamination has been increased
as a result of the emphasis in DOE activities involving decontamination and
decommissioning of older facilities. These activities may compromise the effectiveness of
the installed design features and allow releases of STC contamination to the surrounding
areas. Such releases may cause exposures to individuals in the area and releases of STCs
to the environment, both on- and off-site. In light of such experiences, DOE suggests that
individuals setting up programs for radiological control of STCs contact sites that either
work, with or have worked, with tritium to learn of their experiences with STCs5.
Section 121
5 The Mound Site performed decontamination and decommissioning (D&D) operations involving
STCs during the period this document was developed.
DOE-HDBK-1129-2008
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E.1.3 Appendix Overview
This appendix examines the difficulties associated with STC detection, assessment, and
control, and provides guidance for incorporating effective STC monitoring and control
regimens into the facility’s radiation protection program. It has been developed based on
currently available technology for detecting, identifying, characterizing and monitoring STCs.
Accordingly, in some cases a more conservative approach to radiological controls is
recommended when compared to oxide and gaseous forms of tritium. As technology in this
area changes, more efficient approaches to radiological protection may be instituted.
This appendix should be used in conjunction with DOE’s existing requirements and
guidance documents, including:
• 10 CFR Part 835, Occupational Radiation Protection;
• DOE G 441.1-1C, Radiation Protection Programs Guide;
• DOE-STD-1098-99, Radiological Control Standard (use the revised version, reflecting
the 2007 amendment to 10 CFR 835, when available);
• DOE-STD-1121-98, Internal Dosimetry Standard (use the revised version, reflecting the
2007 amendment to 10 CFR 835, when available);
• DOE-STD-1111-98, DOE Laboratory Accreditation Program Administration, and its
supporting standards (use the revised version, reflecting the 2007 amendment to 10
CFR 835, when available); and
• DOE’s Radiological Control Technical Positions.
http://www.hss.energy.gov/HealthSafety/WSHP/radiation/tpp.html
Should any conflict exist between the guidance provided in this appendix and DOE’s
requirements for radiation protection, DOE’s requirements take precedence. Such conflicts
should be brought to the attention of the DOE office responsible for worker protection policy.
E.2 - NATURE OF SPECIAL TRITIUM COMPOUNDS
E.2.1 General
Hydrogen atoms (including those that exist in the form of tritium) tend to diffuse through
materials with which they come into contact, and may be released at a later time (commonly
referred to as “outgassing”). While this property of hydrogen atoms may complicate
measures implemented to contain tritium, it has been well characterized, and appropriate
materials can be specified to minimize unintended adverse effects. This property can also
be used to practical advantage, as hydrogen atoms can be diffused through other materials
and stored within the matrix for subsequent storage, transportation, release, and use. The
diffusion and outgassing processes may be accelerated through application of heat.
DOE-HDBK-1129-2008
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E.2.2 STC Host Materials
STCs can be created by intentional combination of tritium with the desired materials or by
inadvertent contamination of a material that has been subjected to the presence of tritium for
a period of time. DOE facilities have used a wide variety of metals (e.g., Ti, Zr, U, and Hf) in
tritium research, purification, and storage, creating an equally wide variety of materials
referred to as “metal tritides.” Metal oxides (e.g., rust), siliceous materials (environmental
dust), and carbonaceous materials (e.g., polymers or environmental dust) can also become
tritium contaminated and exhibit particulate properties. Tritium may also react with organic
materials, resulting in the formation of organically-bound tritium (OBT). The main types of
OBT encountered in the DOE complex are solvents, oils, and solid particulates (e.g.,
plastics, nylon, and organic dust forms). OBT can be particulate or non-particulate in
nature.
Section 122
E.2.3 STC categorization
In this appendix, STCs will be categorized according to (1) the ease with which the tritium
(either unbound or bound to an STC) can be taken into the blood stream and (2) the
physical form of the STC (e.g. particle, vapor, large solid, and liquid). Table E.2-1 illustrates
this classification scheme.
Table E.2-1: Categorization of Special Tritium Compounds
Ease of Uptake Insoluble Soluble
Physical Form Liquid/vapor Particle Large Solid
Form Liquid/vapor Particle
Examples of STCs Tritiated pump
Oil
Hf-T
Ti-T
Eu-T
Zr-T
Dust
Rust
Pump oil droplets
Tritiated flyash
Tritiated Ti
source for
neutron
generator,
Tritiated
nylon
Tritated
methane
Tritiated
solvents
(acetone,
octane)
U-T
Pd-T
E.2.3.1 Ease of Uptake
Ease of uptake refers to the rate at which radioactive material can be taken into the
bloodstream. For STCs this process includes both uptake of tritium that has dissociated
from a host or carrier material and uptake of an entire STC molecule. The International
Commission on Radiological Protection (ICRP) (ICRP 1994) categorizes most radioactive
materials in terms of the rate of absorption from the respiratory tract to the bloodstream.
Materials absorbed on the order days are classified as absorption type F (fast), those
absorbed on the order of weeks are classified as absorption type M (moderate) and those
absorbed on the order of years are classified as absorption type S (slow). (In addition to the
three absorption classes, ICRP (ICRP 1998b) categorizes certain vaporous substances that
are very rapidly absorbed by the body as absorption type V.) For purposes of
understanding some of the radiation protection elements expounded in this appendix,
absorption type S and M materials can be considered insoluble and absorption type F
DOE-HDBK-1129-2008
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material can be considered soluble. Note that the ICRP classification forms the basis of the
dosimetric calculations contained in Chapter 5.
Note: The Mound Technical Basis Document (Mound 2000) was the document from which
much of the material in this appendix was derived. In that document, the term stable was
used instead of insoluble to describe particles from which the tritium dissociates slowly, and
the term unstable was used instead of soluble to describe particles from which the tritium
dissociates more rapidly. The terms soluble and insoluble are selected for this appendix in
order to apply the same terminology used to describe the ease of tritium uptake by the body
as the primary means of categorizing STCs.
Particles or particulates can be formed from all types of STCs. To explain the uptake of
these particles, the ICRP in publication 71 (ICRP 1995) assumes that the tritium dissociates
from the rest of the particle and is then taken up by the body. The tritium that is not
dissociated from the particle irradiates those tissues it comes in contact with while it remains
in the body. Tritiated particles from which the tritium dissociates slowly may be considered
insoluble. Tritiated particles from which the tritium dissociates rapidly may be considered
soluble. In this appendix the operational distinction between soluble and insoluble particles
is that insoluble particles do not readily release the bound tritium to either aqueous solutions
or air during the interval between sample collection and analysis.
Section 123
Another class of STCs is organically bound tritium (OBT) compounds. For these types of
STCs, the tritium is not readily released from the carbon-tritium bonds to air or aqueous
solution (Hill, 1993), therefore, the classification as either soluble or insoluble is based on
the ease by which the entire molecule is taken up by the body.
Soluble OBT is rapidly taken up by the body while insoluble OBT is more slowly taken up by
the body.
E.2.3.2 Physical Form
The manner in which in the body takes up STCs, and hence the radiological controls for
STCs, is determined by the physical form of the STC. In this appendix, the primary physical
forms considered are particles, liquids/vapors and large solid forms.
Radiological controls for STC particles that are considered to be insoluble should be based
on the controls used for radioactive particles rather than the controls used for HT, HTO, or
vaporous forms of OBTs. Such tritiated particles are called insoluble tritiated particulates
(ITPs). Examples of ITPs are tritiated metals, and metal oxides; the large molecule
component of OBT oil; and solid OBTs such as flyash, nylon, and organic dust.
Soluble types of particulates rapidly release their bound tritium. For these types of triated
particles, radiation protection measures should be based on those for HT or HTO. In
addition, the detection problems that arise from the binding of tritium within the host particle
are not an issue (see section E.3.1). Examples of such particles are metal tritides of
palladium and uranium.
STCs that are liquids and vapors are primarily comprised of OBTs. Soluble OBT can be
incorporated into the body by inhalation, ingestion, or absorption through skin. Soluble OBT
distributes throughout the body causing a whole body dose. ICRP 78 (ICRP 1998b)
categorizes the dissolution rate for soluble vaporous OBT as Type V (very fast dissolution).
DOE-HDBK-1129-2008
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Solvents are considered to be soluble. Radiological protection measures for vaporous OBTs
are identical to those used for HT and HTO. When establishing controls for liquid forms of
OBTs, it is important to consider absorption of the OBT through the skin, the vapor pressure
of the liquid, the possibility that the liquid is composed of more than one OBT, and dispersal
mechanisms that could aerosolize the liquid. An example of a liquid OBT is tritiated oil that
has been used in pumps and air compressors.
Tritiated oils are a type of OBT that contains both soluble and insoluble components. Oils
can be taken into the body by inhalation when they are in particulate form or can be
absorbed through the skin. Because tritiated oils primarily consist of insoluble components
(see section E.4.4.3) tritiated oils will be treated in this appendix as insoluble particulates
when they become airborne droplets.
The term “large solid forms” denotes the types of STCs that cannot be easily taken into the
body, such as a piece of tritiated metal. Radiological controls for these types of tritides
consist primarily of planning for situations in which portions these materials could be
converted to airborne particles. Otherwise, standard radiation protection measures for the
control of radioactive materials should be applied to these types of STCs. See section
E.3.2.1.2 for additional guidance that may be applicable to large solid forms of STCs.
E.2.4 Sources of STCs
Section 124
As discussed previously, tritium, including that contained in STCs, is not considered an
external exposure hazard. However, particulate tritiated materials, both metals and organic
materials, can be ingested or inhaled, creating an internal exposure hazard. Solid
particulate OBTs, such as plastic, nylon, organic dust, or the large molecule component of
OBT oil, can become airborne by dispersal mechanisms. Equipment that can impart energy
to oil through motion or release of pressure (e.g. pumps and air compressors) can cause an
oil mist aerosol to be generated.
E.2.5 Hazards Associated with STCs
E.2.5.1 Ingestion of Tritiated Particulates
Following ingestion, STCs lose some fraction of their tritium as HTO or soluble OBT in
digestive fluids. The fraction of the infused tritium lost via this mechanism varies depending
on the stability of the specific material in the gastrointestinal (GI) tract; some particles lose
essentially all of the tritium and others lose very little. In any case, the only significant dose
following ingestion of tritiated particles is due to the resulting HTO or soluble OBT that is
released. The remaining intact particles will undergo fairly rapid elimination from the body,
resulting in negligible internal doses. Since HTO or soluble OBT is rapidly assimilated
physiologically, this dose component is readily assessed via urine bioassay.
E.2.5.2 Inhalation of Tritiated Particles
Following inhalation, tritiated particles may be deposited in the lung. Once deposited in the
lung, the infused tritium is removed from the body via two mechanisms:
1 Dissolution of tritium from the particulate and absorption into the body as HTO or soluble
OBT, and removal through urine, expired air, and perspiration.
DOE-HDBK-1129-2008
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2 Mechanical transport of the particulate itself to the GI tract and removal through feces.
(Inhaled tritiated particles removed to the GI tract will cause dose in the same manner as
ingested triatiated particles, as described above.)
Removal of ITPs from the lung through mechanical transport can be slow. ITPs can,
therefore, reside in the lung for a considerable amount of time. Accordingly, a significant
portion of the entire committed effective dose equivalent resulting from the decay of the
associated tritium atoms results from deposition in the lungs. The lung receives 85% of the
committed effective dose equivalent (E50) from Type M ITPs and 96% of the E50 from
absorption type S ITPs (ICRP 71).
E.2.5.3 Skin absorption of OBT
Solvent OBT
Solvent OBT can, if spilled as liquid on the skin, produce a skin absorption pathway. The
potential hazard of this pathway should be assessed using known or analyzed activity of the
liquid. Solvent OBT absorbed through the skin can be assessed using urine bioassay.
OBT Oils
Tritiated oils can be found in pumps and compressors located in areas where work with
tritium has been conducted. Trivedi (1995), in experiments on rats, has shown that tritiated
oils can be absorbed by mammalian skin. Accordingly, skin absorption is a valid intake
pathway for oil components. See section E.4.4.3 for additional information on skin
absorption of OBTs.
E.2.6 Challenges to Radiological Control Programs
Based on the previous discussion, STCs may present the following challenges to a facility’s
radiological control program (above and beyond the challenges presented by more common
types and forms of radioactive material):
Section 125
• Because some of the tritium emissions may be shielded by the particle, routine area
monitoring efforts may not yield an accurate assessment of radionuclide levels on
surfaces and dispersed in workplace atmospheres.
• The difficulties in area monitoring may cause corresponding difficulties in related
activities, such as posting, labeling, work planning, access control, decontamination,
personal protective equipment (PPE) handling, and material control and release.
• Retention of insoluble tritiated particles in the body may render conventional tritium
bioassay methods (urinalysis) ineffective. While ITPs behave as other particulates that
are inhaled, an acceptable bioassay procedure is not currently available for some types
of ITPs.
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E.3 – WORKPLACE MONITORING FOR STCs
E.3.1 Observed Versus Actual Activity
Because of the difficulties associated with detection and quantification of STC levels on
surfaces and in sample media, two terms are used in this appendix to describe analysis
results. The observed activity is that activity that is detected by the prescribed analytical
method. Because of the self-shielding attribute of particulate STCs, the observed activity
(the activity detected by the sample analysis equipment, corrected for efficiency and
detector-to-sample geometric considerations) may not reflect the total quantity of radioactive
material present. The term actual activity is used to describe the total activity present in
STCs. In practice, the actual activity may be estimated from the observed activity by use of
appropriate conversions to adjust for particle self-shielding and other factors that may
interfere with accurate sample analysis. However, in many cases, characterization of metal
tritide species make it difficult to quantify and correct observed activity to actual activity. As
discussed in this document, the use of observed activity is particularly relevant for internal
dose assignment.
Current regulations require that certain radiation protection measures (e.g., contamination
area posting and access control, radioactive material labeling and control) be implemented
based on assessments of the quantities or concentrations of radioactive material present.
This appendix adopts the concept of observed activity (discussed above) as an appropriate
surrogate for the actual activity for STCs. 10 CFR 835 Appendix D, Footnote 2 provides
surface contamination values in disintegrations per minute as meaning “the rate of emission
by radioactive material as determined by correcting the counts per minute observed by an
appropriate detector for background, efficiency, and geometric factors associated with the
instrumentation.” The use of observed activity is consistent with this provision. This
appendix will demonstrate that certain other measures, such as individual dose estimates,
may be based on assessments of observed activity.
E.3.1.1 Conversion from Observed to Actual Activity
The conversion of analysis results from observed to actual activity is relatively
straightforward, once the various factors that introduce analytical uncertainties are
understood and quantified. First, corrections must be applied to convert the analysis results
presented by the instrument, usually counts per unit time, to the desired activity units and to
eliminate the more common analytical uncertainties (e.g., uncertainties arising from detector
efficiencies and counting geometry considerations). Further discussion on the use of
observed activity is discussed in Section E.5.2, especially considerations given to self-
absorption of emissions that do not escape the STC particle.
Section 126
In more conventional sample counting applications, application of these corrections will yield
the actual activity present in the sample, usually in units of disintegrations per minute per
100 square centimeters (dpm/100cm2) for surface contamination monitoring or microcuries
per cubic centimeter (µCi/cm3) for airborne radioactivity monitoring. (These are the units
used for surface contamination and airborne radioactivity control criteria, respectively, in 10
CFR Part 835). However, due to the physical characteristics of STCs, application of these
corrections yields only the observed activity. Further corrections may be made to account
for that fraction of the tritium decays that have escaped detection and accurate
quantification due to the physical characteristics of the STC.
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The corrections needed for conversion from observed to actual STC activity typically include
the following:
• A correction to increase the observed activity to account for the number of tritium
disintegrations that have escaped detection due to shielding effects of the host particle;
• A correction to reduce the observed activity to account for detected events resulting from
bremsstrahlung radiation created by tritium beta interactions with the host particles;
• A correction to reduce the observed activity to account for detected events resulting from
tritium that is present in non-STC form.
Application of these corrections will require knowledge of, or conservative assumptions
regarding, the host particle characteristics, including atomic number, size, and density.
However, using currently available technology, it is difficult to determine the actual activity in
a manner that will make it a better indicator of the hazard to a worker than observed activity.
E.3.2 Area Monitoring
Because tritium emits only low energy beta particles, it is not considered an external
radiation exposure hazard. Therefore, area monitoring efforts are restricted to surface
contamination monitoring and airborne radioactivity monitoring.
Tritiated metals, metal oxides, dust, and oil can occur in nearly any tritium area. Any tritium
contamination collected on a swipe survey or a particulate filter should be viewed as a
potential combination of these. This is particularly the case for residual concentrations of
tritium, i.e., where elemental (HT), aqueous (HTO), or solvent (soluble OBT) tritium sources
have been removed or evaporated. However, it is the insoluble tritiated particulates with
very long biological retention times (i.e., ICRP absorption type S or M) that pose the greatest
hazard to workers. As a result, workplace sampling/monitoring programs that can quantify
specific, and distinguish between various types of STCs, will allow one to depart from the
conservative approaches recommended in this Appendix.
E.3.2.1 Surface Contamination Monitoring
Chapter 11 of DOE G 441.1-1C, Radiation Protection Programs Guide (DOE 1999),
establishes appropriate guidance for developing and implementing a surface contamination
monitoring program. This Guide addresses such issues as monitoring requirements,
techniques, frequencies, and actions. This guidance is generally applicable to monitoring
for STC contamination; however, the sample analysis and activity determination techniques
may be different due to the difficulties in accurately assessing STC levels. Note that if the
host material of the STC is radioactive, the conventional methods in the DOE guidance can
be used to assess the extent and level of surface contamination.
Section 127
E.3.2.1.1 Removable Contamination
The first step in establishing a surface contamination monitoring program for STCs is to
identify the likelihood that STCs may exist in an area, and if they do, identify the most likely
locations. The best sources of this type of information are historical records and workers’
memories of facility usage. Facility management should consult these sources for
information regarding previous usage of the facility and specific areas. Almost any area in
which tritium was used, handled, or stored may be considered a candidate for possible STC
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contamination. For larger facilities, identification of all STC contaminated areas may be
quite time-consuming. Priority should be placed on identifying and controlling those areas
that are likely to have the highest STC contamination levels. In many cases, this will include
areas where STCs were intentionally created, and areas that have (or had) the highest
tritium contamination levels and the highest probability of host particle formation and
distribution. Such a determination should be made by review of historical radiological
monitoring records and facility processes.
Following identification of those areas most likely to be contaminated with STCs, detailed
radiological monitoring should be performed to identify tritium contamination levels in the
area(s). Such monitoring should be performed using routine tritium contamination
monitoring techniques, commonly using either wet or dry smears and liquid scintillation
counting (LSC). In the past, many facilities have used Styrofoam smears for collection of
surface contamination samples for tritium analyses. Recent changes in the composition of
scintillation cocktail fluid have largely eliminated this practice. The actual sample medium
used is not particularly significant as long as its efficacy in collection of particulate material
and suitability for LSC analysis can be demonstrated. Counting techniques should be
capable of detecting contamination at or below the values provided in Appendix D of
10 CFR Part 835.
If the results of comprehensive smear surveys indicate that tritium surface contamination
levels are less than one tenth of the 10 CFR 835 Appendix D value, then it may be
appropriate to assume that there are no significant levels of STC contamination (i.e., levels
requiring additional controls, such as posting, access control, or personnel monitoring). If
the results of the smear surveys indicate that tritium contamination levels equal or exceed
one tenth of the 10 CFR 835 Appendix D values, then further surveys may be conducted to
identify sources of STCs in the area. It may also be necessary to identify the host material(s)
so that appropriate assumptions may be made regarding assimilation and elimination.
E.3.2.1.2 Total Contamination
DOE has not established a total (fixed plus removable) surface contamination value for
tritium and tritium compounds. The reason is that tritium can diffuse into the volume of any
material to which it is exposed – at least in the gaseous forms normally encountered. After
the exposure, the tritium migrates to the surface, making a definitive distinction between
fixed and removable contamination difficult to ascertain.
The external hazard from tritium radiation is not considered to be a significant source of
radiation exposure. Accordingly, compliance with the tritium value for removable
contamination will provide an acceptable level of protection to individuals in controlled areas.
This approach is considered acceptable for most tritium contamination.
Section 128
However, there may be cases where tritium binds tightly to the matrix into which it has
diffused, and removable contamination levels are below the values in 10 CFR Part 835.
Such cases could occur when insoluble tritiated particles are fixed to a surface or from
tritium exposure to bulk quantities of metals of the types from which insoluble metal tritides
are formed. Footnote 6 to appendix D of 10 CFR 835 states that a total surface
contamination value of 10,000 dpm/100 cm2 may be applicable to these types of STCs.
Accordingly, the provisions in 10 CFR 835 subpart L pertaining to total surface
contamination values may be applied to these types of STCs when the total surface
contamination level exceeds 10,000 dpm/100 cm2. Note that when performing operations
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on these types of tritiated materials, it is important to assess the potential for producing
airborne concentrations of respirable ITPs, and if needed, institute radiological controls
appropriate to this hazard.
E.3.2.2 Air Monitoring
Chapter 10 of DOE G 441.1-1C (DOE 2008), Radiation Protection Programs Guide provides
detailed guidance for developing and implementing an air monitoring program. This
guidance is supplemented by that provided in the RCS (DOE 1999g) and in DOE-STD-
1121-98 (DOE 1999h), Internal Dosimetry. This guidance, combined with that provided
above for identifying areas possibly affected by STC contamination, is applicable to the air
monitoring program for STCs. Likewise, the guidance that follows regarding identification of
STCs and analysis of samples is applicable to the air monitoring program.
E.3.2.3 Identification of STCs
After collecting samples of surface contamination or airborne radioactive materials, it is
necessary to conduct radioanalyses to identify the levels of tritium (and other radionuclides)
present in the sample. Tritium analyses are most commonly performed by liquid scintillation
analysis of surface smears and air samples. Although liquid scintillation analysis is very
effective in analyzing for the presence of tritium, this technique does not differentiate
between the various forms of tritium (HT, HTO, STCs). Thus, non-standard techniques must
be used to distinguish STCs from HT and HTO, and to distinguish among the various STC
species. To date, a rapid, simple and reliable method for identifying STCs has not yet been
developed.
In the following paragraphs, several techniques for identifying ITP species are described.
However, all of these approaches have some drawbacks. In practice, some combination of
the suggested analyses, or an entirely new approach, may be needed to evaluate the ITP
contamination levels present in the samples. Such efforts will probably not be
straightforward, and conservatism must be used to ensure that the hazards associated with
ITPs are adequately addressed to provide an adequate level of protection to DOE workers.
If the analyses cannot definitively identify the ITP species, identity of the ITP species may be
based on process or historical knowledge.
In all cases, a conservative approach should be used in identifying STC-contaminated
samples. If the combination of factors identified below (facility history, radioanalytical
identification of tritium, particle species identification) leads to a conclusion that the
presence of STCs is likely, then the appropriate controls should be implemented consistent
with this manual.
Section 129
For ITPs, a scanning electron microscope (SEM) may be used to identify the presence of
particles that are likely hosts for tritium atoms. In combination with conventional
radioanalysis using LSC, an estimate of the gross ITP contamination levels may be
obtained. This technique does have limitations however. While the LSC can definitively
establish the levels of tritium emissions, and the SEM can definitively establish the presence
and size of possible host particles, it is difficult to establish a direct correlation between the
detected tritium emissions and the particulate levels. That is, it is not possible to state with
any degree of certainty what fraction of the detected emissions arise from ITPs versus that
fraction that arises from the more common tritium forms that may also be present. The
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presence of likely host particles does not definitely prove the presence of tritium within those
particles.
The presence, of but not the amount of, ITPs may also be inferred by performance of
multiple LSC analyses of individual samples, and trending the results to evaluate the change
in observed tritium activity as the tritium atoms are released from the host material in the
sample. (The observed tritium activity increases because the betas emitted by the tritium
molecules that have been released from the metal particle are not absorbed by the metal
particle.) This method may only be effective for those ITPs where the tritium is released
from the host particle over a time period ranging from a few hours to a few weeks. If the
tritium binds to the host material very tightly, the growth in observed activity will not be
apparent over any reasonable time interval between repetitive sample analyses. If the ITP
species is soluble, then all of the captured tritium may be released into the counting solution
before the sample is counted. Because the lack of an effect does not mean ITPs are not
present, the use of this method depends on reliable knowledge of the strength of the bond
between the tritium and the host material in the ITPs expected to be present in the work
area. Information on dissolution is contained in Appendix D. If tritium is likely to be present
in both ITP and conventional forms, efforts should be undertaken to differentiate between
the different species so that the appropriate controls (e.g., based on applicable limiting
values) may be applied. One approach is to count a survey or air filter sample in LSC
cocktail. This measurement gives a value for ITP plus HTO content. Addition of fresh water
to the cocktail followed by evaporation (thus removing HTO from the sample) and then
recounting the sample, provides a value for ITP alone. Other approaches at differentiating
between the species may include attempts at ITP dissolution, following by sample counting
to detect changes in analysis results due to particle dissolution and subsequent increase in
detected tritium atom disintegrations. The accuracy of this approach is dependent on
knowledge of the specific species present, the fraction of tritium intra-particle disintegrations
that may be detected, and the effectiveness of the dissolution technique for that species.
A useful characterization method, which could also be considered, is solubility testing:
workplace survey samples tested for tritium released from particulates into simulated lung
fluid. The results of this testing directly affect dose modeling via use of the critical parameter
of ICRP solubility Type (F, M, S) for tritiated particulates in the lung.
Section 130
In the absence of acceptable information with regard to differentiation of species, it may be
necessary to base protective actions on conservative assumptions. Specifically, base
protective actions on the most limiting values for dose conversion factors, airborne
concentration and surface radioactivity levels associated with species likely to be present.
E.3.3 Individual and Workplace Controls for STC-Contaminated Areas
Following identification and quantification of STC contamination in an area, certain
protective actions may be warranted and necessary to ensure compliance with DOE
requirements for protection of individuals in or near the area. These protective actions and
their regulatory basis include:
• Dose limits in accordance with 10 CFR 835 subpart C;
• Area posting in accordance with 10 CFR 835 subpart G;
• Material labeling in accordance with 10 CFR 835 subpart G;
• Material controls in accordance with 10 CFR 835 subpart L;
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• Area control in accordance with 10 CFR 835 subpart F;
• Individual monitoring in accordance with 10 CFR 835 subpart E; and
• Area monitoring in accordance with 10 CFR 835 subpart E.
Guidance needed to implement these requirements is contained in the following sections of
this Appendix.
• Guidance on individual monitoring is in Chapter 4;
• Guidance on intake and dose assessment is in Chapter 5;
• Guidance on dose conversion factors for insoluble tritiated particles (Sv per unit of
observed activity) Table 5-14 and Appendix A; and
• Guidance on workplace controls is in Chapter 6.
NOTE: Both individual and workplace monitoring may require air monitoring, such as
breathing zone air monitoring, grab sampling, and continuous air monitoring.
E.4 – INDIVIDUAL MONITORING
As noted previously, 10 CFR Part 835 requires monitoring of certain individuals’ internal and
external doses. Except for rare situations, exposure to STCs will not result in a significant
external dose; therefore, this appendix does not address external monitoring program
requirements. STCs may contribute to an individual’s internal dose. DOE has provided
internal dose monitoring program guidance in Chapter 5 of DOE G 441.1-1C (DOE 1999),
Radiation Protection Programs Guide, and detailed internal dose monitoring guidance in
DOE-STD-1121-98 (DOE 1999h), Internal Dosimetry Standard. The guidance provided
herein supplements that provided in those two standards and addresses issues that are
specifically related to STCs.
The first step in determining an individual’s internal dose as a result of a radioactive material
intake is to determine the magnitude of the intake (in units of activity). Determinations of
individual radioactive material intakes generally fall under three different methods: 1) in-vivo
analyses, such as whole body or organ counting; 2) in-vitro analyses, using analyses of
excreta (urine or fecal analyses); and 3) air monitoring, using results of airborne
contamination monitoring programs. The actual method used depends on a number of
factors, including the characteristics of the material to be analyzed, results of prior scientific
analyses to develop applicable protocols, and the analytical equipment available. This
chapter discusses evaluations of the need for individual monitoring and the applicability of
these various methods to evaluating intakes of STCs.
E.4.1 Identifying Individuals to be Monitored
Section 131
Compliance with the internal dose monitoring requirements requires consideration of several
factors. One of the first steps in implementing the internal dose monitoring program is
identifying those individuals for whom internal dose monitoring will be required. This
determination depends on the individual’s classification (i.e., radiological worker, declared
pregnant worker, occupationally-exposed minor, or member of the public) and likely dose.
An estimate of an individual’s likely dose requires knowledge of multiple factors, including:
• Areas to which the individual has access;
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• Radiological conditions in those areas;
• Amount of time to be spent in affected areas; and
• Activities that the individual will be performing.
Consistent with Chapter 5 of DOE G 441.1-1C (DOE 1999), this type of assessment is
typically conducted on a work-group, rather than on an individual, basis. However,
individual assessments may be required occasionally to address special or unique activities
(e.g., declared pregnant workers, short term specialist assignments). The assessment
should include all of the individual’s internal exposures at the DOE activity, including those
not related to STC exposure.
If estimates indicate that the individual’s dose is unlikely to exceed the applicable mandatory
monitoring threshold provided in 10 CFR 835.402, then no individual monitoring is required.
However, the area monitoring program should provide sufficient data to support decisions
regarding individual participation in the individual monitoring program. See Chapter 3 of this
Appendix for guidance on the area monitoring program for STCs.
E.4.2 Air Monitoring for STCs
Should an individual monitoring program be required, a decision must be made regarding
the relative merits of radiobioassay versus application of air monitoring results to determine
individual doses. Generally, radiobioassay is the preferred monitoring method for
assessment of individual internal dose. However, 10 CFR 835.209 allows the use of air
monitoring data under certain conditions, including when air monitoring data will provide
more reliable and accurate results. In many cases (as discussed in the remainder of this
chapter), this condition may exist with exposure to certain types of STCs. For more
information on development and implementation of an air monitoring program for purposes
of individual dose assessment, see Chapter 10 of DOE G 441.1-1C (DOE 1999), Radiation
Protection Programs Guide, and DOE-STD-1121-98 (DOE 1999h), Internal Dosimetry.
Historically, insufficient information has been available to facilitate development and
implementation of effective radiobioassay programs for certain insoluble STCs with long
biological retention periods. However, there has been a significant amount of recent
research into such programs, the practical results of which are summarized in this
Handbook.
E.4.2.1 Air Monitoring - Area Monitoring vs. Individual Monitoring
It is important to differentiate between the purposes and scope of the various facets of the
air monitoring program. Monitoring of the air in any specified area is usually performed
using portable air samplers, fixed head air samplers, or continuous air monitors. As a facet
of the area monitoring program, such monitoring is subject to the regulatory requirements
found in 10 CFR 835.401 and 835.403. Air monitoring for the purposes of individual dose
determination is usually performed using a lapel (personal) sampler worn by each affected
individual. Because a lapel sampler is worn by, and monitors the breathing zone of a
specified individual, the results of that sample analysis are applicable to that individual. If
such monitoring meets the conditions of 10 CFR 835.209(b) it may be used to monitor
individuals for exposure to internal radiation. The results of such monitoring may be used to
meet the regulatory requirements in 10 CFR 835.401, 835.402(c), and 835.403. Because
Section 132
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air sampling is distinct from bioassay, the requirements in 10 CFR 835.402(d) for
performance accreditation of radiobioassay analysis do not apply to air sampling programs.
Note however, that the results of area monitoring (using portable, fixed head, or continuous
air monitors) may be used for individual dose assessment under certain conditions (given
that assurance can be provided that the sample is representative of the air actually breathed
by the affected individual(s)). See section 5.2.4.1c for guidance on calculating dose from air
sampling measurements.
E.4.3 Radiobioassay
E.4.3.1 Urinalysis
Soluble materials ingested or inhaled into the body will be excreted via urine. Given a
known concentration of the contaminant in the urine and knowledge of the time of exposure
and rate of dissolution of the material in body fluids, one can derive a total intake quantity.
While determinations of the exposure time and urine concentration may be relatively
straightforward for STCs, determination of dissolution rates is more difficult. Chapter E.5
discusses the use of urinalysis in performing internal dose assessments for intakes of STCs.
E.4.3.2 Fecal Analysis
Insoluble materials that are inhaled into the body will be excreted via feces. Retention
factors and total intake quantity can be calculated based on the models described in Section
E.5.1, given a known concentration of the contaminant in the feces and knowledge of the
time of exposure, radioactive decay rate and solubility. Determination of exposure time is
straight forward, but no reliable protocol currently exists for determining concentrations of
STCs in feces6.
E.4.3.3 In-Vivo Analyses
In-vivo analyses depend on the detection of radiation emitted by radioactive materials within
the body by radiation detectors external to the body. In-vivo analysis is not considered to be
a viable means of assessing tritium intakes, including STC intakes. The are two reasons for
this: 1) Tritium decays by emission of low energy beta particles that will not penetrate
through the body to the external detector, and 2) A significant number of bremastrahlung x-
rays resulting from the interaction of the tritium beta with the metal atoms of the host particle
are not expected to escape to an external detector unless the STC uptake is massive.
E.4.4 Organically Bound Tritium (OBT)
E.4.4.1 Soluble OBT
Soluble OBT migrates through the skin or lung into the bloodstream by the physical
processes of dissolution and diffusion. The two processes are inseparably linked and often
simply called "absorption.” Soluble OBT is also readily absorbed through the GI tract
following ingestion. Rapid dispersion minimizes organ-specific (e.g., lung) differential doses.
6 For intakes expected to result in doses greater than 2 rem CED, one may want to collect and store fecal
samples pending development of a fecal biokinetic model and assay technique.
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Following absorption into the body, soluble OBT is excreted via urine. A biokinetic model is
available which relates intakes of soluble OBT to urine excretion rates, and a dose
conversion factor is available for soluble OBT intakes. Urine bioassay is therefore
considered to be a viable approach to estimating intake and dose from soluble OBT. More
information on dose assessment for soluble OBT is found in Section E.5.2.5.1.
Section 133
Solvents such as octane, cyclohexane, or acetone have been used in pump cleaning and
material dispersion processes. They can become tritium-labeled from extended exposure to
tritiated materials. Since these solvents are volatile, they are considered soluble. Individual
intake of tritiated solvents can occur through inhalation, ingestion, or by diffusion through the
skin. Evaluation of solvent OBT intakes should be performed via urine bioassay.
The potential hazard of the skin absorption pathway should be assessed using known or
analyzed activity of the liquid. Volatile OBT also produces vapors that can become
dispersed in air, resulting in a second potential intake pathway of vapor inhalation and skin
absorption. Therefore, a derived air concentration (DAC) will be derived in the next section
to relate volatile OBT air concentration to the annual E50. Volatile OBT vapors are readily
detected by the tritium gas air monitoring method (e.g. ion chamber).
If a solid particle OBT that has been determined to be soluble in lung fluids is discovered,
urine bioassay should be used to determine internal dose.
E.4.4.2 Insoluble OBT
For insoluble OBT, absorption through the skin is not an intake pathway. Following
ingestion (or inhalation), some fraction of insoluble OBT will likely be digested in the
stomach and converted to HTO or soluble OBT. Since HTO and soluble OBT are rapidly
assimilated physiologically, these dose components are readily assessed via urine
bioassay. In addition however, following inhalation, insoluble OBT may reside in the lung for
a period of time, delivering dose to the lung. This material is largely formed by incidental
contamination of environmental dust and is found in many tritium contamination areas.
Solid particulate OBT is considered primarily insoluble, and intake by skin absorption is not
expected, but inhalation is a possible intake mechanism. Inhalation of this material,
including determination of intake through air monitoring, assignment of doses, and use of
DCFs and DACs, should be treated the same as inhalation of ITPs. Because monitoring
and intake/dose assessments are the same for solid particulate OBT and for general ITP,
these two materials do not need to be distinguished during workplace characterizations
when the dose conversion assumptions are applied.
E.4.4.3 OBT Oils
Trivedi (1995) has shown that tritiated oils can be absorbed by mammalian skin. In this
section skin absorption and inhalation are both discussed as valid intake pathways for
various components of tritiated oils. Tritiated oils can be found in pumps and compressors
located in tritium areas. Tritiated pump oils are considered to be a mixture of three
components: insoluble large molecule OBT (original molecules of oil labeled by tritium),
soluble small molecule OBT (created by radiolytic and degradation processes and labeled
by tritium), and HTO. As a reasonable hypothesis, the tritium in OBT oils should be
expected to partition into the above three components in approximately an 80:10:10 ratio,
respectively. This is consistent with a ~70:20:10 ratio of tritium components removable from
oily surfaces (Johnson, 1988), where all three components were observed. The small
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molecule OBT is expected to be more concentrated on surfaces than in bulk oil due to
absorption of small polar molecules created from degradation processes. Data on liquid
tritiated oil (Trivedi, 1995) indicates that the 80:10:10 assumption should be conservative.
Section 134
The latter two of the three expected OBT oil components can in fact diffuse through the skin.
The HTO component can migrate quickly through the skin into body water and intake should
be assessed via urine bioassay. Small molecule OBT can also migrate through skin and is
considered soluble; intake of this component should also be assessed via urine bioassay.
Estimation of potential absorption intakes of HTO and soluble OBT resulting from direct skin
contact with liquid oil should be performed via analysis of oil samples for total tritium, and
application of the above 80:10:10 ratio. Inhalation intakes of vapors liberated from volatile
HTO and soluble OBT components of oil can also occur. Estimation of potential vapor
intakes should be performed via monitoring of air above the oil by ion chamber.
Large molecule OBT is considered to be insoluble. Estimates of diffusivity of large organic
molecules such as pump oils in polymer films, extrapolated from data for chemically similar
but smaller molecules (Rogers, 1985), suggest that oils migrate extremely slowly (if at all)
into and though polymeric materials. For this reason, the large molecule OBT component of
oils is estimated not to absorb into (or through) skin and therefore not to impart skin (or other
tissue) dose via this pathway.
The large molecule component of oil is not volatile. However, this oil component can be
dispersed into air from the either operation of equipment or the sudden release of residual
pressure, and therefore can be inhaled as a mist (and deliver a lung dose). Tritium from the
insoluble large oil molecules does not dissolve into the body, due to the stability of the
carbon-tritium bond in oils. Oil absorption in lung tissues is low, and clearance rate of oil
from lung could be as slow as that of particulates. Therefore, an oil mist intake should be
treated like an intake of solid particulate OBT (i.e., as an intake of ITP). Oil mist inhalation
should be monitored by air sampling and assessed as ITP inhalation.
Estimation of potential inhalation intakes of OBT oil mists should be performed via analysis
of oil samples for total tritium, and application of the above 80:10:10 ratio. Because OBT oils
are expected to be a mixture of HTO, soluble OBT, and insoluble OBT as discussed above,
radiological protection planning for activities involving OBT oils should consider potential
intakes of, and air monitoring for, all three components. To avoid mist formation, energetic
activities involving unencapsulated OBT oil should be discouraged.
E.5 – INTAKE AND DOSE ASSESSMENT
E.5.1 Biokinetic and Dosimetric Models
A biokinetic model describes in quantitative terms the retention and transport of a material in
the body. A dosimetric model prescribes how to use the biokinetic and radiation transport
models to quantify the dose to specific organs and tissues and how to calculate effective
dose. The biokinetic model used in ICRP 78 is recommended to evaluate intakes of STC.
The dosimetric models for STC are described primarily in ICRP 67 and 71. The STC
biokinetic and dosimetric models will be briefly reviewed in this section and a detailed
benchmark calculation is provided in Appendix B. The relevant ICRP publications should be
consulted for a more detailed discussion of the models and their application.
The STC biokinetic model may be broken down into three major components:
DOE-HDBK-1129-2008
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Section 135
• The respiratory tract model from ICRP 66;
• The systemic retention and excretion model from ICRP 67 and 78; and
• The gastrointestinal (GI) tract model from ICRP 30 and 78.
An example of how these models are coupled is shown in Figure 5-1. Inhaled aerosols of
insoluble metal tritides (IMTs) that are initially deposited in the respiratory tract are:
• mechanically cleared from the body (e.g., by blowing the nose);
• dissolved and absorbed into the bloodstream; or
• mechanically cleared to the GI tract.
Figure E.5-1. Simplified Overview of How the Major Components
of the ICRP 78 Biokinetic Model for Insoluble Metal Tritides are Connected
Note: “Other systemic excreta” refers to ICRP Publication 23 and includes insensible losses,
breath, sweat, diffusion, and transpiration.
Tritium absorbed from the respiratory and GI tracts is assumed to be in the form of tritiated
water (HTO) and to behave exactly like HTO that was absorbed directly into the
bloodstream. The systemic biokinetic model is discussed in more detail in Section 5.1.1.
Material cleared to the GI tract may be dissolved and absorbed into the bloodstream or
cleared to the feces. The ICRP 30 GI tract biokinetic model is used to quantify these
processes, but some modifications have been made to the dosimetric model. More details
on the biokinetic and dosimetric models are provided in section E.5.1.2.
E.5.1.1 The Systemic Biokinetic Model
The systemic biokinetic model and relevant portions of the GI tract model are shown in
Figure E.5-2. STC particles that dissolve in the respiratory tract release tritium that is
converted to HTO and absorbed into the bloodstream. STC particles that dissolve in the GI
tract are also converted into HTO and absorbed into the bloodstream from the small
intestines (SI). The fraction of STC that enters the GI tract and is subsequently absorbed
from the SI is referred to as f1.
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Figure E.5- 2. Systemic Biokinetic Model for Tritiated Water
Coupled to the GI Tract Model
Of the HTO that is absorbed into the bloodstream, 3% is converted to organically bound
tritium (OBT) that is retained in the body with a 40-day half-life and the remaining 97%
remains as HTO and is retained with a 10-day half-life. All of the OBT is excreted into the
urinary bladder and ultimately the urine. HTO is excreted from the systemic compartment in
the following ratios:
• 1.4/3 fraction to the urinary bladder and ultimately the urine;
• 0.1/3 fraction to ULI and ultimately the feces; and
• 1.5/3 fraction to other systemic excreta (e.g., “insensible losses” and sweat).
These ratios are derived from the ICRP 23 (ICRP 1975) Reference Man water balance.
E.5.1.2 Urinary and Fecal Excretion Functions
Urinary and fecal excretion are expressed as 24-hour incremental quantities. For example,
the 24-hour incremental urinary excretion ∆Eu(t) of tritium (not accounting for radioactive
decay) at t days after intake is given by
( ) ( ) ( )1−−=∆ tQtQtE uuu (Eq. E.5-1)
where Qu(t) is the content of the urine compartment at time t and Qu(t-1) is the content of the
urine compartment one day earlier. The 24-hour incremental urinary excretion of tritium that
does not account for radioactive decay is adjusted for radioactive decay to give the
incremental excretion of tritium ∆eu(t)
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∆eu(t) = ∆Eu(t)e-λt (Eq. E.5-2)
Section 136
Urinary excretion of tritium following an intake of HTO is typically expressed as the
concentration of radioactivity per unit volume of urine such as µCi/L, based on the
assumption that the concentration of HTO is the same in all body fluids. The presence of
the OBT compartment in the ICRP 78 model precludes this approach and warrants the use
of 24-hour incremental urinary excretion functions. Incremental fecal excretion is calculated
in an analogous fashion. A detailed example of how to calculate urinary and fecal excretion
is given in Appendix B.
E.5.1.3 The Respiratory Tract Biokinetic Model
The ICRP respiratory tract model is rather complex and is discussed in great detail in ICRP
Publication 66. A brief overview is provided here as an introduction to the model. The
respiratory tract model is composed of five major components:
• anatomical model;
• deposition model;
• particle mechanical clearance model;
• particle dissolution model; and
• dosimetric model.
The respiratory tract is divided into the thoracic and extrathoracic (ET) regions, which are
divided further into compartments that are used in the deposition and clearance models.
These compartments are listed in Table E.5-1. Comparing the regions of the ICRP 66 and
ICRP 30 respiratory tract models, the ET region corresponds to the nasal passage (NP)
region, the BB and bb regions correspond to the trachea and bronchial tree (TB) region, and
the AI region corresponds to the pulmonary parenchyma (P) region.
The deposition model describes quantitatively where inhaled particles will be deposited in
the different regions of the respiratory tract. The sites of initial particle deposition are all the
compartments listed above except for the thoracic and extra-thoracic lymph nodes.
Although it is possible to calculate deposition fractions from first principles, in practice we
usually obtain the fractions from published tables like Table E.5-2 below. These deposition
fractions for occupational exposure were taken from the ICRP-CD7.
7The ICRP Database of Dose Coefficients for Workers and Members of the General Public, Version
1.0 (Pergamon Press: New York) 1998.
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Table E.5-1. Compartments of the Respiratory Tract Model
Extrathoracic
ET1 Anterior nose
ET2 Posterior nose, larynx, pharynx, mouth
ETseq sequestered particles
LNet extrathoracic lymph nodes
Thoracic
BB - bronchial region
BB1 - fast clearing compartment
BB2 - slow clearing compartment
BBseq - sequestered particles
bb - bronchiolar region
bb1 - fast clearing compartment
bb2 - slow clearing compartment
bbseq - sequestered particles
AI - alveolar-interstitial region
AI1- fast clearing compartment
AI2 - moderate clearing compartment
AI3 - slow clearing compartment
LNth - thoracic lymph nodes
Table E.5-2. Deposition Tractions for Different Compartments
of the Respiratory Tract as a Function of Particle AMAD.
AMAD (:m)
0.001 0.003 0.01 0.03 0.1 0.3 1 3 5 10
AI1 1.359E-04 6.714E-03 8.229E-02 1.525E-01 8.688E-02 4.458E-02 3.198E-02 2.314E-02 1.596E-02 7.104E-03
AI2 2.718E-04 1.343E-02 1.646E-01 3.051E-01 1.738E-01 8.916E-02 6.396E-02 4.627E-02 3.191E-02 1.421E-02
AI3 4.530E-05 2.238E-03 2.743E-02 5.085E-02 2.896E-02 1.486E-02 1.066E-02 7.712E-03 5.319E-03 2.368E-03
bbf 2.262E-02 8.770E-02 1.291E-01 7.188E-02 3.328E-02 1.523E-02 8.327E-03 7.580E-03 6.569E-03 4.131E-03
bbs 2.294E-02 8.895E-02 1.309E-01 7.290E-02 3.376E-02 1.544E-02 8.087E-03 5.954E-03 4.384E-03 2.099E-03
Section 137
bbseq 3.212E-04 1.245E-03 1.833E-03 1.021E-03 4.726E-04 2.162E-04 1.157E-04 9.541E-05 7.721E-05 4.392E-05
BBf 3.117E-02 4.420E-02 2.685E-02 1.035E-02 4.746E-03 3.260E-03 6.489E-03 1.127E-02 1.171E-02 9.436E-03
BBs 3.161E-02 4.483E-02 2.723E-02 1.049E-02 4.813E-03 3.293E-03 5.844E-03 7.290E-03 5.921E-03 3.116E-03
BBseq 4.425E-04 6.276E-04 3.812E-04 1.469E-04 6.738E-05 4.619E-05 8.694E-05 1.308E-04 1.243E-04 8.848E-05
ET2 4.390E-01 3.494E-01 1.735E-01 6.994E-02 3.218E-02 5.820E-02 2.111E-01 3.699E-01 3.989E-01 3.836E-01
ETseq 2.196E-04 1.748E-04 8.680E-05 3.499E-05 1.610E-05 2.912E-05 1.056E-04 1.850E-04 1.996E-04 1.919E-04
ET1 4.433E-01 3.327E-01 1.539E-01 6.248E-02 3.071E-02 5.217E-02 1.652E-01 3.001E-01 3.385E-01 3.471E-01
Note that an “f” in Table E.5-2 corresponds to a “1” or “fast clearance compartment” in Table
E.5-1 and an “s” corresponds to a “2” or “slow clearance compartment.” For example, bbf in
Table E.5-2 is the same as bb1 in Table E.5-1.
The model for mechanical clearance of particles from the lung is shown in Figure E.5-3.
While particles are being mechanically cleared, they are also dissolving and being absorbed
into the bloodstream. Mechanical clearance and dissolution are therefore competitive
processes.
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Figure E.5-3. Deposition of Aerosols in the Respiratory Tract and Their Subsequent
Mechanical Clearance
NOTE: Shaded compartments are sites of initial deposition.
According to the model, the rate of mechanical clearance is dependent on where the particle
is deposited, but is independent of the chemical form of the particle. On the other hand, the
dissolution rate is dependent on the chemical form of the particle, but independent of where
the particle is in the respiratory tract8. The dissolution model is shown in Figure E.5-4. To
account for time-dependent dissolution a two-stage dissolution model is used. In this model,
particles either dissolve directly (and are absorbed) or are transformed to an intermediate
form before they dissolve.
Figure E.5-4. Two-stage Dissolution of STC Particles in the Respiratory Tract
8 Except for the ET1, where no dissolution or absorption is assumed to occur.
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Default parameters are supplied in ICRP 66 for the mechanical clearance and dissolution
models. The dissolution rate of particles may be classified as Type F (fast), M (moderate),
or S (slow). These classes correlate roughly with the Class D/W/Y classes in the ICRP 30
respiratory tract model. However, note that D/W/Y refers to total clearance rates
(mechanical plus dissolution) whereas F/M/S refers to dissolution rates only. The
parameters for the time-dependent dissolution model can be experimentally determined by
measuring the dissolution rate in-vitro over time, which is usually represented with two
exponents9:
ts
r
ts
r
sr efeftr −− ⋅−+⋅= )1()( (Eq. E.5-3)
where
• r(t) is the fraction of material not dissolved at time t;
• fr is the fraction that dissolves rapidly with rate constant sr ; and
• ss is the rate constant for the fraction (1 - fr ) that dissolves slowly.
These parameters may then be converted to the sp, spt, and st in the dissolution model
(Figure E.5-4).
E.5.1.4 The GI Tract Biokinetic Model
Section 138
The GI tract biokinetic model, which has
already been discussed to some extent in
Section E.5.1.1, is essentially the same model
used in ICRP 30. STC particles enter the GI
tract though the stomach via clearance from
the lungs and oral ingestion. The f1 is
assumed to be 0.1 for Type M) STC particles
and 0.01 for absorption type S STC particles.
The tritium released from STC particles is
absorbed into the bloodstream from the small
intestines as HTO. Ingestion of HTO is treated
as a direct injection into the bloodstream,
bypassing the GI tract. A fraction of the HTO
excreted from the body leaves via the feces.
As mentioned before, this fraction is (0.1)/3
and it is assumed to enter the GI tract through
the upper large intestine.
9 See ICRP 71, Annexe D, Assignment of Compounds to Absorption Types from Experimental Data.
Figure E.5-5. GI Tract Biokinetic Model
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E.5.1.5 Dosimetric Models
Ultimately, we would like to calculate the equivalent dose to the organs and tissues listed in
the first column of Table E.5-3. These doses are then weighted with the appropriate tissue
weighting factor from the second column and summed to give effective dose He:
∑
=
=
remainder
gonadsi
iie HwH (Eq. E.5-4)
Table E.5-3. Organs and Tissues with Explicit ICRP 60 Tissue Weighting Factors
Tissue
Tissue or Weighting
Organ Factor
gonads 0.20
bone marrow 0.12
colon 0.12
lung 0.12
stomach 0.12
bladder 0.05
breast 0.05
liver 0.05
esophagus 0.05
thyroid 0.05
skin 0.01
bone surface 0.01
remainder 0.05
The first step in calculating He is to calculate the individual organ doses. To do this we must
know:
• The source organs10;
• The number of decays that take place in the source organs;
• The target organs11; and
• The fraction of energy released in the source organs that is absorbed in a target organ.
The source organs for STC are listed in Table E.5-4.
10 The organs in which tritium will decay and release radiation.
11 The organs that absorb the radiation emitted by the source organs.
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Table E.5-4. Dosimetric source organs for intakes of STC
ET1sur bbseq
ET2sur AI
ET2seq LNth
LNet UBcont
BBgel SI
BBsol ULI
BBseq LLI
bbsol tissue
bbgel
The abbreviation “sur” refers to surface, “seq” refers to sequestered, “gel” refers to material
in the fast clearing mucus on top of the cilia, and “sol” refers to material in the slow clearing
solution between cilia. The source organ “tissue” is the soft tissues of the body.
A source organ may be associated with more than one biokinetic compartment. For
example, the source organ ET1sur is composed of only the ET1 biokinetic compartment,
whereas the ET2sur source organ is composed of the ET2 and transformed ET2 (TET2)
biokinetic compartments. The “tissue” source organ is composed of the OBT, HTO, and
blood biokinetic compartments (see Appendix B). The decays U that take place in the
source organs are calculated by integrating the retention function for the biokinetic
compartments that compose the source organ.
Once the source organs and their associated biokinetic compartments are specified, the
target organs must be specified. The target organs for STC are listed in Table E.5-5.
Table E.5-5. Dosimetric Target Organs
Adrenals kidneys muscle
UB wall liver ovaries
BS ET1bas pancreas
brain ET2bas RM
breasts LNet skin
S wall BBbas spleen
SI wall BBsec testes
ULI wall bbsec thymus
LLI wall AI thyroid
LNth uterus
Section 139
In this table “bas” refers to basal cells, “sec” to secretory cells, “UB” to urinary bladder, and
BS to bone surface.
The specific effective energy (SEE) describes the dose delivered to a specific target organ T
for each decay in a specific source organ S. The SEEs are calculated with the computer
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code SEECAL12. The SEEs calculated with SEECAL do not account for self-absorption of
the tritium beta radiation in the tritide particle. If corrections for self absorption are made,
care should be taken not to adjust the dose received from HTO. The dose HT to target
organ T from the decays in source organ S is given by
( )STSEEUH ST ←= (Eq. E.5-5)
The total dose to the target organ is the sum of the dose from all source organs.
( )∑ ←=
i
iST STSEEUH
i
(Eq. E.5-6)
The doses to some target organs are combined in a prescribed fashion to calculate the dose
to an organ composed of two or more other organs or tissues. For example, 57% of the
dose to the upper large intestine is added to 43% of the dose to the lower large intestine to
give the dose to the colon. The tissues of the respiratory tract are another example of this
procedure. Two organs in Table E.5-3 deserve special note. First, the dose to the thymus
is assumed to be the same as the dose to the esophagus. Second, the dose to the
remainder is the mass weighted mean of the doses to the i organs not listed in Table E.5-3.
∑
∑
=
i
i
i
ii
remainder m
mH
H (Eq. E.5-7)
E.5.2 Internal Dose Determination
The first step in determining an individual’s dose resulting from a radionuclide intake is the
intake assessment (i.e., determining the amount of radioactive material present in the body).
Intake assessments for tritium exposure usually rely on radiobioassay. Common
radiobiossay techniques for tritium (urinalysis) are rendered ineffective for some forms of
STC intakes (especially insoluble particulates) because of the difficulties associated with
relating the results of these analyses to specific intake levels. Therefore, representative air
monitoring results are often used for assessment of doses resulting from exposure to
particulate STCs. Variations in individual biological characteristics and statistical uncertainty
associated with any measurement make dose assessment a process that must be
approached with reasonable assumptions and documentation that support the calculation
methodology.
Personal intake and dose assessments can be based on data from representative air
monitoring using any appropriate technique, most commonly lapel sampling. Fixed air
sample heads and portable air samplers may be used for individual dose assessment if one
can ensure the sample is representative of the air inhaled. But, they are primarily used to
verify the adequacy of radiological controls and postings and to document radiological
conditions in the area of interest. See DOE-STD-1211-98 (DOE 1999h) Internal Dosimetry.
12 M. Cristy and K. F. Eckerman, "SEECAL: Program to Calculate Age-Dependent Specific Effective
Energies," ORNL/TM-12351 (1993).
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E.5.2.1 Intake Determination Methodology for Tritiated Particulates
Section 140
Determinations of individual radioactive material intakes generally fall under three different
methods: 1) in-vivo analyses, such as whole body or organ counting; 2) in-vitro analyses,
using analyses of excreta (urine or fecal analyses); and 3) area monitoring, using results of
area surface and air contamination monitoring programs. The actual method used depends
on a number of factors, including the characteristics of the material to be analyzed, results of
prior scientific analyses to develop applicable protocols, and the equipment available. This
section discusses the applicability of these various methods to evaluating intakes of
particulate STCs.
E.5.2.1.1 Air Monitoring
Air monitoring can be used to estimate intake directly, as opposed to indirect bioassay
methods. Intake is considered to be proportional to the actual activity captured on the filter
of an air-sampling device (assuming that the sample is representative of the breathing air for
the individual in question). Particulates tend to shield their tritium beta activity by self-
absorption of the beta radiation within the mass of the particle. Observed activity on a filter
sample, measured by suspending particulates from the filter into liquid scintillation counting
(LSC) solution, therefore under-represents the actual activity available for deposition to the
lung, i.e., intake. Self-absorption factors (SAFs) vary, as a function of respirable (<10 µm
AMAD) particulate size and material, by a factor of approximately 10. However, when
tritiated particulate intake is defined in terms of observed activity (and when DCF is
correspondingly defined in terms of observed activity intake), the uncertainty in the observed
intake essentially disappears, since self-absorption is accounted for.
If large non-respirable tritiated particulates are captured on an air filter, intake amounts are
somewhat overestimated. However, non-respirable particulates are not efficiently
suspended in breathable air and are therefore discriminated against during air monitoring.
Also, some dissolution can occur in the scintillation cocktail, which measures the activity
captured on a filter. Dissolved tritium is not subject to self-absorption. Intake calculations
are therefore overestimated if all activity observed by LSC is taken as “insoluble” and
treated as absorption type S particulate. Since SAFs vary by a factor of ~10, dissolution in
cocktail will not increase intake computations by more than a factor of ~10. Either non-
respirable particulate collection or dissolution in cocktail will act to provide overestimation of
intake (and ultimately dose) from air monitoring results.
Intake (and dose rate) in this case may be expressed as follows:
D(t) ∝ Io + ∆Io (Eq. E.5-8)
where: D(t) = dose rate to lung from observed intake at time t
Io = observed intake to lung from air monitoring results at time zero
∆Io = incremental observed activity from particle dissolution or non-respirable particulates at
time zero.
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Shortfalls
The main shortfalls associated with this methodology for intake (and dose) estimation
are: 1) actual activity intakes are uncertain by a factor of 10 because of self-
absorption. 2) activity collected and measured on filters may over-represent the
intake because of capture of non-respirable particulates and dissolution in
scintillation cocktail.
Section 141
As previously discussed in this appendix, intakes in terms of actual activity do not need to
be determined. Intakes of observed activity are adequate to provide dose estimates as long
as dose conversion factors are available which are described in terms of observed activity.
In Section 5.2.3, self-absorption is investigated in detail. The section shows that actual
activity of an intake is underrepresented by the observed results from scintillation counting
of an air filter sample, but that the actual activity is correspondingly not fully available to
impart dose to lung tissue. In fact, the observed activity more nearly represents dose or
dose potential, since only that beta radiation that is not self-absorbed and escapes the
particulate (i.e., that beta radiation “observed” via LSC analysis) is available to impart dose.
In Section 5.2.4, the ICRP 66 lung model is used to tabulate dose conversion factors for a
given actual intake of tritiated particulate of various materials and various particle size
distributions, assuming an ICRP 78 biokinetic model and absorption type S (slow). ICRP 66
dose, which does not account for self-absorption, is corrected by a "self-absorption factor for
energy" (SAFe) for the various particulates to determine the actual dose from the actual
intake. SAFe is the fraction of the total tritium beta energy generated within a particulate
which is released from that particulate. The tritium beta activity expected to be observed in
LSC analysis from the actual intake is then determined using the "self-absorption factor for
beta particles” (SAFβ) for the various particulates. The result of these calculations is a table
of actual dose conversion factors for intakes, based on observed data, for a variety of
materials and particulate sizes. Because actual activity is not needed to assign dose from
air sampling data, uncertainty in actual activity (because of uncertainty in particle size and
hence SAFs) is not a shortfall to the air monitoring method for dose estimation. In addition,
uncertainty in observed activity is only a function of the LSC assay technique, which is
expected to be small and comparable to the uncertainty when LSC is used to analyze in
urine or fecal bioassay samples.
The remaining expected shortfall is an overrepresentation of tritiated particulate intake
because of capture of non-respirable particulates or dissolution in scintillation cocktail.
These factors are not expected to increase dose calculations significantly. Non-respirable
particulates will tend to be less available to sampling than respirable particulates, due to
rapid settling. Dissolution in scintillation cocktail would have to occur within the few-hour
period prior to analysis during which samples are immersed in the cocktail. These factors
would serve to exaggerate intake estimates. The extent of this overestimation is the only
significant uncertainty in the intake determination from air sampling methodology.
Another uncertainty occurs in the air sampling method which affects all methods. For a
given intake, an expected dissolution rate must be chosen for the determination of the DCF.
If absorption type S is chosen, when in fact captured particulates on an air-sampling filter
more rapidly dissolve in the lung, this constitutes dose overestimation. Dose can be
overestimated by a factor of 50 for this reason. The typical overestimate is expected to be a
DOE-HDBK-1129-2008
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Section 142
factor of less than 10, because the fastest dissolving particulates lose tritium to air during
sampling and prior to analysis.
For the case of materials with extremely slow dissolution rates, such as hafnium tritide, the
assumption of absorption type S is reasonable (Cheng 1999a), and would not lead to
significantly underestimated doses. For absorption type S and Type “Super S” materials,
mechanical clearance is the predominant removal mechanism, as opposed to dissolution.
(“Super S” is a term used to describe any material where the absorption rate for tritium is
slower than that of absorption type S.) Section E.5.2.2 shows that dose conversion factors
for Hf, as derived from absorption type S and “Super S” input data, differ by only a few
percent.
Detectable intake (and dose) is small in the case of air sampling. Section 5.2.2 determines
a derived air concentration (DAC) value for absorption type S tritiated particulate which,
when inhaled for one hour, imparts an E50 of 2.5 × 10-5 Sv (2.5 mrem); this value is shown to
be 4.8 × 104 Bq observed/m3. Doses less than one millirem (10 µSv) are measurable and
can be readily assigned in the case of air monitoring. Sensitivity is not a shortfall, but is in
fact an advantage to air monitoring.
An additional shortfall for analyzing air samples using LSC is self-absorption of tritium beta
radiation due to dust loading. An effective compensatory measure for this shortfall is the
use of detergent in preparing air samples to remove dust from samples and suspend it in the
counting solution.
The ability to obtain air samples that are representative of the monitored individual’s
breathing zone is another potential shortfall of air monitoring. However, according to U. S.
Nuclear Regulatory Commission Regulatory Guide 8.25, samplers located within about 1
foot of the worker’s head may be accepted as representative without further determination.
Therefore, when lapel breathing zone air samplers are properly used, representative air
sampling is not considered a shortfall.
E.5.2.1.2 Urinalysis
Note: This section is reserved pending development of a relevant protocol.
E.5.2.1.3 Fecal Analysis
Note: This section is reserved pending development of a relevant protocol.
E.5.2.1.4 In-Vivo Analyses
As noted in section E.4.3.3, in-vivo analyses depend on the detection of radiation emitted by
radioactive materials within the body by radiation detectors external to the body. Because
tritium decays by emission of low energy beta particles that will not penetrate through the
body to the external detector, in-vivo analysis is not considered to be a viable means of
assessing tritium intakes, including STC intakes.
E.5.2.2 Dose Conversion Factor for Insoluble Tritiated Particulates
Following the intake assessment, the intake amount may be converted to internal dose
using a DCF. Determination of internal dose from a tritiated particulate is mainly dependent
DOE-HDBK-1129-2008
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on two factors: particle size distribution, and dissolution rates of tritium from the particulate
into lung fluid. The impact of these factors on DCF or intake determination, as derived from
either bioassay or air concentration data, is discussed below.
E.5.2.2.1 Particle Size Distribution
Section 143
For any given exposure scenario, the particle size distribution will affect both the dissolution
rates (discussed below) and the deposition fractions (i.e., the fractions of the material that
are deposited into each compartment of the lung). Smaller particle sizes tend to deposit
deeper into the lung, causing a greater dose than particles that are physically larger, but
otherwise similar (e.g., chemical characteristics, quantity of infused tritium). Uncertainty in
the particle size distribution causes uncertainty in the DCF, regardless of the method used
(e.g., bioassay or air monitoring) to determine activity intake. Therefore, the particle size
distribution factor cannot be used to choose a preferred data collection method (urine
bioassay vs. fecal bioassay vs. air concentration values).
Fortunately, errors in determining the particle size distribution tend to result in self-canceling
errors in the dose assessment. If particle sizes are smaller than assumed, the particles will
deposit deeper in the lungs, resulting in the use of a larger DCF and calculation of a larger
dose. However, because the dissolution rate for the smaller particles will be higher than
assumed, intake will be overestimated. Because intake is overestimated while DCF is
under-estimated, the effects of particle size uncertainty on assigned dose tend to cancel.
These effects are explored later in this chapter.
Deposition fractions affect clearance rates of particulates from the lung to the
gastrointestinal (GI) tract. Since urine excretion of tritium dissolved from tritiated particulate
over time is a function of those particles which have not cleared from the lung, interpretation
of urine excretion curves can extract particle size information. This requires extended
monitoring without additional tritium intakes, which can adversely affect project management
activities. To estimate intakes (and therefore doses) accurately and promptly from urine
data, detailed knowledge of the particulate dissolution rates must be available. Tritiated
material and particle size distribution involved in the intake, and the expected dissolution
rate for that material and size, must be known. When tritiated materials and sizes are likely
to range broadly, it will be difficult to provide material identification and size
characterizations in the workplace. Moreover, although dissolution rate data are available
for several materials, these data do not include all the possible combinations of materials
and particle sizes that might be encountered.
E.5.2.2.2 Physical Diameter versus AMAD for Particulates
The ICRP and most technical papers that address respirability of particulate contamination
use the term “activity median aerodynamic diameter” or “AMAD” when referring to particle
size distributions. The AMAD can be very different from the physical diameter of a median
particle, as it is a function of the particle’s density and shape. The relative deposition of
particles in the respiratory tract is dependent on the AMAD. Particles with small AMADs
tend to deposit deeper (higher percentage in the alveolar interstitial region) in the lung than
larger AMAD particles; because of the slow clearance rates of the deep lung, smaller
particles generally cause higher lung doses than larger ones. For particles with AMADs
greater than about 10 µm, the fractional deposition in the deep respiratory region is
considered negligible. The larger sized particles tend to be deposited in the upper
respiratory region where they are rapidly removed to the gut and eliminated in feces. The
Section 144
DOE-HDBK-1129-2008
E-35
lung dose per unit intake is less for larger AMAD particles than for smaller AMAD particles.
Table E.5-6 shows a comparison of physical diameter versus AMAD (calculated per Cheng
1999a) for a variety of materials from low density to high density.
Table E.5-6. Physical diameter versus AMAD for monodisperse particle distribution (σg = 1)
Physical Diameter (µm) vs. AMAD (µm)
Base Material* AMAD = 10 AMAD = 5 AMAD = 2 AMAD = 1 AMAD = 0.5
Organic–[∼(CH2)n] 12.9 6.48 2.61 1.31 0.668
Rust–[∼FeO(OH)] 5.87 2.92 1.15 0.559 0.265
Ti H2 6.17 3.07 1.21 0.591 0.282
Zr H2 4.76 2.36 0.920 0.441 0.202
Hf H2 3.53 1.74 0.666 0.310 0.133
* Variable amounts of elemental hydrogen are isotopically tritium.
NOTE: The organic row listed in this table is for insoluble OBT. In other words the row is
for OBT that is particulate in nature, to include oil mists. See Section 5.2.5 for a discussion
of soluble and insoluble OBT.
Particle size distributions which are “monodisperse” are comprised of particles which are all
the same size. The parameter σg is the geometric standard deviation of the distribution.
When σg = 1, no variability in the size distribution exists. When σg >1, the distribution is
called “polydisperse.”
Subsequent text in this chapter investigates the dose from tritiated particulates as a function
of different particle size distribution assumptions, from 0.5 to 10 µm AMAD. Dose variability
over this range can then be compared to the dose from a 1 µm default size. Sub-
micrometer particle size distributions are only produced by hot processes such as
combustion (Cheng 1999b). This assertion is supported by Newton, 1987, and Dorrian,
1995. These references show that high energy processes such as oxyacetylene torch,
electric arc cut rod, and plasma torch produce sub-micrometer particle size distributions,
while lower energy processes such as band saw, reciprocating saw, and grinder produce
larger particle size distributions. High energy cutting of tritium contaminated objects will
release tritium from the objects in the form of HTO. Evaluation of particle sizes from 0.5 to
10 µm is therefore expected to be an appropriate evaluation of most respirable particulate
STCs.
E.5.2.2.3 Dissolution Rate
The dissolution rate for a tritiated material is the rate at which tritium is released from the
material to physiological (lung) fluid as HTO. For a given tritiated particulate intake, the
dissolution rate affects the amount of tritium that remains in the lung to impart dose there.
The effect of a varying dissolution rate assumption on the dose assigned from a given intake
would be the same regardless of the method used to determine intake. Therefore,
uncertainty in the dissolution rate also cannot be used to choose a preferred data collection
method (urine bioassay vs. fecal bioassay vs. air concentration values). ICRP 71 gives
DCFs for tritiated particulate intakes that vary from 0.3 to 14 times the DCF for HTO intakes,
depending on the Absorption Type, which is primarily a function of the dissolution rate.
Assuming the slowest dissolution rate for an intake would be a conservative assumption, in
lieu of characterizations to the contrary, but would not grossly overestimate dose for a given
DOE-HDBK-1129-2008
E-36
intake. This is the basis behind applying ICRP 66 absorption type S (“slow,” 99.9%
dissolving with a halftime of 7,000 days) in the derivation of tritiated particulate DCF in
Section E.5.2.2.
Section 145
E.5.2.2.4 Default Parameters for ITPs
Dose conversion factors for ITPs are dependent on the particle size distribution and
absorption characteristics of the aerosols in question. ICRP 66 provides guidelines for
default assumptions to be used when detailed characterization data are unavailable. In
many cases, the characterization process may require breach of contaminated systems.
The assumptions listed in Table 5-7 should therefore be used to assess dose from
suspected ITP intakes. These assumptions are conservative and consistent with ICRP 66
recommendations for assessing occupational exposure.
Table E.5-7. Default assumptions for insoluble tritiated particulate intakes
Mode of Intake Inhalation
Particle Size 5µm AMAD
Geometric Standard Deviation (σg) 2.5
Shape Factor 1.5
Absorption Type S
Weighting Factors 10 CFR Part 835
Biokinetic Model ICRP 78
NOTE: The default particle size assumption of 5 µm AMAD is consistent with 10 CFR Part
835. However, values of the various self-absorption factors, dose conversion factors, and
air concentration values are calculated for 1 µm and other values of AMAD. Such values
may be used when justified.
E.5.2.2.5 Computer Codes
The Radiation Protection Division of the United Kingdom’s Health Protection Agency
(formerly the National Radiological Protection Board of Great Britain (NPRB)) has developed
a computer program,called IMBA, (Integrated Modules for Bioassay Analysis) to facilitate the
use of the recent ICRP biokinetic models such as the ICRP 66 Human Respiratory Tract
Model. This model is discussed in Section 5.1. ICRP 71 (which defaults to a 1 µm AMAD
polydisperse particle size distribution with a material density of 3 g/cm3) also uses the ICRP
66 Human Respiratory Tract Model to calculate DCF. The DCFs for a 1 µm AMAD
polydisperse particle size distribution and a material density of 3 g/cm3 listed in ICRP 71 are
the same as those calculated with IMBA. IMBA can also be used to refine the conclusions
of this appendix, and to assess the dose from ITPs of known particle sizes and material
densities or dissolution rates other than absorption type S. However, adjustment for self-
absorption of beta particles and their energy still has to be performed as described
previously to obtain DCFos.
NOTE: A computer program called LuDEP (developed by the NRPB) was used at the
Mound site to perform many of the calculations used in this appendix such as the variability
of the DCFs for ITPs of various particle sizes. IMBA is the successor to LuDEP.
DOE-HDBK-1129-2008
E-37
ITP dose evaluations may be calculated either by using IMBA directly, or by using DCFs
(organ Committed Equivalent Dose and E50) that are developed in this appendix (or that can
be calculated using IMBA).
E.5.2.3 Self-Absorption Factor (SAF) for ITPs
Within the ITP, the mass of the particulate absorbs a portion of the beta particles emitted
during tritium decay. The fraction of beta particles that escapes the ITP is called the “self-
absorption factor for beta particles” (SAFβ). When analyzing air monitoring samples for
ITPs using LSC, it is necessary to consider SAFβ, since ITPs do not dissolve appreciably
and release tritium to LSC cocktail. Only beta radiation that escapes the particles in LSC
cocktail is available for detection. The SAFβ is used to estimate the "actual" ITP activity that
would be “observed” when samples are counted via LSC. This use of SAFβ has been
confirmed experimentally (Kropf, 1998), although the supporting evidence is limited.
Section 146
To assess dose to the lung from ITPs properly, the “self-absorption factor for energy” (SAFe)
is an important consideration. Absorbed dose is a measure of the energy deposited (per
unit mass) in tissue. Only the beta energy that escapes the particles contributes to dose.
SAFe is the fraction of energy that escapes the particles. Because LuDEP does not account
for SAFe, refinement of the results of LuDEP computations is necessary.
The SAFβ and SAFe for given physical particle sizes are calculated numerically here by the
methods described by Kropf (1998). The determinations of SAFβ and SAFe are dependent
on the electron density of a given material, which is proportional to A/(Z∆), where A is the
atomic mass of the material’s empirical formula, Z is the number of protons in the empirical
formula, and ∆ is the density.
The values employed to calculate the self-absorption factors (SAFs) for several
representative materials are given in Table E.5-8 below. DOE has handled tritides of
several metals, considered to be insoluble, which do not appear in the table (in the interest
of brevity), including scandium, yttrium, and alloys of titanium and lanthanum. The
derivation of SAFs for a representative but broad range of tritiated particulate materials is
the prime focus of this section. The materials investigated were selected to represent a
wide range of self-absorption, itself a function of the parameter A/(Z∆). The materials in the
tables of this section have values of this parameter which vary from 0.2 to 1.9. Parameter
values for scandium, yttrium, and lanthanum ditritides are 0.72, 0.52, and 0.47, respectively.
[Values for lanthanum alloys are slightly larger than those for lanthanum because of the
inclusion of lighter elements. Values for iron/titanium alloys are close to those for titanium
as given in the tables.] With respect to SAFs, the materials included in the tables therefore
bracket the metals and alloys not included.
Table E.5-8. Constants for calculating SAFs for various monodisperse (σg = 1) ITPs
Base Material* A Z ∆ A/(Z∆)
Organic [∼(CH2)n] 14 8 0.9 1.944
Rust [∼FeO(OH)] 89 43 3 0.690
Ti H2 47.9 22 3.9 0.558
Zr H2 91.22 40 6.49 0.351
Hf H2 178.49 72 11.68 0.212
* Variable amounts of elemental hydrogen are isotopically tritium.
DOE-HDBK-1129-2008
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NOTE: In Table E.5-8, A and Z for organic and rust are based on the sum of the elements
of the empirical formula. ∆ for organic and rust are an average of a range of values from the
Handbook of Chemistry and Physics (CRC, 1973). A and Z for hydrides are based on the
metal only, since hydrogen is a minor contribution. ∆ for hydrides are taken from
Richardson, 1999 and Cheng, 1999a. Hydrogen in tritium-labeled compounds has been
represented as protium only, as this has a minor effect on the ratio A/(Z∆).
Functional representations (curve-fits) of numerically calculated SAF data (for monodisperse
physical particle sizes), as a function of particle size, were further derived. These
representations are a refinement of those by Kropf (1998), and more accurately fit the data
at small particle sizes.
From the functional representations of SAFs for monodisperse physical particle sizes, SAFs
for polydisperse AMAD particle size distributions were calculated using the methodology
adapted from Kropf (1998) and Cheng (1999a). The resulting values are given in Tables
E5-9 and E.5-10.
Table E.5-9. SAFe for Various ITP Materials and Polydisperse (σg = 2.5) Particle Size
Distributions (in AMAD)
Section 147
Base Material* A/(Z∆) SAFe vs. Particle Size [AMAD(µm), σg=2.5]
10 5 2 1 0.5
Organic [∼(CH2)n] 1.944 0.305 0.474 0.707 0.841 0.925
Rust [∼FeO(OH)] 0.690 0.231 0.381 0.614 0.768 0.879
Ti H2 0.558 0.215 0.362 0.594 0.753 0.871
Zr H2 0.351 0.180 0.312 0.541 0.714 0.852
Hf H2 0.212 0.142 0.260 0.490 0.680 0.842
* Variable amounts of elemental hydrogen are isotopically tritium.
Table E.5-10. SAFβ for Various ITP Materials and Polydisperse (σg = 2.5)
Particle Size Distributions (in AMAD)
Base Material* A/(Z∆) SAFβ vs. Particle Size [AMAD(µm), σg=2.5]
10 5 2 1 0.5
Organic [∼(CH2)n] 1.944 0.205 0.333 0.535 0.677 0.789
Rust [∼FeO(OH)] 0.690 0.140 0.244 0.439 0.602 0.745
Ti H2 0.558 0.133 0.231 0.423 0.590 0.739
Zr H2 0.351 0.104 0.191 0.380 0.555 0.719
Hf H2 0.212 0.077 0.154 0.343 0.529 0.707
* Variable amounts of elemental hydrogen are isotopically tritium.
Other published computations of self-absorption factors (Richardson, 1999; Traub, 1999)
largely confirm the results above. Traub (1999) states that bremsstrahlung photons, created
when beta particles are self-absorbed, are not expected to be a significant contribution to
dose from tritiated particulates.
DOE-HDBK-1129-2008
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E.5.2.4 Dose Conversion Factors (DCFs) and Derived Air Concentrations (DACs) for
ITPs
The broad range of SAF derivations in the previous section allows correction of dose
conversion factors (DCFs) for self-absorption across a broad range of */-/rials and size
distributions. The goal of these derivations and corrections in Section 5.2.2 is to determine
a limiting ("worst case") self-absorption-corrected DCF among a variety of materials with
wide variation in SAF. The variability of DCF as a function of particle size distribution is also
assessed. This determination of a limiting DCF for ITPs allows a material-independent
approach to air sampling and surface surveys following that point. A readily implemented
approach, utilizing data obtained in terms of "observed" activity, is also provided.
E.5.2.4.1 Dose Conversion Factors (DCFs) for ITPs
Using LuDEP, the DCFs for committed equivalent dose to lung and E50 were calculated for a
variety of ITP materials and particle size distributions using the default assumptions given in
Table E.5-5 (except for particle size). The results are shown in Tables E.5-11 and E.5-12
below. LuDEP makes no allowance for self-absorption within particulates.
Table E.5-11. Lung Committed Equivalent Dose DCFs (Sv/Bq) for Various ITPs and Particle
Sizes (AMAD, σg = 2.5), Absorption Type S Assumed
Lung DCF vs. Particle Size [AMAD (µm), σg = 2.5]
Base Material* 10 5 2 1 0.5
Organic [∼(CH2)n] 4.50 x 10-10 9.90 x 10-10 1.65 x 10-9 1.74 x 10-9 1.64 x 10-9
Rust [∼FeO(OH)] 4.51 x 10-10 1.00 x 10-9 1.71 x 10-9 1.98 x 10-9 2.29 x 10-9
Ti H2 4.51 x 10-10 1.00 x 10-9 1.74 x 10-9 2.07 x 10-9 2.52 x 10-9
Zr H2 4.53 x 10-10 1.01 x 10-9 1.81 x 10-9 2.30 x 10-9 3.07 x 10-9
Hf H2 4.56 x 10-10 1.03 x 10-9 1.94 x 10-9 2.70 x 10-9 3.87 x 10-9
* Variable amounts of elemental hydrogen are isotopically tritium.
NOTE: The reason the DCFs differ slightly for a given AMAD in Table E.5-11 is that the
densities differ and the density affects the deposition fractions in the various lung
compartments.
Table E.5-12. DCF (Sv/Bq), E50, for Various ITPs and Particle Sizes (AMAD, σg = 2.5),
Absorption Type S Assumed
E50 DCF vs. Particle Size [AMAD (µm), σg = 2.5]
Base Material* 10 5 2 1 0.5
Organic [∼(CH2)n] 6.10 x 10-11 1.27 x 10-10 2.05 x 10-10 2.14 x 10-10 2.00 x 10-10
Section 148
Rust [∼FeO(OH)] 6.11 x 10-11 1.28 x 10-10 2.13 x 10-10 2.43 x 10-10 2.79 x 10-10
Ti H2 6.15 x 10-11 1.28 x 10-10 2.16 x 10-10 2.54 x 10-10 3.07 x 10-10
Zr H2 6.17 x 10-11 1.3 x 10-10 2.25 x 10-10 2.83 x 10-10 3.74 x 10-10
Hf H2 6.20 x 10-11 1.32 x 10-10 2.41 x 10-10 3.30 x 10-10 4.70 x 10-10
* Variable amounts of elemental hydrogen are isotopically tritium.
NOTE: In Table E.5-12, the E50 DCF for rust, 1 µm AMAD, differs slightly from the E50 DCF
given in ICRP 71 for absorption type S tritiated aerosols (2.6 × 10-10 Sv/Bq), even though the
DOE-HDBK-1129-2008
E-40
particle size distribution and densities are identical. The reason for this difference is that the
ICRP 71 value was computed using the default “Environmental” assumptions (e.g.,
individual is sleeping 33.3% of the time) and the values given in the table above were
computed using the default “Occupational” assumptions because this document focuses on
occupational protection.
The DCFs given in Tables E.5-11 and E.5-12 were not corrected to account for SAFe.
Therefore, the lung component of the DCFs is significantly exaggerated. In order to
determine more realistic DCFs, it is necessary to correct the lung dose for SAFe using the
values from Table E.5-9.
NOTE: This correction should only be applied to lung dose from particulates, not to HTO in
the lung that results from the dissolution of the particle. However for absorption type S
materials, the rate of dissolution is so slow that the contribution to the lung dose from HTO is
negligible.
The correction for SAFe is made as follows:
DCF(corrected for SAFe) = DCF(uncorrected) - 0.12*DCFlung + 0.12*DCFlung x SAFe
(Eq.E.5-9)
where: DCF(uncorrected) is E50 per unit intake (Sv/Bq; values from Table 5-12)
0.12 is the ICRP 60 weighting factor for lung
DCFlung is the Lung committed equivalent dose per unit intake (Sv/Bq;
values from Table 5-11)
SAFe is the corresponding value from Table 5-9
Table E.5-13 shows the E50 DCFs, corrected for SAFe, for various ITPs.
Table E.5-13. DCF (Sv/Bq), E50, for Various ITPs and Particle Sizes (AMAD, σg = 2.5),
Absorption Type S Assumed, with SAFe Corrections Applied to the Lung Dose Component
E50DCF (w/ SAFe) vs. Particle Size [AMAD (µm), σg = 2.5]
Base Material* 10 5 2 1 0.5
Organic [∼(CH2)n] 2.35 x 10-11 6.41 x 10-11 1.47 x 10-10 1.81 x 10-10 1.85 x 10-10
Rust [∼FeO(OH)] 1.95 x 10-11 5.35 x 10-11 1.34 x 10-10 1.88 x 10-10 2.45 x 10-10
Ti H2 1.90 x 10-11 5.17 x 10-11 1.32 x 10-10 1.93 x 10-10 2.67 x 10-10
Zr H2 1.71 x 10-11 4.62 x 10-11 1.25 x 10-10 2.03 x 10-10 3.19 x 10-10
Hf H2 1.51 x 10-11 4.03 x 10-11 1.22 x 10-10 2.27 x 10-10 3.97 x 10-10
Variable amounts of elemental hydrogen are isotopically tritium.
E50 DCFs in Table E.5-13 are now smaller than the E50 DCFs in Table 5-12, because of the
corrections for particulate energy self-absorption. In order to use the values shown in Table
E.5-13, the “actual” activity inhaled must be known. Air monitoring can be performed via
batch air filtration sampling and subsequent LSC analysis of the collected ITPs. An indicator
of air concentration potential can also be provided by pre-job or in-job contamination
surveys. To determine the “actual” activity on a filter, it would be necessary to dissolve the
ITPs. Otherwise, self-absorption of the beta radiation from tritium leads to underestimates of
DOE-HDBK-1129-2008
E-41
Section 149
the airborne activity. However, many ITPs (especially absorption type S) are extremely
difficult to dissolve, requiring strong acids for extended periods of time. E50 DCFs for ITPs of
absorption type S, when determined based on “actual” activity, are found to be highly
dependent upon particle size. Table E.5-13 data indicate that variations for a given material
can be as much as a factor of 30 for particle sizes from 0.5 to 10 µm AMAD.
Fortunately, it is not necessary to rely on “actual” activity or to dissolve ITPs prior to counting
samples. Not only is dissolution cumbersome, but “observed” activity on filters counted by
LSC without dissolution is a much better indicator of dose or dose potential than is “actual”
activity. The reason for this is that (due to self-absorption) only the beta radiation that
escapes ITPs is capable of causing lung dose and, if the ITPs are not dissolved prior to
counting, only the beta radiation that escapes is counted.
Table E.5-14 shows E50 DCFs in terms of Sv per “observed” Bq when undissolved ITPs are
counted via LSC. The values in the table were calculated by dividing the E50 DCFs in Table
E.5-13 by the corresponding SAFβs from Table E.5-10. The term “DCFo” is used to
represent DCFs that are based on “observed” activity, as determined by LSC counting
without dissolution.
Table E.5-14. DCFo (Sv/observed Bq), E50, for various ITPs and particle sizes (AMAD, σg = 2.5),
Absorption Type S assumed
E50 DCFo vs. Particle Size [AMAD (µm), σg = 2.5]
Base Material* 10 5 2 1 0.5
Organic [∼(CH2)n] 1.14 x 10-10 1.92 x 10-10 2.75 x 10-10 2.67 x 10-10 2.35 x 10-10
Rust [∼FeO(OH)] 1.39 x 10-10 2.19 x 10-10 3.04 x 10-10 3.12 x 10-10 3.29 x 10-10
Ti H2 1.42 x 10-10 2.24 x 10-10 3.11 x 10-10 3.27 x 10-10 3.62 x 10-10
Zr H2 1.64 x 10-10 2.42 x 10-10 3.30 x 10-10 3.66 x 10-10 4.44 x 10-10
Hf H2 1.97 x 10-10 2.61 x 10-10 3.55 x 10-10 4.29 x 10-10 5.61 x 10-10
* Variable amounts of elemental hydrogen are isotopically tritium.
Table E.5-14 data indicate that the E50 DCFos, based on “observed” activity of ITPs of
absorption type S, are less dependent on particle size than are the E50 DCFs, based on
“actual” activity, from Table E.5-13. The assumption of a single particle size distribution
would result in much smaller errors than noted above; for example, when using “observed”
activity, E50 DCFs vary only by a factor of about 5 for particles ranging in sizes from 0.5 to
10 µm AMAD. Compare this with a factor of 25 when using “actual” activity.
The 10 CFR Part 835 recommended default particle size for occupational exposure is 5 µm
AMAD (σg = 2.5). From Table E.5-14, the most conservative E50 DCFo for 5 µm AMAD is
about 2.6 × 10-10 Sv per observed Bq (9.7 × 102 rem/Cio). This is the value that should be
used to compute E50 assessments for inhalation intakes of tritiated particulates, based on air
monitoring and observed results from that monitoring.
To calculate internal dose using the various dose conversion factors for ITPs, it is necessary
to estimate the intake of ITPs. Intake of ITPs (I) can be inferred from air sampling results
using equations E5-10 and E5-11. (See DOE-STD 1121-98 for considerations to be applied
when using air sampling results to determine internal dose.)
DOE-HDBK-1129-2008
E-42
To calculate intake from air sampler measurements use equation 5-10.
( ) ( ) ( )
( ) ( )hrT
hrThrmFR
hrmBRBqABqI E
C
F ⋅
⋅
⋅
=
)(/
/
3
3
(Eq E.5-10)
where
Section 150
AF is the activity on the filter sample (either observed or actual)
BR is the breathing rate of the worker
FR is the flow rate of the air sampler
TE is the time period the worker was exposed to air containing radioactive
material sampled
TC is the time over which the sampler was operated.
Note: It is important to make sure that TC reflects the time the sampler was operating in an
atmosphere expected to contain STPs. Including periods when the sampler is not in an STP
containing atmosphere in the determination of TC will tend to reduce the estimated STP
concentration in air and thus, lead to an underestimate of intake.
To calculate intake from personal air sampler measurements use equation E.5-11.
( ) ( ) ( )
( )hrmFR
hrmBRBqABqI F
/
/
3
3⋅
= (Eq E.5-11)
NOTE: To ensure that intake is not underestimated, the sampler should never be turned off
when a worker is in an atmosphere expected to contain STPs.
NOTE: Equations E.5-10 and E.5-11 assume 100% collection efficiency. The filters used at
the Mound Site (Mound 2000) had collection efficiencies that ranged between 0.981 –
0.9999 for 0.3 to 10 um particles. ANSI N13-1 (ANSI 1999) contains a table of collection
efficiencies for various types of filters.
Various types of internal doses for STCs can then be calculated from the product of
equations E.5-10 or E.5-11 and the various DCFs provided in this appendix. For example,
the DCFs in Table E.5-14 table can be used to determine the E50 from inhalation of ITPs of
various sizes and composition using the observed activity on an air filter. In addition, Annex
A contains DCFs for STPs of density 11.7 gm/cm3 (Hf) for absorption types S, M, and F and
AMADs of 1 and 5 µm.
To calculate internal doses (using air sampling results) from inhalation of ITP species that
have particle sizes, densities, and compositions that differ from those cases addressed in
this appendix, it will be necessary to obtain appropriate values for the self absorption factors
for beta and energy, as they are not provided in Tables E.5-9 and E.5-10. The observed air
sample activity would then have to be converted to actual activity by dividing it by the
appropriate SAFβ or by otherwise determining the total activity in the STPs in the sample.
Then use either equation E.5-10 or E.5-11, to calculate the intake in terms of actual activity.
DOE-HDBK-1129-2008
E-43
Next, using a computer code such as IMBA, the E50 can be calculated. The component of
the E50 resulting from exposure to the lung would have to be corrected for energy absorption
using the appropriate SAFe in a manner analogous to that in equation E.5-9.
NOTE: If the base material and particle size are not known, parameters and associated
SAFs for the most conservative material (i.e., HfH2), 1 µm AMAD particle size (σg = 2.5), and
absorption type S should be used for dose computations (See Table E.5-7 for default
assumptions) [absorption type S is believed to be sufficiently conservative: the DCFo for
5 µm AMAD polydisperse HfH2 is 2.61 x 10-10 Sv/Bqo (assuming absorption type S).
Deviations from these parameters should only be allowed in situations where material and
particle size are well known.
As noted above, the variability of E50 DCFo with material or particle size is not great (range is
factor of 5). Therefore, using a conservative assumption of material and particle size
distribution (5 µm AMAD) is accurate within that factor for any material or particle size
distribution; this assumption can be readily implemented when air monitoring is the method
of intake assessment. A factor of dose overestimation (~ 2 – 10) is further applied when all
captured tritiated particulates are assumed to be absorption type S and are measured by
LSC.
Section 151
E.5.2.4.2 DACs for ITPs
Derived Air Concentrations (DACs) can now also be computed; these are concentrations of
tritiated particulate aerosols which, when inhaled, impart prescribed doses over a given time
(i.e., 0.05 Sv in 2,000 hrs).
The equation below converts dose conversion factors (DCFs) to DACs.
( )
( )33 400,2
105.0
m
Bq
SvDCF
Sv
m
BqDAC ⋅
⎟⎟
⎠
⎞
⎜⎜
⎝
⎛
=⎟
⎠
⎞
⎜
⎝
⎛ (Eq. E.5-12)
If the DCFo is used in place of DCF in Eq. E.5-12, then this formula can be used to calculate
DACo. Accordingly, the most conservative DACo for ITPs (based on the E50 DCFo
determined in Section 5.2.4.1 for ITPs [4.3 x 10-10 Sv/Bqo]) is 4.8 × 104 Bqo/m3 (1.2 µCio/m3,
1.3 × 10-6 µCio/cm3).
Appendix A to the June 7, 2008 amendments to 10 CFR Part 835 contains DACs for
radiological protection against insoluble STCs including ITPs. These DACs assume a
particle of density 11.7 gm/cm3, are based on observed activity and were calculated for
absorption types S, M, and F. The methods contained in this appendix were used to
calculate these DACs. The DCFs for these DACs are listed in Annex A to this appendix.
E.5.2.5 Biokinetic Model for Soluble OBT
For soluble forms of OBT, particularly solvents and the small molecule component of OBT
oil, the assumption can be made that all activity deposited is instantaneously absorbed into
the body (ICRP 78, 1997). Soluble OBT is, therefore, amenable to available urine bioassay.
However, the biokinetic model for soluble OBT is different from that for HTO. Table E.5-15
DOE-HDBK-1129-2008
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shows the difference in fractional uptake and biological halftime for soluble OBTs and HTO
(ICRP 78, 1997).
Table 5-15. Fractional Uptake and Biological Halftime for Soluble OBT and HTO
(ICRP 78, 1997)
Fractional uptake with 10-day
biological T1/2
Fractional uptake with 40-day
biological T1/2
HTO 97% 3%
OBT 50% 50%
E.5.2.5.1 Intake and Dose Assessment for Soluble OBT
Soluble OBT solvents or oil components do not cause self-absorption of tritium beta activity
as do solid STCs. A DCF and DAC can therefore be expressed in terms of actual activity.
The E50 DCF that should be used for a soluble OBT intake is 4.1 × 10-11 Sv/Bq (152 rem/Ci)
(ICRP 78), unless a more appropriate DCF is derived and documented for the type of
soluble OBT encountered in the workplace.
To calculate the DAC for vapors of soluble OBT, there are two pathways that must be
considered (which are similar to HTO pathways), inhalation and skin absorption. If there is
no evidence that a soluble OBT is absorbed through the skin, then uptake via skin
absorption is zero and the DAC can be calculated using Eq E.5-12. Using the DCF for
OBTs from ICRP 78 of 4.1 × 10-11 Sv/Bq, a DAC of 5.0 x 105 Bq/m3 is calculated.
If there is evidence that an OBT is absorbed via the skin the following approach should be
used to calculate the DAC. ICRP 30 states that for exposure to airborne HTO, two-thirds
(⅔) of the intake is from inhalation and one-third (⅓) is from skin absorption. Therefore, the
total intake of airborne HTO is 1.5 times the inhaled intake. To determine a DAC, the ICRP
30 assumptions for uptake of airborne HTO are assumed here to be valid for soluble OBT;
i.e., ⅔ of the intake is due to inhalation and ⅓ is due to skin absorption. Therefore, equation
E.5-12 should be divided by a factor of 1.5 to account for the OBT taken into the body from
skin absorption. Accordingly, dividing the result of the calculation from the previous
paragraph by 1.5, the calculated DAC for soluble OBT that accounts for skin absorption is
3.3 × 105 Bq/m3 (9.1 µCi/m3 or 9.1 × 10-6 µCi/cm3).
Section 152
Soluble forms of OBTs are considered to be instantaneously absorbed into the body;
therefore, urinalysis can be used to assess soluble OBT intakes. This approach is adequate
to demonstrate compliance with the dose limits established in subpart C of 10 CFR 835. To
determine the soluble OBT intake, the individual's average urine excretion volume (if not
available, the ICRP 23 Reference Man value of 1.4 liter per day should be used) and the
ICRP 78 expected excretion rate per unit intake of soluble OBT should be used.
Appendix A to the June 7, 2008 amendments to 10 CFR Part 835 contains the DAC for
radiological protection against soluble STCs such as soluble OBT. This DAC is based on
actual activity and dose not consider uptake by the skin. The DCF for this DAC is listed in
Annex A to this appendix.
DOE-HDBK-1129-2008
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Internal soluble OBT doses should be assessed by either:
1. Using the E50 DCF listed above for soluble OBT (IMBA may also be used to calculate
individual organ CDE DCFs); or
2. Using IMBA to convert the intake amount to final E50 (IMBA may also be used to
calculate individual organ CDEs).
NOTE: IMBA can accommodate injection and ingestion intakes of soluble materials, as well
as inhalations of particulates, and can be used to document the soluble OBT dose
calculations. Using the ICRP 78 biokinetic model for soluble OBT above, IMBA calculates
4.2 × 10-11 Sv E50 per Bq intake by injection or ingestion, which is the same as the ICRP 78
E50 DCF for soluble OBT intake by ingestion. This value is slightly larger than the DCF for
soluble OBT (based on inhalation) quoted at the beginning of this section (4.1 × 10-11 Sv/Bq).
Therefore, using IMBA for soluble OBT intakes provides a slight overestimate of the E50,
compared to that which would be obtained by simply using the DCF listed above.
E.6 WORKPLACE CONTROLS
In establishing workplace controls for STCs, the extent of workplace controls should be
commensurate with the hazard presented by the specific STC for which protection is
required. For certain STCs, such as certain types of organically bound tritium, existing
technology permits institution of a radiological control system that is commensurate with
systems used to protect workers from exposure to the oxide and gaseous forms of tritium.
Alternatively, establishing a level of workplace control commensurate with the hazard
presented by other types of STCs (such as ITPs) poses a significant challenge because of
difficulties in identifying and characterizing these types of STCs. As a result of such
limitations in individual and workplace monitoring, the system of workplace controls should
be conservative in order to demonstrate that workers are adequately protected.
E.6.1 Design/Engineered Controls
Current regulations and standard practices for occupational radiation protection require a
primary reliance on design and engineered controls for protection, unless such controls are
impractical or ineffective. The distinction between design/engineered controls and
administrative controls is not always definitive. For example, an item of protective clothing
that blocks the incident radiation is functioning as a form of shielding, but is most commonly
considered an administrative control. Likewise, a temporary HEPA-filtered ventilation
system may require adherence to administrative procedures to ensure its proper installation
and operation, but is most commonly considered an engineered control. In this appendix,
the term “design/engineered controls” includes such controls as shielding systems,
confinement systems, and ventilation systems. Those controls that require direct
intervention and proper operation by individual users, such as respiratory protection,
protective clothing, and access controls, are considered to be administrative controls.
Section 153
Because the physical behavior of ITPs mimics that of similar particulates, there are no
design/engineered controls that are unique to ITP contamination in the workplace.
Design/engineered controls for ITPs should be evaluated and applied in the same manner
as for other particulate contaminants, with particular attention to such factors as likelihood of
contamination spread, particle sizes, contamination levels, likely individual doses, planned
and potential activities and events, and planned future uses for the affected area.
DOE-HDBK-1129-2008
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Consistent with the as low as reasonably achievable (ALARA) process, consideration should
be given to efforts that may be necessary to recover from the use of engineered control
systems for STC contamination protection, such as special decontamination, storage and
handling needs, purchase of new equipment, and special waste handling needs.
E.6.2 Administrative Controls
Following development and implementation of appropriate design features, including
engineered controls, administrative controls are typically developed and applied to ensure
that the design features are properly installed, maintained, and operated. In addition,
administrative controls provide an additional level of safety above and beyond that provided
by the design features alone, consistent with the ALARA process.
E.6.2.1 Administrative Systems
An adequate structure of administrative systems is necessary to ensure that projects are
completed safely, satisfactorily, and in compliance with applicable requirements. The actual
components of the administrative systems, and the content of those systems, is dependent
on a number of factors, including the nature of the work to be performed, education, skills
and training of the individuals performing the work, and the magnitude of any associated
hazards. Management oversight is required to achieve the appropriate balance between the
various components of the administrative systems. For example, certain high-hazard work
may require extensive pre-job planning and rigid adherence to detailed written procedures
and radiological work permits (RWPs). For lower hazard work, or more routine and
repetitive work, it may be appropriate to place more reliance on employee training and
experience. The appropriateness of the balance achieved should be routinely assured
through a rigid system of management oversight that closely examines the work processes,
and detects potential problems before they adversely affect safety and achievement of the
facility’s mission.
10 CFR 835.501 requires written authorizations to enter into and perform work in
radiological areas. While there is a great deal of flexibility provided for establishing the
exact nature of and details provided in these authorizations, they generally fall into one or
more of the classifications discussed below.
E.6.2.1.2 Policies and Procedures
Facility requirements for safe work with STCs should be clearly delineated in written policies
and procedures. These requirements may be established in either generally applicable
procedures, or in procedures that are established and limited in scope to address STC
affected areas and topics only. For example, requirements for controlling access to STC-
contaminated areas may be specified in procedures that apply only to the specified areas, or
the requirements may be established as a sub-section of a generally applicable procedure
that addresses control of access to a wide variety of hazardous areas. Likewise, there need
not be a separate ALARA policy addressing only exposure to STCs if the existing ALARA
policy adequately addresses all radiation exposures, including STC exposure.
Section 154
In addition to any procedures that may be implemented to ensure compliance with 10 CFR
835.501, 10 CFR 835.104 requires that written procedures be developed and implemented
as necessary to ensure compliance with the applicable regulatory requirements of that rule.
The procedures should be written in sufficient detail to ensure that the user is able to
DOE-HDBK-1129-2008
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complete the relevant task properly, and in compliance with applicable requirements. The
style of writing should be appropriate to the assigned procedure user.
Facilities should have written procedures to address the following issues associated with
STCs, in addition to the procedural controls required for the remainder of the radiological
control program:
• Methods for identifying and quantifying STC levels in the workplace;
• Methods for controlling the spread of airborne and surface STC contamination, including
design features and engineered controls;
• Methods for controlling and handling materials (e.g., protective clothing, respirators,
tools, etc.) that are exposed to STC contamination;
• Methods for tracking those areas of the facility affected by STC contamination;
• Methods for controlling individual exposure to STCs;
• Radiological and activity based criteria for which STC controls are required;
• Criteria for selecting individuals for participation in the STC-internal dose monitoring
program;
• Methods for performing STC monitoring;
• Individual STC dose assessment techniques;
• Criteria for selecting individuals to participate in enhanced training required for STC
control; and
• Requirements for assessing STC-control program effectiveness, identifying program
shortcomings, and implementing programmatic changes as necessary to ensure
continuing improvement.
Written procedures form only one component of an adequate administrative system. Active
management involvement is required to determine the proper balance between the
components of the administrative system. For example, details regarding techniques used
to perform repetitive actions may be more appropriately addressed through radiation safety
training. Certain job-specific actions may be more appropriately addressed in radiological
work permits rather than written procedures.
E.6.2.1.3 Technical Work Documents
While generally applicable written procedures are frequently used to establish standardized
methods where consistency of techniques or results (e.g., regulatory compliance) is
important, technical work documents (TWDs) are often used to address measures
associated with specific tasks. Included within the scope of technical work documents are
certain specific procedures, work packages, and research plans.
TWDs should be developed and implemented for any task that requires more detailed
written guidance than that provided in the generally applicable procedures.
Chapter 3 of the Radiological Control Standard (RCS) provides guidance for implementing a
system of TWDs.
E.6.2.1.4 Radiological Work Permits
Radiological Work Permits (RWPs) are used to establish specific radiological control
requirements for work in areas that exceed, or have the potential to exceed specified
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radiological hazard levels. This would usually include tasks that require specific worker
actions due to the likelihood of severe radiological consequences, such as surface
contamination levels or airborne radioactivity levels exceeding 100 times the applicable
Appendix A or Appendix D levels, respectively. The RWP should address those issues
discussed in the RCS, with emphasis on conditions and controls that are related to the
presence of STCs. Chapter 3 of the RCS provides guidance for developing and
implementing RWPs.
Section 155
E.6.2.1.5 Administrative System Integration
The components of the administrative system are usually linked. For example, the
administrative system may address the requirements for repairing a component located in a
contamination area as follows:
A written procedure establishes standard requirements for entering a contamination area;
Another written procedure establishes criteria (radiological conditions, work activities, etc.)
that require specific tasks to be performed in accordance with an RWP/TWD;
• The TWD establishes specific requirements (e.g., valve operation sequences, torque
settings, sequence of operations, etc.) for performing the task; and
• The RWP provides more detailed radiological control requirements for repairing the
component within the specified contamination area.
E.6.2.1.6 Pre- and Post-Job Briefings
For higher hazard work, many facilities include requirements for pre- and post-job briefings
in the RWP. The pre-job briefing provides an opportunity to discuss the details of the job, its
hazards, and required controls with affected workers. The post-job briefing provides an
opportunity to review the completed work, identify both strengths and weaknesses
associated with its planning and performance, and institutionalize these lessons for future
reference. Briefings may also be conducted during job performance to analyze the current
status and address emergent issues.
The thresholds and processes associated with briefings for STC work need not differ from
those for other jobs. However, special attention should be paid to STC identification and
control issues. Mechanisms should be in place to capture any lessons learned, not only for
similar work, but for both similar and dissimilar work involving STC hazards. Specific
guidance is provided in Chapter 3 of the RCS.
E.6.2.2 Administrative Control Levels
Facilities typically use a system of administrative control levels to limit individual doses and
to direct management attention toward those individuals, work groups, and/or activities that
result in the most significant doses. Management establishes the value(s) of the
administrative control level(s) on a yearly basis, such that line management and workers are
challenged to control, and find innovative ways to reduce, their individual and workgroup
doses. Greater levels of control are achieved by establishing administrative control levels
on a work group-specific basis, reflecting management attention to specific workgroup
activities and hazards. As individual doses approach the established administrative control
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level, successively higher levels of management approval are required to raise the level,
thereby bringing greater management attention to ALARA issues in the workplace.
Administrative control levels should be set at a level that is challenging, but achievable in
view of the planned activities and the radiological conditions in the workplace. However, if it
is never necessary to consider authorizing an individual to exceed the previously
established administrative control level (thus requiring active management attention), the
level probably has been set too high. On the other hand, if the administrative control level is
set at an unnecessarily stringent level, costly delays in planned activities may result,
reflecting inattention to the cost/benefit aspect of ALARA planning.
Section 156
The presence of STCs in the workplace does not profoundly affect the administrative control
level program. In setting or extending administrative control levels, consideration should be
given to the levels of surface and airborne STC contamination, the individual doses likely to
result from that contamination, uncertainties in relating workplace conditions to actual doses,
and any delays in determination of individual doses following exposure to STCs. The
administrative control level should be set in a manner that challenges individuals and
organizations to seek innovative means of reducing their doses, while avoiding unnecessary
interference with scheduled activities.
Chapter 2 of the RCS provides specific guidance for implementing a system of
administrative control levels.
E.6.2.3 Decontamination
When it is necessary to perform work in an STC-contaminated area or on STC-
contaminated equipment, consideration should be given to performing a thorough
decontamination of the area/equipment prior to performing the required work. This
assessment should be conducted in a manner consistent with the ALARA process. A
thorough decontamination effort may eliminate any significant STC contamination levels,
thus eliminating the need for STC controls for the remainder of the evolution. This may in
turn reduce collateral impacts, such as the need to launder STC-contaminated protective
clothing, maintain STC-contaminated respirators and ventilation systems, and determine
STC doses for all individuals involved in the work. These benefits should be balanced
against the costs of performing the decontamination (including the collateral impacts
discussed above), the likelihood of success, the likelihood and possible impact of spreading
STC contamination during the decontamination operation. With either approach,
consideration should be given to the costs and difficulties associated with handling any
resulting waste products.
E.6.2.4 Personal Protective Equipment
Because STCs can exist in particulate form, the personal protective equipment (PPE) used
for ITP control is not unique – that equipment used for control of other radioactive
particulates in the workplace should be sufficient for ITP control also. Different from
respiratory protection for exposure to HT and HTO, air purifying respirators may be used for
ITP work. Consideration should be given to the need for special cleaning and handling
needs for STC-contaminated PPE to reduce the probability of spreading STC contamination
to previously unaffected areas or to minimizing the handling and cleaning of STC
contaminated PPE. These needs may be met by establishing separate facilities for STC-
contaminated PPE, by using disposable anti-contamination clothing, or by ensuring the
handling areas are free of STC contamination before handling non-STC-contaminated PPE.
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In most cases, the cost of establishing special facilities for handling STC-contaminated PPE
will be prohibitive. If offsite facilities are used for cleaning/processing of PPE (e.g.,
contracted laundry facilities for contaminated protective clothing), the contractor should be
made aware of the possibility of STC contamination so that he may implement an effective
STC control program at his facility.
E.6.2.5 Area Posting
10 CFR Part 835 requires that certain areas be posted to alert individuals to the presence of
specific conditions, including specified levels of:
Section 157
• penetrating external radiation;
• removable surface contamination; and
• airborne radioactivity.
These requirements are augmented by requirements for posting areas where radioactive
items or containers of radioactive material are used, handled, or stored, and requirements
for posting areas to which access is controlled for radiation protection purposes.
Because tritium, including STCs, is not typically considered an external radiation hazard,
posting for penetrating external radiation hazards is not expected to be an issue for areas
where STCs are used, handled or stored.
The need for posting to alert individuals to the presence of removable contamination,
airborne radioactivity, and radioactive items or containers of radioactive materials, consisting
in whole or part of STCs, depends on the results of efforts to identify the presence, and
quantify levels of, STCs in specified areas. General guidance for establishing area postings
for radiological hazards is provided in Chapter 12 of DOE G 441.1-1C (DOE 1999),Radiation
Protection Programs Guide This guidance is applicable to posting for the presence of
STCs; however, the STC surface or airborne contamination level should be evaluated
consistent with the guidance provided in Sections E.3.1 and E.3.2 of this appendix. Section
E.3.2.1.2 provides guidance pertinent to areas or objects where tritium is bound tightly to
surfaces and/or to the matrix below such surfaces. This guidance is applicable to efforts to
evaluate the total (fixed plus removable) STC activity levels, which are used as a basis for
radioactive material area posting.
Circumstances may arise in which it is desirable to establish a controlled area due solely to
the presence of STCs. 10 CFR Part 835 requires that controlled areas be established
whenever radiological or radioactive material areas are present, but does not establish
specific criteria that define the controlled area boundaries. Controlled area postings should
be established to enclose any area where it is likely that personnel activities in the area will
result in the spread of:
• STC removable surface contamination beyond the current area boundaries at levels
exceeding one tenth of the levels specified in Appendix D of 10 CFR 835; or
• STC airborne radioactivity beyond the current area boundaries at levels exceeding one
tenth of the airborne concentration value specified in Sections E.5.2.4.2 and E.5.2.5.1 of
this Appendix.
DOE-HDBK-1129-2008
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The controlled area boundaries should be established so that all of the affected area is
encompassed, and area monitoring should be performed on a periodic basis to verify the
adequacy of the boundaries. The area boundaries should be altered as necessary, based
on the results of the area monitoring.
It is often desirable to restrict access to STC-contaminated areas, to specified individuals or
workgroups so as to limit the scope of the STC dose assessment program. If this has been
done, posting for STC-contaminated areas should provide additional information that will
allow individuals to identify the area as one affected by STCs, and to take appropriate action
to avoid or facilitate entry, as appropriate.
E.6.2.6 Access Control
NOTE: The access control measures discussed in this section are in addition to the
radiation safety training measures discussed in Section E.6.2.9 of this appendix.
Section 158
Access control measures may be necessary to control individual access to areas where
STC surface contamination or airborne radioactivity is present. 10 CFR Part 835 requires
entry control measures for all radiological areas. The established controls should be
appropriate for the radiological conditions in the area and the planned activities, some of
which may cause changes in the radiological conditions or in the conditions (e.g., relative
position, exposure time, contaminant resuspension) under which individuals are exposed.
DOE has provided guidance in the RCS.
For low levels of STC contamination (e.g., surface contamination levels less than the 10
CFR 835 Appendix D values; airborne radioactivity levels resulting in an intake less than 12
DAC-hours in a week [0.3 times the DAC values]), only rudimentary entry control measures
are necessary. These measures may include basic engineered and administrative controls.
NOTE: Although repeated exposure to STCs in unposted areas with airborne radioactive
materials could lead to a dose of up to 1500 mrem (E50) in a year, DOE requirements in 10
CFR Part 835 specify initiation of individual and workplace monitoring when annual
exposures are expected to exceed 40 DAC-hours (100 mrem). In addition, 10 CFR Part 835
requires the institution of the ALARA process when establishing workplace controls for
radiation exposure during routine operations. Thus, it is unlikely planned exposures
exceeding 100 mrem would occur without knowledge of either the site or the facility’s
radiological protection organization.
If the STC contamination levels are elevated (e.g., surface contamination levels exceed the
10 CFR 835 Appendix D values, but are less than 10 times those values; exposures to
airborne radioactivity could exceed 12 DAC-hours, but are less than 120 DAC-hours, per
week), more aggressive measures should be implemented. Such measures may include
both design features and administrative controls, such as filtered ventilation systems,
physical barriers to both individual access and contamination spread, area decontamination,
individual sign-in (written or electronic), written procedures and/or radiological work permits,
as appropriate, designated access routes, etc. These controls should be considered in
addition to those discussed above for lower levels of contamination. Note that these levels
correspond to those levels defining a radiological area as provided in 10 CFR 835.2(a);
therefore, specific actions are required to ensure compliance.
DOE-HDBK-1129-2008
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If STC contamination levels are very high (e.g., surface contamination levels exceed ten
times the 10 CFR 835 Appendix D values; airborne radioactivity levels exceed ten times the
DAC values), then the most aggressive contamination control measures should be
considered and implemented, consistent with the ALARA process.
See section E.3.2.1.2 for guidance relating to areas containing locations where tritium is
bound tightly to the surface and/or to the matrix below the surface.
E.6.2.7 Radioactive Material Labeling
Labeling of radioactive items and containers of radioactive material is required under some
circumstances to alert individuals to the radiological hazards associated with those items or
containers. DOE has provided appropriate guidance for implementing these requirements in
Chapter 12 of DOE G 441.1-1C, Radiation Protection Programs Guide, and in the RCS.
Section 159
The thresholds under which radioactive material labeling is required are provided in 10 CFR
835.605, which requires labeling when the total quantity of radioactive material exceeds one
tenth of the 10 CFR 835 Appendix E values. Appendix E does not currently provide a
specific value for STCs, but does provide a value for tritium. This value is applicable to
radioactive items and containers of radioactive material containing STCs.
It is often desirable to restrict access to STC-contaminated materials to specified individuals
or workgroups so as to limit the scope of the STC dose assessment program. If this has
been done, labels for STC-contaminated materials should provide additional information that
will allow individuals to identify the material as affected by STCs, and to take appropriate
action to avoid exposure or facilitate proper handling.
10 CFR 835.606 establishes several conditions under which labeling of radioactive items
and containers of radioactive material is not required. When using these exceptions,
caution should be exercised to ensure that individuals working in the vicinity of radioactive
items and containers of radioactive material are provided appropriate information in the
absence of radioactive material labels. For example, inclusion of appropriate information on
area postings or in employee training or pre-job briefings may prove to be an effective
substitute for radioactive material labeling under the specified conditions.
Note that the 10 CFR Part 835 radioactive material labeling requirements are applicable
only to “items and containers.” Piles and areas of granular solids, such as soil and sand,
are generally not considered to be “items” or “containers”; therefore, labeling of such piles
and areas may not be required or practical. However, consideration should be given to the
need for posting such piles or areas as contaminated areas consistent with 10 CFR
835.603. See Chapter 12 of DOE G 441.1-1C for further guidance on application of the 10
CFR Part 835 posting requirements to areas of soil and similar materials.
Another situation for which labeling may not be required by 10 CFR Part 835, but for which
labeling would be useful, is for materials that have been exposed to tritium long enough for
the tritum to bind tightly in the matrix of the material. Labels could be used to warn
individuals that operations performed on these materials that generate particles could create
an airborne radiological hazard.
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E.6.2.8 Contaminated Material Control
Appropriate controls on the storage, use, and movement of materials contaminated with
STCs are necessary to limit the spread of STC contamination to other materials, areas, and
individuals. Such a spread would result in a need to expand the scope of the STC
monitoring program beyond its initial boundaries. This is undesirable due to both the
possible individual and environmental exposures that may occur, and the relative expense
and complexity of the STC monitoring and control program.
Subpart L of 10 CFR 835 establishes DOE’s regulatory requirements for control of
contaminated material and equipment. In general, the regulations require that material and
equipment that is located in a contamination, high contamination, or airborne radioactivity
area be monitored for the presence of surface contamination prior to release to the
controlled area. The regulations also establish provisions allowing for release of
contaminated materials under certain controlled conditions.
Section 160
Material and equipment that is located in areas where STC contamination is known to exist
should be monitored consistent with the requirements of 10 CFR 835 Subpart L prior to
release to the controlled area. The monitoring should be performed consistent with Sections
E.3.1 and E.3.2 of this appendix and should be capable of identifying STC contamination at
or below the 10 CFR 835 Appendix D values.
If STC contamination is discovered on material and equipment that is to be moved, or that is
located in an area that is to be released from contaminated area status, efforts should be
made to both contain the contamination, and to warn individuals of its presence. All
contaminated items should be securely packaged or wrapped in such a manner that the
STC contamination will not be inadvertently disturbed by individual activities, environmental
forces (such as air or liquid flow), or work activities (such as the application of mechanical
force or heat). Packages and wrapping materials should be appropriate for the surface to
be contained and the expected environment. Programs should be established to
periodically inspect packages and wrapping materials to ensure they do not degrade in long-
term storage or use. If degradation is noted, surface contamination monitoring should be
performed to detect and determine the magnitude of the release of STC contamination. The
package or wrapping material should be repaired or replaced, as appropriate.
Material and equipment that are contaminated with STCs should be clearly labeled to
indicate the type and extent of the contamination, and thereby facilitate tracking of the items
and ensure implementation of appropriate controls and monitoring during activities involving
the contaminated items. If practical, a log of STC-contaminated material and equipment
should be maintained. Such a document may prove useful when planning work activities
and associated monitoring and control activities. STC-contaminated material and
equipment that is no longer in use should be decontaminated and released or disposed of
as soon as practicable. This will reduce the likelihood of spreading STC contamination
during storage periods, and as a result, any unplanned or unauthorized access to the
material.
If practicable, separate spaces and facilities should be dedicated to storage, use, and
decontamination of STC-contaminated material and equipment. Likewise, consideration
should be given to laundering STC-contaminated protective clothing and other launderable
items separately. These measures will reduce the likelihood of spreading STC
DOE-HDBK-1129-2008
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contamination to previously unaffected areas, systems, and items, necessitating expansion
of the STC monitoring and control program, and will facilitate control over these items.
Should it be necessary to use, handle, or store STC-contaminated items in common areas,
then it will be necessary to expand the STC contamination monitoring program to
encompass affected surfaces and systems, such as ventilation and drain systems and
surrounding areas. Similarly, areas, items, and systems that are dedicated to STC-
contamination purposes, such as decontamination areas and laundry equipment, should be
routinely monitored for residual STC contamination.
See section 3.2.1.2 for guidance relating to areas containing materials or equipment where
tritium is bound tightly to the surface and/or to the matrix below the surface.
E.6.2.9 Training
Section 161
E.6.2.9.1 General Employee and Radiological Worker Training
Because of the specialized control and monitoring requirements that are necessary for
STCs, enhanced training should be provided to individuals entering affected areas, or
working in the vicinity of affected items to ensure they are equipped to recognize and
respond to STC hazards.
Subpart J of 10 CFR 835 establishes regulatory requirements for radiation safety training for
DOE activities. Chapter 14 of DOE G 441.1-1C, Radiation Protection Programs Guide,
provides guidance for achieving compliance with these requirements. The training
requirements are generally divided into two levels, depending on the types of hazards
encountered. General Employee Radiological Training is provided to individuals who enter
only the controlled area and receive minimal exposure to radiation. Radiological Worker
Training is provided to individuals who enter radiological areas or perform radiological work
that is likely to result in doses exceeding 0.1 rem in a year. These requirements are
augmented by 10 CFR 835.103, which requires that all individuals who are responsible for
developing and implementing measures necessary for ensuring compliance with the
requirements of 10 CFR Part 835 have the appropriate education, training, and skills to
discharge their responsibilities.
For those activities affected by radiological hazards arising from STCs, General Employee
Radiological Training and Radiological Worker Training should include material on the
following topics, to the extent appropriate for the target audience:
• The physical and radiological characteristics of STCs;
• Radiological hazards associated with exposure to STCs;
• Measures used to monitor (areas and individuals) for STC contamination;
• Limits and action levels associated with STCs;
• Radiological controls implemented to control the spread of STC contamination;
• Special considerations for work planning and execution;
• Special warning signs and labels used in areas affected by STCs, and appropriate
responses to those signs and labels;
• Any special records or reports associated with STCs that may be generated and
retrieved; and
• Appropriate responses to emergency situations involving STCs.
DOE-HDBK-1129-2008
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Although members of the public entering the controlled area are subject to the radiation
safety training requirements of 10 CFR 835.901, these requirements may be met, in part,
through provision of an escort or area entry controls to ensure the individual’s safety and
compliance with the documented RPP. If members of the public are granted unescorted
access to the controlled area, then radiation safety training is required. DOE does not
expect members of the public to receive any significant exposure to STCs; therefore, the
required training should be augmented by provisions to identify, and a warning to avoid
entering, the affected areas.
E.6.2.9.2 Training of Radiological Control Staff
Individuals in the radiological control organization will require specialized training to allow
them to develop and coordinate implementation of effective programs for STC control.
Training should be provided to affected radiological control organization managers,
supervisors, engineers, administrators, and technicians. The training should address the
same subjects as those specified above, but in more detail as is appropriate to the
individuals’ responsibilities.
E.6.2.9.3 Training of Facility Managers, Supervisors and Work Planners
Section 162
Managers and supervisors should complete the same or higher level of radiation safety
training as the individuals who report to them. Managers and supervisors should receive
additional training that will prepare them to address employee concerns about radiological
hazards, including occupational exposure to STCs. Managers, supervisors, and work
planners should also receive training that will prepare them to complete any measures that
are necessary to execute their responsibilities for coordinating, planning, and completing
work in areas affected by STCs.
E.6.2.10 Work Processes
DOE’s requirements for safety management are established in the DOE P 450.4 series of
directives and guides focusing on Integrated Safety Management (ISM). The ISM system
addresses the following seven guiding principles:
1. Line management responsibility for safety
2. Clearly defined roles and responsibilities
3. Personnel competence commensurate with responsibilities
4. Balance of priorities
5. Identification of safety standards and requirements
6. Hazard controls tailored to the work being performed
7. Operations authorization
For any particular facility, most of these guiding principles are unaffected by the presence of
STCs; that is, the implementation of the guiding principles spans a wide range of issues and
is not hazard- or isotope-specific. The STC protection and control program should not be
separated from other radiological and industrial safety programs; it should be fully integrated
with related safety programs so that the hazards associated with STCs are considered in a
manner consistent with those arising from other sources of workplace hazards. However,
the provisions of this appendix should be considered in developing safety programs for
STCs. For example, Guiding Principle #1 will require consideration of the training guidance
provided above. Likewise, Guiding Principles # 6 and #7 will require consideration of the
DOE-HDBK-1129-2008
E-56
results of the workplace monitoring program to provide an accurate assessment of the
relative hazards arising from the presence of STCs in the workplace.
Finally, it is important that implementation of work processes be carried out in a manner that
involves all categories of individuals. These categories should include workers, supervisors
and managers as well as individuals from the various safety disciplines who will participate
in operations involving exposure to STCs.
ANNEX A – VALUES OF SIGNIFICANT DOSIMETRIC PROPERTIES OF STCS
Derived Air Concentration (DAC) Values
DAC for HTO2 (Includes a 50% allowance for skin absorption) 2 x 10-5 µCi/ml
7 x105 Bq/m3
DAC for HT2
2 x 10-1 µCi/ml
9 x 109 Bq/m3
DAC for ITPs (If host material not known)
AMAD = 1 µm
4.8 x 104 Bqo/m3
1.2 x 10-6 µCio/ml
DACo for ITPs (If host material not known)
AMAD = 5 µm
8.0 x 104 Bqo/m3
2.0 x 10-6 µCio/ml
DAC for soluble OBTs (Divide by 1.5 if skin absorption
expected but magnitude not known)
5.0 x 105 Bq/m3
1.4 x 10-5 µCi/ml
Dose Conversion Factors (DCFs) for Inhalation of HTO and STCs
HTO (Does not include an allowance for skin absorption. Multiply
estimated intake by 1.5 to account for skin absorption when
calculating derived exposure controls)1
1.8 x 10-11 Sv/Bq
6.7 x 10-2 mrem/ µCi
ITPs AMAD = 1 µm
ITP Type F Density = 11.7 gm/cm3 1.3 x 10-11 Sv/Bqo
4.8 x 10-2 mrem/ µCio
ITP Type M Density = 11.7 gm/cm3 7.6 x 10-11 Sv/Bqo
2.8 x 10-1 mrem/ µCio
ITP absorption type S Density = 11.7 gm/cm3 (use this DCFo if
host material not known)
Section 163
4.3 x 10-10 Sv/Bqo
6.7 x 10-2 mrem/ µCio
DCFo (Ti, Zr, Hf, rust, Organic [oil droplets]) absorption type S See Table 5-14
ITPs AMAD = 5 µm
ITP Type F Density = 11.7 gm/cm3 5.5 x 10-11 Sv/Bqo
2.0 x 10-1 mrem/ µCio
ITP Type M Density = 11.7 gm/cm3 8.6 x 10-11 Sv/Bqo
3.1 x 10-1 mrem/ µCio
ITP absorption type S Density = 11.7 gm/cm3 (use this DCFo if
host material not known)
2.6 x 10-10 Sv/Bqo
9.6 x 10-1 mrem/ µCio
DCFo (Ti, Zr, Hf, rust, Organic [oil droplets]) absorption type S See Table 5-14
Soluble OBT Compounds (Adjustment for skin absorption, if
applicable, should be accounted for when calculating DACs [see
section E.5.2.5.1])
OBT2 4.1 x 10-11 Sv/Bq
1.5 x 10-1 mrem/ µCi
Tritiated Methane3 (CH4-xTx) 1.8 x 10-13 Sv/Bq
6.7 x 10-2 mrem/ µCi
DOE-HDBK-1129-2008
E-57
1 ICRP 1979
2 ICRP 1995
3 ICRP 1998b
ANNEX B – INSOLUBLE METAL TRITIDE BENCHMARK
This is a benchmark calculation of dose and excretion following an intake of a type M
Insoluble Metal Tritide (IMT) using the ICRP 66 respiratory tract model and ICRP 78
systemic model. The calculations were implemented in MathCad 200013 and Excel 9714.
(Note that when performing internal dose estimated for the purpose of demonstrating
compliance with 10 CFR Part 835, the tissues weighting factors specified in 10 CFR Part
835 must be used.) A basic knowledge of Mathcad syntax will facilitate the study of this
benchmark, but anyone having experience with a higher level language (e.g., FORTRAN)
should be able to follow the calculations.
First, load in definitions and subroutines from the file FUNCTIONS.MCD. The content of this
file is given in the end of this appendix.
The physical decay constant for tritium in units of 1/day is given by
λ ln 2( )
(12.3·365)=
The deposition of the SMT aerosol in the compartments of the respiratory tract is a function
of the AMAD of the aerosol and is calculated with the subroutine “Depo” (which is defined in
the next appendix). For occupational exposure, an AMAD of 5 :m is assumed.
AMAD 5=
D Depo AMAD( )=
The initial content q0 of the compartments are defined below. The initial content of any
compartment not explicitly defined has a value of zero because the initial content of the last
compartment (i.e., urine) is defined as zero15. The intake of the SMT ISMT is defined as unity
and the intake of HTO IHTO as zero. Intakes of HTO are modeled as direct instantaneous
depositions into the blood compartment.
Ismt 1≡
Ihto 0≡
i AI1 ET1..=
q0i Ismt Di⋅=
q0urine 0=
13 Mathsoft, Inc. 101 Main Street, Cambridge MA.
14 Microsoft
15 This is a characteristic of Mathcad.
DOE-HDBK-1129-2008
E-58
q0blood Ihto=
The lung dissolution rate constants and f1 are defined below. All rate constants are in units
of 1/days. Defaults are for type M SMT are: fr=0.1, sr=100, ss=0.005, f1=0.1. For type S:
fr=0.001, sr=100, ss=0.0001, f1=0.01.
fr 0.1=
sr 100=
ss 0.005=
sp ss fr sr ss−( )⋅+=
spt 1 fr−( ) sr ss−( )⋅=
st ss=
f1 1 10 1−
⋅=
Setting the total removal rate constant for urine to zero defines a zero matrix that has
dimensions of urine x urine (39 x 39 for this model). The individual transfer rate constants
for the respiratory tract are then defined per ICRP 66.
kurine urine, 0=
kAI1 bb1, 0.02=
kbb2 BB1, 0.03=
kETseq LNet, 0.001=
kAI1 blood, sp=
kbb2 blood, sp=
kETseq blood, sp=
kAI1 TAI1, spt=
kbb2 Tbb2, spt=
kETseq TETseq, spt=
kAI2 bb1, 0.001=
kBB1 ET2, 10=
kBBseq LNth, 0.01=
kAI2 blood, sp=
Section 164
kBB1 blood, sp=
kBBseq blood, sp=
kAI2 TAI2, spt=
kBB1 TBB1, spt=
kBBseq TBBseq, spt=
kAI3 bb1, 0.0001=
kBB2 ET2, 0.03=
kbbseq LNth, 0.01=
kAI3 LNth, 0.00002=
kBB2 blood, sp=
kbbseq blood, sp=
kAI3 blood, sp=
kBB2 TBB2, spt=
kbbseq Tbbseq, spt=
kAI3 TAI3, spt=
kET2 S, 100=
kLNth TLNth, spt=
kbb1 BB1, 2=
kET2 blood, sp=
kLNet blood, sp=
kbb1 blood, sp=
kET2 TET2, spt=
kLNet TLNet, spt=
kbb1 Tbb1, spt=
kET1 ENV, 1=
kLNth blood, sp=
DOE-HDBK-1129-2008
E-59
The transfer rate constants for the transformed respiratory tract compartments are defined:
kTAI1 Tbb1, kAI1 bb1,=
kTBB2 TET2, kBB2 ET2,=
kTAI1 blood, st=
kTBB2 blood, st=
kTAI2 Tbb1, kAI2 bb1,=
kTET2 S, kET2 S,=
kTAI2 blood, st=
kTET2 blood, st=
kTAI3 Tbb1, kAI3 bb1,=
kTETseq TLNet, kETseq LNet,=
kTAI3 TLNth, kAI3 LNth,=
kTETseq blood, st=
kTAI3 blood, st=
kTBBseq TLNth, kBBseq LNth,=
kTbb1 TBB1, kbb1 BB1,=
kTBBseq blood, st=
kTbb1 blood, st=
kTbbseq TLNth, kbbseq LNth,=
kTbb2 TBB1, kbb2 BB1,=
kTbbseq blood, st=
kTbb2 blood, st=
kTLNet blood, st=
kTBB1 TET2, kBB1 ET2,=
kTLNth blood, st=
kTBB1 blood, st=
The transfer rate constants for the systemic compartments, urine, feces, and other excreta are
defined:
khto bladder,
1.4
3
ln 2( )
10
⋅=
khto ULI,
0.1
3
ln 2( )
10
⋅=
kobt bladder,
ln 2( )
40
=
kblood obt, 0.03
ln 2( )
0.25
⋅=
kblood hto, 0.97
ln 2( )
0.25
⋅=
khto excreta,
1.5
3
ln 2( )
10
⋅=
kbladder urine, 12=
Finally, the transfer rate constants for the GI tract are defined:
kS SI, 24=
kSI ULI, 6=
kSI blood,
kSI ULI, f1⋅
1 f1−
=
kULI LLI,
24
13
=
kLLI feces, 1=
DOE-HDBK-1129-2008
E-60
ANNEX C – MATHCAD DEFINITIONS AND SUBROUTINES
As an alternative to calculating each total removal rate constant individually, one may use the
function total, which sums the rate constants in each row and assigns the sum to the diagonal
element of the rate matrix. The function is defined in the next appendix.
k total k λ,( )=
The eigenvalues and coefficients for each compartment are calculated. Note that the content of
each compartment at time t is defined in the function q(t,comp) by a sum of 39 exponential
terms.
e eigenvals kT( )=
C coeff k q0,( )=
q t comp,( )
1
cols k( )
i
Ccomp i, exp ei( ) t⋅⎡⎣ ⎤⎦⋅∑
=
=
The content of all compartments at time t=0 calculated with the function qall should equal the
sum of what was deposited in the body.
qall t( )
1
cols k( )
j
q t j,( )∑
=
=
In other words, if everything goes OK, what goes into the system
AI1
urine
i
q0i∑
=
0.81957=
should equal the material that is in the system at t=0 days for a radioactive material(or any other
time for insoluble material).
qall 0( ) 0.81957=
The function Decays is used to calculate the number of decays that occur in each compartment
of the biokinetic model.
Decays x( ) s 0←
s s
Cx j,
ej
exp ej 0⋅( ) exp ej 50⋅ 365⋅( )−( )⋅−← Cx j, 0>if
j AI1 urine..∈for
Decays s 24⋅ 3600⋅←
=
DOE-HDBK-1129-2008
E-61
Note that a dosimetric source organ may consist of more than one biokinetic compartment. For
example, the number of decays on the surfaces of ET2 is the sum of the decays in the ET2 and
TET2 biokinetic compartments.
UsET1sur Decays ET1( )=
UsET2sur Decays ET2( ) Decays TET2( )+=
UsET2seq Decays ETseq( ) Decays TETseq( )+=
UsBBsol Decays BB2( ) Decays TBB2( )+=
UsBBgel Decays BB1( ) Decays TBB1( )+=
UsBBseq Decays BBseq( ) Decays TBBseq( )+=
Usbbsol Decays bb2( ) Decays Tbb2( )+=
Usbbgel Decays bb1( ) Decays Tbb1( )+=
Section 165
Usbbseq Decays bbseq( ) Decays Tbbseq( )+=
a Decays TAI2( ) Decays AI3( ) Decays TAI3( )+( )+=
b Decays AI1( ) Decays TAI1( )+ Decays AI2( )+=
UsAI a b+=
UsLNet Decays LNet( ) Decays TLNet( )+=
UsLNth Decays LNth( ) Decays TLNth( )+=
UsS Decays S( )=
UsSI Decays SI( )=
UsULI Decays ULI( )=
UsLLI Decays LLI( )=
UsUBcont Decays bladder( )=
UsTissue Decays obt( ) Decays hto( )+ Decays blood( )+=
In summary, the decays in the source organs are given in array U:
DOE-HDBK-1129-2008
E-62
U
1
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
29241.9
362.4
2522.4
489.5
311.3
13098
637.9
952.5
9697.9
396.2
531041
2311.1
355.5
1510
5436
17820.4
32894.2
142132
=
The dose to each target organ is the sum of the decays in each organ and the appropriate SEE:
target tAdrenals tUterus..=
Htarget
sET1sur
sTissue
source
Usource SEEtarget source,⋅∑
=
=
The array H is loaded into an Excel 97 spreadsheet to complete the dose calculation. The
organ doses are combined as shown in the spreadsheet to give ICRP 60 50-year committed
effective dose in units of Sv/Bq.
DOE-HDBK-1129-2008
E-63
ICRP 60 Committed Effective Dose in Sv
Ht A A x Ht Wt Mass (g) Ht x Mass Ht x Wt
Adrenals 1.88E-12 14 2.63E-11
UB_Wall 1.88E-12 0.050 9.40E-14
Bone_Sur 1.88E-12 0.010 1.88E-14
Brain 1.88E-12 1400 2.63E-09
Breasts 1.88E-12 0.050 9.40E-14
St_Wall 4.63E-12 0.120 5.56E-13
SI_Wall 8.07E-12 640 5.16E-09
ULI_Wall 3.88E-11 0.570 2.21E-11
LLI_Wall 1.13E-10 0.430 4.85E-11
Kidneys 1.88E-12 310 5.83E-10
Liver 1.88E-12 0.050 9.40E-14
ET1-bas 1.88E-12 0.001 1.88E-15
ET2-bas 1.91E-12 0.998 1.90E-12
LN-ET 3.16E-11 0.001 3.16E-14
BBi-bas 1.88E-12 0.167 3.13E-13
BBi-sec 1.88E-12 0.167 3.13E-13
bbe-sec 1.98E-12 0.333 6.58E-13
AI 4.42E-10 0.333 1.47E-10
LN-Th 7.20E-11 0.001 7.20E-14
Muscle 1.88E-12 28000 5.27E-08
Ovaries 1.88E-12
Pancreas 1.88E-12 100 1.88E-10
R_Marrow 1.88E-12 0.120 2.26E-13
Skin 1.88E-12 0.010 1.88E-14
Spleen 1.88E-12 180 3.38E-10
Testes 1.88E-12 0.200 3.76E-13
Thymus 1.88E-12 20 3.76E-11
Thyroid 1.88E-12 0.050 9.40E-14
Uterus 1.88E-12 80 1.50E-10
Composite Organs
lungs 1.49E-10 0.120 1.78E-11
ET 1.94E-12 15 2.91E-11
colon 7.06E-11 0.120 8.47E-12
oesophagus 1.88E-12 0.050 9.40E-14
remainder 2.01E-12 0.050 1.00E-13
1.000 30759 6.18E-08
effective 2.81E-11
The 24-hour incremental urinary and fecal excretion functions are defined as shown below.
Note that the increment excreted in urine and feces is calculated with “insoluble” tritium. The
incremental excretion is then adjusted for radioactive decay. Because we are starting with
radioactive tritium, the incremental excretion is adjusted to insoluble tritium first.
DOE-HDBK-1129-2008
E-64
∆eu t( ) exp λ− t⋅( ) q t urine,( ) exp λ t⋅( )⋅ q t 1− urine,( ) exp λ t 1−( )⋅⎡⎣ ⎤⎦⋅−⎡⎣ ⎤⎦⋅=
∆ef t( ) exp λ− t⋅( ) q t feces,( ) exp λ t⋅( )⋅ q t 1− feces,( ) exp λ t 1−( )⋅⎡⎣ ⎤⎦⋅−⎡⎣ ⎤⎦⋅=
The following plot shows the 24-hour urinary and fecal excretion for days 1 through 180 after an
acute inhalation intake of 5 µm AMAD type M IMT.
t 1 180..=
eut
∆eu t( )=
ef t
∆ef t( )=
0 20 40 60 80 100 120 140 160 180
1 . 10 5
1 . 10 4
1 . 10 3
0.01
0.1
1
urine
feces
Time After Intake (days)
Tritium
in Urine
and Feces
(1/day)
In Mathcad, the first element is designated as being in the zeroth row and zeroth column, i.e.,
having the (0,0) coordinate. When defining a matrix for biokinetic models it is useful for the
matrix to begin with the (1,1) coordinate. This is accomplished by setting the built-in variable
ORIGIN to 1.
Section 166
ORIGIN 1≡
The compartments in the biokinetic model are assigned names to clarify their use in the
definition of the rate matrix. For example, rather than define the transfer rate constant k1,4, we
define it as kAI1,bb1. The respiratory tract compartments are:
AI1 1=
AI2 2=
AI3 3=
bb1 4=
bb2 5=
bbseq 6=
BB1 7=
BB2 8=
BBseq 9=
ET2 10=
ETseq 11=
ET1 12=
LNet 13=
LNth 14=
ENV 15=
The transformed respiratory tract compartments are:
DOE-HDBK-1129-2008
E-65
TAI1 16=
TAI2 17=
TAI3 18=
Tbb1 19=
Tbb2 20=
Tbbseq 21=
TBB1 22=
TBB2 23=
TBBseq 24=
TLNth 25=
TET2 26=
TETseq 27=
TLNet 28=
Finally, the GI tract, systemic compartments, and excreta compartments are:
S 29=
SI 30=
ULI 31=
LLI 32=
feces 33=
blood 34=
bladder 35=
excreta 36=
obt 37=
hto 38=
urine 39=
The sources (beginning with "s") in the dosimetric model are assigned names to clarify their use
in the definition of the SEE and dose matrices:
sET1sur 1=
sET2sur 2=
sET2seq 3=
sLNet 4=
sBBgel 5=
sBBsol 6=
sBBseq 7=
sbbgel 8=
sbbsol 9=
sbbseq 10=
sAI 11=
sLNth 12=
sUBcont 13=
sS 14=
sSI 15=
sULI 16=
sLLI 17=
sTissue 18=
Likewise, the targets (beginning with "t") in the dosimetric model are assigned numbers to clarify
their use in the definition of the SEE and dose matrices:
tAdrenals 1=
tUB 2=
tBS 3=
tBrain 4=
tBreasts 5=
tS 6=
tSI 7=
tULI 8=
tLLI 9=
tKidneys 10=
tLiver 11=
tET1bas 12=
tET2bas 13=
tLNet 14=
tBBbas 15=
tBBsec 16=
tbbsec 17=
tAI 18=
tLNth 19=
tMuscle 20=
tOvaries 21=
tPancreas 22=
tRM 23=
tSkin 24=
DOE-HDBK-1129-2008
E-66
tSpleen 25=
tTestes 26=
tThymus 27=
tThyroid 28=
tUterus 29=
Once the transfer rate constants are defined, the total removal rate constants may be calculated
by summing across the rows of the rate matrix:
total k λ,( ) K k←
Kcomp comp, 0←
Kcomp comp, Kcomp comp, kcomp j,+← comp j≠if
j 1 cols k( )..∈for
Kcomp comp, Kcomp comp, λ+( )−←
comp 1 cols k( )..∈for
K
=
The coefficients and rate constants for the retention functions are calculated by the eigensystem
method. This approach to solving systems of ODEs is described by G. G. Killough and K. F.
Eckerman in “A Conversational Eigenanalysis Program for Solving Differential Equations,” in
Computer Applications in Health Physics, Proceedings of the Seventeenth Midyear Topical
Symposium of the Health Physics Society, 1984 (Killough 1984). Excellent examples may be
found in “The Linear Algebra Problem Solver” by the Research and Education Association,
1980, gives excellent examples and discussion of the method (see problems 18-6 through 18-
11). Given the initial content of each compartment at t=0 and the rate matrix, the following
function calculates the coefficients for the retention functions:
coeff k q0,( ) q0 submatrix q0 1, rows k( ), 1, 1,( )←
V eigenvecs kT( )←
M lsolve V q0,( )←
Ci j, Vi j, Mj⋅←
i 1 cols k( )..∈for
j 1 cols k( )..∈for
C
=
Deposition fractions for aerosol AMADs in the range of 0.001 to 10 microns are calculated by
interpolating from the respiratory tract deposition table given in the ICRP CD-ROM16. The
ICRP 66 respiratory tract model for occupational exposure (light work) was used to calculate the
values given in this table.
16 The ICRP Database of Dose Coefficients for Workers and Members of the General Public, Version 1.0
(Pergamon Press: New York) 1998 (ICRP 1998a).
DOE-HDBK-1129-2008
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D
0.001 0.003 0.01 0.03 0.1 0.3
Section 167
AI1 1.359E-04 6.714E-03 8.229E-02 1.525E-01 8.688E-02 4.458E-02
AI2 2.718E-04 1.343E-02 1.646E-01 3.051E-01 1.738E-01 8.916E-02
AI3 4.530E-05 2.238E-03 2.743E-02 5.085E-02 2.896E-02 1.486E-02
bbf 2.262E-02 8.770E-02 1.291E-01 7.188E-02 3.328E-02 1.523E-02
bbs 2.294E-02 8.895E-02 1.309E-01 7.290E-02 3.376E-02 1.544E-02
bbseq 3.212E-04 1.245E-03 1.833E-03 1.021E-03 4.726E-04 2.162E-04
BBf 3.117E-02 4.420E-02 2.685E-02 1.035E-02 4.746E-03 3.260E-03
BBs 3.161E-02 4.483E-02 2.723E-02 1.049E-02 4.813E-03 3.293E-03
BBseq 4.425E-04 6.276E-04 3.812E-04 1.469E-04 6.738E-05 4.619E-05
ET2 4.390E-01 3.494E-01 1.735E-01 6.994E-02 3.218E-02 5.820E-02
ETseq 2.196E-04 1.748E-04 8.680E-05 3.499E-05 1.610E-05 2.912E-05
ET1 4.433E-01 3.327E-01 1.539E-01 6.248E-02 3.071E-02 5.217E-02
=
The following function performs a linear interpolation of the values in the table to calculate the
deposition fractions in each compartment of the respiratory tract.
Depo AMAD( ) d submatrix D 1, 13, 2, 11,( )←
Depoi 1− linterp dT( ) 1〈 〉
dT( ) i〈 〉
, AMAD,
⎡
⎣
⎤
⎦←
i 2 13..∈for
Depo
=
All SEEs are from SEECAL17 except for the SEE for the bladder wall <--- bladder contents,
which is set to zero in accordance with ICRP 6718. The SEE have the units of SV/decay. The
SEE for the body tissues as source and all body tissues and organs as targets is defined by
target tAdrenals tUterus..=
SEEtarget sTissue, 1.323 10 17−
⋅=
Specific target-source combinations for the respiratory and GI tract are:
SEEtET2bas sET2seq, 1.088 10-17
⋅=
SEEtLNet sLNet, 6.069 10-14
⋅=
SEEtbbsec sbbsol, 9.853 10-18
⋅=
SEEtAI sAI, 8.276 10-16
⋅=
SEEtAI sLNth, 4.138 10-16
⋅=
17 M. Cristy and K. F. Eckerman, "SEECAL: Program to Calculate Age-Dependent Specific Effective
Energies," ORNL/TM-12351 (Cristy 1993).
18 “Urinary excretion will not result in a significant additional dose to the bladder wall which is assumed to
receive the same dose as other tissues,” Table C-1.1, ICRP 67 (ICRP 1994b).
DOE-HDBK-1129-2008
E-68
SEEtLNth sLNth, 3.035 10-14
⋅=
SEEtS sS, 1.821 10-15
⋅=
SEEtSI sSI, 1.138 10-15
⋅=
SEEtULI sULI, 2.069 10-15
⋅=
SEEtLLI sLLI, 3.372 10-15
⋅=
ANNEX D - PARAMETERS FOR DISSOLUTION OF INSOLUBLE TRITIATED PARTICULATE
MATERIALS
(From Mound Technical Basis Document for Stable Tritiated and Particulate and Organically
Bound Tritium (Mound 2000))
The following table compiles literature data for dissolution of tritium into physiological fluid from
various forms of tritium-containing particulate materials. Parameters are given for retention of
tritium in the source material as described by (typically) the double exponential:
S(t) = Fr exp(-Rrt) + Fs exp(-Rst) (eq. D-1)
Where: S(t) = the tritium fraction retained in source material at time t
Fr = the fraction of rapidly dissolving material ("fast component")
Fs = the fraction of slowly dissolving material ("slow component")
Rr = the dissolution rate of rapidly dissolving material
Rs = the dissolution rate of slowly dissolving material
Particle size characteristics and literature references are also provided.
Source
Material
Fr
Rr, d-1
Fs
Rs, d-
1
Size
Parameters
(µm)
Reference
TiTx
0.55
4.6
0.35
(a)
0.093
(a)
CMD=0.95
σg=1.93
AMD=3.5
AMAD=5.7
Cheng (1999a)
TiTx 0.24 0.71 0.76 0.021 Same as
above
Cheng (1997)
TiTx
-
-
1.0
0.0019
CMD=103
σg=1.58
AMD=193
AMAD=312
Cheng (1997)
ZrTx 0.48 0.0165 0.52 0.0018
CMD=0.32
σg=2.24
AMD=2.25
AMAD=4.78
Cheng(1999b)
Kropf (1998)
HfTx
(b)
0.0006
0.0095
Section 168
0.9994
2.3E-6
CMD=1.04
σg=2.41
AMD=10.6
AMAD=30
Cheng (1999c)
HfTx 0.00015 0.02 0.9997 1E-7 Same as Cheng (1999c)
DOE-HDBK-1129-2008
E-69
(a) An additional slow component (F~0.1 and R<0.01) is apparent from Fig 2 in
reference.
(b) Represent each of two separate data sets within this study.
(c) An additional fast component of F=0.00015 and R=100 occurred for this HfTx
sample.
(d) Parameters are recalculated from Fig 1 of reference. An additional slow
component of F=0.61 and unspecified Ris apparent. Particle sizes are from Cool
(1984).
(e) Parameters are recalculated from Table 2 of reference, assuming 30%
dissolution at day 100. An additional slow component of F=0.70 and unspecified
R is apparent. Particle sizes are from Cool (1984).
(b) (c) (c) above
HfTx 0.008 0.2 0.992 ~5E-6 “respirable” Ref 4 in McConville (1995)
Glass
0.23
0.079
0.16
0.0032
CMD=3.8
σg=2.8
AMD~20
AMAD~19
Cool (1983)
[Sample KMS2]
(d)
Glass
0.27
0.23
0.027
0.03
Same as
above
Cool (1983)
[Sample KMS1]
(e)
Luminous
Paint
0.12 ~10 0.88 0.019 ---- Rudran (1988)
DOE-HDBK-1129-2008
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DOE-HDBK-1129-2008
F-1
APPENDIX F: RADIOLOGICAL TRAINING FOR TRITIUM FACILITIES
APPENDIX F1: Program Management Guide ...........................................................................F-2
APPENDIX F2: Instructor's Guide............................................................................................F-11
APPENDIX F3: Student's Guide ..............................................................................................F-61
DOE-HDBK-1129-2008
F-2
APPENDIX F1: Program Management Guide
Table of Contents
Introduction ........................................................................................................................F-3
Purpose and Scope.....................................................................................................F-3
Management Guide Content .......................................................................................F-3
Training Goal...............................................................................................................F-3
Organizational Relationships and Reporting Structure ...............................................F-3
Instructional Materials Development ..................................................................................F-4
Target Audience..........................................................................................................F-4
F-Prerequisites............................................................................................................F-4
Training Material .........................................................................................................F-4
Exemptions .................................................................................................................F-4
Training Program Standards and Policies..........................................................................F-5
Section 169
Qualification of Instructors...........................................................................................F-5
Technical Qualifications .............................................................................................F-5
Instructional Capability and Qualifications ..................................................................F-6
Selection of Instructors................................................................................................F-7
Test Administration .....................................................................................................F-7
Program Records and Administration .........................................................................F-8
Training Program Development/Change Requests ...................................................F-8
Audits (internal and external) .....................................................................................F-8
Evaluating Training Program Effectiveness ...............................................................F-8
Course-Specific Information...............................................................................................F-9
Purpose.......................................................................................................................F-9
Course Goal ................................................................................................................F-9
Target Audience..........................................................................................................F-9
Course Description......................................................................................................F-9
Prerequisites ...............................................................................................................F-9
Length .........................................................................................................................F-9
Test Bank ....................................................................................................................F-9
Retraining....................................................................................................................F-9
Instructor Qualifications...............................................................................................F-9
Materials Checklist ....................................................................................................F-10
DOE-HDBK-1129-2008
F-3
INTRODUCTION
Purpose and Scope
This beginning section discusses in general recommendations for the implementation of
radiation safety training. Course specific guidance follows
This Appendix describes a recommended implementation process for conducting the radiation
safety training required by Title 10 Code of Federal Regulations Occupational Radiation
Protection, (10 CFR 835) Subpart J and as outlined in the DOE standard DOE-STD-1098-99,
Radiological Control (RCS). The Appendix is to assist those individuals, both within the
Department of Energy (DOE) and Managing and Operating (M&O) contractors, identified as
having responsibility for implementing the training required by 10 CFR 835 and recommended
by the RCS.
Management Guide Content
The management guide is divided into the following sections:
• Introduction
• Instructional Materials Development
• Training Program Standards and Policies
• Course Specific Information
Training Program Goal
Section 170
The goal of the training program is to provide a baseline knowledge for those individuals
completing the training. Use of the DOE developed material provides personnel with the
information necessary to perform their assigned duties at a predetermined level of expertise.
Implementing the training program helps ensure consistent and appropriate training of
personnel.
Organizational Relationships and Reporting Structure
The DOE Office of Health, Safety and Security’s Office of Worker Safety and Health Policy (HS-
11) is responsible for approving and maintaining the DOE developed training materials
associated with the training program.
The establishment of a comprehensive and effective contractor site radiological control training
program is the responsibility of line management and their subordinates. The training function
can be performed by a separate training organization, but the responsibility for quality and
effectiveness rests with the line management.
Copies of this Appendix may be obtained from the DOE Radiation Safety Training Home Page
Internet site (http://www.hss.energy.gov/radiation/RST/rstmater.htm).
DOE-HDBK-1129-2008
F-4
Instructional Materials Development
Target Audience
Course instructional materials were developed for specific employees who are responsible for
knowing or using the knowledge or skills for each course. With this in mind, the participant
should never ask the question, "Why do I need to learn this?" However, this question is often
asked when the participant cannot apply the content of the program. It is the responsibility of
management to select and send workers to training who need the content of the program.
When workers can benefit from the course, they can be motivated to learn the content and
apply it on their jobs. Care should be taken to read the course descriptions along with the
information about who should attend. Participants and DOE facilities alike will not benefit from
workers attending training programs unsuitable for their needs.
Prerequisites
A background and foundation of knowledge facilitates the trainee in learning new knowledge or
skills. It is much easier to learn new material if it can be connected or associated to what was
previously learned or experienced. Curriculum developers who have been involved in preparing
instructional materials for the core training know this and have established what is referred to as
"prerequisites" for each course.
Certain competencies or experiences of participants were also identified as necessary prior to
participants attending a course. Without these competencies or experiences, the participants
would be at a great disadvantage and could be easily discouraged and possibly fail the course.
It is not fair to the other participants, the unprepared participant, and the instructor to have this
misunderstanding.
Training Material
Training materials for the program consist of lesson plans, study guides and handouts. The
training content should be presented in its entirety. Overhead transparencies are provided in
support of the training content and may be substituted or supplemented with updated or site-
specific information.
Supplemental material and training aids may be developed to address site-specific radiological
concerns and to suit individual training styles. References are cited in each lesson plan and
may be used as a resource in preparing site-specific information and training aids.
Section 171
Each site is responsible for establishing a method to differentiate the site-specific information
from the DOE developed lesson plan material. When additional or site-specific information is
added to the text of the core lesson plan material, a method should be used to differentiate site
information from DOE developed material.
Exemptions
Qualified personnel can be exempted from training if they have satisfactorily completed training
programs, (i.e., facility, college or university, military, or vendor programs) comparable in
instructional objectives, content, and performance criteria. Documentation of the applicable and
exempted portions of training should be maintained.
DOE-HDBK-1129-2008
F-5
Training Program Standards and Policies
Qualification of Instructors
The technical instructor plays a key role in the safe and efficient operation of DOE facilities.
Workers must be well qualified and have a thorough understanding of the facility's operation,
such as processing, handling, and storage of materials, and maintenance of equipment.
Workers must know how to correctly perform their duties and why they are doing them. They
must know how their actions influence other worker's responsibilities. Because workers' actions
are so critical to their own safety and the safety of others, their trainers must be of the highest
caliber. The technical instructor must understand thoroughly all aspects of the subjects being
taught and the relationship of the subject content to the total facility. Additionally, the instructor
must have the skills and knowledge to employ the instructional methods and techniques that will
enhance learning and successful job performance. While the required technical and
instructional qualifications are listed separately, it is the combination of these two factors that
produces a qualified technical instructor.
The qualifications are based on the best industry practices that employ performance-based
techniques to ensure that workers receive the highest quality training possible. This is possible
only when technical instructors possess the technical competence and instructional skills to
perform assigned instructional duties in a manner that promotes safe and reliable DOE facility
operations.
Technical Qualifications
Instructors must possess technical competence (theoretical and practical knowledge along with
work experience) in the subject areas in which they conduct training. The foundation for
determining the instructor's technical qualifications is based on two factors:
• the trainees being instructed, and
• the subject being presented
The following is an example of a target audience, subject to be taught, and instructor technical
qualifications.
TARGET
AUDIENCE
SUBJECT BEING
TAUGHT
INSTRUCTOR
TECHNICAL QUALIFICATIONS
Tritium Facilities
Personnel, Visitors,
DOE Employees
Tritium Hazards
and Safety Training
Demonstrated knowledge and skills in radiation
protection, above the level to be achieved by the
trainees, as evidenced by previous
training/education and through job performance,
AND
Completion of all qualification requirements for the
senior-level radiation protection technician position at
the trainees' facility or a similar facility.
Methods for verifying the appropriate level of technical competence may include the review of
prior training and education, observation, and evaluation of recent related job performance, and
oral or written examination. Other factors that may be appropriate for consideration include
DOE, NRC, or other government qualification, certification by the American Board of Health
Physics and/or registration by the National Registry of Radiation Protection Technologists,
Section 172
DOE-HDBK-1129-2008
F-6
vendor or facility certification, and most importantly, job experience. To maintain technical
competence, a technical instructor should continue to perform satisfactorily on the job and
participate in continuing technical training.
Instructional Capability and Qualifications
Qualifications of instructional capability should be based on demonstrated performance of the
instructional tasks for the specific course requirements and the instructor's position. Successful
completion of instructor training and education programs, as well as an evaluation of on-the-job
performance, is necessary for verification of instructional capability. Instructional capability
qualification should be granted as the successful completion of an approved professional
development program for training instructors. The program should contain theory and practice
of instructional skills and techniques, adult learning, planning, conducting, and evaluating
classroom, simulator, laboratory, and on-the-job training activities.
Illustrated talks, demonstrations, discussions, role playing, case studies, coaching, and
individual projects and presentations should be used as the principal instructional methods for
presenting the instructional training program. Each instructional method should incorporate the
applicable performance-based principles and practices. Every effort should be made to apply
the content to actual on-the-job experience or to simulate the content in the
classroom/laboratory. The appropriate methodology required to present the instructional
content will indicate a required level of instructional qualification and skill.
Current instructors' training, education, and job performance should be reviewed to determine
their training needs for particular courses. Based on this review, management may provide
exemptions based on demonstrated proficiency in performing technical instructor's tasks.
Through training or experience, technical instructors should be able to*:
• Review instructional materials and modify them to fully meet the needs of the training group.
• Arrange the training facility (classroom/laboratory or other instructional setting) to meet the
requirements for the training sessions.
• Effectively communicate, verbally and non-verbally, lessons to enhance learning.
• Invoke student interaction through questions and student activities.
• Use appropriate instructional materials and visual aids to meet the lesson objectives.
• Administer performance and written tests.
• Ensure that evaluation materials and class rosters are maintained and forwarded to the
appropriate administrative personnel.
• Evaluate training program effectiveness.
• Modify training materials based on evaluation of training program.
*Stein, F. Instructor Competencies: The Standards. International Board of Standards for
Training, Performance and Instruction; 1992.
DOE-HDBK-1129-2008
F-7
Selection of Instructors
Selection of instructors should be based on the technical and instructional qualifications
specified in the Course Specific Information section of this guide. In addition to technical and
instructional qualifications, oral and written communication skills, and interpersonal skills, should
be included in the process of selecting and approving instructors.
Since selection of instructors is an important task, those who share in the responsibility for
ensuring program effectiveness should:
Section 173
• interview possible instructors to ensure they understand the importance of the roles and
responsibilities of technical instructors and are willing to accept and fulfill their
responsibilities in a professional manner
• maintain records of previous training, education, and work experience
Procedures for program evaluation will include documentation of providing qualified instructors
for generic and site-specific training programs.
Test Administration
A test bank of questions for this training, with site specific information, should be developed and
the content validated. As the test banks are used, statistical validation of the test bank should
be performed in order to fully refine the questions and make the tests as effective as possible.
The questions contained in the test bank are linked directly to the objectives for each course. In
this way, trainee weaknesses can be readily identified and remedial procedures can be put into
place. The test outcomes can also be used to document competence and the acquisition of
knowledge.
The test banks should also be used by the instructors to identify possible weaknesses in the
instruction. If numerous trainees fail to correctly answer a valid set of questions for an objective,
the instruction for that objective needs to be reviewed for deficiencies.
Written examinations should generally be used to demonstrate satisfactory completion of
theoretical classroom instruction. The following are some minimal recommendations for the test
banks and tests:
• Tests are randomly generated from the test bank.
• Test items represent all objectives in the course.
• All test bank items are content-validated by a subject matter expert.
• Test banks are secured and are not released either before or after the test is administered.
• Trainees receive feedback on their test performance.
• Test banks undergo statistical analysis.
• For the first administrations of tests, a minimum passing score of 80% should be required for
a passing score. As statistical analysis of test results is performed, a more accurate
percentage for a passing score should be identified.
Test administration is critical in accurately assessing the trainee's acquisition of knowledge
being tested. Generally, the following rules should be followed.
DOE-HDBK-1129-2008
F-8
• Tests should be announced at the beginning of the training sessions.
• Instructors should continuously monitor trainees during completion of tests.
• All tests and answers should be collected at the conclusion of each test.
• No notes can be made by trainees concerning the test items.
• No talking (aside from questions) should be allowed.
• Answers to questions during a test should be provided but answers to test items should not
be provided or alluded to.
• Where possible, multiple versions of each test should be produced from the test bank for
each test administration.
• After test completion, trainees may turn in their materials and leave the room while other
trainees complete their tests.
• Trainee scores on the tests should be held as confidential.
Program Records and Administration
Training records and documentation shall meet the requirements of 10 CFR 835.704.
Training Program Development/Change Requests
All requests for program changes and revisions should be sent to the DOE Technical Standards
Program using the form "Document Improvement Proposal" provided at the conclusion of the
material, as provided on the DOE Technical Standards website.
Audits (internal and external)
Section 174
Internal verification of training effectiveness should be accomplished through senior instructor or
supervisor observation of practical applications and discussions of course material. All results
should be documented and maintained by the organization responsible for Radiological Control
training.
The training program materials and processes is evaluated on a periodic basis by DOE-HQ.
The evaluation includes a comparison of program elements with applicable industry standards
and requirements.
Evaluating Training Program Effectiveness
Verification of the effectiveness of Radiological Training for Tritium Facilities should be
accomplished by surveying a limited subset of former students in the workplace. This
evaluation should include observation of practical applications and discussion of the course
material. DOE/HS has issued guidelines for evaluating the effectiveness of radiological training
through the DOE Operations Offices and DOE Field Offices. These guidelines are available as
an attachment to the Program Management Guide of DOE-HDBK-1122-99, Radiological Control
Technician Training.
For additional guidance, refer to DOE STD 1070-94, A Guide for Evaluation of Nuclear Facility
Training Programs. The guidelines contained in these documents are relevant for the
establishment and implementation of post-training evaluation programs.
DOE-HDBK-1129-2008
F-9
Course-Specific Information
Purpose
This section of the program management guide is to assist those individuals assigned
responsibility for implementing the Radiological Training for Tritium Facilities. Standardized
implementation of this training helps ensure consistent and appropriate training for all
personnel.
Course Goal
Upon completion of this training, the student will have a basic understanding of the
characteristics of tritium and understand the precautions and safeguards needed for working in
a tritium facility.
Target Audience
Individuals who have assigned duties in tritium facilities.
Course Description
This course illustrates and reinforces the skills and knowledge needed to provide personnel with
an understanding of the characteristics of tritium and the precautions needed for working with or
around it in a DOE facility. This course is designed to meet Article 663 of the RCS for
individuals who have assigned duties in a tritium facility.
Prerequisites
Training which is considered commensurate with site-specific hazards. Radiological Worker II
or the equivalent is recommended prior to receiving or concurrently with this tritium facilities
safety training. Some of those basic concepts contained in Radiological Worker II are used
extensively throughout this training.
Length
2 - 4 hours (depending on site-specific information)
Test Bank
Test banks, as applicable, should be developed by the sites, incorporating site-specific
information.
Retraining
Retraining is not required for this course.
Instructor Qualifications
Instructors of this course have a major role in making it successful and meeting the specified
objectives. Instructors must have related experience and be technically competent. In this
DOE-HDBK-1129-2008
F-10
course it is imperative that the instructor have the background and experience of working in a
tritium facility. Instructors must be able to relate their own work experience to the workers in a
tritium facility. Instructors must be able to answer specific questions and use a variety of
instructional material to meet the objectives.
Section 175
Education:
Minimum of B.S. degree in Health Physics or related discipline is preferred.
Experience:
At least five years of applied radiological protection experience in an operating
radiological facility is preferred. The areas of experience should include:
• Tritium hazards
• Radiological controls associated with tritium
• Conducting surveys and monitoring for tritium
Comprehensive knowledge of Federal regulations and guidance and best nuclear
industry practices pertaining to radiological protection.
Materials Checklist
The following checklist should be used to ensure all training materials are available. The
Program Management Guide, Instructor's Guide, Student's Guide, and Lessons Learned section
are provided in Word 2003 format. The Overhead Transparencies are provided in Power Point
2003 for windows format.
• Program Management Guide
• Instructor's Guide
• Student's Guide
• Overhead Transparencies
The following checklist should be used before training is provided to ensure that equipment is
available and working.
• Overhead projector
• Screen
• Flip chart
• Markers
DOE-HDBK-1105-2002
Radiological Training for Tritium Facilities
Instructor’s Guide
F-11
APPENDIX F2: Instructor's Guide
Core Course Material
Course Goal: Upon completion of this training the student will have a basic understanding
of the characteristics of tritium and understand the precautions and
safeguards needed for working in a tritium facility as outlined in the course
objectives.
Target Audience: Individuals who have assigned duties in Tritium Facilities.
Description: This course illustrates and reinforces the skills and knowledge needed to
provide personnel with an understanding of the characteristics of tritium and
the precautions needed for working with or around it in a DOE facility. This
course is designed to be consistent with Article 663 of the DOE RSC for
individuals who have assigned duties in a tritium facility.
Prerequisites: Training which is considered commensurate with site-specific hazards.
Radiological Worker II or the equivalent is recommended prior to receiving
or concurrently with this tritium facilities safety training. Some of the basic
concepts contained in Radiological Worker II are used extensively
throughout this training.
Length: 2 - 4 hours (depending on site-specific information)
Course Objectives: EO1 IDENTIFY the following properties of tritium:
- physical/chemical
- radioactive.
EO2 IDENTIFY sources of tritium:
- natural
- byproduct
- weapons.
EO3 IDENTIFY uses of tritium:
- weapons applications
- research
- fusion energy production
DOE-HDBK-1105-2002
Radiological Training for Tritium Facilities
Instructor’s Guide
F-12
- industrial/commercial.
EO4 IDENTIFY modes of tritium exposure:
- inhalation
- ingestion
- absorption
- injection/wound.
EO5 IDENTIFY the biological effects of tritium:
- biological half-life
- dose.
EO6 IDENTIFY the radiological control methods for tritium:
- engineered
- administrative
- surface contamination limits
- personnel protective equipment
- application of ALARA principles.
EO7 IDENTIFY methods for monitoring for tritium:
- air sampling for worker safety
- contamination surveys
- bioassay.
EO8 IDENTIFY tritium waste minimization and handling
techniques. (Site-Specific)
EO9 IDENTIFY alarms and proper response to abnormal
conditions in the tritium facility. (Site-Specific)
Training Aids: Overhead transparencies (may be supplemented or substituted with
Section 176
updated or site-specific information)
Equipment Needs: - Overhead projector
- Screen
- Flip chart
- Markers
Student Materials: Students Guide
DOE-HDBK-1105-2002
Radiological Training for Tritium Facilities
Instructor’s Guide
F-13
LESSON SUMMARY
Introduction
Welcome students to the course.
Introduce self and instructor team.
Define logistics.
- safety briefing - exits
- restrooms
- hours
- breaks
- sign-in sheets
- test - accountability
- end of course evaluation
Remind the participants that they need to have completed
Radiological Worker Training prior to this course. They
should be familiar with terms like rem, contamination, etc.
Show Title OT-1
Course Goal
At the end of this course, the participant should be able to
demonstrate a basic understanding of the characteristics of
tritium and precautions for working in a tritium facility as
outlined in the course objectives. We will attempt to answer
the following questions:
- Tritium, what is it?
- How does it behave?
- What are the benefits and hazards?
- How do we control it?
State Course Objectives
Show OT 2
Show OT 3, OT 4,
and OT 5
DOE-HDBK-1105-2002
Radiological Training for Tritium Facilities
Instructor’s Guide
F-14
Course Content
Briefly review the content of the course, noting that there is a
logical sequence ("flow"), and that as you present the
material you will relate the material covered to the
circumstances that they can expect to find in the facility
workplace and procedures. (You will be inserting site-
specific tritium information.)
1. Properties of Tritium
2. Sources and Uses of Tritium
3. Modes of Exposure and Biological Behavior of Tritium
4. Radiological Controls for Tritium
5. Monitoring for Tritium
6. Tritium Waste Minimization and Handling
7. Response to Abnormal Conditions in the Tritium Facility
8. Lessons Learned
9. Summary and Review
Show OT 6
DOE-HDBK-1105-2002
Radiological Training for Tritium Facilities
Instructor’s Guide
Notes
F-15
I.
PROPERTIES OF TRITIUM - What is tritium?
Tritium is a radioactive isotope of hydrogen (H).
Hydrogen is the lightest and most abundant
element in the universe. Hydrogen has only one
proton in its nucleus. Tritium has, in addition to the
single proton, two neutrons in its nucleus. This
makes it three times heavier than the most
common form of hydrogen.
Show OT 7
Show OT 8
A. Isotopes of Hydrogen
1. Protium (H) (99.985% natural
abundance)
2. Deuterium = hydrogen + 1
neutron (D) (0.015% natural
abundance)
3. Tritium = hydrogen + 2 neutrons
(T)
Show OT 9
B. Symbol for Tritium
Tritium is designated as:
H or 3,H- T, 3
1
Show OT 10
C. Chemical Properties of Hydrogen/Tritium
Tritium "behaves" just like hydrogen
chemically because it has one proton
and one electron like ordinary
hydrogen.
Reaction rates may vary
from hydrogen.
DOE-HDBK-1105-2002
Radiological Training for Tritium Facilities
Instructor’s Guide
Notes
F-16
1. Substitution
Tritium atoms can easily substitute
for hydrogen atoms. Examples:
a. elemental hydrogen (tritium
gas, HT, DT, or T2)
b. tritiated water (tritium oxide:
HTO, DTO, or T2O)
c. organically bound tritium: These
compounds may result in more
dose per intake than tritiated
water.
d. metals and tritium (metal
tritides): These compounds may
result in more dose per intake
than tritiated water. Accordingly,
additional controls may be
needed, such as special air
monitoring or enhanced
personnel protective equipment.
Section 177
Show OT 11
Show OT 12
Show OT 13 - Tritium can
replace a loosely bounded
hydrogen atom of an
organic molecule.
Show OT 14 - Hydride
storage of elemental tritium
is common. Uranium
Hydride is most frequently
used for this purpose.
Tritium is released by
heating the metals to 400
degrees C for 1 atm.
dissociation pressure.
Refer to RCTP 2001-02
and Health Physics Journal
September 2001 for more
information.
2. Solubility
Exchanges with hydrogen in
organic and other materials (oils,
plastics, etc.)
3. Flammability
Tritium gas is flammable and can
explode under certain conditions.
Instructor should
emphasize that the
biological exchange of
tritium with hydrogen in the
body is of concern.
Show OT 15 - The range of
flammable concentrations
of tritium in air is between
4% and 75% by volume in
air.
DOE-HDBK-1105-2002
Radiological Training for Tritium Facilities
Instructor’s Guide
Notes
F-17
D. Physical Properties
1. Diffusion
Tritium gas is lighter than air and
diffuses rapidly in air.
Show OT 16
Show OT 17
2. Permeability
Tritium gas permeates through most
materials, that is, it travels through
them by way of spaces or interstices
in them. The rate depends upon the
material and its thickness. Tritium's
radioactive, chemically reducing and
diffusive properties result in
degradation of many useful
polymeric materials, pump oils,
plastics, and o-rings. This can
cause loss of mechanical functions
in certain situations within a short
period of time.
Show OT 18
υβ + + He to decaysH 3
2
− 3
1
E. Radioactive Decay of Tritium
Helium = He 3
2
neutrino-anti = υ
minus beta = β −
Tritium "decays" by emitting a beta
particle and becoming an atom of
helium.
Show OT 19
DOE-HDBK-1105-2002
Radiological Training for Tritium Facilities
Instructor’s Guide
Notes
F-18
1. Beta Energy
A very low energy beta is emitted.
Max energy = 18.6 keV
Ave. energy = 5.7 keV
2. Beta Range
Tritium is not an "external" radiation
hazard.
Instructor should
emphasize the radiological
controls are to keep tritium
outside the body. Explain
what is meant by "external"
radiation hazard.
a. Travels less than 1/4 inch in air
b. Cannot penetrate through the
dead layer of the skin
c. Cannot penetrate clothing or
gloves
3. Half-life
Radioactive half-life = 12.3 years.
Show OT 20
F. X-Ray Production
Tritium betas can produce low energy
x rays. Because the beta particle is of
such low energy the x rays it may
produce are not very penetrating and
are not normally considered a hazard.
DOE-HDBK-1105-2002
Radiological Training for Tritium Facilities
Instructor’s Guide
Notes
F-19
G. Fusion
Fusion is the process of two nuclei
joining together. The energy source in
most stars is nuclear fusion of
hydrogen isotopes.
fusionper mev 1
n + H H + H 1
0
3
2
2
1 e 2
1 →
Show OT 21
fusionper mev 17
n + H H + H 1
0
4
2
2
1 e 3
1 →
SOURCES AND USES OF TRITIUM
How is tritium produced and what is it used for?
A. Sources of Tritium
There are three primary sources of
tritium in our environment. Tritium is
present in our environment from both
man-made and natural sources as
discussed below. Natural tritium is
indistinguishable from man-made
tritium.
1. Natural Sources
Section 178
Tritium occurs naturally. It is
formed by the reactions between
cosmic rays and the nitrogen in
the upper atmosphere. Nitrogen
makes up 80% of the earths
atmosphere.
Cosmic rays generate
approximately 4 million curies of
tritium per year. With tritium being
continually produced and at the
same time decaying, the natural
tritium in our environment is about
70 million curies.
Show OT 22
Show OT 23
Modes of production:
1. The nitrogen nucleus
captures a neutron and
decays to tritium and
carbon.
C + H
yieldsn + N
12
6
3
1
1
0 14
7
H + H
yields H + H
1
1
3
1
2
1 2
1
2. Two hydrogen-2 atoms
(deuterium) combine to
form tritium and normal
hydrogen.
DOE-HDBK-1105-2002
Radiological Training for Tritium Facilities
Instructor’s Guide
Notes
F-20
2. Byproduct of Reactor Sources
a. Lithium-7 captures a neutron
and decays with tritium as a
product.
b. Boron captures a neutron and
decays with tritium as a product.
c. Activation of deuterium in water.
d. Ternary fission - A fission
resulting in three fission
products, one of which is tritium.
This process has a 0.1% yield.
α +n + H
yieldsn + Li
1
0
3
1
1
0 7
3
α2 + H yieldsn + B 3
1
1
0 10
5
Show OT 24
H yieldsn + H 3
1
1
0 2
1
The production of tritium from power
reactors around the world is less
than one-half that naturally formed
(approximately 1 to 2 million curies
a year).
3. Weapons Testing as a Source
The amount of tritium in the world
from weapons testing has been
steadily declining since the 1970's
when atmospheric testing was
curtailed.
Show OT 25
Atmospheric testing from 1945-
1975 produced about 8 billion
curies. This has decayed to about
400 million curies.
DOE-HDBK-1105-2002
Radiological Training for Tritium Facilities
Instructor’s Guide
Notes
F-21
4. DOE Production of Tritium
DOE has produced tritium at the
Savannah River Site with the use
of a reactor. Tritium is
commercially available from from
Canada and the European
Community for non-weapons use.
α + H
yieldsn + Li
3
1
1
0 6
3
B. Uses of Tritium
1. Consumer Products
a. Gaseous tritium light sources
- exit signs (1 Ci to tens of
Ci's)
- aviation landing aids (30-
165 Ci per light)
(1 curie of tritium has a mass
of approximately 0.1 mg)
Show OT 26
Instructor - emphasize that
tritium has use in everyday
activities.
Approximately 100,000 Ci
per runway
b. Luminizing industry: Self-
luminous compounds for dials
(several mCi's) and controls as
well as other general industry
uses.
2. Research - Tritium Labeling
Tracers for medical and laboratory
research.
Show OT 27
3. Department of Energy
a. Weapons development and
applications
b. Fusion energy: As a fuel source
Show OT 28
DOE-HDBK-1105-2002
Radiological Training for Tritium Facilities
Instructor’s Guide
Notes
F-22
III.
MODES OF EXPOSURE AND BIOLOGICAL
BEHAVIOR OF TRITIUM - How can I be exposed to
tritium and what would it do to me?
Show OT 29
A. External Dose
- Tritium is not an external hazard.
- Tritium is not a dose concern if it is
located outside the body.
- Tritium betas will not penetrate a
dosimeter.
- We are interested only in tritium
inside the body.
Show OT 30
Section 179
The tritium beta when it is
stopped (particularly in
high atomic numbered
materials, e.g., lead) will
produce a low energy x-
ray. This x-ray cannot
penetrate into the body,
because of the low energy
of the x-ray.
There may be rare
circumstances where
external dose should be
considered (i.e., using
large quantities of tritium).
B. Internal Dose
Tritium is an "internal" radiation
hazard.
C. Modes of Exposure
Tritium can deliver a radiation dose if it
gets inside our bodies. Modes of entry
include:
- inhalation
- absorption
- injection (cuts/wounds)
- ingestion
Show OT 31
DOE-HDBK-1105-2002
Radiological Training for Tritium Facilities
Instructor’s Guide
Notes
F-23
1. Inhalation
a. Tritium gas: is only slightly
incorporated into the body when inhaled.
Most tritium gas inhaled is subsequently
exhaled. There are other chemical and
physical processes to convert tritium gas
to tritiated water.
b. Tritiated water vapor: Nearly 100% of
tritiated water vapor inhaled is
incorporated into body fluids/tissues.
c. Hazard: Exposure to tritiated water is
approximately 25,000 times more
hazardous than exposure to elemental
tritium gas.
d. Special Tritium Compounds: consist of
organically bound tritium and tritium
particulate aerosols.
Exposure to organically bound tritium
can be up to approximately 13 times
more hazardous than exposure to HTO.
Exposure to tritium particulate aerosols
can deliver up to approximately 20 times
more dose to the whole body than
exposure to HTO. The dose to the
lungs from tritium particulate aerosols
could be 2 orders of magnitude higher
than from HTO.
Show OT 32
An extremely low
percent (in the
order of 0.005%)
of tritium gas
inhaled is
converted to
tritiated water
prior to being
exhaled.
Tritiated water
vapor is more
hazardous due to
its ability to be
almost 100%
assimilated,
increasing the
dose received by
the individual.
2. Ingestion
Ingestion may occur by eating, drinking,
chewing tobacco, and applying makeup
where tritium contamination is present.
Always wash hands thoroughly when
leaving areas where there is a potential
for contamination, and never eat, drink
etc. where tritium contamination may be
present.
DOE-HDBK-1105-2002
Radiological Training for Tritium Facilities
Instructor’s Guide
Notes
F-24
3. Absorption
Absorption is also a hazard
because an individual can receive,
in certain situations, 1/3 of their
uptake from absorption through
the skin if not properly using
personal protective equipment.
a. Tritium gas: There is negligible
skin absorption for tritium gas.
b. Tritiated water: Tritiated water
can be absorbed through the
skin. It has been observed that
moisture on hands enhances
absorption.
c. Solvents: Some solvents
(organically bound tritium) can
also go through the skin.
Tritium will penetrate gloves; therefore
gloves must be changed at a
prescribed routine basis.
Show OT 33
The assumption is that an additional
50% of the inhalation intake is
absorbed through the skin.
This is an important fact for
maintenance workers to know.
Insert site specific information
concerning gloves.
D. Biological Behavior of Uptakes of Tritium
Tritiated water in the body acts just like
water.
1. Distribution
Section 180
Tritiated water is rapidly and
uniformly distributed throughout
the entire body. The Committed
Effective Dose from an uptake of
one curie of tritiated water is 63
rem. Soluble organically bound
tritium behaves in the body in a
similar manner.
Stable tritium particulate aerosols
and insoluble organically bound
tritium behave in the body in a
similar manner as the particulate to
which the tritium is bound.
Show OT 34
Typical production reactor coolant
has approximately 10 Ci/L of tritium.
So 100 ml of such coolant has
about 1 Ci of tritium. If
approximately 8 ml was ingested a
committed effective dose of 5 rem
(the annual limit) would result.
DOE-HDBK-1105-2002
Radiological Training for Tritium Facilities
Instructor’s Guide
Notes
F-25
2. Biological Half-life
Half of the HTO is eliminated from
the body in about 10 days. Through
normal biological processes, it would
take 70 days or more to eliminate
99% of the assimilated tritiated water.
Stable tritium particulate aerosols
and insoluble organically bound
tritium behave in the body in a similar
manner as the particulate to which
the tritium is bound and would have a
longer half life.
Show OT 35
E. Medical Treatment
The biological half-life can be shortened by
increasing the water elimination in the body.
Therefore, individuals who have uptakes of
tritium are encouraged to drink water.
Drinking copious amounts of water should
not be done without a physician's guidance.
Certain medical conditions may be affected
by liquid intake.
Show OT 36
Insert site-specific policy.
IV.
RADIOLOGICAL CONTROLS FOR TRITIUM - How
can I protect myself from exposures to tritium?
Tritium can be present in a variety of chemical
forms. Ongoing research indicates that the form of
tritium which gives the highest dose (per unit intake)
is tritium particulate aerosols. However, these
compounds are not found in the quantities and
various locations as tritiated water. If we can rule
out special tritium compounds as being of concern,
we assume it may be tritiated water.
The preferred hierarchy of control is as follows:
- engineered
- administrative
- personal protective equipment
Show OT 37
Show OT 38
DOE-HDBK-1105-2002
Radiological Training for Tritium Facilities
Instructor’s Guide
Notes
F-26
A. Engineered Controls
1. Containment and Confinement
Containment or confinement is
a series of physical barriers,
minimizes exposure of
workers.
Show OT 39
Confinements such as
gloveboxes are almost always
used when handling large
quantities of tritium. However,
hoods are acceptable for
handling small quantities, such
as in a laboratory.
Instructor should insert site
specific information
concerning what is
considered large or small
quantities for handling
tritium.
2. Airflow
Maintaining negative ventilation
is essential for the safe
operation of a tritium facility.
Airflow should be from areas of
LEAST to MOST
contamination.
Show OT 40
May need to use site
specific terminology.
3. Local Exhaust Ventilation
The primary advantage of local
exhaust ventilation techniques
is the removal of airborne
tritium, regardless of its release
rate or chemical or physical
form. In addition, these
techniques use relatively low
volume rates compared to
normal ventilation
requirements.
DOE-HDBK-1105-2002
Radiological Training for Tritium Facilities
Section 181
Instructor’s Guide
Notes
F-27
4. Dilution Ventilation
Dilution ventilation is the once-
through flow technique of
exchanging outside air for
inside air for comfort and the
reduction of airborne sources.
5. Storage
Tritium can be stored in
storage beds. Metal tritide and
uranium hydride are the most
common for these storage
systems. Tritium is generally
released by heating the metal
tritide.
Tritium is considered
valuable and needs to be
recovered. (i.e. not to send
up the stack)
B. Administrative Controls
There are many administrative controls to
reduce doses. The following are just a few
that should apply to all sites:
- limitation of access time
- procedures/RWPs
- postings
For tritium and tritium compounds, 10 CFR
835 Appendix D requires posting
contamination areas based on removable
contamination values of 10,000 dpm/100cm2.
Show OT 41
Ask students to name
other ways to prevent or
reduce doses.
Insert site specific posting
requirements.
DOE-HDBK-1105-2002
Radiological Training for Tritium Facilities
Instructor’s Guide
Notes
F-28
C.
Personal Protective Equipment
1. Air Supplied Suits
Because of the absorption
through the skin associated
with the use of respirators and
other breathing apparatus, air-
supplied plastic suits that
completely enclose the body
are widely used by facilities
that handle large quantities of
tritium.
Show OT 42
2. Protective Clothing
Protective clothing (PC), or
anti-contamination clothing
(anti-Cs), is used to minimize
the spread of contamination
from contaminated to clean
areas.
In many operations, the hands
and forearms of workers are
vulnerable to contact with
tritium surface contamination.
The proper selection of gloves
and glove materials is
important. In many instances a
plastic/water proof suit is
required.
Discuss site specific
requirements
Insert site specific
information concerning
selection of PCS.
Even with a plastic or
water-proof PC suit, a stay
time may be assigned due
to the ability of tritium to
permeate through plastic.
V.
MONITORING FOR TRITIUM - How do I know if
tritium is present?
Show OT 43
DOE-HDBK-1105-2002
Radiological Training for Tritium Facilities
Instructor’s Guide
Notes
F-29
A. Personnel Monitoring
1. External Dose
Dosimeters are not typically
used to monitor for
radiological doses resulting
from tritium. The weak
energy beta radiation will not
penetrate the dosimeter.
(insert any site specific
monitoring procedures)
Show OT 44
Insert site specific
requirements
2. Internal Dose
The best method used to determine if an
individual has an uptake of HTO or soluble
organically bound tritium is by bioassay
(urinalysis). Routine urine samples,
collected at some predetermined frequency
and counted for the tritium content, provide
a very sensitive measurement of tritium in
the body. This is especially true if the time
of uptake is known.
Air sampling results may be
used to assess dose from other
types of special tritium
compounds.
Show OT 45
3. Routine Versus Non-Routine
Bioassay Monitoring
a. Routine: Routine
urinalysis is conducted on a
preset periodic basis.
b. Non-routine or Special:
Non-routine bioassay is
done whenever a potential
exposure to tritium is
suspected.
(insert site specific bioassay
Section 182
procedures)
1. Prospective: Prospective
bioassay is routine
bioassay.
DOE-HDBK-1105-2002
Radiological Training for Tritium Facilities
Instructor’s Guide
Notes
F-30
B. Workplace Monitoring
Air monitoring and surface contamination
surveys are used to verify that loose
contamination is not present. They provide
an early indication of potential problems.
Show OT 46
1. Airborne Tritium Monitoring
Airborne tritium monitoring is
used for:
a. Prompt detection of
airborne contamination for
worker protection;
b. Determination of the status
of processes; and
c. Identification of any leaks in
primary or secondary
containments or
confinements.
Show OT 47
Insert and discuss site
specific information
concerning equipment.
2. Contamination Surveys
Despite contamination control
measures, tritium is easily
spread.
All workplaces shall be
surveyed for contamination
levels on a regularly
scheduled basis. The
frequency of such surveys will
depend on the potential for
dispersement of the tritium-
contaminated material in the
area and the quantity of
tritium in the area. During
routine surveys, all work
enclosures, work surfaces,
floors, equipment, etc., within
the workplace should be
surveyed.
Show OT 48
DOE-HDBK-1105-2002
Radiological Training for Tritium Facilities
Instructor’s Guide
Notes
F-31
At the surface contamination levels in
10 CFR 835 Appendix D, tritium is
difficult to measure directly because
the low-energy beta is readily absorbed
in air and the window of the detector.
Normal frisking methods (use of
pancake probe) will not detect tritiated
water.
Surfaces are normally wiped (smeared)
with a small paper, either dry or
moistened, which will pick up loose
tritiated material. The wipe is then
normally counted by liquid scintillation
techniques.
Show OT 49
VI.
TRITIUM WASTE MINIMIZATION AND
HANDLING- Why is it important and how do you
minimize tritium waste?
(insert site specific controls)
Methods below are given as a reference only.
A. Minimizing Tritium-Contaminated Waste
Show OT 50
This material maybe
covered in Radiological
Worker I or II training.
Emphasis should be on
site specific information. It
is not necessary to repeat
information.
1. Avoid generating wastes by not
bringing unnecessary material into
the controlled area.
2. Whenever possible, avoid use of
porous materials or those known to
be highly permeable to tritium.
3. Designate an area to store
contaminated tools for reuse or
consider all tools in the area to be
contaminated.
DOE-HDBK-1105-2002
Radiological Training for Tritium Facilities
Instructor’s Guide
Notes
F-32
4. Plan work so that, whenever possible,
construction and clean maintenance
can be done in a clean area.
5. When transporting items
contaminated with tritium, adequate
contamination control such as
wrapping in plastic or placing in
sealed containers should be
considered.
Insert site-specific
information concerning
procedures for transporting
tritium contaminated items.
B. Minimizing Mixed Waste
(insert site specific controls)
Methods below are given as a reference
only.
1. Use non-hazardous cleaning
materials for decontamination
whenever possible.
2. Segregate radioactive-only from
Section 183
hazardous-only at the source.
3. Explore the use of other materials
which are non-hazardous for use in
radiological areas to prevent the
generation of mixed waste.
VII.
RESPONSE TO ABNORMAL CONDITIONS IN
THE TRITIUM FACILITY- What should I do in an
emergency involving tritium?
To properly deal with unexpected adverse
situations occurring in a tritium facility, a well-
thought-out response program and personnel
trained to execute the response should be in place.
Show OT 51
This material may be
covered in Radiological
Worker I or II training.
Emphasis should be on
site specific information. It
is not necessary to repeat
information.
DOE-HDBK-1105-2002
Radiological Training for Tritium Facilities
Instructor’s Guide
Notes
F-33
A. Abnormal Conditions
Abnormal conditions in a tritium facility could
include:
- fire/explosion
- natural disaster
- tritium releases
- other hazards
Personnel found contaminated should follow site
specific decontamination procedures which would
typically include showering with cold water and the use
of mild detergents.
B. Facility Alarms
(insert site specific alarms and emergency
response procedures)
C. Facility Emergency Responses
(insert site specific alarms and emergency
response procedures)
Insert site specific emergency
plan and hazards assessment
documents.
LESSONS LEARNED
(insert site specific lessons learned)
Show OT 52
SUMMARY AND REVIEW
Show OT 53
DOE-HDBK-1105-2002
Radiological Training for Tritium Facilities
Instructor’s Guide
F-34
OVERHEADS
(in Power Point folder)
D
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O
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Radiological Training for
Tritium Facilities
Overhead Transparencies
D
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O
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Tritium - what is it?
How does it behave?
What are the benefits and hazards?
How do we control it?
DOE-HDBK-1105-2002
Radiological Training for Tritium Facilities
Instructor’s Guide
F-35
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Radiological Training for Tritium Facilities
Objectives
IDENTIFY the following properties of tritium
physical/chemical
radioactivity
IDENTIFY sources of tritium
natural
by-product
weapons
IDENTIFY uses of tritium
weapons applications
research
fusion energy production
industrial/commercial
D
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Objectives
(Continued)
IDENTIFY modes of tritium exposure
inhalation
ingestion
absorption
injection/wounds
IDENTIFY biological effects of tritium
biological half-life
dose
IDENTIFY radiological control methods for tritium
engineered
administrative
surface contamination limits
personal protective equipment
application of ALARA principles
DOE-HDBK-1105-2002
Radiological Training for Tritium Facilities
Instructor’s Guide
F-36
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Objectives
(Continued)
IDENTIFY methods for monitoring tritium
air sampling for worker safety
contamination surveys
bioassay
IDENTIFY tritium waste minimization and
handling procedures
IDENTIFY alarms and proper response to
abnormal conditions in the tritium facility
D
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Outline
Properties of tritium
Sources and uses of tritium
Modes of exposure and biological effects of
tritium
Radiological controls for tritium
Monitoring for tritium
Tritium waste minimization and handling
Response to abnormal condition in the tritium
facility
Lessons learned
Summary and Review
DOE-HDBK-1105-2002
Radiological Training for Tritium Facilities
Section 184
Instructor’s Guide
F-37
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What is Tritium?
Properties of Tritium
H-3
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O
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All hydrogen atoms have one proton (H)
Electron
DOE-HDBK-1105-2002
Radiological Training for Tritium Facilities
Instructor’s Guide
F-38
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The number of neutrons may vary
ISOTOPES of hydrogen
Protium H Deuterium D Tritium T
No neutrons 1 neutron 2 neutrons
H D T
n nn
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O
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Tritium is designated as:
T or H-3 or H3
1
DOE-HDBK-1105-2002
Radiological Training for Tritium Facilities
Instructor’s Guide
F-39
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O
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Tritium can easily substitute for protium (H)
Normal Hydrogen Gas
Tritiated Gas
Tritium Gas
H2
HT
TT or T2
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Tritium behaves just like hydrogen
Normal Water
Tritiated Water
H O2
HTO
DOE-HDBK-1105-2002
Radiological Training for Tritium Facilities
Instructor’s Guide
F-40
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O
verhead 13
Tritium can form organic compounds
C6H12+T2 "Benzene" C6 H11T+HT or
CH
4
+T
2
"Methane" CH3T+HT
D
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O
verhead 14
Tritium can be captured in metallic compounds called
"Hydrides" and then released by heating
Heat
DOE-HDBK-1105-2002
Radiological Training for Tritium Facilities
Instructor’s Guide
F-41
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Hydrogen/tritium gas may be flammable
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Hydrogen/tritium gas is lighter than air
DOE-HDBK-1105-2002
Radiological Training for Tritium Facilities
Instructor’s Guide
F-42
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Hydrogen/tritium gas rapidly disperses in air
D
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verhead 18
Hydrogen/tritium gas and tritiated water penetrates through
most materials, including gloves
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Tritium decays by emitting a weak beta
particle
Beta
Stopped By
1/4 Inch of Air
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The radioactive half-life of tritium is
12.3 years
0 12.3 24.6 36.9 49.2 Years
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Fusion of hydrogen and other light element
isotopes fuels the stars
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Sources of Tritium
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Tritium is produced naturally by cosmic rays
and is carried to the earth's surface by rain
World inventory of natural tritium from cosmic ray
interactions is approximately 70 million curies.
4 million curies (approximately 0.41 kg)
produced per year
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Commercial production
Nuclear reactors
1 million curies per year
1-2 million curies per year
-
-
Tritium is formed in reactors by ternary
fission and activation of light elements
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The world inventory of tritium from atmospheric testing is
approximately 400 million curies (approximately 41 kg).
Environmental tritium from atmospheric
testing will be at natural levels by about 2030
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Section 185
Tritium is used commercially in a variety of
products
Illuminating Signs
Runway Lights
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Tritium is used extensively in biology and
medical research
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Tritium is the fuel in
fusion reactions
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Modes of Exposure
and
Biological Behavior of
Tritium
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Tritium is NOT an external radiation hazard-It is an internal
hazard when taken into the body
external
The beta particle cannot
penetrate through the
dead layer of the skin. Tritium is
incorporated
into cells.
internal
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The main pathways for uptake of tritium are:
Inhalation Absorption
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Tritiated water vapor is more hazardous than tritium gas,
as it is readily incorporated into the body
Exhaled
Tritiated water is assimilated in the body
20,000 times more than tritium gas
HT
HT
HTO
HTO
HTO
HT
99.9%
Less than 0.1%
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Tritiated water can also be absorbed
through skin into body water.
HTO
HTO
HTO
HTO
HTO
HTO
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Tritium taken into the body is distributed
throughout the body.
1 Curie of tritiated water
63 rem
10CFR835
establishes 5 rem/year
as the occupational
dose limit.
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The biological half-life of tritium
is about 10 days.
0 Days 10 Days 20 Days 30 Days 40 Days 50 Days
100% 50% 25% 12.5% 6.25% 3.125%
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The elimination of tritium from the body can
be increased by increasing water intake
However, this should only be performed
under medical supervision
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Administrative
Personal Protective Equipment
Radiological Controls
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Engineered controls are preferred over
administrative ones.
Engineered Administrative
Glovebox
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Larger quantities of tritium are handled in
engineered containment systems.
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Airflow should be from areas of LEAST to
MOST contamination in tritium facilities
Building
Room
Hood
Glovebox
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Access controls may also be
administrative.
Caution
RADIOACTIVE MATERIALS
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Because of the permeability of tritium, large quantities
must be handled using air supplied suits.
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Monitoring for Tritium
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Section 186
Your dosimeter is NOT used to monitor
tritium dose which results from assimilation
of tritiated water in the body.
Bioassay is used to
determine tritium dose.
TLDs are used for external
exposure. Tritium betas
cannot penetrate the TLD
case.
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Urinalysis is used to monitor for possible
uptakes of tritium.
Both: Routine and
Non-Routine
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Workplace monitoring for tritium
Monitor
Swipes
Glovebox
Personal Air Sampler
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Area fixed air monitors and tritium sniffers
are used to detect tritium leaks/releases.
FUNCTION
OFF
ON
A
L
A
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M
ZERO
AIR IN
TRITIUM uCi/m3
0 10
PUMP
AIR OUT
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Tritium spreads easily, therefore
contamination control requires constant
vigilance.
Tritium is like sand at the beach...
It gets into everything!
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Tritium contamination is detected and
measured by taking swipes/smears.
Swipe/Smear
Counting Vial
Liquid Scintillation
Counter
LS
Cocktail
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Tritium Waste Minimization
and Handling
Avoid generating waste by not bringing unnecessary
material into the controlled area.
Whenever possible, avoid use of porous materials or
those known to be highly permeable to tritium.
Designate an area to store contaminated tools for reuse.
Plan work so that, whenever possible, construction and
clean maintenance can be done in a clean area.
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Response
to
Abnormal Conditions
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Lessons Learned
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Summary and Review
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APPENDIX F3: Student's Guide
Course Objectives: EO1 IDENTIFY the following properties of tritium:
- physical/chemical
- radioactive.
EO2 IDENTIFY sources of tritium:
- natural
- byproduct
- weapons.
EO3 IDENTIFY uses of tritium:
- weapons applications
- research
- fusion energy production
- industrial/commercial.
EO4 IDENTIFY modes of tritium exposure:
- inhalation
- ingestion
- absorption
- injection/wound.
EO5 IDENTIFY the biological effects of tritium:
- biological half-life
- dose.
EO6 IDENTIFY the radiological control methods for tritium:
- engineered
- administrative
- surface contamination limits
- personnel protective equipment
- application of ALARA principles.
EO7 IDENTIFY methods for monitoring for tritium:
- air sampling for worker safety
- contamination surveys
- bioassay.
EO8 IDENTIFY tritium waste minimization and handling
techniques. (Site-Specific)
EO9 IDENTIFY alarms and proper response to abnormal
conditions in the tritium facility. (Site-Specific)
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I.
PROPERTIES OF TRITIUM - What is tritium?
Section 187
Tritium is a radioactive isotope of hydrogen (H).
Hydrogen is the lightest and most abundant
element in the universe. Hydrogen has only one
proton in its nucleus. Tritium has, in addition to the
single proton, two neutrons in its nucleus. This
makes it three times heavier than the most
common form of hydrogen.
A. Isotopes of Hydrogen
1. Protium (H) (99.985% natural
abundance)
2. Deuterium = hydrogen + 1
neutron (D) (0.015% natural
abundance)
3. Tritium = hydrogen + 2 neutrons
(T)
B. Symbol for Tritium
Tritium is designated as:
H or 3,H- T, 3
1
C. Chemical Properties of Hydrogen/
Tritium
Tritium "behaves" just like hydrogen
chemically because it has one proton
and one electron like ordinary
hydrogen.
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1. Substitution
Tritium atoms can easily substitute
for hydrogen atoms. Examples:
a. elemental hydrogen (tritium
gas, HT, DT, or T2)
b. tritiated water (tritium oxide:
HTO, DTO, or T2O)
c. organically bound tritium: These
compounds may result in more
dose per intake than tritiated
water.
d. metals and tritium (metal
tritides): These compounds may
result in more dose per intake
than tritiated water. Accordingly,
additional controls may be
needed, such as special air
monitoring or enhanced
personnel protective equipment.
2. Solubility
Exchanges with hydrogen in
organic and other materials (oils,
plastics, etc.)
3. Flammability
Tritium gas is flammable and can
explode under certain conditions.
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D. Physical Properties
1. Diffusion
Tritium gas is lighter than air and
diffuses rapidly in air.
2. Permeability
Tritium gas permeates through most
materials, that is, it travels through
them by way of spaces or interstices
in them. The rate depends upon the
material and its thickness. Tritium's
radioactive, chemically reducing and
diffusive properties result in
degradation of many useful
polymeric materials, pump oils,
plastics, and o-rings. This can
cause loss of mechanical functions
in certain situations within a short
period of time.
v 3
1 + + He to decays H -3
2 β −
E. Radioactive Decay of Tritium
= Helium
= antineutrino
β¯ = beta minus
Tritium "decays" by emitting a beta
particle and becoming an atom of
helium.
He3
2
v
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1. Beta Energy
A very low energy beta is emitted.
2. Beta Range
Tritium is not an "external" radiation
hazard.
a. Travels less than 1/4 inch in air
b. Cannot penetrate through the
dead layer of the skin
c. Cannot penetrate clothing or
gloves
3. Half-life
Radioactive half-life = 12.3 years.
F. X-Ray Production
Tritium betas can produce low-energy
x-rays. Because the beta particle is of
such low energy, the x-rays it may
produce are not very penetrating and
are not normally considered a hazard.
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G. Fusion
Fusion is the process of two nuclei
joining together. The energy source in
most stars is nuclear fusion of
hydrogen isotopes.
SOURCES AND USES OF TRITIUM
How is tritium produced, and what is it used for?
A. Sources of Tritium
Section 188
There are three primary sources of
tritium in our environment. Tritium is
present in our environment from both
man-made and natural sources as
discussed below. Natural tritium is
indistinguishable from man-made
tritium.
1. Natural Sources
Tritium occurs naturally. It is
formed by the reactions between
cosmic rays and the nitrogen in
the upper atmosphere. Nitrogen
makes up 80% of the earths
atmosphere.
Cosmic rays generate
approximately 4 million curies of
tritium per year. With tritium being
continually produced and at the
same time decaying, the natural
tritium in our environment is about
70 million curies.
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2. Byproduct of Reactor Sources
a. Lithium-7 captures a neutron
and decays with tritium as a
product.
b. Boron captures a neutron and
decays with tritium as a product.
c. Activation of deuterium in water.
d. Ternary fission - A fission
resulting in three fission
products, one of which is tritium.
This process has a 0.1% yield.
The production of tritium from power
reactors around the world is less
than one-half that naturally formed
(approximately 1 to 2 million curies
a year).
3. Weapons Testing as a Source
The amount of tritium in the world
from weapons testing has been
steadily declining since the 1970's
when atmospheric testing was
curtailed.
Atmospheric testing from 1945-
1975 produced about 8 billion
curies. This has decayed to about
400 million curies.
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4. DOE Production of Tritium
DOE has produced tritium at the
Savannah River Site with the use
of a reactor. Tritium is
commercially available from from
Canada and the European
Community for non-weapons use.
B. Uses of Tritium
1. Consumer Products
a. Gaseous tritium light sources
- exit signs (1 Ci to tens of
Ci's)
- aviation landing aids (30-
165 Ci per light)
(1 curie of tritium has a mass
of approximately 0.1 mg)
b. Luminizing industry: Self-
luminous compounds for dials
(several mCi's) and controls as
well as other general industry
uses.
2. Research - Tritium Labeling
Tracers for medical and laboratory
research.
3. Department of Energy
a. Weapons development and
applications
b. Fusion energy: As a fuel source
DOE-HDBK-1105-2002
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Student’s Guide
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F-69
III.
MODES OF EXPOSURE AND BIOLOGICAL
BEHAVIOR OF TRITIUM - How can I be exposed to
tritium and what would it do to me?
A. External Dose
- Tritium is not an external hazard.
- Tritium is not a dose concern if it is
located outside the body.
- Tritium betas will not penetrate a
dosimeter.
- We are interested only in tritium
inside the body.
B. Internal Dose
Tritium is an "internal" radiation
hazard.
C. Modes of Exposure
Tritium can deliver a radiation dose if it
gets inside our bodies. Modes of entry
include:
- inhalation
- absorption
- injection (cuts/wounds)
- ingestion
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1. Inhalation
a. Tritium gas: is only slightly
incorporated into the body
when inhaled. Most tritium
gas inhaled is subsequently
exhaled. There are other
chemical and physical
processes to convert tritium
gas to tritiated water.
b. Tritiated water vapor: Nearly
100% of tritiated water vapor
inhaled is incorporated into
body fluids/tissues.
Section 189
c. Hazard: Exposure to tritiated
water is approximately 25,000
times more hazardous than
exposure to elemental tritium
gas.
d. Special Tritium Compounds:
consist of organically bound
tritium and tritium particulate
aerosols.
Exposure to organically bound tritium can be
up to approximately 13 times more
hazardous than exposure to HTO.
Exposure to tritium particulate aerosols can
deliver up to approximately 20 times more
dose to the whole body than exposure to
HTO. The dose to the lungs from tritium
particulate aerosols could be 2 orders of
magnitude higher than from HTO.
2. Ingestion
Ingestion may occur by eating, drinking,
chewing tobacco, or applying makeup where
tritium contamination is present. Always
wash hands thoroughly when leaving areas
where there is a potential for contamination,
and never eat, drink, etc. where tritium
contamination may be present.
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3. Absorption
Absorption is also a hazard because an
individual can receive, in certain situations,
1/3 of their uptake from absorption through
the skin if not properly using personal
protective equipment.
a. Tritium gas: There is negligible skin
absorption for tritium gas.
b. Tritiated water: Tritiated water can be
absorbed through the skin. It has been
observed that moisture on hands
enhances absorption.
c. Solvents: Some solvents (organically
bound tritium) can also go through the
skin.
Tritium will penetrate gloves; therefore gloves
must be changed at a prescribed routine
basis.
D. Biological Behavior of Uptakes of Tritium
Tritiated water in the body acts just like water.
1. Distribution
Tritiated water is rapidly and
uniformly distributed throughout
the entire body. The Committed
Effective Dose from an uptake of
one curie of tritiated water is 63
rem. Soluble organically bound
tritium behaves in the body in a
similar manner.
Stable tritium particulate aerosols
and insoluble organically bound
tritium behave in the body in a
similar manner as the particulate
to which the tritium is bound.
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F-72
2. Biological Half-life
Half of the HTO is eliminated from the body
in about 10 days. Through normal biological
processes, it would take 70 days or more to
eliminate 99% of the assimilated tritiated
water.
Stable tritium particulate aerosols and
insoluble organically bound tritium behave in
the body in a similar manner as the
particulate to which the tritium is bound and
would have a longer half life.
E. Medical Treatment
The biological half-life can be shortened by
increasing the water elimination in the body.
Therefore, individuals who have uptakes of
tritium are encouraged to drink water.
Drinking copious amounts of water should
not be done without a physician's guidance.
Certain medical conditions may be affected
by liquid intake.
IV.
RADIOLOGICAL CONTROLS FOR TRITIUM - How
can I protect myself from exposures to tritium?
Tritium can be present in a variety of chemical
forms. Ongoing research indicates that the form of
tritium which gives the highest dose (per unit intake)
is tritium particulate aerosols. However, these
compounds are not found in the quantities and
various locations as tritiated water. If we can rule
out special tritium compounds as being of concern,
we assume it may be tritiated water.
Section 190
The preferred hierarchy of control is as follows:
- engineered
- administrative
- personal protective equipment
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Student’s Guide
Notes
F-73
A. Engineered Controls
1. Containment and Confinement
Containment or confinement is
a series of physical barriers,
minimizes exposure of
workers.
Confinements such as
gloveboxes are almost always
used when handling large
quantities of tritium. However,
hoods are acceptable for
handling small quantities, such
as in a laboratory.
2. Airflow
Maintaining negative ventilation
is essential for the safe
operation of a tritium facility.
Airflow should be from areas of
LEAST to MOST
contamination.
3. Local Exhaust Ventilation
The primary advantage of local
exhaust ventilation techniques
is the removal of airborne
tritium, regardless of its release
rate or chemical or physical
form. In addition, these
techniques use relatively low
volume rates compared to
normal ventilation
requirements.
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4. Dilution Ventilation
Dilution ventilation is the once-
through flow technique of
exchanging outside air for
inside air for comfort and the
reduction of airborne sources.
5. Storage
Tritium can be stored in
storage beds. Metal tritide and
uranium hydride are the most
common for these storage
systems. Tritium is generally
released by heating the metal
tritide.
B. Administrative Controls
There are many administrative controls to
reduce doses. The following are just a few
that should apply to all sites:
- limitation of access time
- procedures/RWPs
- postings
For tritium and tritium compounds, 10 CFR
835 Appendix D requires posting
contamination areas based on removable
contamination values of 10,000 dpm/100cm2.
DOE-HDBK-1105-2002
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C.
Personal Protective Equipment
1. Air-Supplied Suits
Because of the absorption
through the skin associated
with the use of respirators and
other breathing apparatus, air-
supplied plastic suits that
completely enclose the body
are widely used by facilities
that handle large quantities of
tritium.
2. Protective Clothing
Protective clothing (PC), or
anti-contamination clothing
(anti-Cs), is used to minimize
the spread of contamination
from contaminated to clean
areas.
In many operations, the hands
and forearms of workers are
vulnerable to contact with
tritium surface contamination.
The proper selection of gloves
and glove materials is
important. In many instances a
plastic/water proof suit is
required.
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V. How do I know if tritium is present?
A. Personnel Monitoring
External Dose
Dosimeters are not typically used to monitor
for radiological doses resulting from tritium.
The weak energy beta radiation will not
penetrate the dosimeter.
insert any site specific monitoring
procedures)
2. Internal Dose
The best method used to
determine if an individual has
an uptake of HTO or soluble
organically bound tritium is by
bioassay (urinalysis). Routine
urine samples, collected at
some predetermined frequency
and counted for the tritium
content, provide a very
sensitive measurement of
tritium in the body. This is
especially true if the time of
uptake is known.
Air sampling results may be
used to assess dose from other
types of special tritium
compounds.
Section 191
3. Routine Versus Non-Routine
Bioassay Monitoring
a. Routine: Routine urinalysis
is conducted on a preset
periodic basis.
b. Non-routine or Special:
Non-routine bioassay is
done whenever a potential
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exposure to tritium is
suspected.
(insert site-specific bioassay
procedures)
B. Workplace Monitoring
Air monitoring and surface contamination
surveys are used to verify that loose
contamination is not present. They provide
an early indication of potential problems.
1. Airborne Tritium Monitoring
Airborne tritium monitoring is used for:
a. Prompt detection of airborne
contamination for worker
protection;
b. Determination of the status of
processes; and
c. Identification of any leaks in
primary or secondary
containments or confinements.
2. Contamination Surveys
Despite contamination control
measures, tritium is easily spread.
All workplaces shall be surveyed for
contamination levels on a regularly
scheduled basis. The frequency of
such surveys will depend on the
potential for dispersement of the
tritium-contaminated material in the
area and the quantity of tritium in the
area. During routine surveys, all work
enclosures, work surfaces, floors,
equipment, etc., within the workplace
should be surveyed.
DOE-HDBK-1105-2002
Radiological Training for Tritium Facilities
Student’s Guide
Notes
F-78
At the surface contamination levels in 10 CFR
835 Appendix D, tritium is difficult to measure
directly because the low-energy beta is readily
absorbed in air and the window of the detector.
Normal frisking methods (use of pancake
probe) will not detect tritiated water.
Surfaces are normally wiped (smeared) with a
small paper, either dry or moistened, which will
pick up loose tritiated material. The wipe is
then normally counted by liquid scintillation
techniques.
VI.
TRITIUM WASTE MINIMIZATION AND
HANDLING- Why is it important and how do you
minimize tritium waste?
(insert site specific controls)
Methods below are given as a reference only.
A. Minimizing Tritium-Contaminated Waste
1. Avoid generating wastes by not
bringing unnecessary material into
the controlled area.
2. Whenever possible, avoid use of
porous materials or those known to
be highly permeable to tritium.
3. Designate an area to store
contaminated tools for reuse or
consider all tools in the area to be
contaminated.
DOE-HDBK-1105-2002
Radiological Training for Tritium Facilities
Student’s Guide
Notes
F-79
4. Plan work so that, whenever
possible, construction and clean
maintenance can be done in a clean
area.
5. When transporting items
contaminated with tritium, adequate
contamination control such as
wrapping in plastic or placing in
sealed containers should be
considered.
B. Minimizing Mixed Waste
(insert site-specific controls)
Methods below are given as a reference
only.
1. Use non-hazardous cleaning
materials for decontamination
whenever possible.
2. Segregate radioactive-only from
hazardous-only at the source.
3. Explore the use of other materials
which are non-hazardous for use in
radiological areas to prevent the
generation of mixed waste.
VII.
RESPONSE TO ABNORMAL CONDITIONS IN
THE TRITIUM FACILITY- What should I do in an
emergency involving tritium?
To properly deal with unexpected adverse
situations occurring in a tritium facility, a well-
thought-out response program and personnel
trained to execute the response should be in place.
Section 192
A. Abnormal Conditions
Abnormal conditions in a tritium facility
could include:
DOE-HDBK-1105-2002
Radiological Training for Tritium Facilities
Student’s Guide
Notes
F-80
- fire/explosion
- natural disaster
- tritium releases
- other hazards
Personnel found contaminated should follow site-
specific decontamination procedures, which would
typically include showering with cold water and the
use of mild detergents.
B. Facility Alarms
(insert site-specific alarms and emergency
response procedures)
C. Facility Emergency Responses
(insert site-specific alarms and emergency
response procedures)
VIII.
LESSONS LEARNED
(insert site-specific lessons learned)
IX.
SUMMARY AND REVIEW
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G-1
APPENDIX G: GOOD PRACTICES
DOE-HDBK-1129-2008
G-2
OVERVIEW
This Appendix (Primer) contains an introduction and sections on the following topics:
• Radiological Fundamentals
• Physical and Chemical Properties of Tritium
• Biological Properties of Tritium
• Tritium Monitoring
• Radiological Control and Protection Practices
• Emergency Response
This document contains selected information from the Health Physics Manual of Good Practices
for Tritium Facilities, which was prepared by EG&G Mound Applied Technologies at the Mound
tritium facility. The authors acknowledge their expertise and experience.
DOE-HDBK-1129-2008
G-3
TABLE OF CONTENTS
INTRODUCTION ......................................................................................................................G-5
RADIOLOGICAL FUNDAMENTALS.........................................................................................G-5
Hydrogen and Its Isotopes ..................................................................................................G-5
Sources of Tritium...............................................................................................................G-7
Stable and Unstable Nuclides.............................................................................................G-7
Ions and Ionization..............................................................................................................G-8
Types of Radiation ..............................................................................................................G-9
Radioactivity......................................................................................................................G-11
Nuclear and Radioactive Properties..................................................................................G-12
Penetration Depths of Beta Particles ................................................................................G-13
Chemical Properties..........................................................................................................G-14
Contamination...................................................................................................................G-15
Section 193
BIOLOGICAL PROPERTIES OF TRITIUM ............................................................................G-15
Metabolism of Gaseous Tritium ........................................................................................G-16
Metabolism of Tritiated Water ...........................................................................................G-16
Metabolism of Other Tritiated Species ..............................................................................G-16
Metallic Getters .................................................................................................................G-17
Tritiated Liquids.................................................................................................................G-17
Other Tritiated Gases........................................................................................................G-17
Biological Half-Life of HTO................................................................................................G-17
Bioassay and Internal Dosimetry ......................................................................................G-18
Sampling Schedule and Technique ..................................................................................G-18
Dose Reduction.................................................................................................................G-19
TRITIUM MONITORING .........................................................................................................G-20
Air Monitoring ....................................................................................................................G-20
Differential Air Monitoring..................................................................................................G-21
Discrete Air Sampling........................................................................................................G-21
Process Monitoring ...........................................................................................................G-22
Surface Monitoring ............................................................................................................G-22
Tritium Probes...................................................................................................................G-23
Off-Gassing Measurements ..............................................................................................G-23
Liquid Monitoring...............................................................................................................G-24
RADIOLOGICAL CONTROL AND PROTECTION PRACTICES............................................G-24
Airborne Tritium.................................................................................................................G-24
Secondary Containment....................................................................................................G-24
Temporary Enclosures ......................................................................................................G-25
Protection by Local Ventilation..........................................................................................G-25
Supplied-Air Respirators ...................................................................................................G-26
Supplied-Air Suits..............................................................................................................G-26
Protection from Surface Contamination ............................................................................G-26
Protective Clothing............................................................................................................G-27
Section 194
Lab Coats and Coveralls.............................................................................................G-27
Shoe Covers ...............................................................................................................G-27
Gloves .........................................................................................................................G-27
EMERGENCY RESPONSE....................................................................................................G-30
Emergency Steps to Take.................................................................................................G-30
Decontamination of Personnel ..........................................................................................G-30
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G-4
Decontamination of Surfaces............................................................................................G-30
Operational Emergencies……………………………………………………………………………G-42
LIST OF FIGURES
Figure G-1 Hydrogen Isotopes...................................................................................................... G-6
Figure G-2 Radioactive Decay...................................................................................................... G-8
Figure G-3 Neutral and Ionized Atoms ......................................................................................... G-8
Figure G-4 Alpha Particle.............................................................................................................. G-9
Figure G-5 Alpha Shielding........................................................................................................... G-9
Figure G-6 Neutron Shielding ..................................................................................................... G-11
Figure G-7 Half Life..................................................................................................................... G-12
Figure G-8 Reducing HTO Uptake.............................................................................................. G-29
LIST OF TABLES
Table G-1 Hydrogen Isotopes....................................................................................................... G-6
Table G-2 Important Nuclear Properties of Tritium ..................................................................... G-13
Table G-3 Penetration Depths of Tritium Betas .......................................................................... G-14
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G-5
INTRODUCTION
This Primer is designed for use by operations and maintenance personnel to improve their
knowledge of tritium safe handling practices. It is applicable to many job classifications and can
be used as a reference for classroom work or for self-study. It is presented in general terms so
that it can be used throughout the DOE Complex.
The information in this Primer should enable the reader to do the following:
• Describe methods of measuring airborne tritium concentration.
• List the types of protective clothing that are effective against tritium uptake from surface and
airborne contamination.
• Name two methods of reducing the body dose after a tritium uptake.
• Describe the most common method for determining the amount of tritium uptake in the body.
• Describe the steps to take following an accidental release of airborne tritium.
• Describe the damage to metals that results from absorption of tritium.
• Explain how washing hands or showering in cold water helps reduce tritium uptake.
• Describe how tritium exchanges with normal hydrogen in water and hydrocarbons.
Section 195
The organization of the Primer is as indicated in the Overview. The following section contains
background information on "Radiological Fundamentals." Those familiar with these topics may
elect to skip this section and begin reading at the section entitled "Physical and Chemical
Properties of Tritium." Additional information about tritium is available from the sources listed in
the "Bibliography" section.
RADIOLOGICAL FUNDAMENTALS
This section provides a review of radiological fundamentals. The reader is assumed to be
familiar with this information from radiological worker training. The section discusses hydrogen
and its isotopes and describes basic radiological concepts.
Hydrogen and Its Isotopes
Atomic nuclei of a particular element (such as hydrogen or oxygen) have the same number of
protons (positively charged), but may have a different number of neutrons (no net charge).
Those that have a different number of neutrons are isotopes of that element. Most elements
exist in nature in several isotopic forms. For example, hydrogen has one proton. The isotopes
of hydrogen either have no neutrons (normal hydrogen, called protium), one neutron
(deuterium), or two neutrons (tritium) (Figure G-1). Although isotopes of an element have
almost the same chemical properties, the nuclear properties can be quite different.
DOE-HDBK-1129-2008
G-6
Figure G-1 Hydrogen Isotopes
Nuclear notation uses the chemical symbol (H for hydrogen) and an arrangement of subscripts
and superscripts. The total number of protons and neutrons is shown as a superscript:
1
H for
protium,
2
H for deuterium, and
3
H for tritium. The number of protons (which identifies the
element) is shown as a subscript. However, the common practice of using H, D, and T for these
isotopes, respectively, will be followed in this document, except where nuclear reactions are
illustrated.
The atomic masses, symbols, and natural abundances of the three isotopes of hydrogen are
given in Table G-1.
Table G-1 Hydrogen Isotopes
Symbol
Physical Common Name
(%) Natural
Abundance
Mass
(mass units)
H1
1 H Protium 99.985 1.007825
H2
1 D Deuterium 0.015 2.01400
H3
1 T Tritium 1 × 10-18 3.01605
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G-7
Sources of Tritium
Tritium occurs naturally in the environment. Reactions between cosmic radiation and gases in
the upper atmosphere produce most of the world's natural tritium. For example,
N14
7 + n1
0 H3
1 + C12
6
Tritium converts into water and reaches the earth's surface as rain. An estimated production
rate of 4 × 106 Ci/yr results in a world steady-state natural inventory of ~70 × 106 Ci19.
In addition, commercial producers of radioluminescent and neutron generator devices release
about 1 × 106
Ci/yr. Atmospheric nuclear test explosions from 1945 to 1975 added about 8 × 109
Ci of tritium to the environment, much of which has since decayed. However, about 5 × 108 Ci
remain in the environment, mostly diluted in the oceans. Underground nuclear tests appear to
add little tritium to the atmosphere. The nuclear power and defense industries now release
1-2 × 106 Ci/yr, a small fraction of which comes from light-water reactors. Tritium is also a by-
product of light-water and heavy-water nuclear reactor operation. In their coolants, these
reactors produce about 500 to 1,000 and 2 × 106
Ci/yr, respectively, for every 1,000 MW(e) of
power. Tritium is a fission product within nuclear fuel, generated at a rate of 1-2 × 104
Ci per
Section 196
year/1000 MW(e). U.S. DOE reactors have produced tritium by the neutron bombardment of
lithium (Li).
Stable and Unstable Nuclides
In the lighter elements, the ratio of neutrons to protons in their stable nuclei is usually 1 (one
neutron for every proton). For the heavier elements, this ratio gradually increases to about 1.5
(1.5 neutrons for every proton). Although one cannot always predict from its ratio whether an
isotope is stable or unstable, the relationship between the number of protons and neutrons is
extremely important.
When an isotope is unstable, its nucleus will emit rays or particles or it may split into two
different nuclei. Some combinations of neutrons and protons lead to stable nuclei. If there are
too many or too few neutrons, the resulting nucleus is not stable. This unstable nucleus tries to
become more stable by releasing excess energy. Atoms with unstable nuclei are radioactive.
The process of nuclei releasing this energy is referred to as radioactive decay or disintegration
(Figure G-2). If a nucleus is still unstable after radioactive decay, further decay will occur.
19The curie (Ci) is a unit of activity defined as 3.7×10
10
disintegrations per second (dps). A more basic unit
is 1 dps, which is the definition of the becquerel (Bq). Throughout this Primer, the curie will be used
instead of the becquerel.
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G-8
Figure G-2 Radioactive Decay
Ions and Ionization
Atoms can combine chemically to form molecules. Atoms and molecules are surrounded by
orbiting electrons (negatively charged). If the number of electrons equals the total number of
protons (positively charged) in the nucleus, the atom or molecule is neutral (uncharged).
Electrically charged atoms or molecules are called ions. Ions are either positively or negatively
charged, depending on the number of orbiting electrons relative to the number of protons in the
nucleus. As shown in Figure G-3, ions with more electrons than protons are negatively charged,
while ions with more protons than electrons are positively charged. The process of breaking a
neutral atom or molecule into electrically charged parts is called ionization. This process
requires energy. Ionization removes electrons from the atom, or molecule, leaving an ion with a
positive charge. The negatively charged electron (which can attach itself to a neutral atom or
molecule) and the positively charged ion are called an ion pair. Radiation that causes ionization
is called ionizing radiation.
Figure G-3 Neutral and Ionized Atoms
DOE-HDBK-1129-2008
G-9
Types of Radiation
There are four basic types of ionizing radiation emitted from nuclei: alpha particles, beta
particles, gamma rays, and neutrons.
• alpha particle (α )—consists of two protons and two neutrons and is the same as the
nucleus of a helium atom ( He4
2 ) (Figure 4). Generally, only the heavy nuclides can emit
alpha particles.
A typical example of an α -emitting nuclide is uranium-238:
U238
92 Th234
90 + α + energy.
Figure G-4 Alpha Particle
The mass of an alpha particle is about four times the mass of a single neutron or proton, and
has a positive charge of +2 (it has no electrons). This positive charge causes the alpha particle
2 neutrons, 2 protons no electrons to ionize nearby atoms as it passes through body tissue.
The strong positive charge and its relatively slow speed (resulting from its large mass) causes
the alpha particle to interact strongly with orbiting electrons of atoms and molecules and to lose
large amounts of energy in a short distance. This limits the penetrating ability of the alpha
particle, making it easy to stop. A few centimeters of air, a sheet of paper, or the outer layer of
skin stops alpha particles (Figure G-5).
Section 197
Figure G-5 Alpha Shielding
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G-10
Alpha particles are not an external radiation hazard because they are easily stopped by
protective clothing or the outer layer of skin. However, if an alpha emitter is inhaled or ingested,
it becomes an internal radiation hazard. Because the source is in close contact with body
tissue, the alpha particle will dissipate its energy in a short distance of the tissue.
• beta particle ( β ) is equivalent to an electron except for its source. Beta-emitting nuclides
have too many neutrons. A neutron emits a β particle, and the neutron is then converted to
a proton. Tritium decay provides a good example of this process:
H3
1 β + He3
2 + energy.
A β particle is identical to an electron, and its mass and charge are the same as those of an
electron. As in the case of alpha particles, beta particles ionize atoms by removing electrons
from their orbits. This reaction occurs from charged particle interactions or "collisions" with
orbiting electrons.
Beta particles penetrate further than alpha particles of the same energy. A high-energy beta
particle can penetrate a few centimeters of organic tissue. The higher the energy, the greater
the penetrating ability. However, low-energy beta particles of tritium can be shielded by skin,
paper, or only about 6 mm of air.
• gamma ray (γ ) is emitted when the nucleus of a nuclide releases stored energy without
releasing a particle. Many gamma-emitters are found among the products of nuclear fission.
During pure γ emission the nucleus does not emit particles or change its nuclear structure or
chemical characteristics. For instance,
XA
Z γ + XA
Z .
Gamma radiation is in the form of electromagnetic waves (or photons). Gamma rays are similar
to x-rays, but they differ in their origin and energy. Gamma rays originate within the nucleus,
and x-rays originate outside the nucleus.
Gamma rays have a very high penetrating power because they have no charge or mass.
Depending on their energy, a stream of gamma rays may penetrate with gradually diminishing
intensity through several inches of concrete or similar material. They can be shielded effectively
by very dense materials, such as lead and uranium. Gamma rays are a whole-body hazard.
That is, because of their penetrating ability, the damage caused by gamma rays is not restricted
to any particular body organ.
• neutron (n)—may be emitted spontaneously by heavy nuclei during fission or may be
emitted during radioactive decay. They are uncharged particles that have mass and a high
penetrating ability.
A neutron has about 2,000 times the mass of an electron, but only one-fourth the mass of an
alpha particle. Neutrons are difficult to stop because they lack a charge. Neutrons mainly
interact with matter by striking hydrogen nuclei or interacting with the nucleus of atoms. These
collisions generally cause charged particles or other radiation to be emitted. These particles
DOE-HDBK-1129-2008
G-11
may then ionize other atoms. Collisions between neutronsand hydrogen nuclei (protons) are
effective in stopping or slowing down high-energy neutrons. Neutrons are best shielded by
materials with a high hydrogen content, such as water or plastic (see Figure G-6).
Figure G-6 Neutron Shielding
Radioactivity
Section 198
As radioactive isotopes decay, the number of radioactive nuclei decreases. The time required
for half of the nuclei in a sample of a specific radioactive isotope to undergo decay is called its
(physical) half-life (Figure G-7). Each radioactive isotope has its own characteristic half-life.
Radioactive isotopes decay to less than 1% of their original quantity after about seven half-lives.
Half-lives vary widely with different radionuclides, as shown by the following examples:
N16 -7.35 seconds
H3 -12.43 years
U238 -4.5 × 109 years (4.5 billion years)
The activity of a radioactive isotope sample is defined as the number of nuclei that decay per
unit of time.
It has been shown that for a pure radioactive isotope the number of nuclei decaying per unit
time (rate of decay) is proportional to the number of nuclei available to decay. If the substance is
not being replenished, its activity will decrease accordingly. Therefore, in terms of half-life, the
remaining activity after a period of time can be expressed as follows:
At = A0 × (1/2)n
or A0 / At = 2n
DOE-HDBK-1129-2008
G-12
Figure G-7 Half Life
example where:
A0 = the initial activity (Ci)
At = activity after elapsed time, t (Ci)
n = number of half-lives during elapsed time, equal to t/T1/2,
t = elapsed time (time units)
T1/2 = half-life (time units).
For example, assume we have stored 10,000 Ci of tritium.
How many curies will be left after 50 years of storage?
A0 = 10,000 Ci; n = 50/12.43 = 4.02
At = A0 (1/2)n
At = 10,000 (1/2)
4.02
= 10,000 × 0.062
= 620 Ci (approximately)
PHYSICAL AND CHEMICAL PROPERTIES OF TRITIUM
This section reviews the nuclear properties of tritium and discusses of some of the physical and
chemical properties that are important in understanding tritium handling, containment, and
contamination control.
Nuclear and Radioactive Properties
Being an isotope of hydrogen, tritium has many of the properties of ordinary hydrogen (such as
chemical reactions, permeability, and absorption). Differences may occur because the decaying
tritium atoms can speed up (catalyze) reactions of undecayed tritium, or because atoms that
have undergone decay have changed into helium atoms (3He). Additionally, small differences in
chemical reaction rates may result from the relative masses of the isotopes.
DOE-HDBK-1129-2008
G-13
Some of the useful properties of tritium are listed in Table G-2. Note that the properties listed
are those of molecules of TT (or T2) i.e., two tritium atoms bound together. The specific activity
and power density of HT (a hydrogen and tritium atom bound together) and DT (a deuterium
and tritium atom bound together) are approximately one-half those for T2. The activity density
of HT and DT is exactly one-half that of T2.
Table G-2 Important Nuclear Properties of Tritium
Penetration Depths of Beta Particles
The penetration and absorption of beta particles in a material are important factors for detecting
tritium and understanding the mechanisms by which tritium can degrade materials. A beta
particle interacts with matter by colliding with electrons in the surrounding material. In each
collision, the beta particle may lose several electron volts (keV)20 of energy, and the electron is
stripped from its atom (ionization) or promoted to an excited state. The beta particle has a finite
penetration depth that depends on its energy. Recall that tritium undergoes beta decay
according to the following equation:
H3
1 β + He3
Section 199
2 + energy
The helium daughter ( He3
2 ) is stable, but lighter than common helium ( He4
2 ). The decay energy
is constant (18.6 keV), but is shared between the beta particle and an antineutrino (a tiny
particle). The result is that not all beta particles have the same energy. The average energy is
5.7 keV. Consequently, not all tritium betas have the same penetration depth in a given
material. Where beta ranges are given, it is customary to list both the highest energy and the
average, most representative energy, as listed in Table G-3.
20An electron volt is a small unit of energy used in descriptions of nuclear and chemical reactions. It
equals the energy gained by an electron when it moves across a potential of 1 volt.
Half-Life 12.43 yrs
Specific Activity 9,545 Ci/g
Power Density 0.328 W/g
Activity Density
(T2 gas, 1 atm, 0 degrees C) 2.589 Ci/cm3
(T2 gas, 1 atm, 25 degrees C) 2.372 Ci/cm3
DOE-HDBK-1129-2008
G-14
Table G-3 Penetration Depths of Tritium Betas
With one unimportant exception, tritium is the weakest beta emitter known. The range of the
most energetic tritium beta particles is only about 5 mm in air or 0.005 mm in water or soft
tissue. This range makes it a nonhazard outside the body, but presents a detection problem.
Where other radioisotopes can be detected by virtue of their penetrating radiation, tritium has to
be introduced directly inside the detector or counter to be measured.
Chemical Properties
Laboratories that have large quantities of tritium usually handle it in the form of HT. However, at
any time the tritium may be stored on metal getter beds (such as titanium, zirconium, or
uranium). These beds form weak chemical compounds with hydrogen. Some of the beds are
stable in air; and others are not and can only be used in certain atmospheres. The tritium is
released (or delivered) by heating the beds to the required temperature.
Laboratories may also handle tritiated gases (such as ammonia and methane) and other
compounds. By far the most common of these is HTO, which is formed from HT whenever it is
exposed to oxygen or water vapor. The conversion reactions are oxidation and exchange:
oxidation
2HT + O2 2HTO
2T2 + O2 2TO2
exchange
HT + H2O H2 + HTO
T2 + H2O HT + HTO
DOE-HDBK-1129-2008
G-15
These reaction rates are increased by radiation (from nearby tritium at high concentrations),
heat, or the presence of metal catalysts (especially palladium or platinum). All chemical
reactions involving hydrogen can also be performed with tritium, sometimes at a higher rate if
the tritium concentration is high enough to catalyze the reaction. One of the most important
reactions occurs when a tritium atom exchanges with a loosely bonded hydrogen atom of an
organic molecule. However, where HT is dissolved in water (H2O), the exchange process is
fairly slow because the hydrogen in is tightly bonded and the reaction is not catalyzed.
Contamination
Tritium as HT or HTO will readily adsorb onto the surface of most metals (such as stainless
steel, copper, or aluminum), plastics, and rubbers. The tritium will remain fairly close to the
surface unless the metal is heated to a high temperature. At room temperature, permeation into
these metals is usually extremely slow.
Section 200
In the case of metal contamination, the tritium remains on or very close to the surface. The
contamination can be removed with water or water vapor if the surface is contaminated with
HTO or with hydrogen (H2 or D2) if the contamination is HT. Heating also speeds up the
decontamination process. The initial application of heat to surfaces can also be used to prevent
or lessen the contamination by HT or HTO. Metal surfaces exposed to high pressures of HT or
HTO for extended periods, especially at high temperatures, may allow enough penetration to
cause structural damage to the metal. This is especially true if the decaying tritium causes a
buildup of helium within the structure of the metal.
If adsorbed onto hydrogenous material, the tritium will easily permeate into the material. The
HTO will move much more rapidly into the bulk material than will HT. The permeation rate
varies with the type of material and is accelerated by increasing the temperature. As a result of
this movement, plastics and rubbers exposed to tritium (especially as HTO) are readily
contaminated deep into the bulk material and are impossible to decontaminate completely. After
a period of time, the tritium exchanges with bulk hydrogen and presents little biological risk.
Highly contaminated metal or plastic surfaces may release some of the loosely-bound tritium
immediately after exposure to the contaminating tritiated atmosphere or liquid. This is referred
to as outgassing. The personnel risk from outgassing tritium is generally much less than that
from making unprotected skin contact with the outgassing surface.
BIOLOGICAL PROPERTIES OF TRITIUM
At most tritium facilities, the most commonly encountered forms of tritium are tritium gas (HT)
and tritium oxide (HTO). Other forms of tritium may be present, such as metal tritides, tritiated
pump oil, and tritiated gases such as methane and ammonia. As noted earlier, deuterated and
tritiated compounds generally have the same chemical properties as their protium counterparts,
although some minor isotopic differences in reaction rates exist. These various tritiated
compounds have a wide range of metabolic properties in humans under similar exposure
conditions. For example, inhaled tritium gas is only slightly incorporated into the body during
exposure, and the remainder is rapidly removed (by exhalation) following the exposure. On the
other hand, tritiated water vapor is readily taken up and retained in the body water. In this
Primer, we will address only those compounds likely to be found at DOE laboratories: gaseous
tritium, tritiated water, other tritiated species, metallic getters, and other tritiated liquids and
gases.
DOE-HDBK-1129-2008
G-16
Metabolism of Gaseous Tritium
During a brief exposure to tritium gas, the gas is inhaled and a small amount is dissolved in the
bloodstream. The dissolved gas circulates in the bloodstream before being exhaled along with
the gaseous waste products (carbon dioxide) and normal water vapor. If the exposure persists,
the gas will reach other body fluids. A small percentage of the gaseous tritium is converted to
the oxide (HTO), most likely by oxidation in the gastrointestinal tract. Early experiments
involving human exposure to a concentration of 9 µCi/mL resulted in an increase in the HTO
concentration in urine of 7.7 × 10-3 µCi/mL per hour of exposure. Although independent of the
breathing rate, this conversion can be expressed as the ratio of the HTO buildup to the tritium
inhaled as HT at a nominal breathing rate (20 L/min). In this context, the conversion is 0.003%
of the total gaseous tritium inhaled. More recent experiments with six volunteers resulted in a
conversion of 0.005%. For gaseous tritium exposures, there are two doses: (a) a lung dose
from the tritium in the air inside the lung and (b) a whole body dose from the tritium gas that has
been converted to HTO. The tritiated water converted from the gas in the body behaves as an
exposure to tritiated water.
Section 201
Intake of gaseous tritium through the skin has been found to be negligible compared with that
from inhalation. Small amounts of tritium can enter the skin through unprotected contact with
contaminated metal surfaces, which results in organically bound tritium in skin and in urine.
Ordinarily this is not a serious problem because surfaces highly contaminated with tritium gas
are inaccessible to skin contact. Also, most tritium exposed to air will be converted to the oxide
form (water vapor) before the internal surfaces of equipment are handled during maintenance or
repair operations.
Metabolism of Tritiated Water
The biological incorporation (uptake) of airborne HTO can be extremely efficient: up to 99% of
inhaled HTO is taken into the body by the circulating blood. Ingested liquid HTO is also almost
completely absorbed by the gastrointestinal tract and quickly appears in the blood stream.
Within minutes, it can be found in varying concentrations in the organs, fluids, and tissues of the
body. Skin absorption of airborne HTO is also important, especially during hot weather, because
of the normal movement of water through the skin. For skin temperatures between 30 and 40
degrees C, the absorption of HTO is about 50% of that for HTO by inhalation (assuming an
average breathing rate associated with light work, 20 L/min). No matter how it is absorbed, the
HTO will be uniformly distributed in all biological fluids within one to two hours. This tritium has
a retention that is characteristic of water. In addition, a small fraction of the tritium is
incorporated into easily exchanged hydrogen sites in organic molecules. Hence, retention of
tritiated water can be described as the sum of several terms: one characteristic of body water,
and one or more longer-term components that represent tritium incorporated into organic
hydrogen sites.
Metabolism of Other Tritiated Species
Most tritium handled in laboratories is in the form of tritiated gas or tritium oxide. However,
tritium handling operations may form other compounds, such as tritiated hydrocarbons and
metal tritides. Tritium may also contaminate surfaces and liquids such as pump oil. These
materials may present special safe handling problems.
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Metallic Getters
Although many metals are commonly used for gettering (chemically combining with) tritium, little
information on their metabolic properties is available. Some of these compounds (such as
uranium tritide and lithium tritide) are unstable in air. For these, exposure to air produces
different results. Uranium tritide, being pyrophoric, releases large quantities of tritiated water;
lithium tritide, a hydroxyl scavenger, releases mostly tritium gas.
Tritides of metals (such as titanium, niobium, and zirconium) are stable in air. For particles of
these tritides, the primary organ of concern is the lungs. Some of the tritium may leach out in
the lung fluids and then be incorporated into the body water. These particles may also produce
organically bound tritium from contact with lung tissue, which would further complicate the
metabolic process. However, in laboratories where such tritiated metals are handled, the
possibility for exposure to airborne particulates of these metals is extremely remote except in
accident situations.
Tritiated Liquids
Section 202
Next to HTO, the most common tritiated liquid is tritiated vacuum pump oil. Experience at DOE
facilities has shown that the specific activities of pump oils can easily range from a few mCi/L to
a few tens of Ci/L. The wide range in specific activities may result from variations in the tritium
concentration and total throughput of tritium. Depending on the history of these pumps, the
tritium may be found as HT, HTO, or tritiated hydrocarbons.
Next to pump oils, the next most common group is tritiated solvents. All solvents can be
absorbed through the skin and are relatively volatile and toxic. The overall toxicity of tritiated
solvents is usually dominated by the chemical nature of the solvent.
Other Tritiated Gases
If tritium is released in a nitrogen- or air-filled glovebox, other tritiated gases may be formed,
such as ammonia and methane. The conversion of tritium to tritiated ammonia is small unless
the tritium concentration is very high. The toxicity of these gases is not believed to be greater
than that of tritium oxide.
Biological Half-Life of HTO
Studies of biological elimination rates of body water in humans date back to 1934, when the
body water turnover rate was measured using HDO. Since that time, several additional studies
have been conducted with HDO and HTO. A simple average of the data suggests a value of
9.5 days for the measured biological half-life of water in the body with a deviation of ±50%.
Calculations based on total fluid intake indicate a similar value. This is reasonable because the
turnover rate of HTO should be identical to that of body water. In other words, the biological
half-life of tritium is a function of the average daily throughput of water.
The biological half-life of HTO has been studied when outdoor temperatures varied at the time
of tritium uptake. The data suggest that biological half-lives are shorter in warmer months. For
example, the 7.5-day half-life measured in southern Nigeria is not surprising because the mean
outdoor temperature there averages 27 degrees C. In contrast, an average 9.5-day half-life was
measured in North America, where the mean outdoor temperature averages 17 degrees C.
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Such findings are consistent with metabolic pathways involving sensible and insensible
perspiration. As such, the skin absorption and perspiration pathways can become an important
part of body water exchange routes. It is important to note that personnel who are perspiring
will have a greater absorption of tritium from contact with tritiated surfaces. For planning
purposes, it is customary to use an average half-life of 10 days. However, it is not used to
calculate doses from actual exposures.
Prolonged exposures can be expected to affect the biological half-life. Tritium's interaction with
organic hydrogen can result in additional half-life components ranging from 21 to 30 days and
250 to 550 days. The shorter duration indicates that organic molecules in the body retain tritium
relatively briefly. The longer duration indicates long-term retention by other compounds in the
body that do not readily exchange hydrogen or that metabolize more slowly. However, the
overall contribution from organically bound tritium is relatively small, that is, less than about 5%
for acute exposures and about 10% for chronic exposures. Methods used to compute the
annual limits on intake of air and water specify only the body water component and include the
assumption of a 10-day biological half-life, as mentioned above.
Section 203
Bioassay and Internal Dosimetry
Exposure to tritium oxide (HTO) is by far the most important type of tritium exposure. The HTO
enters the body by inhalation or skin absorption. When immersed in tritiated water vapor, the
body takes in approximately twice as much tritium through the lungs as through the skin. Once
in the body, it is circulated by the blood stream and finds its way into fluids both inside and
outside the cells.
According to International Commission on Radiological Protection (ICRP), the derived air
concentration (DAC)21 for tritium gas (HT) and HTO are 200,000 µCi/m3 and 20 µCi/m3,
respectively. The ratio of these DACs (10,000) is based on the fraction of the gas converted to
HTO in the lines. During exposure to HT, a small fraction of the tritium exchanges in the lung
and is transferred by the blood to the gastrointestinal tract where it is oxidized by enzymes.
This process results in a buildup of HTO until the HT is removed by exhalation at the end of the
exposure. The resultant dose from exposure to this HTO is roughly comparable to the lung
dose from exposure to HT. Thus, the total effective dose from an HT exposure is about 10,000
times less than the total effective dose from an equal exposure to airborne HTO. For both HTO
and HT exposures, a bioassay program that samples body water for HTO is essential for
personnel monitoring at tritium facilities.
Sampling Schedule and Technique
After HTO enters the body, it is quickly distributed throughout the blood system and, within 1 to
2 hours, throughout all water in the body. Once equilibrium is established, the tritium
concentration is found to be the same in samples of blood, sputum, and urine. For bioassay
purposes, urine is normally used for determining tritium concentrations in body water.
21The DAC is defined as that concentration of an airborne material, which, if a worker were exposed to it
for one working year (2,000 hours), would result in a dose of 5 rem to the whole body or 50 rem to any
organ or tissue.
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Workers who may be or who have been exposed to tritium are normally required to submit urine
samples for bioassay periodically. The sampling period may be daily, biweekly, or longer,
depending on the potential for significant exposure.
Special urine samples are normally required after an incident or a work assignment with a high
potential for exposure. After a possible exposure, the worker should empty the bladder 1 to 2
hours later. A sample taken after the bladder is emptied should be reasonably representative of
the body water concentration. A sample collected before equilibrium is established will not be
representative because of dilution in the bladder, or because of initial high concentration in the
blood. However, any early sample may still be useful as a sign of the potential seriousness of
the exposure.
A pure HT exposure is considered as a combination of a lung exposure from the HT and a
whole body exposure from HTO. The HTO comes from the conversion of HT dissolved in the
blood. The whole body dose can be determined as outlined above by analysis for HTO in the
urine. Because the effective dose equivalents from the lung and whole body exposures are
about equal, the total effective dose can be obtained conservatively by multiplying the HTO
whole body dose by 2. However, in general, this is too conservative because a release of pure
tritium gas with less than 0.01% HTO is highly unlikely. With only a slight fraction (~0.1%) of
HTO in the air, the total effective dose is essentially the HTO whole body dose determined by
bioassay.
Section 204
As noted above, tritium-labeled molecules in the skin result from contact with metal surfaces
contaminated with HT. This form is associated with a longer half-life. Lung exposure to
airborne metal tritides may also cause unusual patterns of tritium concentrations in body water
because of the slow release of tritium to the blood stream. If such exposures are possible at the
facility, it is good practice to follow the elimination data carefully and to look for organically
bound tritium in the urine.
The results of the bioassay measurements and their contribution to the worker's dose and
general health must be shared with the worker in a timely fashion.
Dose Reduction
The committed dose following an HTO exposure is directly proportional to the biological half-life,
which in turn is inversely proportional to the turnover rate of body water. This rate varies from
individual to individual. Such things as temperature, humidity, work, and drinking habits may
cause rate variations. Although the average biological half-life is 10 days, it can be decreased
by simply increasing fluid intake, especially diuretic liquids such as coffee, tea, beer, and wine.
Even though the half-life may be easily reduced to 4 to 5 days in this way, a physician must be
consulted before persons are placed on a regimen that might affect their health. Chemical
diuretics require medical supervision because the resultant loss of potassium and other
electrolytes can be very serious if they are not replaced. Such drastic measures can result in a
decrease in half-life to 1 to 2 days. Even more drastic is the use of peritoneal dialysis or a
kidney dialysis machine, which may reduce the half-life to 13 and 4 hours, respectively. Such
extreme techniques should be used only in life-threatening situations involving potential
committed dose equivalents that would exceed about 100 rem without any treatment. Based on
a 10-day half-life, the committed dose for an intake of 1 mCi of HTO is approximately 63 mrem.
Individuals whose urine concentrations exceed established limits should stop work that involves
possible exposure to radiation, whether from tritium or other sources. Work restrictions are
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suggested or imposed to make certain that the annual dose limits for workers are not exceeded.
The operating group may impose stricter limits on their staff than those imposed by the health
physics group. Depending on the number of workers available and the importance of the work to
be done, doses can be managed to safe levels (from 5 to 100 µCi/L in urine).
Results of bioassay sampling should be given to workers who have submitted samples as soon
as they are available. The results may be posted, or the workers may be notified personally.
Moreover, the results must be kept in the workers' radiation exposure records or medical files.
Like any other radiation exposure, any dose in excess of the limits specified by applicable
regulations must be reported to DOE.
TRITIUM MONITORING
The tritium monitoring system at a tritium handling facility is critically important to its safe
operation. Operators and others at the facility need to be informed of the status of the
processes, the development of any leaks in the primary or secondary containments, or of any
releases to the room or environment so that protective measures and corrective action may be
taken quickly. The location and degree of surface contamination are equally important to
prevent accidental uptakes of tritium by personnel.
Section 205
In this section, the various techniques used to monitor for tritium in gases (including air), in
liquids, and on surfaces will be discussed.
Air Monitoring
Fixed ionization chamber instruments are the most widely used instruments for measuring
gaseous forms of tritium in laboratory and process monitoring applications. Portable ionization
chamber instruments are also used to control contamination and to supplement fixed instrument
measurements. Such simple devices require only an electrically polarized ionization chamber,
suitable electronics, and a method for moving the gas sample through the chamber—usually a
pump. Chamber volumes typically range from a tenth to a few tens of liters, depending on the
required sensitivity. The output is usually given in units of concentration (typically µCi/m3) or, if
a commercial electrometer or picoammeter is used, in current units that must be converted to
those of tritium concentration. The following rule of thumb can be used to convert current to
concentration: 1015 × current (amps)/chamber volume (liters) = concentration (µCi/m3). For real-
time tritium monitoring, the practical lower limits of sensitivity range from 0.1 to 10 µCi/m3.
External background radiation or the presence of radon can lower the sensitivity of the
instrument.
For measurements of low concentrations, sensitive electrometers are needed. For higher
concentrations (>1 mCi/m3 for example), the requirements on the electronics can be relaxed,
and smaller ion chambers may be used. Smaller chambers also need less applied voltage.
Because of a greater ratio of surface area to volume, residual contamination in the chamber is
more likely and is called "memory." This residual contamination elevates the background
chamber current. Response times for higher level measurements can be made correspondingly
shorter. However, because small chambers and chambers operated at low pressures may have
significant wall effects, the above rule-of-thumb may not apply. Such instruments would have to
be calibrated to determine their response.
Although most ionization chambers are of the flowthrough type that require a pump to provide
the flow, a number of facilities use "open window" or "perforated wall" chambers. These
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chambers, which employ a dust cover to protect the chamber from particulates, allow the air or
gas to penetrate through the wall to the inside chamber without the need for a pump. These
instruments are used as single point monitors to monitor rooms, hoods, gloveboxes, and ducts.
Differential Air Monitoring
Because HTO is more toxic than HT (10,000 to 25,000 times greater), it may be desirable to
know the relative amounts of each species following a significant release into a room or to the
environment. In the case of stack monitoring, discrete samples of the stack effluent should be
taken using bubblers or desiccants with a catalyst for oxidizing the HT. Another technique for
differential monitoring uses a desiccant cartridge in the sampling line of an ionization chamber
monitor. The result is a measurement of the HT concentration. Without the cartridge, the total
tritium concentration is measured. Subtraction of HT from the total produces the HTO
concentration. The technique may be used with two instruments or one instrument in which the
desiccant cartridge is automatically switched in and out of the sampling line.
Section 206
Another technique uses a semipermeable membrane tube bundle in the sampling line to
remove the HTO (preferentially over the HT), which is directed to an HTO monitor. After
removing the remaining HTO with another membrane dryer, the sampled air is directed to the
HT monitor. Although this technique is slower than the one requiring a desiccant cartridge, it
does not require a periodic cartridge replacement. Furthermore, it can be adapted to measure
tritium in both species in the presence of noble gases or other radioactive gases by adding a
catalyst after the HTO dryers, followed by additional membrane dryers for the HTO. However,
because of its slow response, it is more suitable for effluent or stack monitoring than for room
monitoring. Because significant releases into a room are quite rare, it is easier to treat any such
release as one of HTO than use complicated techniques for continuous differential monitoring.
Discrete Air Sampling
Discrete sampling differs from real-time monitoring in that the sampled gas (usually air) must be
analyzed for tritium content (usually by liquid scintillation counting). The usual technique is to
flow the sampled air through either a solid desiccant (molecular sieve, silica gel, or Drierite) or
water or glycol bubblers. For low-flow rates (about 0.1 to 1 L/min), bubblers may be used.
Bubblers are more convenient for sampling, but are less sensitive than the solid desiccant
cartridges if the water in the desiccant is recovered by heating. Glycol or water may be used,
but glycol is preferred for long-term sampling. In any case, the collected water is then analyzed
for HTO. For differential monitoring of HTO and HT, a heated catalyst (usually a palladium
sponge) is used between the HTO desiccant cartridge or bubblers and the HT cartridge or
bubblers. This is currently the preferred method for monitoring stacks for reporting purposes. In
a different arrangement, palladium is coated on the molecular sieve in the HT cartridge to
oxidize the HT into HTO, which is then absorbed by the molecular sieve. However, this
technique is used primarily for environmental monitoring.
Another technique for sampling HTO in room air is to use a "cold finger" to freeze HTO out of
the air. An alcohol and dry ice mixture in a stainless steel beaker works well. To determine the
concentration, the relative humidity must be known. Another sampling technique is to squeeze
a soft plastic bottle several times to introduce the air (containing the HTO) into the bottle. A
measured quantity of water is then introduced, and the bottle is capped and shaken. In a
minute or less, essentially all the HTO is taken up by the water, which is then analyzed.
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Other techniques involve placing a number of vials or other small specially designed containers
of water, cocktail, or other liquid in selected locations in the area being monitored. After a
period of time (usually a number of days), the liquid in the containers is analyzed. The result is
qualitative (for open containers) to semiquantitative (for specially designed containers).
Process Monitoring
Section 207
Ionization chambers are typically used for monitoring stacks, rooms, hoods, gloveboxes, and
processes. The outputs can be used to sound alarms, activate ventilation valves, activate
detritiation systems, and perform other functions. In general, it can be expected that stack,
room, and hood monitors will require little nonelectronic maintenance (i.e., chamber
replacement because of contamination). Under normal circumstances, the chambers are
constantly flushed with clean air and are not exposed to high tritium concentrations. However,
glovebox monitors can be expected to eventually become contaminated, especially if exposed
to high concentrations of HTO. Process HT monitor backgrounds can also be expected to
present problems if a wide range of concentrations (4 to 5 orders of magnitude) are to be
measured.
Mass spectrometers, gas chromatographs, and calorimeters are the main instruments used for
process monitoring. Because of their relative insensitivities, these instruments cannot detect
tritium much below a few parts per million (Ci/m3). For this reason, the analytical results and the
related health physics concerns must be interpreted carefully. It is not uncommon to find that
samples showing no trace of tritium when analyzed on a mass spectrometer may actually have
a concentration of several curies of tritium per cubic meter. In spite of their contamination
problems, ionization chamber instruments are useful for measuring these lower concentrations
and for providing instant indications of changing concentrations that are not possible with the
more sophisticated instruments.
Surface Monitoring
Any material exposed to tritium or a tritiated compound has the potential of being contaminated.
Although it is difficult to quantify tritium contamination levels, several methods are available to
evaluate the extent of contamination, including smear surveys and off-gassing measurements.
Good housekeeping and work practices are essential in maintaining contamination at
acceptable levels.
For health or safety implications, an indication of loose, removable tritium contamination is more
valuable than a measurement of the total surface contamination. Loose tritium can be
transferred to the body by skin contact or inhalation if it becomes airborne. As a result, loose
contamination is routinely monitored by smears, which are wiped over a surface and then
analyzed by liquid scintillation or proportional counting.
The smears are typically small round filter papers used dry or wet (with water, glycol, or
glycerol). Wet smears are more efficient in removing tritium, and the results are more
reproducible, although the papers are usually more fragile when wet. However, results are only
semiquantitative, and reproducibility within a factor of 2 agreement (for wet or dry smears) is
considered satisfactory. Ordinarily, an area of 100 cm2 of the surface is wiped with the
smearpaper and quickly placed in a vial with about 10 mL of liquid scintillation cocktail, or 1 or 2
mL of water with the cocktail added later. The paper must be placed in liquid immediately after
wiping because losses from evaporation can be considerable, especially if the paper is dry. The
efficiency of the liquid scintillation cocktail is only slightly affected by the size of the swipe. Foam
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smears are also available commercially. These smears dissolve in most cocktails and do not
interfere significantly with the normal counting efficiency.
Section 208
Smears may be counted by gas-flow proportional counting. However, because of the inherent
counting delays, tritium losses before counting can be significant. Moreover, counting
efficiencies may be difficult to determine and may vary greatly from one sample to the next.
Another drawback is potential contamination of the counting chamber when counting very "hot"
smears. For all of these reasons, a liquid scintillation spectrometer is the preferred system.
An effective tritium health physics program must specify the frequency of routine smear surveys.
Each facility should develop a routine surveillance program that may include daily smear
surveys in laboratories, process areas, step-off pads, change rooms, and lunchrooms. In many
locations within a facility, weekly or monthly routine smear surveys may be sufficient. The
frequency should be dictated by operational experience and the potential for contamination. In
addition to the routine survey program, special surveys should be made following spills or on
potentially contaminated material being transferred to a less controlled area to prevent the
spread of contamination from controlled areas.
The surface contamination levels acceptable for the release of materials from radiological areas
may be found in the DOE Radiological Control Standard and DOE Order 5400.5.
Tritium Probes
In general, the total tritium contamination on a surface can be measured only by destructive
techniques. When tritium penetrates a surface even slightly, it becomes undetectable because
of the weak energy of its beta particles. With open-window probes operated in the Geiger
Mueller (GM) or proportional regions, it is possible to measure many of the betas emitted from
the surface. Quantifying that measurement in terms of the total tritium present is difficult
because the history of every exposure is different. Consequently, the relative amounts of
measurable and unmeasurable tritium are different.
Such monitoring probes are used to survey areas quickly before more careful monitoring by
smears, or to monitor the smears themselves while in the field. The probe must be protected
carefully from contamination. When monitoring a slightly contaminated surface after monitoring
a highly contaminated one, contamination of the probe can be an immediate problem. Placing a
disposable mask over the front face of the probe can reduce, but never eliminate this
contamination, particularly if the tritium is rapidly outgassing from the surface. Sensitivity of the
instrument depends on many factors, but should be about 103 to 104 dpm/cm2.
For highly contaminated surfaces (>1 mCi/100 cm2), a thin sodium iodide crystal or athin-
window GM tube can be used to measure the characteristic and continuous x-rays
(Bremsstrahlung) emitted from the surface as a result of the interaction of the beta particle with
the surface material.
Off-Gassing Measurements
Off-gassing can be measured using one of two methods. The simplest method is to "sniff" the
surface for airborne tritium using a portable or fixed tritium monitor. The most reliable method,
however, uses a closed-loop system of known volume and a flow-through ionization chamber
monitor. By placing the sample inside the volume and measuring the change in concentration
over time, tritium off-gassing rates can be determined accurately on virtually any material. The
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Section 209
initial off-gassing rate is the required value because the equilibrium concentration may be
reached quickly in a closed volume, especially if the volume is small because of
recontamination by the airborne tritium.
The uptake of tritium from off-gassing materials is difficult to predict. Off-gassing tritium that is
readily measured indicates contaminated equipment that should not be released for
uncontrolled use.
Liquid Monitoring
Liquid is almost universally monitored by liquid scintillation counting. The liquid must be
compatible with the cocktail. Certain chemicals can degrade the cocktail. Others may retain
much of the tritium; still others result in a high degree of quenching. In addition, samples that
contain peroxide or that are alkaline may result in chemiluminescence that can interfere with
measuring. Such samples should first be neutralized before counting. Chemiluminescence and
phosphorescence both decay with time. Phosphorescence, activated by sunlight or fluorescent
lighting, decays in the dark in a few minutes (fast component) to several days (slow
component). Chemiluminescence, the result of chemical interaction of sample components, may
take days to decay at room temperatures, but takes only hours to decay at the cold
temperatures of a refrigerated liquid scintillation spectrometer. Distillations may be necessary
for some samples.
For rather "hot" samples, as may be the case for vacuum pump oils, Bremsstrahlung counting
may be useful. This technique may also be useful for active monitoring of "hot" liquids. Liquids
may be monitored actively with scintillation flow cells, which are often made of plastic scintillator
material or of glass tubing filled with anthracene crystals. However, both types are prone to
memory effects that result from tritium contamination. In addition, flow cells are also prone to
contamination by algae or other foreign material that can quickly degrade their counting
efficiency.
RADIOLOGICAL CONTROL AND PROTECTION PRACTICES
Airborne Tritium
Tritium released to room air moves readily with normal air current. The room or building
ventilation system should be designed to prevent the air from being carried to uncontaminated
areas, such as offices or other laboratories where tritium is not allowed. For that reason,
differential pressure zoning is commonly used, and released tritium is directed outside through
the building stack. In some newer facilities where the large quantities of tritium are being
handled, room air cleanup systems are available for emergency use. Following a significant
release, the room ventilation system is effectively shut down, the room is isolated, and cleanup
of room air is begun.
Secondary Containment
The most important control for preventing a release of tritium to the room atmosphere is the use
of containment around the source of tritium. This containment usually takes the form of a
glovebox, which is then a secondary containment if the tritium is already contained within the
process plumbing, which is the primary containment. Even if the tritium is on the outside
surface of a piece of equipment and located inside the glovebox, through popular usage, the
box is still referred to as the secondary containment.
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Section 210
Gloveboxes used for tritium work typically are made of stainless steel or aluminum and use
gloves made of butyl, neoprene, or Hypalon. Windows are made of glass or Lexan. In order to
reduce the amount of tritium released to the atmosphere, gloveboxes where significant
quantities of tritium are handled incorporate detritiation systems that process the glovebox
atmosphere and remove the tritium. These detritiation systems, including the room cleanup
systems mentioned above, convert released HT to HTO and collect the HTO on a molecular
sieve for later recovery or burial. Newer systems use metal getters that recover HT without
resorting to oxidation. These getters, which can only be used in certain glovebox atmospheres,
can be heated to release and recover the HT easily.
The atmosphere in the glovebox may be air, nitrogen, argon, or helium, depending on the type
of activity in the box. Even in boxes with inert gas atmospheres, small amounts of moisture and
oxygen exist. Any release of tritium gas in the box will eventually be converted to the oxide. As
a result, the oxide will slowly diffuse through the gloves and contaminate their outside surfaces.
For that reason, personnel using gloveboxes that have had tritium releases are required to wear
one or more additional pairs of disposable gloves when working in the glovebox.
Glovebox monitors are used to alert personnel of a release in the box and may be used to
activate a cleanup system or to increase the rate of the cleanup process. With releases of
tritium in the box, the monitor chamber will eventually develop a memory from contamination,
mainly by HTO. Heated monitor chambers are useful in minimizing contamination by HTO.
The relative pressure of the glovebox atmosphere is normally kept negative in order to prevent
the gloves from hanging outside the box where passersby may brush against them and to
prevent tritium from escaping into the room should a leak develop in the glovebox. However,
outward permeation of HTO through the gloves and inward permeation of room moisture are not
affected by the pressure inside the glovebox.
Temporary Enclosures
At times, maintenance or repair work is done on equipment that cannot be moved into a
glovebox or fume hood and that has a high potential to release tritium. For these activities a
temporary box ("tent"), may be constructed over the equipment, and an existing cleanup system
installed to process the air. Alternatively, if the tritium at risk is not significant, the enclosing
atmosphere may be purged to the stack. If the enclosure is small, gloves and glove ports may
be fitted to the side of the enclosure. For larger enclosures entry may be required. In such
cases, personnel must work in air-supplied suits inside the enclosure.
Protection by Local Ventilation
In spite of the greater protection afforded by gloveboxes, fume hoods are commonly used at
tritium facilities for handling or storing material with low quantities of tritium or with low-level
contamination. Limits are generally imposed on the quantities used or stored in these hoods.
Fume hoods are also used to protect personnel at the outside door of glove-box pass boxes
where materials are passed into and out of the boxes. Ideally, any tritium released in a hood
from outgassing or a leaky container, for instance, is routed to the hood's exhaust duct.
However, turbulence may occur at the hood entrance, resulting in backwash and possible
contamination of personnel if the face velocity is not adequate for the design of the hood, the
Section 211
DOE-HDBK-1129-2008
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activities in the hood, or the local conditions (such as traffic in front of the hood). No hood
should be used that has not been thoroughly surveyed and judged acceptable for tritium use.
For small operations local ventilation is commonly provided at the work site through a flexible
ventilation duct ("elephant trunk") directed to the room exhaust system. The exhaust of these
ducts is generally directed to the building ventilation exhaust system, which of itself may be
adequate to supply the needed air flow for the duct without help from an additional in-line
blower.
Flexible ducts can provide adequate ventilation during maintenance in a glovebox with a panel
removed. In this application, a flexible duct can be connected to a gloveport before the panel is
removed, and then the work can proceed safely.
Supplied-Air Respirators
In general, only supplied-air respirators are effective in preventing inhalation of airborne tritium.
Two types of air-supplied respirators are available: self-contained breathing apparatus (SCBA)
and full-face supplied air masks.
An SCBA, consisting of a full-face mask fed by a bottle of compressed air carried on the
worker's back, provides excellent protection against HTO inhalation. Because the mask
provides no protection against absorption by most of the skin, the SCBA is normally reserved for
emergency use only. The protection factor of 3 or more afforded by the SCBA may be
adequate for some applications. An SCBA can be used as an added precaution during certain
maintenance or operations that experience has shown should not result in the release of
significant amounts of HTO. Nevertheless, the potential for exposure is real, and the SCBA
gives the worker time to leave the area if necessary before a skin exposure occurs.
Full-face supplied-air masks are also available. Because the air is normally supplied by a fixed-
breathing-air system, they are not practical for many emergency situations and, consequently,
are not as popular as SCBAs.
Supplied-Air Suits
Because of the inherent disadvantages associated with respirators and other breathing
apparatus, supplied-air plastic suits that completely enclose the body are often used by facilities
that handle large quantities of tritium. Although they afford reasonably complete body
protection, they are slow to don and cumbersome to wear. For these reasons, they are not
favored for rescue work where time and mobility are important considerations. For certain
maintenance operations outside of gloveboxes with a high degree of risk, supplied-air suits may
be quite useful.
For tritium work, supplied-air suits are constructed of materials that have acceptable permeation
protection against HTO and provide good tear and abrasion resistance. Because of the closed
environment, and the additional background noise caused by the flow of air into the suits,
communication between personnel may require special equipment or methods.
Protection from Surface Contamination
Experience at tritium laboratories has shown that many tritium exposures to personnel occur as
a result of contact with highly contaminated surfaces. Sudden and significant releases of
DOE-HDBK-1129-2008
G-27
Section 212
airborne tritium occur mostly as the less toxic form HT and are quickly detected by portable or
strategically placed, fixed tritium monitors. The result is that the exposure and uptake of
airborne tritium are minimized. (Heavy-water reactors, of course, present a more significant risk
of exposure to tritiated water vapor than to tritium gas.) The presence and degree of
contamination may be unknown until measurements are made. Consequently, the importance
of routine and special monitoring surveys for surfaces that personnel might contact cannot be
overestimated.
Protective clothing worn by workers is one of the most important aspects of an effective health
physics program. Because tritium can be absorbed easily through the skin or by inhalation,
personnel protective equipment must protect against both exposure routes. The following
paragraphs describe protective measures and equipment.
Protective Clothing
Lab Coats and Coveralls
Lab coats and coveralls (fabric barriers) are worn in most tritium facilities. Lab coats are
routinely worn to protect personal clothing. Coveralls are sometimes worn for added protection
instead of a lab coat when the work is unusually dusty, dirty, or greasy. The protection afforded
by lab coats and coveralls is minimal (except for short exposures) when tritium is airborne, but
they are more effective in preventing skin contact with contaminated surfaces.
Disposable waterproof and water-resistant lab coats and coveralls have been tested at various
laboratories. They are not popular for everyday use because of the cost and excessive
discomfort inflicted on the worker. Most facilities prefer using ordinary open-weave fabrics for
lab coats and coveralls and using an approved laundry for contaminated clothing. Some
facilities have chosen to use disposable paper lab coats and coveralls, exchanging the costs
associated with a laundry for the costs associated with replacement and waste disposal.
Shoe Covers
Although shoe covers provide protection against the spread of contamination and exposure, the
routine use of shoe covers in a tritium facility is usually weighed against actual need. Shoe
covers can offer both a degree of personnel protection and control over the spread of
contamination on floors. However, in modern facilities where tritium is largely controlled by the
use of secondary containment, shoe covers may not be required. Such facilities can easily
maintain a clean laboratory environment by the use of regular smear surveys and good
housekeeping. Using liquid-proof shoe covers until spills are cleaned up should be considered
following spills of tritium-contaminated liquids and solids to prevent the spread of local
contamination.
Gloves
In most operations, the hands and forearms of workers are vulnerable to contact with tritium
surface contamination. The proper use and selection of gloves are essential. Many factors
should be considered in selecting the proper type of glove. These include chemical
compatibility, permeation resistance, abrasion resistance, solvent resistance, glove thickness,
glove toughness, glove color, shelf life, and unit cost. Gloves are commercially available in
butyl rubber, neoprene, polyvinyl chloride (PVC) plastics, latex, etc.
DOE-HDBK-1129-2008
G-28
Section 213
The most common gloves found in tritium laboratories are the light-weight, disposable short
glove (usually PVC or latex) used for handling lightly contaminated equipment. Depending on
the level of contamination, such gloves may be changed frequently (every 10–20 minutes), a
second pair may be worn, or heavier gloves may be used instead. When using gloves for this
purpose, the work should be planned so that contaminated gloves doe not spread
contamination to surfaces that are being kept free of contamination.
When working in a glovebox using the box gloves, disposable gloves are worn to prevent
uptake of HTO contaminating the outside of the box gloves. Again, depending on the level of
contamination, more than one additional pair may be required, one of which may be a longer,
surgeon's length, glove.
In spite of all the precautions normally taken, workers may occasionally be contaminated with
tritium. The skin should be decontaminated as soon as possible after any potential skin
exposure to minimize absorption into the body. Effective personal decontamination methods
include rinsing the affected part of the body with cool water and soap. If the entire body is
affected, the worker should shower with soap and water that is as cool as can be tolerated. Cool
water keeps the pores of the skin closed and reduces the transfer of HTO across the skin. The
importance of washing the affected skin as soon as possible after contamination cannot be
overemphasized. Figure G-822 illustrates the effect of speed on reducing the uptake and the
resultant dose. Even if gloves are worn when handling contaminated equipment or when
working in contaminated glovebox gloves, it is good practice to wash the hands after removing
the gloves.
22W. R. Bush, Assessing and Controlling the Hazard from Tritiated Water, AECL-4150, Atomic Energy of
Canada LTD., Chalk River, Ontario, 1972.
DOE-HDBK-1129-2008
G-29
Figure G-8 Reducing HTO Uptake
This figure shows reduction in HTO uptake by washing after exposure to HTO vapor.
DOE-HDBK-1129-2008
G-30
EMERGENCY RESPONSE
It is important to examine the history of accidents that have occurred in tritium facilities and to
consider foreseeable unplanned events in order to minimize or mitigate their effects or to
prevent their taking place at all. When an accident does occur, requirements for reporting
accidents must be followed.
Facilities that handle significant quantities of radioactive material must have a site-specific
emergency plan. All radiological workers at the site must be familiar with certain aspects of this
plan. In addition, job assignments involving radiological hazards are typically covered by
procedures and work permits that include steps for emergency situations that may arise during
the course of the work. Radiological workers must be familiar with these procedures or be
accompanied by a radiological control technician (RCT) to provide guidance in case of an
emergency.
Emergency Steps to Take
The initial steps to be undertaken following a serious accident must always include the
following:
• Warning others in the vicinity
• Evacuating the laboratory if an airborne release has occurred
• Requesting any necessary assistance
• Giving urgent first aid in the event of serious injuries (This should take priority over problems
that arise from contamination)
• Starting personnel decontamination procedures
• Submitting urine samples following the schedule outlined for nonroutine samples.
Section 214
Decontamination of Personnel
Personnel should be decontaminated by the following procedures:
• Remove clothing thought to be contaminated
• Wash hands with soap and cool water
• Wash other parts of the body (such as face, hair, and arms) that may have been exposed to
tritium, or immediately shower with cool water and soap
• If mouth-to-mouth resuscitation must be given to a contaminated victim, the victim's mouth
should first be wiped with a damp cloth.
Decontamination of Surfaces
Following a tritium spill involving a liquid with high specific activity, the area may have to be
isolated and other protective measures taken before cleaning up the liquid. Monitoring for
possible airborne tritium must be started to determine the need for respiratory protection or skin
protection. After the spill has been cleaned up, residual contamination will remain. Depending
on the level of contamination, any further steps needed to prevent the spread of contamination
and reduce the level to an acceptable value should be determined.
Following a release of tritium gas, surfaces would not be expected to be heavily contaminated. If
tritiated water vapor is released, the contamination may be greater, depending on the amount
DOE-HDBK-1129-2008
G-31
and activity of the released vapor. In any case, smear and air surveys will be used to determine
the course of action needed to control and reduce the contamination safely.
Operational Emergencies
This Primer is provided as an information resource only, and is not intended to replace any
radiation worker or hazardous materials training. The Primer presents the theoretical concepts
and good practices that form the basis of safe tritium handling.
Facilities that handle significant quantities of radioactive material must have a site-specific
emergency plan and implementing procedures. The plan and procedures are required by
DOE O 151.1C and implementing guidance on the topics of recognition, categorization/
classification; protective actions; notification; consequence assessment; etc., can be found in
the DOE G 151.1-series, particularly DOE G 151.1-4. All radiological workers at the site must
be familiar with certain aspects of this plan, the Order, and the Guides.
DOE-HDBK-1129-2008
G-32
This page is intentionally blank.
DOE-HDBK-1129-2008
H-1
APPENDIX H: ENDNOTES
1. U.S. Environmental Protection Agency’s Federal Guidance Report No. 11, Table 1 “Limiting
Values of Radionuclide Intake and Air Concentration and Dose Conversion Factors for
Inhalation, Submersion, and Ingestion,” September 1988.
2. Heung, L.K., Titanium for Long Term Tritium Storage, WSRC-TR-94-0596, December 1994.
3. Drolet, T.S., Wong, K.Y., and Dinner, P.J., Canadian Experience with Tritium – The Basis of
a New Fusion Project, Nuclear Technology/Fusion, Vol. 5, January 1984.
4. Kherani, N.P., and Shmayda, W.T., Bulk Getters for Tritium Storage, Ontario Hydro
Research Division.
5. Shmayda, W.T. and Kherani, N.P., On the Unloading of Titanium Getter Beds, Ontario
Hydro Research Division, Report No. 85-118-K, October 2, 1985.
6. Kherani, N.P., and Shmayda, W.T., Titanium Sponge for Immobilization Tritium Containers,
Ontario Hydro Research Division, Report No. M85-120-K, December 19, 1985.
7. Noga, J.O., Investigations of Titanium and Zirconium Hydrides to Determine Suitability of
Recoverable Tritium Immobilization for the Pickering Tritium Removal System, Ontario
Hydro Research Division, Report No. 81-368-K, November 12, 1981.
Section 215
8. “Lanthanum Nickel Aluminum Alloy,” United States Patent 4,142,300.
9. Kirk Shanahan, et al., “Tritium Aging Effects in LaNi4.25A10.75,” WSRC-MS-2002-00564,
Rev. 1 November 12, 2002.
10. DOE Environment, Safety and Health Advisory, “Stakeholder Sensitivity to Tritium Releases”
2006-4, DOE/EH-0699, July 2006.
11. Preamble of the First Third Land Disposal Restrictions Final Rule, 53 FR 31149, August 17,
1988.
12. Memorandum, Environmental Protection Agency, Marcia E. Williams and Christina Kaneen
to Robert L. Duprey, “Applicability of Bevill Amendment to the American Natural Gas Coal
Gasification Facility,” September 1987.
13. Letter, Marcia E. Williams, EPA, to G. N. Weinreich, ANG Coal Gasification Co., June 16,
1986.
14. Memorandum, Environmental Protection Agency, John H. Skinner to Harry Seraydarian,
“Clarification of Mining Waste Exclusion,” May 16, 1985.
15. RCRA Superfund Hotline Report, February 1985.
16. DOE-STD-1027-92, CHG 1 Change Notice 1, “Hazard Categorization and Accident Analysis
Techniques for Compliance with DOE Order 5480.23, ‘Nuclear Safety Analysis Reports,’”
September 1997.
17. “Implementation Guidance for Authorization Basis,” DOE Office of Defense Programs,
Revision 1, August 21, 1995.
18. “Selection of a Tritium Dose Model: Defensibility and Reasonability for DOE Authorization
Basis Calculations, Kevin R. O’Kula and Jackie M. East, Westinghouse Safety Management
Solutions, Inc., Aiken, SC, June 1998
DOE-HDBK-1129-2008
H-2
19. W. Raskob, “Description of the New Version 4.0 of the Tritium Model UFOTRI Including
User Guide, “Kernforschungszentrum Karlsurhe GmbH, Karlsruhe, Kfk 5194, (August 1993).
20. LP-50 SARP, "Safety Analysis Report for Packaging (SARP): USA/9507/BFL (ERDA-
AL),Model AL-M1", MLM-2447 Sept 30, 1977
21. P. D. Gildea, H. G. Birnbaum, and W. R. Wall, “Modification and Testing of the Sandia
Laboratories, Livermore Tritium Decontamination Systems,” Proceedings of the 15th DOE
Nuclear Air Cleaning Conference, CONF-788019 Vol. I, August 1978.
22. R.O. Loutfy, E. M. Wexler; “Feasibility of Fullerene Hydride as a High Capacity Hydrogen
Storage Material”, Proceedings of the 2001 DOE Hydrogen Program Review , DOE 2001
23. “Tritium Facility Decommissioning, Pioneering Success at the Savannah River Plant,”
DOE/SR-5000-510, October 1997
24. John Gill, Babcock & Wilcox of Ohio, Personal Communication to Bill Weaver, July 1998
25. Jofu Mishima and Chris Steele, “Oxidation of Tritium Gas under Accident and Transport
Conditions”, LA-UR-02-3803, July 2002
26. DOE Memorandum, from S. Blush, NS-1, to R. Claytor, DP-1 and P. Ziemer, EH-1, RTF
Assessment of Fire Barriers, October 28, 1991
27. DOE Memorandum from Tom Rollow, Acting Director, Office of Nuclear Safety, to Neal
Goldenberg, NE 70, “NS Response to Request for Deviation for Replacement Tritium
Facility (RTF),” May 7, 1993
28. K.J. Hofstetter, et al., “Field Deployable Tritium Analysis System for Ground and Surface
Water Measurements,” accepted for publication in the Journal of Radioanalytical and
Nuclear Chemistry.
29. N.P. Kherani, W.T. Shmayda, “Ionization Surface Activity Monitor for Tritium,” Fusion
Technology 28(3) (1995) 893.
30. W.T. Shmayda, N.P. Kherani, D. Stodilka, “Evaluation of the Tritium Surface Activity
Monitor,” Proceedings of the Symposium on Fusion Technology, Lisbon, 1996.
31. N.P. Kherani, W.T. Shmayda, “Monitor for Measuring the Radioactivity of a Surface,” US
and European patents pending.
Section 216
32. SRS H1616 Hydride Transport Vessel Qualification Report (U), WSRC-RP-92-1161,
Revision 2, 1995.
33. Bill Weaver, Guidelines for Valves in Tritium Service, Fusion Technology, Vol. 25, July 1994.
34. “Response to Questions and Clarification of Requirements and Processes: DOE 5400.5 Chg
2, Section II.5 and Chapter IV Implementation (Requirements Relating to Residual
Radioactive Material),” DOE Office of the Assistant Secretary for Environmental Safety and
Health, Office of Environment, November 17, 1995.
35. Robert Machacek, Ontario Hydro, Personal Communication to Bill Weaver, 1997.
36. Dave Baldwin, Pacific Northwest Laboratory, Personal Communication to Bill Weaver, 2008
DOE-HDBK-1129-2008
I-1
APPENDIX I: CHARTER OF THE TRITIUM FOCUS GROUP
GOALS – The goals of the TFG are to promote continuous, cost-effective improvement in safety
and operations, and enhance the proactive management of the spectrum of Department of
Energy (DOE) facilities handling tritium.
OBJECTIVES – The objectives of the TFG are to:
1. Provide a forum which fosters exchange of information and ideas, especially conduct of
operations, lessons-learned, and root cause determinations;
2. Serve as a DOE-wide resource for tritium operations management with authority to conduct
special studies, develop and propose guidelines and best practices for operations, and
facilitate peer review of relevant documentation;
3. Develop consistency in implementation of as-low-as-reasonably-achievable (ALARA)
programs and the assessment and reporting of risks and hazards;
4. Promote implementation of a staged and graded program of upgrades to facilities and
procedures;
5. Promote sharing and application of state-of-the-art design and engineering technology and
operating techniques in DOE; and
6. Develop consistency in terminology utilized in DOE tritium operations.
ORGANIZATION – A Tritium Operations Management Focus Group (TOMFG), consisting of the
TFG Chairperson, Co-Chairperson, and Headquarters Program Managers and Facilities
Management Division Directors, will review and approve TFG activities, including submittal of
the initial Charter, and any revisions thereto, to the Program Secretarial Officers for final
approval. The TOMFG shall serve as the principal Headquarters liaison and management
element to facilitate successful operation of the TFG. The TFG membership will consist of the
TOMFG, plus a DOE and contractor member and an alternate for each, to be designated by the
respective management at each site responsible for the processing and handling of tritium. The
members will be from organizational levels having cognizance over tritium operational aspects
at their respective facilities, including processing, hazards, and improvement programs. The
TFG will be chaired by a DOE Field Office representative and co-chaired by a contractor
representative from the same site, as designated by the TOMFG in coordination with the
appropriate Field Office Manager. The chairperson and co-chairperson will serve a 2-year term.
ADMINISTRATION – The TFG activities will receive sufficient management priority in terms of
resource commitment to achieve the stated goals and objectives. Priorities will be established
jointly between the respective DOE Program Managers and Facility Management Division
Directors at Headquarters, and the DOE Field Office managers. The TFG shall look to the
TOMFG to resolve any conflicts in site priorities and to achieve consensus guidelines and best
practices proposed for approval by the DOE line organization.
Section 217
MEETINGS – The TFG will meet on a periodic basis of at least two times per year. Meeting
topics and agenda will be jointly developed by group members, and approved and issued by the
Chairperson. Meeting locations will be rotated among the respective sites. DOE oversight
organizations will be invited, as appropriate. As a minimum, the minutes of each meeting will be
DOE-HDBK-1129-2008
I-2
written and distributed to members within 10 days. The TOMFG will meet, as necessary, to
assure timely action on proposals and continuity of the TFG efforts.
TRITIUM FOCUS SUBGROUPS (TFS) – The TFG will initiate formation of TFSs, as necessary,
to recommend solutions to problems or concerns that may arise within the tritium complex. This
may include the hosting of workshops to address issues such as implementation of specific XXX
orders. Conclusions of the TFSs will be documented and distributed to TFG members.
Proposals from the TFG will be provided through the TOMFG to appropriate DOE line
management for approval.
TECHNICAL EXCHANGE – The TFG will encourage exchange of related technical information
via meetings, conferences, and symposia.
DELIVERABLES – Initial deliverables will be timely communication and sharing of operational
experiences among the facilities, meeting minutes, and proposals. Other deliverables will be
developed in accordance with associate milestone schedules and IFS activity.
CHARTER REVIEW – The Charter will be reviewed annually and revised, as necessary.
Approved by:
Assistant Secretary for Defense Programs, DP-1 Date
(signed by) William H. Young 12/24/91
Assistant Secretary for Nuclear Energy, NE-1 Date
(signed by) Jill E. Lytle (EM-30) for 12/27/91
Assistant Secretary for Environmental Date
Restoration and Waste Management, EM-1
(signed by) William Happer 12/26/91
Director of Energy Research Date
(signed by) Melvin H. Chiggioji (NP-3) for 12/26/91
Director of New Production Reactors, NP-1 Date
DOE-HDBK-1129-2008
CONCLUDING MATERIAL
Review Activity:
HQ Offices Field Offices Site Offices
DR AL Berkeley
EE CH Kansas City
EM ID Livermore
HS OR Los Alamos
NA ORP Nevada
NE RL NNSA Y-12
RW SR Pantex
SC
Laboratories Facilities
Ames NL................. Hanford
ANL......................... Kansas City
BNL......................... ORISE
Fermi NAL .............. Pantex
INL .......................... NTS
LANL....................... Savannah River
LBNL....................... Y-12
LLNL
PNNL
PPPL
SNL
SLAC
SRNL
TJNAF
Preparing Activity:
DOE-CNS_EM-60
Project Number:
SAFT-0123
Section 218
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Section 220
/DAN <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>
/NLD <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>
/ESP <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>
/SUO <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>
Section 221
/ITA <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>
/NOR <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>
/SVE <FEFF0041006e007600e4006e00640020006400650020006800e4007200200069006e0073007400e4006c006c006e0069006e006700610072006e00610020006e00e40072002000640075002000760069006c006c00200073006b0061007000610020005000440046002d0064006f006b0075006d0065006e00740020006d006500640020006800f6006700720065002000620069006c0064007500700070006c00f60073006e0069006e00670020006f006300680020006400e40072006d006500640020006600e50020006200e400740074007200650020007500740073006b00720069006600740073006b00760061006c0069007400650074002e0020005000440046002d0064006f006b0075006d0065006e00740065006e0020006b0061006e002000f600700070006e006100730020006d006500640020004100630072006f0062006100740020006f00630068002000520065006100640065007200200035002e003000200065006c006c00650072002000730065006e006100720065002e>
>>
>> setdistillerparams
<<
/HWResolution [2400 2400]
/PageSize [612.000 792.000]
>> setpagedevice