DOE-HDBK-1216-2015 Chg Notice 1 (Reaffirmed 2022), Environmental Radiological Effluent Monitoring and Environmental Surveillance

DOE-HDBK-1216-2015 March 2015 Change Notice 1 Reaffirmed September 2022 DOE HANDBOOK Environmental Radiological Effluent Monitoring and Environmental Surveillance U.S. Department of Energy AREA ENVR Washington, D.C. 20585 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. NOT MEASUREMENT SENSITIVE DOE HDBK-1216-2015 March 2015 Change 1: September 2022 ADMINISTRATIVE CHANGE TO DOE HDBK-1216, ENVIRONMENTAL RADIOLOGICAL EFFLUENT MONITORING AND ENVIRONMENTAL SURVEILLANCE LOCATION OF CHANGES: Page Paragraph Changed To 142 8.4.4, Number 8 Footnote Replaced nonfunctional link: http://www.minitab.com/uploadedFiles/ SharedResources/Documents/Articles/no rmal_probability_plots.pdf With: RyanJoinerInst.pdf (southeastern.edu) 176 Reference 14 Added note to reference Reference: See ANSI/HPS N13.1- 2011 which is analogous to ANSI/HPS N13.1-1999) 176 Reference 17 Added update note to ANSI 3.11-2005 reference Note: Conforms with ANSI 3.11- 2015 revision 179 Reference 46 Updated DOE-STD-1153-2002 DOE-STD-1153-2019 throughout document 179 Reference 51 Updated DOE-STD-1196-2011 DOE-STD-1196-2021 throughout document 180 Reference 58 Outdated NESHAPs link final_report_9_04.pdf (epa.gov) 181 Reference 71 Outdated NESHAPs link nshpinspman_092702.pdf (epa.gov) 186 Reference 125 Updated reference from 1996 To 2015 C.3.0 References Page C-10 Reference 8 Updated reference from 435.1 chg. 1 To Certified January 9, 2007 http://www.minitab.com/uploadedFiles/SharedResources/Documents/Articles/normal_probability_plots.pdf http://www.minitab.com/uploadedFiles/SharedResources/Documents/Articles/normal_probability_plots.pdf http://www.minitab.com/uploadedFiles/SharedResources/Documents/Articles/normal_probability_plots.pdf https://www2.southeastern.edu/Academics/Faculty/dgurney/Math241/TI8384Stats/RyanJoiner/RyanJoinerInst.pdf https://www2.southeastern.edu/Academics/Faculty/dgurney/Math241/TI8384Stats/RyanJoiner/RyanJoinerInst.pdf https://www.epa.gov/sites/default/files/2015-05/documents/final_report_9_04.pdf https://www.epa.gov/sites/default/files/2015-05/documents/nshpinspman_092702.pdf https://www.epa.gov/sites/default/files/2015-05/documents/nshpinspman_092702.pdf INTENTIONALLY BLANK DOE-HDBK-1216-2015 iii TABLE OF CONTENTS PARAGRAPH PAGE 1 INTRODUCTION ............................................................................................................ 1 1.1 Objectives ............................................................................................................ 1 1.2 Environmental Monitoring .................................................................................... 1 1.3 Key Requirements and Supporting Documents .................................................... 2 2 DESIGNING, REVIEWING, AND DOCUMENTING RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAMS ........................................................................................... 5 2.1 Designing an Environmental Monitoring Program ................................................ 5 2.2 Reviewing the Environmental Monitoring Program ............................................... 8 2.3 Updating the Environmental Monitoring Program. ................................................ 9 3 LIQUID RADIOLOGICAL EFFLUENT MONITORING AND SAMPLING ........................ 11 3.1 Key Requirements ............................................................................................. 12 3.2 Summary of General Criteria and Monitoring Program Needs for Liquid Effluents12 3.3 Performance Standards for Liquid Effluent Monitoring Systems ......................... 14

3.3.1 Continuous Monitoring/Sampling ............................................................ 15 3.3.2 Sampling Systems .................................................................................. 15 3.3.3 System Calibration. ............................................................................... 15 3.3.4 Environmental Conditions ....................................................................... 15 3.4 Sampling System Design Criteria ....................................................................... 16 3.4.1 Selection Criteria for Liquid Effluent Monitoring and Sampling Systems. 16 3.4.2 General Design Criteria for Sampling Systems ....................................... 17 3.4.3 Stream Flow Characteristics ................................................................... 18 3.4.4 Sampling Locations ................................................................................ 18 3.4.5 Delivery Lines ......................................................................................... 19 3.4.6 Liquid Movers ......................................................................................... 19 3.4.7 Sample Collectors .................................................................................. 19 3.4.8 Special Considerations for Liquid Effluent Monitoring and Sampling Systems ................................................................................................. 19 3.4.9 Environmental Considerations ................................................................ 20 3.5 Monitoring System Design Considerations ......................................................... 21 3.5.1 Monitoring Purposes............................................................................... 21 3.5.2 General Design Criteria .......................................................................... 21 3.5.3 Batch Release ........................................................................................ 22 3.5.4 Types of Radiation ................................................................................. 22 3.5.5 High Background .................................................................................... 22 3.6 Environmental Effects ........................................................................................ 23 3.7 Alarm Levels ...................................................................................................... 23 3.8 Operational Considerations for All Monitoring and Sampling Systems ............... 23 3.9 Quality Assurance .............................................................................................. 24 4 AIRBORNE RADIOLOGICAL EFFLUENT MONITORING AND SAMPLING .................25 4.1 Key Requirements ............................................................................................. 26 4.2 Summary of General Objectives. ....................................................................... 28 4.2.1 Performance Standards for Air Sampling Systems ................................. 29 4.2.2 Gases vs. Particulates ............................................................................ 29 4.2.3 Design Criteria for System Components ................................................. 31 4.2.4 Alarm Levels .......................................................................................... 31 4.3 Point Source Emissions ..................................................................................... 31 4.3.1 Direct Effluent Sampling ......................................................................... 32

DOE-HDBK-1216-2015 iv 4.3.2 Direct Effluent Monitoring ....................................................................... 36 4.3.3 Specific Radionuclide Monitors ............................................................... 37 4.4 Diffuse Sources and Fugitive Emissions ............................................................ 42 4.4.1 Diffuse Sources ...................................................................................... 43 4.4.2 Diffuse Source Release Rates ................................................................ 43 4.4.3 Diffuse Source Assessment .................................................................... 45 4.5 Quality Assurance .............................................................................................. 45 5 METEOROLOGICAL MONITORING ............................................................................. 47 5.1 Key Requirements ............................................................................................. 48 5.2 Meteorological Monitoring Program Design ........................................................ 48 5.3 Meteorological Monitoring Program Models and Data ........................................ 49 5.4 Meteorological Data Requirements for Other Applications ................................. 53 5.5 Meteorological Data Requirements for Quantifying Turbulent Diffusion .............. 53 5.6 Criteria for Meteorological Measurements. ......................................................... 55 5.6.1 Criteria for Siting and Locating Meteorological Measurements ...............56 5.6.2 Instrument Mounting Criteria .................................................................. 57 5.6.3 Measurement Recording Systems Criteria ............................................. 58 5.7 Measurement System Accuracy Criteria ............................................................ 58 5.8 Inspection, Maintenance, Protection, and Calibration Criteria ............................ 59 5.9 Criteria Associated with Supplementary Meteorological Instrumentation ............ 60 5.10 Meteorological Data Processing Criteria ............................................................ 60 5.11 Data Summarization and Archiving Criteria. ....................................................... 61 5.12 QA and Documentation Criteria ......................................................................... 61 6 ENVIRONMENTAL SURVEILLANCE ............................................................................ 63 6.1 Key Requirements ............................................................................................. 63 6.2 Summary of General Criteria.............................................................................. 64 6.2.1 Evaluation of Need for Sampling ............................................................ 66 6.2.2 Emergency Monitoring Provisions .......................................................... 68 6.3 Performance Requirements for Environmental Surveillance Programs .............. 69 6.3.1 Specific Performance Requirements ...................................................... 69 6.3.2 Air Sampling System .............................................................................. 70 6.3.3 Consultation with Game Officials ............................................................ 70 6.3.4 Consultation with Local, State and Regional EPA Representatives ....... 70

6.4 Design Criteria ................................................................................................... 70 6.4.1 Environmental Surveillance Program Objectives .................................... 71 6.4.2 Program Planning and Design ................................................................ 72 6.5 External Exposure Monitoring ............................................................................ 73 6.5.1 External Exposure in Air ......................................................................... 73 6.5.2 External Exposure in Water .................................................................... 73 6.5.3 External Radiation Measurement Locations and Frequency ...................74 6.5.4 Factors in Selection of Indicator Locations ............................................. 75 6.5.5 Location of Background Measurement Stations ...................................... 75 6.5.6 Offsite Locations ..................................................................................... 75 6.5.7 Shoreline Locations ................................................................................ 76 6.5.8 Height and Frequency of Measurements ................................................ 76 6.6 Direct Radiation Measurement (Pressurized Ion Chamber-Type Instrumentation)76 6.6.1 Continuous Exposure Monitoring ............................................................ 76 6.6.2 Neutron Monitoring ................................................................................. 77 6.6.3 Instruments and Methods ....................................................................... 77 6.7 Air Measurements and Sampling ....................................................................... 78 6.7.1 Basis for Air Sampling ............................................................................ 78 DOE-HDBK-1216-2015 v 6.7.2 Sampling Locations ................................................................................ 80 6.7.3 Sampling Frequency............................................................................... 81 6.7.4 Sampling Methods and Criteria .............................................................. 82 6.7.5 Radioiodine ............................................................................................ 85 6.7.6 Tritium .................................................................................................... 85 6.8 Sampling of Terrestrial Foodstuffs...................................................................... 88 6.8.1 Possibility of Long-Term Buildup ............................................................ 89 6.8.2 Agricultural Products .............................................................................. 89 6.8.3 Game Animals ........................................................................................ 94 6.9 Basis for Sampling Soil ...................................................................................... 96 6.9.1 Soil Sampling Location and Frequency .................................................. 97 6.9.2 Soil Sampling Methods ........................................................................... 98

6.10 Water Sampling ................................................................................................. 98 6.10.1 Water Sampling Locations ...................................................................... 99 6.10.2 Surface Water ........................................................................................ 99 6.10.3 Storm Water Runoff .............................................................................. 101 6.10.4 Drinking Water...................................................................................... 103 6.10.5 Ground Water ....................................................................................... 104 6.10.6 Water Sampling Methods ..................................................................... 105 6.10.7 Settleable Solids in Effluent Discharge ................................................. 109 6.11 Basis for Sampling for Aquatic Foodstuffs ........................................................ 110 6.11.1 Freshwater Foods ................................................................................ 111 6.11.2 Marine Foods ....................................................................................... 114 6.12 Basis for Sampling Sediment ........................................................................... 114 6.12.1 Location and Frequency of Sediment Sampling .................................... 115 6.12.2 Sediment Sampling Methods ................................................................ 116 6.13 Quality Assurance ............................................................................................ 116 7 SAMPLE HANDLING, PREPARATION, AND ANALYSIS PROCEDURES .................. 117 7.1 Key Requirements and Supporting Documents ................................................ 117 7.2 Summary of Laboratory Procedure Requirements ........................................... 118 7.2.1 Documentation. ................................................................................... 118 7.2.2 Sample Identification System ............................................................... 118 7.2.3 Chain-of-Custody ................................................................................. 118 7.2.4 Screening of Samples .......................................................................... 119 7.2.5 Preventing Cross-Contamination .......................................................... 119 7.2.6 Sample Preservation ............................................................................ 119 7.2.7 Sample Packaging and Transportation ................................................. 120 7.2.8 Sample Handling .................................................................................. 120 7.2.9 Sample Preparation .............................................................................. 120 7.2.10 Instrumentation..................................................................................... 121 7.2.11 Laboratory Qualifiers ............................................................................ 122 7.3 Uncertainty....................................................................................................... 122 7.3.1 Estimation of the Measurement Uncertainty ......................................... 122 7.3.2 Significant Figures ................................................................................ 124

7.4 Analytical Procedures ...................................................................................... 125 7.4.1 Alpha and Beta Measurements ............................................................ 125 7.4.2 Gamma-Ray Spectroscopy................................................................... 126 7.4.3 Alpha Spectroscopy ............................................................................. 127 7.4.4 Liquid Scintillation Counting................................................................. 127 7.4.5 Elemental Analysis ............................................................................... 128 7.5 Quality Assurance ............................................................................................ 129 DOE-HDBK-1216-2015 vi 8 DATA ANALYSIS AND STATISTICAL TREATMENT .................................................. 131 8.1 Key Requirements and Supporting Documents ................................................ 132 8.2 Data Verification and Validation ....................................................................... 132 8.3 Preliminary Data Assessment .......................................................................... 134 8.3.1 Basic Statistical Quantities ................................................................... 134 8.3.2 Graphical Reviews ............................................................................... 135 8.3.3 Data Variability. .................................................................................... 135 8.4 Data Distribution Evaluation ............................................................................. 137 8.4.1 Measures of Central Tendency ............................................................. 137 8.4.2 Measures of Dispersion ........................................................................ 138 8.4.3 Distribution Analyses ............................................................................ 139 8.4.4 Testing for Outliers ............................................................................... 141 8.5 Statistical Analyses .......................................................................................... 142 8.5.1 Statistical Tests for the Presence of Radioactivity ................................ 143 8.5.2 Less-Than-Detectable Values .............................................................. 143 8.6 Draw Conclusions from the Data: Hypothesis Testing ...................................... 145 8.6.1 Parametric Tests .................................................................................. 148 8.6.2 Nonparametric Tests ............................................................................ 150 8.6.3 Regression and Trend Analysis ............................................................ 153 8.7 Computational Tools ........................................................................................ 155 8.7.1 Visual Sample Plan .............................................................................. 155 8.7.2 ProUCL Software ................................................................................. 155 8.8 Quality Assurance ............................................................................................ 156 8.8.1 Software Validation and Verification ..................................................... 156

9 DOSE CALCULATIONS .............................................................................................. 157 9.1 Key Requirements ........................................................................................... 157 9.2 Required Performance Standards for Public Dose Calculations ....................... 158 9.3 Documentation and Conformance with Other Requirements ............................ 158 9.4 Pathway Analysis Modeling ............................................................................. 159 9.5 Misuse of Models ............................................................................................. 160 9.6 Transport Models ............................................................................................. 161 9.6.1 Atmospheric Transport and Dispersion Models .................................... 161 9.6.2 Surface and Ground Water Transport Models ...................................... 162 9.7 Environmental Restoration ............................................................................... 163 9.8 Protection of Biota ............................................................................................ 165 9.9 Dose Coefficients ............................................................................................. 166 9.10 Quality Assurance ............................................................................................ 167 10 RECORDS, RETENTION AND REPORTING. ............................................................ 169 10.1 Key Requirements ........................................................................................... 169 10.2 Recordkeeping, Retention and Reporting Activities .......................................... 170 10.3 Quality Assurance ............................................................................................ 170 11 QUALITY ASSURANCE .............................................................................................. 171 11.1 Key Requirements and Supporting Documents ................................................ 171 11.2 QA Program Implementation ............................................................................ 172 11.2.1 Management ........................................................................................ 172 11.2.2 Performance ......................................................................................... 172 11.2.3 Assessment .......................................................................................... 173 12 REFERENCES ............................................................................................................ 175 APPENDIX A: Acronyms and Technical Definitions ................................................................. A-1 DOE-HDBK-1216-2015 vii APPENDIX B: Considerations for Self-Assessments of Environmental Monitoring and Surveillance Programs .................................................................................................. B-1 APPENDIX C: Radiological Control and Release of Game for Human Consumption .............. C-1 C.1.0 INTRODUCTION ............................................................................................... C-1 C.2.0 SCREENING CONCENTRATION GUIDELINES (SCG) FOR RELEASE OF GAME FOR POSSIBLE HUMAN CONSUMPTION .......................................... C-6 C.3.0 REFERENCES ................................................................................................ C-10

DOE-HDBK-1216-2015 viii Table of Figures FIGURE 2-1. Potential Radiation Exposure Pathways to Man .................................................... 6 FIGURE 2-2. Potential Radiation Exposure Pathways to Biota ................................................... 7 FIGURE 7-1: Example of reporting significant figures (MARLAP) ........................................... 125 FIGURE 8-1: Example of Test of Normality for Arco Gross Beta Data (INL 2005) .................. 140 FIGURE 8-2: Example of Test of Lognormality for Arco Gross Beta (INL 2005) ..................... 141 FIGURE 9-1: Pathways Considered in the RESRAD Family of Codes ................................... 164 Table of Tables TABLE 3-1. Recommended Criteria for Liquid Radiological Effluent Monitoring .......................13 TABLE 4-1. Emission Point Criteria for Airborne Radiological Effluent Sampling and/or Monitoring .........................................................................................................................30 TABLE 4-2. Collection Methods for Specific Radioactive Effluent ............................................. 35 TABLE 4-3. Examples of Diffuse and Fugitive Sources at DOE Sites ....................................... 43 TABLE 5-1. Key to Pasquill Stability Categories ....................................................................... 55 TABLE 5-2. Standards of Accuracy of Meteorological Criteria .................................................. 59 TABLE 6-1: Minimum Criteria for Determining Need for Environmental Surveillance................ 65 TABLE 6-2: Minimum Air Sample Collections and Analyses to Be Performed as a Function of Estimated Total Effective Dose (TED) to the Maximally Exposed Individual (MEI) or Representative Person, as Determined from Gaseous Effluent Releases ......................... 84 TABLE 6-3: Global fallout activity relative to Pu-239, Pu-240 ................................................. 103 TABLE 7-1: Common Matrix-Specific Analytical Planning Issues ........................................... 123 TABLE 8-1: Variability in Effluent Monitoring Data (adapted from DOE 1981) ........................ 136 TABLE 8-2: Guidelines for Managing Non-detects (adapted from EPA 2000d) ...................... 145 TABLE 8-3: Examples of Statistical Tests for Multiple Hypothesis Goals (ORAU 2013) ......... 147 TABLE 9-1: Potential Pathways to Be Considered in Environmental Pathway Analyses ........ 160 TABLE C-1: Radionuclide Screening Concentration Guidelines(SCG) That Yield a 25 mrem TED for a Meat Intake of 100 Kg/year............................................................................... C-8 DOE-HDBK-1216-2015 ix FOREWORD Effluent monitoring and environmental surveillance of radioactive materials are a continuing major part of the radiological protection programs at Department of Energy (DOE) sites. The purpose of this Handbook is to identify procedures, systems, methods, instruments and practices that may be used to plan and implement radiological effluent monitoring and environmental surveillance that meet the requirements in DOE Order (O) 458.1, Radiation Protection of the Public and the Environment. Effluent monitoring and environmental surveillance activities, like other DOE activities, present risks and hazards that need to be considered in planning the work. The focus of this document is on the sampling, monitoring and analysis activities and although not addressed in detail in this Handbook, appropriate job hazard

analyses are necessary to ensure worker safety. DOE-HDBK-1216-2015 x INTENTIONALLY BLANK DOE-HDBK-1216-2015 1 1 INTRODUCTION The Department of Energy’s (DOE) environmental and public radiation protection framework is principally contained in DOE Order (O) 458.1, Radiation Protection of the Public and the Environment. This Handbook describes elements that may be used to implement the radiological effluent monitoring and environmental surveillance requirements in DOE O 458.1. The Handbook can be used by all DOE elements, including the National Nuclear Security Administration (NNSA), and their contractors to support implementation of DOE O 458.1. The information in this Handbook may also be useful in developing plans and programs for other DOE activities that require monitoring to comply with requirements. Many of the principles described herein may also be of use in designing the non-radiological portions of an integrated environmental monitoring or environmental surveillance program. This Handbook is not a “requirements” document and may not be considered as requirements in any audit or assessment of compliance with associated Policy, Order, Notice, or Manual. This Handbook updates information contained in Environmental Regulatory Guide for Radiological Effluent Monitoring and Environmental Surveillance (DOE/EH-0173T, 1991). 1.1 Objectives The objectives of this Handbook are to: • Assist DOE elements in establishing and maintaining effective environmental monitoring activities: to measure radionuclide releases for DOE activities; characterize the radiological condition of the environs on and around DOE activities; and support assessment of potential public exposure through available pathways (e.g., air, water, soil, and biota); • Provide information on appropriate methods for sampling and analyzing effluent and environmental media for radionuclides of interest; and • Present information on appropriate methods for performing data assessments and statistical analyses. 1.2 Environmental Monitoring Environmental monitoring is the collection and analysis of samples or direct measurements of environmental media. For the purposes of DOE O 458.1, “Environmental Monitoring” includes, but is not limited to effluent monitoring, environmental surveillance, meteorological monitoring, and pre-operational monitoring. DOE-HDBK-1216-2015 2 Environmental monitoring is a necessary part of characterizing routine and non-routine releases of radioactive materials from DOE operations, evaluating the distribution of the releases to the environs, and determining the potential pathways of exposure to members of the public to demonstrate compliance with the public dose limit cited in DOE O 458.1. Effluent and environmental monitoring should start prior to the commencement of site or facility operations and continues for the entire operational phase. Sampling and analyses of effluent releases and environmental pathways are performed on a periodic basis (e.g., weekly, monthly, quarterly, annually) or when additional information is necessary to verify compliance. Therefore, temporal and spatial variations in the concentrations of the analyte(s) of interest are important to evaluate potential effects on environmental pathways, and the eventual dose to members to the public. Environmental monitoring should be commensurate with the radiological activities at the site and adapted to unique physical, geological, hydrological, and meteorological characteristics.

Environmental monitoring should include: sampling points located on prioritized areas of the site that are particularly susceptible to contamination and represent the contaminant pathway into the environment; sample collection that reflects specific facility needs (type and frequency of sampling); sample analysis protocols that are approved by appropriate regulatory agencies; monitoring data recordkeeping; and data assessment and quality assurance mechanisms to demonstrate the validity of the data. The overall objective of environmental monitoring is to demonstrate that discharges are at safe planned levels, identify trends and anomalies, and provide early detection of unplanned releases to the environment. In the event of an unplanned release, environmental monitoring is designed to trigger a response according to the site contingency plan and to provide sufficient data to characterize the release. 1.3 Key Requirements and Supporting Documents DOE O 458.1, Radiation Protection of the Public and the Environment, contains requirements for protecting the public and the environment by establishment of the Public Dose Limit. One way DOE sites can demonstrate compliance with the Public Dose Limit is through environmental monitoring. DOE O 458.1 requires that environmental monitoring be conducted to: (1) characterize routine and non-routine releases of radioactive material from radiological activities; (2) estimate the dispersal pattern in the environs; (3) characterize the pathway(s) of exposure to members of the public; and (4) estimate the doses to individuals and populations in DOE-HDBK-1216-2015 3 the vicinity of the site or operation commensurate with the nature of the DOE radiological activities and the risk to the public and the environment. Site-specific environmental monitoring criteria need to be established to ensure that representative measurements of quantities and concentrations of radiological contaminants are conducted and that the effects from DOE radiological activities on members of the public and the environment are monitored sufficiently to demonstrate compliance. DOE O 458.1 also requires that DOE sites perform dose evaluations to demonstrate compliance with the public dose limit and to assess collective dose. DOE O 231.1B, Environment, Safety and Health Reporting, requires that annual site environmental reports include information on: (1) effluent releases; (2) environmental monitoring; (3) types and quantities of radioactive materials emitted or discharged; (4) total effective dose and collective dose; (5) where it is of concern, radon and its decay products; and (6) property clearance activities. DOE O 232.2, Occurrence Reporting and Processing of Operations Information, includes reporting criteria pertinent to DOE O 458.1 for the following: releases of radionuclides from a DOE facility; spread of radioactive contamination; and radiation exposure. DOE-STD-1196-2021, Derived Concentration Technical Standard, supports the implementation of DOE O 458.1 and supersedes the Derived Concentration Guides for Air and Water contained in DOE Order 5400.5. DOE-STD-1196-2021 establishes Derived Concentration Standards (DCS) values that reflect the current state of knowledge and practice in radiation protection. DOE-STD-1153-2019, A Graded Approach for Evaluating Radiation Doses to Aquatic and Terrestrial Biota, provides practical screening and analysis methods that can be used to

demonstrate compliance with the DOE O 458.1 requirements for protection of biota. DOE-HDBK-1216-2015 4 INTENTIONALLY BLANK DOE-HDBK-1216-2015 5 2 DESIGNING, REVIEWING, AND DOCUMENTING RADIOLOGICAL ENVIRONMENTAL MONITORING PROGRAMS The impact on the surrounding environment (i.e., on-site and off-site) is measured, documented, evaluated and responded to in environmental monitoring programs. Appendix B of this Handbook identifies lines of inquiry. A lines of inquiry approach is provided to: conduct self- assessments; verify that the program is effective and in compliance with appropriate requirements; and ensure the existence of continuous improvement of the program. 2.1 Designing an Environmental Monitoring Program According to DOE O 458.1, DOE or DOE contractors conducting radiological activities must develop and implement a documented Environmental Radiological Protection Program (ERPP). The ERPP is a composite of plans, procedures, protocols, and other documents describing the methods used to achieve compliance with DOE O 458.1. The environmental monitoring program should be flexible and use a graded approach for monitoring activities. A graded approach allows the degree of planning, the scope of programs, and the level of detail in documentation to be tailored to the particular radiological activities at a site and to be commensurate with the risk to the public and the environment associated with DOE operations. The graded approach allows the environmental monitoring program to be modified as necessary to include newly identified potential pathways of exposure. Additionally, the graded approach may provide flexibility for excluding pathways of exposures not present or considered to be an insignificant contributor at a site. A comprehensive environmental monitoring program includes mechanisms to assess the impact to the site and the environs. The comparison reference for assessing environmental impact is obtained during the pre-operational phase. In general, the environmental monitoring program should: (1) demonstrate compliance with applicable requirements; (2) confirm adherence to DOE environmental and radiation protection policies and directives, and (3) support of environmental management decisions. Other specific objectives of the environmental monitoring program include, but are not limited to: • Collecting data for characterizing the pre-operational radiological condition of the site; • Determining background levels and site contributions of radionuclides in the environment; DOE-HDBK-1216-2015 6 • Supporting the assessment of radiological doses to the public and biota from DOE operations; • Providing data to support preparation of an annual site environmental report (ASER); • Identifying and reporting alarm levels and potential doses exceeding DOE reporting limits; • Determining long-term accumulation of site-related radionuclides in the environment and predicting trends; • Determining the effectiveness of treatment and controls in reducing effluents and emissions; • Determining the validity and effectiveness of models used to predict the concentration of radionuclides and their movement in the environment; • Detecting and quantifying unplanned releases; • Evaluating the effectiveness of remedial actions; • Evaluating and quantifying radionuclide transport into the environment; and • Identifying and quantifying existing or new environmental quality concerns.

FIGURE 2-1. Potential Radiation Exposure Pathways to Man DOE-HDBK-1216-2015 7 FIGURE 2-2. Potential Radiation Exposure Pathways to Biota The gaseous and liquid effluent monitoring activities for all media may be included in a site’s environmental monitoring plan or in other appropriate documentation. Some sites develop independent facility effluent monitoring plans. The determination to develop independent effluent monitoring plans is based on an initial evaluation of potential radioactive material sources within a facility. If a significant quantity of releasable radioactive material is present in a specific location, then a plan may be prepared for that facility. The effluent monitoring plan should include radiological material inventories; discussions on source-term identification and characterization for each effluent stream; identification and characterization of fugitive sources (if applicable); release pathways; and effluent points of discharge. Facility-specific effluent monitoring plans are focused on the “major” sources of effluents located on the site which are sources that, if uncontrolled, may release radionuclides sufficient to cause a dose of 1 percent of the 10 mrem in a year air pathway dose limit (40 CFR Part 61). Therefore, effluent monitoring plans should be prepared for any facility having the potential to release quantities of airborne radioactive materials that could cause a total effective dose in excess of 0.1 millirem (mrem) per year to the maximally exposed individual (MEI). DOE-HDBK-1216-2015 8 The environmental monitoring program should be designed to allow the identification of major releases or migration of radionuclides, pathways of exposure, sampling locations, and data trends over time. Samples should be collected and analyzed from areas near the operational activities and effluent release points; areas within the site boundary where radioactive material may accumulate due to air or water dispersion; and areas beyond the site boundary where members of the public may be exposed to radioactive materials. Environmental monitoring includes monitoring ground water, water impoundments, runoff water, soil, sediment, food, and biota sources that potentially may be affected by site operations. The sampling frequency for environmental media and the mechanisms used to determine compliance with the public dose limits should be described in the environmental monitoring program. Statistical analyses may be performed to identify abnormalities or changes over time. These analyses may lead to the collection of additional samples or remediation activities. 2.2 Reviewing the Environmental Monitoring Program As part of the environmental monitoring program maintenance, a radiological pathway analysis and exposure assessment should be performed at a periodic frequency determined by the level of significance of the potential effluents and how often there are changes in the program or mission(s) of the site. The pathway analysis should be based on source term data and on the comprehensive pathway and dose assessment methodology used for estimating radiation doses to the public and the environment from site operations. The results of the pathway analysis and exposure assessment should serve as a basis for future years’ environmental monitoring program design. Environmental and food-chain pathways are monitored near facilities releasing effluents and at potential offsite receptor locations. Figure 2-1 and Figure 2-2

illustrate the identification of potential pathways of radiation exposure to humans and biota, respectively. The design of the environmental monitoring program should be reviewed periodically along with planned waste management and environmental restoration activities, including decontamination and decommissioning (D&D) activities. The need for changes in the effluent monitoring program or surveillance monitoring should be evaluated continuously in response to changes in operations, environmental conditions and/or land use. Input from local residents, including Native American tribes and other stakeholders, needs to be considered in the final monitoring program design. The final sampling design and schedule should be documented and updated periodically as necessary. DOE-HDBK-1216-2015 9 2.3 Updating the Environmental Monitoring Program As the needs and requirements of the environmental monitoring program change, the design of the program has to change. Site-specific information on radiation source dispersion patterns, location and demography of members of the public in the vicinity of DOE radiological activities, land use, food supplies, and exposure pathway information should be updated, as necessary, to document significant changes that could affect dose evaluations. Site organization representatives should discuss proposed updates of the environmental monitoring program. Updates should consider the input of personnel from environmental monitoring, radiation protection, operations, planning and scheduling, budget, site strategy, security, laboratory analyses, and any other organization that could contribute information on proposed site activities during the next 1 to 5 years. The environmental monitoring program updates should also consider the potential impact on the overall site budget. The shifting and sharing of resources (e.g., equipment and personnel) may be part of the planning and necessary to maintain the adequacy of the environmental monitoring program. DOE-HDBK-1216-2015 10 INTENTIONALLY BLANK DOE-HDBK-1216-2015 11 3 LIQUID RADIOLOGICAL EFFLUENT MONITORING AND SAMPLING Liquid radiological effluent monitoring and sampling is performed as part of the overall environmental monitoring for a site. This can be accomplished using either monitoring or sampling systems or a combination of both. In the context of this chapter of the Handbook, “monitoring” is active, essentially real-time monitoring using a detection system to characterize the liquid effluent. “Sampling” is the collection of samples from the effluent for analysis by a laboratory; additionally, screening can be performed in the field with less sensitive instrumentation. All liquid effluents from DOE facilities should be evaluated and their potential for release of radionuclides assessed. Liquid effluents from DOE facilities that have the potential for radioactive discharges should be monitored in accordance with DOE O 458.1. Monitoring results should be documented (e.g., in the ASER, monitoring reports, etc.). The liquid radiological effluent monitoring program should be integrated with monitoring for non- radiological effluents and environmental surveillance when possible. As necessary, the following elements should be documented for all liquid effluent monitoring programs: • Sampling locations used for providing quantitative effluent release data for each outfall; • Procedures and equipment used to perform the extraction and measurement;

• Frequency and analyses required for each extraction (continuous monitoring and/or sampling location); • Minimal detectable activity (MDA) and uncertainty for equipment used for measurements; • Quality Assurance (QA) components; and • Effluent outfall alarm settings and technical bases. Appendix B of this Handbook identifies lines of inquiry. A lines of inquiry approach is provided to conduct self-assessments; to verify that the program is effective and in compliance with appropriate requirements; and to ensure the existence of continuous improvement of the program. DOE-HDBK-1216-2015 12 3.1 Key Requirements DOE O 458.1, Radiation Protection of the Public and the Environment, establishes requirements for control and management of radionuclides from DOE activities in liquid discharges (see DOE O 458.1, paragraphs 4.g (1) - (11)). Operators of DOE facilities discharging or releasing liquids are required to characterize planned and unplanned releases of liquids containing radionuclides from DOE activities, consistent with the potential for on- and off-site impacts, and provide an assessment of radiological consequences as necessary to demonstrate compliance with the requirements of the Order. 3.2 Summary of General Criteria and Monitoring Program Needs for Liquid Effluents Operators of DOE facilities should provide monitoring of liquid effluents to: (1) demonstrate compliance with the applicable requirements of DOE O 458.1; (2) quantify radionuclides released from each discharge point; and (3) alert affected personnel of accidents/malfunctions/ disruptions in processes and emission controls. Criteria in Table 3-1 can be used to guide development of the liquid radiological effluent monitoring program at the site. Continuous radionuclide monitoring should be provided within the effluent stream to estimate radionuclide discharges at release points that could contain radionuclides in concentrations that are a significant fraction of, or exceed, the Derived Concentration Standard (DCS) (averaged over one year) (See Table 3-1). The recommendations in Table 3-1 are generally applicable to process streams but may not be appropriate for intermittent or low-flow streams where potential for exposure is low; in such cases, alternatives such as periodic grab sampling may be appropriate irrespective of the concentration. For non-routine releases, continuous monitoring should be considered when unplanned or unanticipated releases to the environment could cause the effluent stream annual average concentration to exceed the DCS and could produce Tritium in liquid effluents is a potential issue for some DOE sites. DOE recognizes there is no practical treatment method for removal of low concentrations of tritium, and that it is difficult to detect at low concentrations with a continuous monitoring system. It is necessary, however, that process alternatives be reviewed to ensure that tritium releases are ALARA. Tritium in liquid effluent streams represents an important exemption to the DOE BAT selection process. DOE-HDBK-1216-2015 13 potential doses to a likely receptor from the uncontrolled releases that exceed 100 mrem or a significant fraction thereof. TABLE 3-1. Recommended Criteria for Liquid Radiological Effluent Monitoring Derived Concentration Standards (DCS) Sum-of-fractions And Potential Annual Dose from Exposure to a Likely Receptor (mrem) Minimum Criteria for Liquid Radiological Effluent Monitoring

≥ 1 -- 1. Apply BAT to reduce effluent releases (except 3H) 2. Use continuous monitoring/sampling, but where effluent streams are low flow and potential public dose is very low, (<<1 mrem in a year) alternative sampling approaches may be appropriate. ≥ 0.01 to 1 >1 1. Continuously monitor or sample 2. Identify radionuclides contributing ≥ 10 percent of the dose 3. Determine accuracy of results (± percent accuracy and percent confidence level) ≥ 0.001 to 0.01 < 1 1. Monitor using a graded approach to select the appropriate method and duration 2. Identify radionuclides contributing ≥ 10 percent or more of the dose 3. Assess annually the facility inventory and potential for radiological effluent release < 0.001 -- 1. No monitoring required 2. Evaluate annually the potential for liquid radiological effluent release Continuous sampling (with frequent analysis) may be used in lieu of continuous monitoring if radioactive materials in the effluents are not detectable by state-of-the-art continuous monitoring devices. The monitoring efforts for liquid effluents should be commensurate with the release potential of the sources during routine operations and with the impacts of potential accidents on the potential contribution to public dose or to the contamination of the environment. When continuous monitoring or continuous sampling is provided, the overall accuracy of the results should be determined (± % accuracy and the % confidence level) and documented. DOE-HDBK-1216-2015 14 The detection limits of the continuous monitoring system (e.g., lower limit of detection (LLD), minimum detectable activity (MDA) or minimum detectable concentration (MDC)) should be stated in the Environmental Monitoring Plan or equivalent environmental monitoring documentation. The LLD and the associated MDC or MDA should be sufficient to ensure that analyses necessary to comply with the reporting requirements of DOE O 458.1 can be completed. Additionally, provisions for monitoring liquid effluents during an emergency should be considered when determining routine liquid effluent monitoring program needs. Emergency liquid effluent monitoring systems and procedures should be specified in the site/facility Emergency Response Plan. 3.3 Performance Standards for Liquid Effluent Monitoring Systems The selection or modification of a liquid effluent monitoring and sampling systems should be based on a careful characterization of: (1) the sources, (2) contaminants (characteristics and quantities); (3) sample-collection systems (if applicable); (4) treatment systems; and (5) final release points of the effluents. Pre-operational assessments should be conducted and documented for all new or modified facilities where liquid effluent and monitoring or sampling system characteristics could be affected. These assessments should document the types and quantities of liquid effluents expected from the facility and establish the associated effluent monitoring needs of the facility. The actual or potential presence of radionuclides and chemical and physical properties that could affect performance of the sampling or monitoring equipment should be identified. The performance of the effluent monitoring systems should be sufficient to determine whether effluent releases of radioactive material are within the values contained in DOE-STD-1196- 2021, and to calculate doses that will demonstrate compliance with DOE O 458.1 limits and

constraints. LLDs of the analysis and associated MDCs or MDAs for the monitoring systems should be sufficient to demonstrate compliance with all applicable requirements consistent with the characteristics of the radionuclides that are present or expected to be present in the liquid effluent. DOE-HDBK-1216-2015 15 3.3.1 Continuous Monitoring/Sampling For those effluent streams requiring continuous monitoring/sampling, all data received from the continuous monitoring system should be used when performing statistical analyses. In the case of discharge points releasing radionuclides emitting alpha or weak beta radiation, with no documentable ratios to beta and/or gamma emitters that could be used as indicator radionuclides (i.e., where it is not technologically feasible to monitor continuously), continuous proportional sampling and analysis can be used as an alternative to continuous monitoring. However, the consideration of new technologies to continuously monitor such effluent streams is encouraged. 3.3.2 Sampling Systems Sampling systems should be sufficient to: (1) collect representative samples that provide for an adequate record or timeline of facility releases; (2) predict trends; and (3) quantify releases. 3.3.3 System Calibration Continuous monitoring and sampling systems should be calibrated before use and recalibrated any time they are subject to maintenance, modification, or system changes that could affect equipment calibration. Monitoring and sampling systems should be recalibrated at least annually and routinely checked with known sources to determine that they are consistently functioning properly. Proper functioning of the monitoring or sampling system should be verified before a facility is placed in operation. A redundant monitoring system may be used if necessary to provide adequate sampling capabilities and prevent delays in process operation. Alternatively, one of the following options could be used to permit continued monitoring during replacement or servicing of the system: (1) a substitute sampling method that provides the capabilities, or (2) an alternate method for estimating releases when the system is not capable of operating. 3.3.4 Environmental Conditions Environmental conditions (e.g., temperature, humidity, radiation level, dusts, and vapors) should be considered when locating liquid effluent monitoring and sampling systems to avoid conditions that could influence the operation of the system, including unusual operational impacts. At sample collection points, the ambient dose rate originating in the effluent line and the sampling apparatus should be evaluated for compliance with shielding and contamination control DOE-HDBK-1216-2015 16 requirements necessary to reduce worker exposure. Components of the sampling system should be replaced if they become contaminated (to the point where the sensitivity or reliability of the system is affected) with radioactive materials or if they become ineffective in meeting the design basis within the established accuracy/confidence levels. 3.4 Sampling System Design Criteria Reliable quantification of radionuclides in liquid effluent streams requires representative sampling, which in turn requires: (1) consideration of stream flow rate and variability; (2) sample port and collector design; (3) delivery system reliability; (4) effluent stream chemical and biological characteristics; and (5) the need for sample preservation.

3.4.1 Selection Criteria for Liquid Effluent Monitoring and Sampling Systems Detection of radionuclides in liquid effluents can be performed using either: (1) continuous monitoring systems, or (2) sampling systems. Selecting and designing an appropriate monitoring or sampling system for a facility should include consideration of the purpose, types and levels of expected radionuclides in the effluent, potential background dose rates, expected duration of releases, and environmental effects of the expected radionuclides. Continuous monitoring systems can either be in-line, where a radiation detector is placed in the effluent stream, or off-line, where a portion of the effluent is extracted and run by the detector. Continuous monitoring systems generally are limited to direct detection of gamma-emitting radionuclides with sufficient gamma energy to penetrate the effluent stream and reach the detector. Gross beta measurement may be possible using thin, plastic scintillator detectors. The ambient external dose rate from the effluent stream should be considered. Moderate dose rates may require system shielding, while high dose rates may prevent use of an in-line system and require use of a remote, shielded off-line monitor. NCRP (2010) identifies currently available types of in-line monitoring equipment. If the primary purpose of the monitoring system is to alert operating personnel to significant unplanned increases in gamma-emitting radionuclides in the liquid effluent, then in-line monitoring may be preferred. A combination of in-line and off-line monitoring may be needed to accommodate both routine and emergency monitoring. An off-line continuous monitoring One of the main reasons to use a continuous monitoring system is its ability to provide a prompt signal if a significant release occurs. DOE-HDBK-1216-2015 17 system requires consideration of some of the same criteria used for sampling systems because of the extraction (sampling) of a portion of the effluent stream for monitoring. If there are well-known and documented ratios of strong gamma-emitters to weak beta-gamma or alpha-emitting radionuclides then continuous monitoring systems can be used to indirectly detect these radionuclides. Follow-up sampling and associated radioanalysis should be conducted to verify and document the radionuclide release. Sampling systems can be used to quantify beta and alpha-emitting radionuclides as well as strong and weak gamma-emitters. Sampling and analysis takes longer than monitoring but provides LLDs and more definitive and quantitative information. There are four basic types of liquid effluent sampling systems: • Continuous sampling – samples are collected continuously at a known, uniform rate; appropriate for taking samples at a constant rate from effluents that have near constant flow (i.e., flow that does not vary by more than 50 percent). • Flow proportional sampling – a known fraction of the effluent is collected at defined volume intervals for laboratory analysis; appropriate for obtaining representative samples from streams with fluctuating flow rates or radionuclide concentrations. • Time proportional sampling – used when a stream flow rate is relatively constant so that effluent streams are sampled by taking timed aliquots, which are analyzed in the laboratory; suitable for quantifying uniformly low concentrations of radionuclides being released via effluent lines to the environs.

• Periodic (grab) sampling – samples of effluent streams are taken periodically, composited if desired, and submitted for laboratory analysis; suitable for ensuring that previously determined release rates have not changed significantly or that radionuclides are not being introduced into the previously non-radioactive liquid effluent being sampled. 3.4.2 General Design Criteria for Sampling Systems The following should be considered when operating a liquid effluent sampling system: • Location of sampling and monitoring systems; • Use of a pump in areas where necessary to provide a uniform continuous flow in the main sample line; DOE-HDBK-1216-2015 18 • Location of sample ports in liquid effluent lines sufficiently far downstream from the last feeder line to allow complete mixing (as complete as possible) of liquid and design of the sample port to allow intake of a proportional part of the liquid effluent stream; • Capability to determine the effluent stream and sample-line flows within an accuracy of at least ±10 percent; and • Design of the system to minimize deformation and sedimentation and to prevent freezing of effluent sample lines. 3.4.3 Stream Flow Characteristics Variability in the flow rate of liquid effluents may be the most significant factor in sample calculations. Therefore, continuous measurement and recording of effluent flow rate should be performed. If continuous monitoring or determination of the effluent flow rate is directed by the criteria in Table 3-1 but is not feasible for a specific effluent stream, the extenuating circumstances and justification for not doing it should be documented. Liquid effluent flow rates should be measured with an uncertainty of no more than 10 percent and recorded. A variety of measuring devices are available for measuring flow rates, such as V-notch weirs or ultrasonic or turbine flow meters. Very little accuracy is gained from using flow proportional sampling systems where effluent streams having near constant continuous flow. Continuous constant rate sampling (sampling continuously over regular time intervals) is more reliable and simpler. Thus, time proportional (rather than flow proportional) sampling is recommended for near constant, continuous flow effluent streams (i.e., flow that does not vary by more than 50 percent). Constant rate sampling may also be used for intermittent effluent streams when during the time the streams flow the discharge rate is constant and known. 3.4.4 Sampling Locations The sampling ports should be located in accessible sections of the liquid effluent lines sufficiently far enough downstream from the last feeder line to allow liquid mixing to be as complete as possible. When appropriate, design sample ports to allow proportional effluent sampling. If proportionality cannot be automated, both the effluent and sample flow rates should be measured, with the capability to determine the effluent stream and sample-line flows within an uncertainty of no more than ± 10 percent. DOE-HDBK-1216-2015 19 3.4.5 Delivery Lines For buried pipe or pressurized lines, maintain the integrity of the junction of the liquid effluent sample line with the sampling port by considering expansion and contraction of the liquid effluent lines due to thermal loading variation. Design for such a junction should consider either line scrubbers or special fabrications to handle the added mechanical stress. 3.4.6 Liquid Movers

A constant volume sampling pump should be used to maintain a uniform continuous flow in the main sample line, unless sufficiently high and constant hydraulic pressure exists within the effluent system. Removal of the sample from the liquid effluent line where a sampling pump is required should be accomplished using a constant-volume pump that will maintain a constant flow, regardless of line pressure changes. 3.4.7 Sample Collectors The collector portion of the sampling system should be designed to allow for the collection of a sample that is consistent with the method of analysis. For example, if the effluent stream has a small flow, a small container might be used to obtain a grab sample that is counted directly in the laboratory. If concentration of the sample is necessary, a large volume sample is required. If the collection system requires measured aliquots taken sequentially every few minutes, then both the frequency and required sensitivity of analysis have an impact on the size of the container to be used. The return sample line (after the sample collection) should be routed back to either the effluent line or a waste treatment system. Location of the sample collection system can be based in part on the sample return line. 3.4.8 Special Considerations for Liquid Effluent Monitoring and Sampling Systems The following special conditions should be considered when designing and operating a liquid effluent monitoring or sampling system for a DOE facility: • Effluent lines are frequently buried in soil, which creates accessibility problems for monitoring and sampling unless special provisions are considered in the discharge system design; • Effluent monitoring and sampling system lines and components should be designed to be compatible with the chemical and biological nature of the liquid effluent; DOE-HDBK-1216-2015 20 • Biological growths can cause sample line flow restrictions. Biological growth around or within a sampling/monitoring system can plug or distort sampling orifices and equipment. If biocides are used, they should be selected and applied so as not to interfere with the sampling and analytical processes; • Effluent lines often move or are stressed mechanically; • The system should be designed to minimize deformation and sedimentation and to prevent freezing of the sample lines. For example: - Sampling heads can be placed above the streambed where sedimentation issues are less problematic, and - Sampling heads with strainers may further reduce problems; • Large fluctuations in effluent flow rates are common, especially during a rain storm incident or flood which in turn affect the accuracy of the measurement results; • Sample collection may require extra precautions (e.g., pre-coating sample containers); • Effluent velocity and corrosion can significantly affect in-line sampling or monitoring probes; • Effluent monitoring systems and procedures should be designed to identify and quantify the full range of potential accidental releases as well as those from normal operating conditions; • Small volume wastes are easier to collect in batch tanks, lending themselves to grab sampling and analysis before release. When batch tanks are used for collecting liquid effluents before release to the environment, these factors should be considered: - Adequate mixing of the sampled volume to ensure that liquids in the tank are homogeneous for sample withdrawal; - Recirculation of tank liquid through the sample lines so that he sample is

representative; and - Frequent checks for residual liquid or sludge accumulation as needed; and • Components of the monitoring system should be readily accessible for maintenance. 3.4.9 Environmental Considerations The external environment surrounding the sampling system and effluent lines needs to be considered. The sampling system should be protected from adverse environmental factors including unusual operational impacts. At sample collection points, the ambient dose rate originating in the effluent line(s) and the sampling apparatus should be evaluated for compliance DOE-HDBK-1216-2015 21 with shielding and contamination control requirements necessary for reducing worker exposure. Components of the sampling system should be readily accessible for maintenance. 3.5 Monitoring System Design Considerations Design considerations for liquid effluent monitoring systems should include the purpose of the monitoring, the types and levels of expected radionuclides, potential background dose rates, expected duration of releases, and environmental effects. One of the primary purposes of using a monitoring system is to utilize its ability to provide a prompt signal if a significant release occurs. Therefore, responsible personnel should continuously monitor the output signal from monitoring systems. In addition, written response procedures should be provided to describe the actions that responsible personnel need to take if an abnormal signal is detected. The output signal instrumentation, monitoring system recorders, and alarms should be in a location that is continuously monitored or occupied by operations or security personnel. 3.5.1 Monitoring Purposes An unshielded in-line monitoring system should be sufficient to quantify the gamma-emitting radionuclides in the liquid effluent line, if low ambient dose-rate conditions exist. For moderate ambient dose rates, in-line monitoring may be sufficient, but shielding should be employed. For high ambient dose conditions (i.e., those above which shielding is no longer a practical solution to controlling the ambient background influence), off-line monitoring should be used. If the primary purpose of the monitoring system is to alert operating staff to significant unplanned increases in gamma-emitting radionuclides within the liquid effluent line, in-line monitoring may be preferred. A combination of in-line and off-line monitoring may be necessary to accommodate both routine and emergency monitoring. 3.5.2 General Design Criteria The following general design criteria should be considered in the design and operation of routine liquid effluent monitoring systems: 1) If off-line monitoring is used: a. Use adequate shielding for detector operation and to maintain personnel exposure as low as reasonably achievable (ALARA); b. Locate alarm annunciators in normally occupied locations and use stable electric power sources to provide uniform voltage to the monitor and alarm systems; and DOE-HDBK-1216-2015 22 c. Use a predefined alarm level that is above normal variations in release levels. The alarm should provide timely warning of the potential to exceed administrative levels designed to keep releases ALARA and of the potential to exceed established concentration guides or limits. 2) If in-line monitoring is used: a. Use the criteria for off-line monitoring, and b. Computer software programs should provide rapid readout of radionuclide release

rates. Alternatively, develop conversion factors or interpretive curves (primarily for ion chamber and Geiger-Muller (GM) tube monitors) that allow quick conversion of dose rates or count rates to radionuclide release rates (e.g., microcuries per minute (µCi/min)), such that both concentrations of and curies released by the pertinent radionuclides can be estimated. Maintain these methods as a back-up method in case of computer failure. 3.5.3 Batch Release Release duration is a factor in selecting a monitoring or sampling system. If the release is not continuous, the effluent is considered a “batch” release. Before a batch is released, a representative grab sample should be drawn from the batch and analyzed to determine if release criteria are met. 3.5.4 Types of Radiation In liquid effluent streams, direct measurement is only possible with gamma-emitters or by making gross beta-gamma measurements. In situ alpha measurement is not feasible (at this time) with existing technology. Exceptions may exist when coincident gamma radiation is involved with alpha emissions. Gross beta measurement is possible using thin, plastic scintillators. It should be demonstrated that the chosen detector has the necessary sensitivity. Sampling and analysis should be used to quantify release of alpha emitters and some beta emitters (i.e., those that cannot be adequately measured using detectors). 3.5.5 High Background Even though some shielding is provided by the liquid contents themselves, direct or indirect measurements in areas with high ambient radiation levels require shielding or off-line analysis. Even with shielding, the low-energy gamma spectrum may be biased when using in situ monitoring in locations of relatively high background dose rates, depending on the DOE-HDBK-1216-2015 23 radionuclide(s) being measured and the composition of the background. A high background can interfere with the measurement of low dose rates from the radionuclides. Consequently, when designing installations for locations that are expected to have relatively high radiation dose rates, off-line monitoring should be used. 3.6 Environmental Effects Environmental conditions can play a key role in the efficient design of a monitoring or sampling system. Air conditioning for hot locations and heating for cold locations should be considered to provide reliable system operation, particularly for systems using electronic components. The system should be designed and located so that the ambient dose rates will permit access for system calibration and servicing, and reduce worker exposure consistent with the ALARA process. Shielding may be required to control worker exposure during calibration and servicing. 3.7 Alarm Levels To signal the need for corrective actions that may be necessary to prevent public or environmental exposures from exceeding the requirements of DOE O 458.1, when continuous monitoring systems are required, they should have alarms set to provide timely warnings. To prevent the cumulative impacts of small releases from producing a significant impact, routine grab, continuous or proportional samples should be collected often enough to detect radionuclides of interest including those with relatively short half-lives. 3.8 Operational Considerations for All Monitoring and Sampling Systems Procedures to address the full range of potential accidental release conditions as well as normal

routine operations should be developed and implemented. The proper operation of continuous monitoring equipment should be verified at a frequency justified by the site to ensure required accuracy and precision. Operational checks should include positive air- or liquid-flow indication, non-zero response to background activity, and internal check sources or 60-Hertz electronic checks when available (DOE-STD-1098-2008). All data received from continuous monitoring or continuous sampling systems when performing statistical analyses should be used. The liquid effluent flow rates and the concentrations of radionuclides measured in the sample provide the information needed to compute the total amount of radioactive material released to the environment via the sampled liquid effluent stream. DOE-HDBK-1216-2015 24 Calibrate monitoring and sampling system components before use and recalibrate at any time maintenance, modification, or system changes occur that could affect equipment calibration. Systems should be recalibrated at least annually and detectors routinely checked with known sources to demonstrate that they are functioning properly. Calibration(s) should be performed in a manner consistent with manufacturers’ instructions and specifications. Replace off-line liquid transport lines that become radioactively contaminated (to the point where the sensitivity of the system is affected) or become ineffective in meeting the design basis within the established accuracy/confidence levels. 3.9 Quality Assurance As they apply to the monitoring of liquid effluents, the general quality assurance (QA) program provisions described in Chapter 11 of this Handbook should be followed. DOE-HDBK-1216-2015 25 4 AIRBORNE RADIOLOGICAL EFFLUENT MONITORING AND SAMPLING Airborne effluent streams with the potential to release radionuclides to ambient air (i.e., emission points) should be identified and assessed for direct effluent sampling and continuous air monitoring. Diffuse sources of emissions require identification and release assessment, as well. Quality assurance is essential to the airborne radiological program. Environmental surveillance of radioactive air emissions, which may supplement the effluent sampling and monitoring program, is addressed in Chapter 6. A point source is a single well-defined point (origin) of an airborne release, such as a stack or vent or other functionally equivalent structure. Point sources are actively ventilated or exhausted. A diffuse (fugitive) source is an area source from which radioactive air emissions are continuously distributed over a given area or emanate from a number of points randomly distributed over the area (generally, all sources other than point sources). Diffuse sources are not actively ventilated or exhausted. Diffuse sources include: emissions from large areas of contaminated soil, resuspension of dust deposited on open fields, ponds and uncontrolled releases from openings in a structure. Direct effluent radioactive air sampling is typically conducted at the exhaust point (i.e., point source) and considers particulates and gases in use. Depending on the types and quantities of emissions to the environment, monitoring (e.g., a continuous air monitor [CAM]) may be required. A CAM provides timeliness in assessing releases and alarm capabilities. Radiological effluent results are used in determining doses to members of the public from airborne releases.

Objectives of the airborne radiological effluent sampling and monitoring program include: • Evaluation of compliance with applicable Federal, State, and local environmental radiation protection requirements; • Evaluation of the performance of radioactive waste-confinement systems; • Determination of concentration trends of radiological airborne effluents in the environment at, and adjacent to, DOE facilities, waste disposal sites, and remedial action activities; • Monitoring all inactive, existing, and new low-level waste-disposal sites to assess radiological hazards (also see Chapter 6); DOE-HDBK-1216-2015 26 • Determining the effectiveness of treatments and controls used to reduce radiological airborne effluents; • Detecting and quantifying unplanned radiological airborne releases; • Sampling and/or monitoring point sources that have a potential to exceed 1 percent of the site-wide 10 mrem/yr NESHAPs standard (per 40 CFR Part 61, Subpart H (61.93(b)(4)); • Monitoring fugitive emissions; • Monitoring surplus facilities before decontaminating or decommissioning; • Sampling and/or monitoring new and existing sites, processes, and facilities to determine potential environmental impacts and releases of radiological airborne contaminants; and • Monitoring and assessing radiological airborne effluents and potential exposure to the public and the environment. Documentation of the site’s airborne radiological effluent monitoring program should show: • Rationale for the design and selection of airborne radiological effluent sampling and/or monitoring (sampling or in situ measurement) extraction locations used for providing quantitative emission data; • Procedures and equipment needed to perform the extraction and measurement; • Frequency and analyses required for each location; • Required minimum detectable concentration (or limit) and uncertainty; • QA components; and • Investigation and alarm levels. A lines of inquiry approach is provided to conduct self-assessments; to verify that the program is effective and in compliance with appropriate requirements; and to ensure the consideration of continuous improvement of the program. Lines of inquiry are identified in Appendix B of this Handbook. 4.1 Key Requirements DOE O 458.1, Radiation Protection of the Public and the Environment, establishes requirements for airborne radioactive effluents. Airborne radioactive effluents need to comply with EPA regulatory standards. Further requirements specify waste and operations emissions of radon- 220 and radon-222 emissions which apply to certain DOE facilities. The ALARA process is also required. DOE-HDBK-1216-2015 27 40 CFR Part 61, National Emission Standards for Hazardous Air Pollutants (NESHAP), Subpart H, establishes the limits for the release of radionuclide emissions other than radon to the air from DOE facilities, and specifies corresponding requirements for monitoring, annual reporting and recordkeeping. According to 40 CFR §61.92, the emissions of radionuclides to the ambient air from DOE facilities shall not exceed those amounts that would cause any member of the public to receive in any year an effective dose equivalent of 10 mrem/yr. Compliance is demonstrated by calculating doses to the public at offsite locations1 (40 CFR §61.94) using standardized methods (40 CFR §61.93). [Additional EPA requirements that cover specific DOE operations are found in 40 CFR Part 192, regulating emissions from uranium and

thorium mill tailings operations.] 40 CFR Part 61, Appendix B, Method 114, Test Methods for Measuring Radionuclide Emissions from Stationary Sources, establishes the requirements for: (1) stack monitoring and sample collection methods appropriate for radionuclides; (2) radiochemical methods which are used in determining the amounts of radionuclides collected by the stack sampling; and (3) quality assurance methods which are conducted in conjunction with these measurements. 40 CFR Part 61, Appendix D, Methods for Estimating Radionuclide Emissions, establishes the adjustment factors for the physical form of the radioactive material as well as emission factors for effluent controls. ANSI/HPS N13.1-199, Sampling and Monitoring Releases of Airborne Radioactive Substances From the Stacks and Ducts of Nuclear Facilities, establishes the guidelines and performance criteria for sampling the emissions of airborne radioactive substances in the air discharge ducts and stacks of nuclear facilities. Emphasis is on the extractive sampling from a location where the contaminant is well mixed. ANSI/HPS N13.1-1999 1 Under certain circumstances (e.g., where DOE permits members of the public to work on a DOE site without DOE access controls) dose estimates for onsite locations may be required for demonstration of compliance. Note: Section 61.91 of 40 CFR Part 61, Subpart H, defines a “Facility” to mean all buildings, structures and operations on one contiguous site (e.g., Hanford Site, Oak Ridge Reservation, Savannah River Site, Idaho National Laboratory). DOE-HDBK-1216-2015 28 provides performance-based criteria whereas the 1969 version of the standard was prescriptive with an emphasis on the isokinetic sampling of airborne radioactive material from exhaust points (some DOE systems may be grandfathered to use the 1969 version as promulgated by EPA). A grandfathered sampling system may become subject to ANSI/HPS N13.1-1999 standards if dose estimates substantially increase as a result of facility changes, modifications, or new construction. DOE O 414.1D, Quality Assurance, contains requirements for the development and implementation of a QA program using a graded approach by DOE elements. DOE O 436.1, Departmental Sustainability, establishes requirements for: (1) the systematic planning, integrated execution, and evaluation of programs for protecting public health and the environment; (2) pollution prevention; and (3) assuring site compliance with applicable environmental protection requirements. Memorandum of Understanding Between the U.S. Environmental Protection Agency (EPA) and the U.S. Department of Energy Concerning The Clean Air Act Emission Standards for Radionuclides 40 CFR Part 61 Including Subparts H, I, Q & T, established an agreement between the two agencies on implementation of the NESHAPs requirements related to radioactive air emissions from DOE sites. 4.2 Summary of General Objectives The air sampling and monitoring activities at each facility and each emission point at a facility should be commensurate with potential radiological emissions and their estimated contributions to public dose during both routine operation and in unplanned release scenarios. While EPA has established standards for public dose from a facility’s emissions, criteria for each emission point need to be considered and incorporated into the whole of the facility program. Note: Although 40 CFR Part 61, Subpart H provides procedures for evaluating only

emissions from point sources, under a 1995 Memorandum of Understanding (DOE 1995) DOE and EPA agreed to the collection, analysis and review of emissions data from diffuse sources. Therefore, the dose standards in the regulation are applicable to emissions from diffuse sources as well as point sources. DOE-HDBK-1216-2015 29 4.2.1 Performance Standards for Air Sampling Systems The emission point criteria for airborne radiological effluent sampling and monitoring listed in Table 4-1 should be used to establish the airborne emission monitoring program for DOE sites. Application of these criteria to an emission point requires that an adequate study of the expected releases, potential exposure pathways, and resulting dose be conducted. Quality assurance applies to radiological air sampling systems. A graded approach should be used and incorporated into a quality assurance plan and applied during implementation. Pre-operational assessments should be conducted for all new emission points or emission points that have been modified such that the effluent release quantity or quality, or the sensitivity of the monitoring or surveillance systems is affected. These assessments should document the types and quantities of airborne emissions to be expected from the emission point, and establish the associated airborne emission monitoring needs of the emission point. According to 40 CFR Part 61, new emission points that require sampling or modified emission points resulting in an effective dose equivalent greater than 1 percent of the 40 CFR Part 61 Subpart H standard must use ANSI/HPS N13.1-1999. For existing grandfathered sources with emissions resulting in an effective dose equivalent greater than 1 percent of the standard, the air sampling system design needs to use either ANSI N13.1-1969 or ANSI/HSP N13.1-1999. However, applicable maintenance, calibration, and field check requirements specified in ANSI/HPS N13.1-1999 need to be followed for all emission points. The performance of the airborne emissions monitoring systems should be sufficient for determining whether the releases of radioactive materials are also within the limits or requirements specified in DOE O 458.1. Sampling and monitoring systems should be calibrated before use and recalibrated any time they are subject to maintenance or modification that may affect equipment calibration status. These systems should be recalibrated at least annually and routinely checked with known sources to determine that they are consistently functioning properly. Provisions for monitoring airborne emissions during non-routine situations should be considered when determining routine airborne emission monitoring needs. 4.2.2 Gases vs. Particulates Radionuclides in gaseous airborne effluents can be in the form of non-condensable gases and particulate materials. Inertial forces play a role in the distribution of gases and particulates in the exhaust air stream. For gases/vapors (considered to have similar flow behaviors) sample design criteria can be less rigorous since the effects of inertial forces are less prominent. For DOE-HDBK-1216-2015 30 new emission points, sampling at a well-mixed location is required as identified in ANSI/HPS N13.1-1999. TABLE 4-1. Emission Point Criteria for Airborne Radiological Effluent Sampling and/or Monitoring HE (mrem/yr) * Minimum airborne radiological effluent criteria HE ≥ 5

Continuous sampling for a record of emissions with retrospective, off-line periodic analysis. Continuous in-line, real-time monitoring with alarm capability; consideration of separate accident monitoring system.** Additional considerations: 1) Identify radionuclides that contribute > 10 percent of the dose 2) Determine accuracy of results (± percent accuracy and percent confidence level) 3) Establish alarm set-points for continuous monitoring 4) Conduct a confirmatory environmental survey annually or Monitor at a representative receptor location with prior EPA approval***: 1) Continuously sample air at a representative receptor location 2) Collect and measure any radionuclide contributing ≥ 1 mrem above background 3) Establish sampler density sufficient to estimate dose to critical receptor given typical variability of meteorological conditions 4) Recommended completion of a data quality objectives document for program implementation 5) See Chapter 6, Environmental Surveillance guidance 0.1 < HE < 5 Continuous sampling for record of emissions, with retrospective, off-line periodic analysis.** Additional considerations: 1) Identify radionuclides that contribute > 10 percent of the dose 2) Determine accuracy of results (± percent accuracy and percent confidence level) 3) Conduct a confirmatory environmental survey at a frequency consistent with a graded approach but at least once every 3 years HE < 0.1 Using a graded approach, conduct periodic confirmatory sampling and off- line analysis, or complete an annual administrative review including engineering calculations of emission point uses to estimate emissions and/or confirm the absence of radioactive materials in forms and quantities not conforming to prescribed specifications and limits. Additional considerations: 1) Test to determine need to sample by calculating dose (HE) for normal operations, assuming that the effluent controls are inoperative 2) Conduct a confirmatory environmental survey at least every five years * HE = calculated maximum dose (mrem/yr) from airborne radiological effluent to members of the public with no abatement controls in place ** 40 CFR Part 61 Subpart H requires effluent streams that have the potential to result in doses to a receptor >0.1 mrem/year to be directly monitored continuously with an in-line detector or have representative samples withdrawn continuously ***40 CFR Part 61 Subpart H requires EPA approval to use environmental monitoring as an alternative compliance measurement to effluent monitoring DOE-HDBK-1216-2015 31 4.2.3 Design Criteria for System Components Airborne emission sampling and monitoring systems should demonstrate that quantification of airborne emissions is timely, representative, and adequately sensitive. The design of airborne radiological effluent sampling and monitoring systems begins with a characterization and documentation of the effluent sources. Cross-sectional homogeneity of the radionuclide distribution in the effluent stream at the sampling point is addressed in ANSI/HPS N13.1-1999. The level of detail should be sufficient to prove that the system is qualified for the task (i.e., a graded approach). A number of factors are critical to this characterization, but their importance can vary in a specific situation. The following are among those factors that should be considered: • Identification of the actual or potential radionuclides present (e.g., type, concentration);

• Identification of fallout and naturally occurring (i.e., background) radionuclides; • Presence of materials (e.g., chemical, biological) that could adversely affect the sampling and monitoring system or detection of radionuclides; • Internal and external conditions that could have a deleterious effect on the quantification of emissions; • Process descriptions and variability; and • Particle-size distribution of the particulate materials (nominally set at 10 microns). 4.2.4 Alarm Levels Continuous air monitoring systems require alarms that provide timely warnings to signal the need for investigation or corrective actions. Alarm levels should be set to provide timely warnings and yet avoid spurious alarms. Background fluctuations should be considered when setting the alarm levels. Requirements to protect the public and environment in DOE O 458.1 should be considered when establishing alarms. 4.3 Point Source Emissions For point sources that require effluent sampling and/or monitoring, the important characteristics of the exhaust handling system, other pertinent structural information, the pertinent characteristics of the process and process-emission control systems, and the sampling and measurement systems should be documented as part of an Environmental Management System. Reports or data from studies conducted to evaluate systems that may have real or DOE-HDBK-1216-2015 32 suspected deficiencies of the systems should be retained at a single, readily accessible location. 4.3.1 Direct Effluent Sampling Direct effluent sampling systems include probes, transport lines, air handling systems, flow measurement devices, and sample collection devices which are discussed below. 4.3.1.1 Sample Extraction Sites Samples should be extracted from the effluent stream at a location and in a manner that provides a representative sample taking into account the velocity profile, gas and aerosol particle concentration profiles, and cyclonic flow. Sample extraction sites should be from an accessible location in the stack downstream from any obstruction, preferably near the outlet, so that concentrations of the material of concern are uniform and so that the physical state is similar to what will enter the atmosphere. Details are provided in ANSI/HPS N13.1-1999, and test methods for velocity traverses and cyclonic flow are in 40 CFR Part 60, Appendix A (Smith 1984). 4.3.1.2 Sampling System Components Sampling components include extraction (sample) probes, transport lines, air flow measurements and controls, and sample collectors. 4.3.1.2.1 Extraction Probes ANSI/HPS N13.1-1999 states that, in place of multiple point sampling, single-point representative sampling should be used with the requirement that both fluid momentum and contaminant mass are well mixed at the sample extraction location; the ANSI/HPS N13.1-1999 standard promotes the use of shrouded nozzles/probes. While now discouraged, if multiple inlet probes are used, the volume flow through each inlet should be proportional to the volume fraction of the airborne radiological effluent flow in the annular area sampled. Transmission of sample constituents through the probe needs to meet specific performance criteria (e.g., the transmission ratio of 80 percent to 130 percent). If the material of concern exists as a gas or vapor that does not interact with particulate material in the gaseous airborne effluent, simply extracting a known fraction of the airborne radiological

effluent flow is adequate, provided the criteria for uniform flow and concentration are met. DOE-HDBK-1216-2015 33 Position probes for sampling iso-axially in the stack or exhaust duct, and size them for the appropriate exhaust velocity. The presence of the probe should not obstruct the contaminant stream in the duct. For new or modified facilities that use ANSI/HPS N13.1-1999, the recommendation for isokinetic sampling is no longer required by EPA in 40 CFR Part 61, Subpart H, effective on October 9, 2002. Probe nozzles for the sampling of aerosols should be made of seamless stainless-steel tubing (or, for corrosive atmospheres, other rigid, seamless tubing that will not degrade under sampling conditions) with sharp, tapered edges. Probes should be designed so that they can be removed easily for cleaning, repair, replacement, or deposition evaluation. 4.3.1.2.2 Transport Lines Sample transport lines should be kept as short as possible and designed to minimize sample loss. Systems that directly expose the collector or monitor to the airborne radiological effluent stream are preferred. Line diameter and materials of construction should be selected to minimize wall losses under anticipated sampling conditions (ANSI/HPS N13.1-1999). Aerosol transport lines should be rigid and should be electrically grounded to the point where the particles are collected or accumulated. Transport lines should be made of materials resistant to corrosion under anticipated sampling conditions and should be insulated and/or trace-heated to prevent condensation of materials under anticipated sampling conditions. Aerosol transport lines should not have sharp bends. Changes in direction should be minimized and be made with radii of curvatures of at least three tube diameters and no greater than 10 (NCRP 2010). There should be no inward facing steps at tubing connections in excess of a 1 percent reduction in tube diameter. Flattening of a bend cannot exceed 15 percent. Bends, steps, and flattening, cause sample losses that need to be accounted for in the sample transport line. In general, sample penetration can be demonstrated empirically or by using models where the penetration of a 10 micron particle through the sample line should not be less than 50 percent (ANSI/HPS N13.1-1999). If the material(s) of concern is (are) in the form of gas(es) or vapor(s), ensure that the lines have no significant leakage or loss of material (e.g., chemical reactions and condensation). For consistency with 40 CFR Part 60, Appendix A, Method 5, “significant leakage” is any leakage rate in excess of either 4 percent of the average sampling rate or 0.02 cubic feet per minute (cfm), whichever is less (Smith 1984). DOE-HDBK-1216-2015 34 4.3.1.2.3 Air Flow Measurement and Control Air-moving systems for gaseous airborne radiological effluent sampling should be constant displacement systems (e.g., rotary vane, gear) or other systems that will maintain constant air flow in anticipated sampling conditions. Pumps and other mechanical components should be designed to operate continuously under anticipated operating conditions, with scheduled preventive maintenance and repair. Equipment used for intermittent or grab sampling should be designed to operate continuously for the duration of the sampling period(s). Sampler gas flows should be measured continuously and recorded over the duration of the sampling period. Periodic gas-flow gauge readings during collection should be conducted and

recorded. If it can be demonstrated that the sample flow rate is essentially constant from the start to the end of each sampling period, then periodic gas-flow readings may not be essential. Unless extenuating circumstances dictate otherwise, the flow measurements should be accurate to ± 10 percent by calibration with standards traceable to the National Institute of Standards and Technology (NIST) (DOE 1983). Regardless of the type of device used, calibrate it under conditions of anticipated use with NIST-traceable or equally acceptable standards (in the case where an NIST standard does not exist). Flow-measuring devices used for compliance determinations should be located downstream from the extraction probe. ANSI/HPS N13.1-1999 established performance standards and design criteria for the measurement and control of the bulk airborne radiological effluent flows. The characteristics and conditions of gas flow can vary widely, therefore, the need for airflow feedback systems should be considered and take into account the potential for large fluctuations in flow. The frequency of the measurements needed to accurately meet flow-rate determination will be based on the stability of flow and the significance of the radiological impact to the environment. Gas-stream measurement methods include 40 CFR Part 60, Appendix A, Method 1 (used to determine location and quantity of velocity measurements), Method 2 (used to measure and determine stack gas velocity, static pressure, and volumetric flow rate), and Method 4 (used to determine moisture content in stack gases) (Smith 1984); ASTM D3154-00 (2006); ASTM D3195M-10 (2010); ASTM D3464-96 (2007); and ASTM D3796-90 (2004). Measurements may be impacted by various characteristics such as the velocity, static pressure, temperature, and moisture content. DOE-HDBK-1216-2015 35 4.3.1.2.4 Sample Collectors The design and capabilities of the sample collector will depend on the physical and chemical form of the radionuclides to be collected, the sampling conditions, and the analytical techniques to be used. The radionuclides in airborne effluents can be found in three forms — gases, vapors and particulate materials. Different techniques are needed to collect and separate the physical forms or individual chemical compounds within the forms. Collector housing and hardware should be designed to minimize sample loss and leakage. Sample preservation methods should be consistent with the analytical procedures used. Table 4-2 illustrates a variety of sample elements and their associated sampling methods. Additional guidance can be found in ANSI N13.1-1969 or ANSI/HPS N13.1-1999 (for new or modified facilities) as well as NCRP 169 (NCRP 2010); ISO 2889 (ISO 2010); 40 CFR Part 61, Appendix B, Method 114; and Maiello and Hoover (2010). These resources provide detailed information on the sampling methods, media, processes, efficiencies, and analytical approaches. TABLE 4-2. Collection Methods for Specific Radioactive Effluent Radioactive Effluent Collection Method Particulates Filter media including acrylic copolymers, glass fiber, cellulose, and quartz. High Temperature Particulates Sintered metals or mineral particles. Tritium Oxide Ethylene glycol bubbler, silica gel, molecular sieves, and condensers. Elemental Tritium Palladium or other catalyst to transform to the oxide for collection as the Tritium Oxide collection method.

Tritium in Organic Compounds Platinum or aluminum oxide catalyst in combustion chamber for collection as the Tritium Oxide collection method. Noble Gases (excluding Radon) Silver zeolite, flow-through or evacuated chambers, activated carbon, cryogenic condensing, and compressed gas. Radon Activated carbon, alpha track, and continuous radon monitors. Elemental Iodine Plain or cadmium iodide treated activated carbon. Organic Radioiodine Potassium iodide or triethylene-diamine treated activated carbon. Other Gases (e.g., oxygen, carbon, nitrogen, and sulfur compounds) Bubble through sodium hydroxide solutions, solid-phase sorbents, and activated carbon. DOE-HDBK-1216-2015 36 4.3.2 Direct Effluent Monitoring Direct continuous effluent monitoring, as shown in Table 4-1, is system specific and includes specifications for continuous monitoring systems, in-line and off-line approaches, and radionuclide monitoring systems for specific radionuclides. 4.3.2.1 Continuous Monitoring Systems Where the offsite radiological impacts to the applicable receptor location are well below the standard, radionuclide sampling and collection with periodic measurement (e.g., laboratory analysis) are sufficient to quantify the radionuclides. However, where a significant potential (greater than once per year) exists for approaching or exceeding a large fraction of the emission standard (e.g., 20 percent), continuous monitoring should be required. Continuous monitoring system specifications require a careful balancing of sensitivity, energy response, response time, and accuracy for the radionuclide of interest (ANSI N42.18-2004). Compensation or adjustment in the system should accommodate pressure, temperature, humidity, and external background. To interpret the measurements correctly, the composition of any noble gases present needs to be known. If significant amounts of tritium are present, tritium removal may be necessary before other measurements are taken. Gross alpha and gross beta monitoring may be accomplished using gas flow proportional counters. When monitoring for gamma-emitting radionuclides, use monitors that have a stainless-steel vessel with a known volume of gas and a lithium-drifted germanium detector [Ge(Li)] or an intrinsic germanium detector or equivalent (DOE 1983). The requirements of sampling at a well-mixed location apply equally to continuous monitoring systems. However, additional maintenance, repair, and calibration are necessary. The continuous monitoring system is particularly useful in either normal or upset conditions where appropriate alarm levels have been set. 4.3.2.2 In-Line/Off-Line System Specifications Air monitoring can be performed by either in-line or off-line systems. In-line systems are those in which the detector assembly is immersed in the airborne radiological effluent stream, usually in a well or other protective enclosure, while off-line systems pull an aliquot from the airborne radiological effluent stream for collection or conveyance to a detector assembly. In-line systems are less complex than off-line systems but may not provide specific radionuclide measurements directly (DOE 1983). These approaches provide for near real-time analysis and feedback. DOE-HDBK-1216-2015 37 For in-line monitoring, special housing may be necessary to meet the specifications identified below.

• Place only the detectors and small electronic assemblies in, or adjacent to, the airborne radiological effluent stream (IEC 60761, 2002). A detector should not be particularly sensitive to environmental conditions or need frequent attention or adjustment. • Use appropriate calibrations for radionuclides to be measured, including ratios to other non-measurable radionuclides, if present. • Meet performance requirements within the anticipated environmental conditions (e.g., temperature, humidity, and radiation levels). Systems to control the environment for the proper functioning of the monitors should be provided. • Have adequate access for maintenance, repair, and calibration. • Have a stable source of electrical power. The available signal range should include the full range of operating conditions. The signal range of routine airborne radiological effluent monitoring systems that also are identified for use during non-routine emissions should be sufficient to monitor releases projected from applicable design basis accidents. If a measuring cell or gas chamber is used to provide a known volume of gas for measurement with an immersed or adjacent detector, consider the following design features: • A flow-through type vessel or chamber with or without absorbing medium or pressurization; • Specifications for cell volume and pressure; • Separation of the detector from the sample by a protective screen, if practicable; and • A readily removable detector mounted so that it will be returned to, and maintained in, its original position and provision for an alternate position or other means of varying response by a factor of at least 10 to accommodate non-routine situations (includes accidents). An alternative method would be to use two detectors, the second one with a higher range. 4.3.3 Specific Radionuclide Monitors The following sections summarize monitoring methods for a variety of specific emission types. Other methods not discussed here may be more applicable in certain situations. As state-of- DOE-HDBK-1216-2015 38 the-art technology improves and new detector methods become available, additional or alternate methods may become standard practice. 4.3.3.1 Tritium Ionization chambers are widely used for measuring gaseous tritium (DOE 1983). Tritium measurements of about 10-5 µCi/mL are possible in low-background environments, which produce ions at a rate equivalent to 1 mrem/hr. Shielding may be necessary for specific applications. If shielding is not practical, a second chamber exposed to the same gamma field without tritium is recommended. Ionization chambers are more sensitive to radioactive (noble) gases that produce larger energies per disintegration and may cause major interferences. Proportional counters also are used to measure airborne tritium (DOE 1983). They are relatively insensitive to background radiation and have energy discrimination capabilities. Systems using proportional counters are more complicated than those using ionization chambers. Proportional counters require a counting gas, and many gases are flammable or combustible. Radioactive material present in natural products (e.g., commercial natural gas) may provide interference for tritium measurements and should be accounted for if used. Additional concerns that should be considered in instrument design for tritium monitors based on the IEC standard (IEC 60761, 2002) are as follows:

• Temperature control during sample transport to prevent condensation (much of the tritium may be in the form of airborne water vapor), and • Trapping or retention of water by a filter or sorbent (since much tritium is commonly in the form of tritiated water (HTO)). 4.3.3.2 Iodine Activated charcoal, charcoal, and silver zeolite cartridges used to collect radioiodine may be monitored at the collection point with a shielded gamma spectrometer/detector. Usually the cartridge is placed downstream of the particulate filter which removes other airborne radioactive contaminants that might otherwise be collected on the cartridge and therefore interfere with the iodine analysis. Considerations for determining the frequency of sampling or replacing the cartridge include cartridge loading, breakthrough potential, the number of cartridges in series, cost, and radioiodine species half-life. DOE-HDBK-1216-2015 39 In-line measurements of low concentrations of radioiodine in air usually will not be feasible because of the presence of other radionuclides or radiation fields. Additionally, the monitoring of airborne radioiodines may be complicated by the occurrence of several species, including particulate iodine (bound to inert particles), elemental iodine vapor, and gaseous (usually organic) compounds. Monitoring system design should consider the iodine forms in the effluent. While it may not be necessary to differentiate routinely between the various species, care should be taken so that no significant error results by neglecting one or more of them (DOE 1981). Several designs (e.g., Keller et al. 1970) have been used to distinguish the several chemical forms of radioiodine that may be present in the atmosphere (as related to environmental surveillance). Cartridges for the collection of radioiodine in air are subject to channeling, as with any packing of loose materials. Baffled-flow cartridge design, packing to a minimum required weight, and pre-testing of randomly selected cartridges for pressure drop before operation in the field should minimize the problem (DOE 1981). Specifications to be considered for iodine monitors are as follows: • Protection of the detector head from particulate contamination by an interchangeable thin screen, easy removal of supplemental devices such as temperature sensors and heaters in the inlet for decontamination, and use of construction materials that are easily decontaminated or are contamination resistant; • Design of radioiodine monitors will be such that the replacement of sorbent and filter should not disturb the geometry between the collector and detectors; • Design of collection assembly and detector to minimize the holdup of gases; • Establish minimum levels of detectability for various iodine isotopes; and • Determination of the characteristics (e.g., collection efficiency, retention capacity, delay- time constants) for all media in the collection train (solid sorbent, absolute particulate filter) for various radioactive gases of significance in the gaseous effluents, including radon. DOE-HDBK-1216-2015 40 4.3.3.3 Noble Gases (Excluding Radon) The radioactive noble gases include forms of argon, krypton, and xenon.2 Flow-through ionization chambers or proportional counters may be used. Usable signals from noble gas monitors may depend on the adequate removal of other radionuclides from the sample stream. Activated charcoal cartridges monitored by a gamma spectrometer may also be used for noble

gases. Cartridges would be placed downstream of the particulate filter. This method requires knowing the adsorption coefficient for the noble gas which is affected by temperature, pressure, concentration, and carrier gas on the activated charcoal/carbon (Underhill 1996). Additional concerns whether using ionization chambers, proportional counters, or activated charcoal cartridges include establishing minimum levels of detectability. 4.3.3.4 Radon Radon effluent monitoring may be accomplished using a scintillation cell or ionization chamber (continuous radon monitors), passivated ion-implanted planar silicon detection which includes the collection of radon progeny with spectral analysis output, or activated charcoal cartridges monitored by a gamma spectrometer. Because radon tends to a lower pressure it migrates easily making monitoring difficult. As with other gases, minimum levels of detectability need to be established. 4.3.3.5 Other Gases (Oxygen, Carbon, Nitrogen, and Sulfur) Radionuclides of elements such as oxygen, carbon, nitrogen, and sulfur may be in gaseous form but also in particulate form. Particulate measurements are addressed in the section below. For gases, flow through ionization chambers, proportional counters/beta detectors, and gamma spectrometry may be used. As with the noble gases, minimum levels of detectability need to be established. Additional concerns include the low emission energies of these elements and interference from 2 Note: radon releases are subject to separate requirements and specific sampling guidance is provided in Section 4.3.3.4. DOE-HDBK-1216-2015 41 background and other radioactive materials; therefore, results from these methods are often difficult to quantify. 4.3.3.6 Particulates Particulates are generally extracted from the effluent stream and passed through a filter media to remove the particles. Gross alpha and gross beta/gamma counting can be accomplished using a gas-flow proportional counter. Other alpha and gamma spectrometry and beta counters may be used, as appropriate, for specific applications. In addition to ANSI/HPS N13.1-1999, IEC 60761 (2002) and ANSI N42.18-2004 address aerosol airborne radiological (gross alpha and gross beta) effluent monitoring. Chapter 6 provides additional filter media details. DOE (1983) and IEC 607461 (2002) provide additional information on specific types of aerosol monitors — alpha-emitting transuranics; uranium; and other particulates. • Transuranics (e.g., plutonium): ANSI N317-1980 addresses CAMs that also are used as gaseous airborne radiological effluent monitors; these instruments can be used for monitoring transuranic (TRU) effluent. • Uranium: The continuous strip filter counters with combined alpha and beta counting ratios can be considered if uranium is the only particulate radionuclide present. Gamma spectroscopy is suggested for consideration at high concentrations. • Other Particulates Including Fission and Activation Products: Other radionuclides in the form of particulate materials commonly are monitored by collection on filters and counted for gross beta activity if the identities and ratios of radionuclides are known (DOE 1983). Shielded beta detectors are considerably more practical than gamma detectors, and most gamma emitters also emit beta radiation. If measurements of specific, gamma- emitting radionuclides are necessary, sodium iodide (thallium activator) (NaI(Tl)) or

intrinsic germanium detectors should be used. Additional characteristics that should be considered include: • The best estimate of the surface emission rate determined from a primary or secondary standard or by reference to an instrument that has been calibrated against a primary or secondary standard; • A check source, supplied with the monitor, designed to be used in place of the filter in the retention device; • A protective cover over the detector that can be easily exchanged from the front of the detector or designed to facilitate decontamination of the detector head; DOE-HDBK-1216-2015 42 • Filter properties (e.g., Maiello and Hoover, 2011; ANSI/HPS N13.1-1999; and Barnett et al., 2009), see also Chapter 6; • Filter holder design (e.g., leakage minimization, ease of use); • Assessment of minimum detectable activities for instruments used; • Avoidance of gross non-uniform particle deposition on the collection surface; • The total equivalent window thickness in units of milligrams per square centimeter (mg/cm2) that an ionizing particle normally emitted from the surface of the collected aerosol will cross to reach the sensitive area of the detector (i.e., distance covered in air plus the window thickness and that of any thin, protective screen); • A useful detector area approximately equal to that of the particle collecting surface; • Assess the collection efficiency of the retention device over the range of 0.01 to 10.0 µm aerodynamic equivalent diameter under normal conditions of proposed use; • Assess detector characteristics (e.g., maximum total equivalent window thickness, protective coating, and variation in detector efficiency as a function of energy); and • Methods of discrimination against natural background radiation (i.e., delayed measurements after suitable decay, energy spectrum analysis; physical properties; and electronic compensation to subtract the contributions from radon and its progeny). 4.4 Diffuse Sources and Fugitive Emissions Diffuse sources should be identified and assessed for their potential to contribute to public dose and should be considered in designing site emissions monitoring programs. With regard to annual compliance assessment, DOE (1995) was signed by EPA and DOE to address the supplemental evaluation of diffuse releases, which are not specifically included in the 40 CFR Part 61, Subpart H, requirements. DOE O 458.1 addresses the ALARA process and compliance with radon emissions. The category of diffuse sources covers many situations, most of which are difficult to characterize. Examples are shown in Table 4-3 (based in part on Savannah River Nuclear Solutions (2012), and NCRP (2010)). Attempts to precisely define the airborne emissions under such an array of conditions, as well as other complex and ill-defined factors that affect the transport of the emissions (generally meteorological and topographical factors), could necessitate complex and costly sampling techniques and configurations. Therefore, alternative methods for diffuse emissions release estimates are used in many cases. DOE-HDBK-1216-2015 43 TABLE 4-3. Examples of Diffuse and Fugitive Sources at DOE Sites Structures without ventilation or with ventilation that does not result in a well-defined release point Passively vented stacks or vents Breathing buildings or tanks Decontamination or demolition activities Surface soils from future or active remediation sites Windblown dust from storage piles Evaporative losses from ponds

Losses from open tanks or tank connections Unplanned intrusions/disruptions (animals, flooding, digging) Airborne emissions from past liquid releases to soil Plant transpiration of groundwater plumes Abandoned sealed sources All diffuse sources should be identified, assessed, documented, and verified annually. Identification and assessment includes determination of release rates, airborne dispersion modeling, and public dose determinations. 4.4.1 Diffuse Sources Diffuse sources, by definition have no well-confined emission release location. Determination of the radioactive material release rates can be done by calculational methods, sometimes in conjunction with environmental surveillance. Additional considerations for diffuse source evaluations include knowledge of local point source emissions and background, and may also include non-routine emissions from on-site events and emissions from off-site events. 4.4.2 Diffuse Source Release Rates Environmental surveillance is used to determine release rates for some diffuse sources (see Chapter 6). For large sites, close-in environmental monitoring can be used to more precisely estimate releases. Environmental surveillance can also be done and assumed to occur over the entire year to approximate annual emissions. The validity of all release estimates relies on the professional judgment and knowledge of the individuals involved and usually is difficult to verify. As a general rule, reliance will be placed on the site environmental surveillance program to confirm predictions. Diffuse emissions rates are typically overestimated. Expenditures to fine- tune the overestimate depend on how close the overestimate is to a limit of concern. DOE-HDBK-1216-2015 44 Calculational methods for determining release rates depend on the radioactive source and the characteristics of the potential environmental release. The radioactive emissions from diffuse sources can be calculated using 40 CFR Part 61, Appendix D methodology or a previously approved method. Documenting the operating parameters or source specific activity data is important, and all assumptions should be stated. Meteorological conditions are responsible for dispersing the emissions once they are airborne. Other factors that have a significant influence on the air suspension of radionuclides from diffuse source situations depend on the force applied (which results in suspension of the radionuclide in air) and the factors that resist suspension (e.g., subdivision of liquid surface by shear stress (sprays) from ambient winds, over-pressure phenomena within a structure that result in the atmospheric release of radionuclides, the exchange of indoor and outdoor atmospheres at portals, and aerodynamic entrainment of contaminated soil.) A potential diffuse source should be described adequately enough to show the radionuclides present, the form of the materials, and the factors contributing to suspension. The rationale to substantiate the approach used to assess and characterize the source should be documented. The radionuclide amounts in fugitive emissions can be, but are not necessarily, lower than point source discharges. This is notably the case at legacy sites with much newer laboratory facilities. It may not be feasible to directly measure and quantify fugitive emissions. Because of low concentrations, unpredictable release patterns, and different release points, values of fugitive

releases from a given facility generally can only be estimated (NCRP 2010). Fugitive radionuclide emissions can be estimated by screening models or calculation methods using operating parameters or site-specific radioactivity data. A report prepared for EPA entitled Methods for Estimating Fugitive Air Emissions of Radionuclides from Diffuse Sources at DOE Facilities (Eastern Research Group 2004) contains extensive information on: (1) various release mechanisms that affect fugitive emissions; (2) methods for estimating the fugitive emissions from various operations; (3) step-by-step procedural guidance for estimating fugitive radionuclide emissions from diffuse emission sources; (4) selected models for calculating the fugitive emissions of radionuclides; and (5) case studies illustrating various activities performed at DOE sites to quantify fugitive emissions. For situations where these methods or models are not appropriate, alternative methods may be proposed for consideration provided that they are technically justified and fully documented. Regardless of the method or model utilized, data on diffuse and fugitive emissions at DOE facilities need to be reported in the ASER and, per DOE (1995), in annual radioactive air emissions compliance reporting. DOE-HDBK-1216-2015 45 4.4.3 Diffuse Source Assessment A diffuse source assessment is recommended for all diffuse sources potentially emitting radionuclides that contribute to the receptor dose. In most situations the receptor location will be at an offsite location; however, in some situations (e.g., where DOE permits members of the public to conduct non-DOE work on a DOE site) the receptor location may be onsite. The following procedures should be applied to assessments: • The assessment should be accomplished by using appropriate computational models and/or a downwind array of samplers arranged and operated over a sufficient period to characterize the concentrations of radionuclides in any resulting plumes. • Empirical data and sound assumptions should be used with the computational models to define the source term for a diffuse source. Computer codes such as CAP88 (Beres 1990; EPA 1992; EPA 2000b; and Rosnick 2007) and AIRDOS-PC can provide supporting documentation for the diffuse source assessment. Additional insight into the parameters necessary for estimating dose from fugitive effluents is provided by Whelan et al. (1987), Gilbert et al. (1989), and EPA (1987). If prior approval is granted from the regulator, compliance for emissions can be demonstrated using environmental surveillance results (or equivalent) and 40 CFR Part 61, Appendix E, Table 2. 4.5 Quality Assurance Follow the general QA program provisions in Chapter 11, as applicable to the monitoring of airborne effluent. The emission monitoring requirements in 40 CFR Part 61, Subpart H, Section 61.93(b) includes the implementation of a QA program where appropriate that meets the requirements described in 40 CFR Part 61, Appendix B, Method 114. Additionally, compliance aspects of a radioactive airborne effluent program include assessment and conformance to not only the regulations but also permit authorization requirements. In addition, government bodies (e.g., DOE 2002b) carry out occasional performance reviews. Two applicable standards for continual improvement and quality are: (1) Environmental Management Systems (ISO 14001, 2004), and (2) Quality Management Systems (ISO 9001,

2008). ANSI/HPS N13.1-1999 also outlines a basic QA program plan. DOE-HDBK-1216-2015 46 INTENTIONALLY BLANK DOE-HDBK-1216-2015 47 5 METEOROLOGICAL MONITORING Meteorological monitoring programs acquire information on atmospheric conditions that can be used to characterize atmospheric dispersion of normal operational or unplanned releases of radiological material. The scope of the meteorological monitoring program should be based on an evaluation of the applicable requirements in regulations and DOE directives, and on a determination of the meteorological data sufficient to support: (1) environmental monitoring and surveillance programs; (2) emergency response field survey team deployment; (3) in situ radiological data acquisition; (4) facility operations; (5) environmental impact assessments; (6) safety analyses; (7) environmental restoration activities; and (8) the consequence assessment element of emergency preparedness and response programs. Additional guidance documents or consensus standards appropriate for use in the design and operation of meteorological monitoring programs include EPA (2000a), NRC (2007b), and ANS/ANSI (2010). A meteorological monitoring program should consider the following factors: • Level of radiological activities at the site, including the type and magnitude of potential sources of radioactive and hazardous materials; • Topographic characteristics of the site that affect atmospheric transport that generate complex flows; • Distances from release points to each critical receptor (i.e., worker, co-located worker, MEI); • Planned future uses of the site; • Possible pathways of these materials to the atmosphere; • Frequency of extreme weather conditions (e.g., lightning, tornadoes, hurricanes, extreme straight-line winds, extreme precipitation events); and • Proximity of the site to other DOE facilities as well as to non-DOE facilities that handle radioactive and/or hazardous materials and nearby stationary and mobile offsite sources (for example, proximity to river barges and trains that transport hazardous materials). A lines of inquiry approach is provided to conduct self-assessments; to verify that the program is effective and in compliance with appropriate requirements; and to ensure the existence of continuous improvement of the program. Appendix B of this Handbook identifies lines of inquiry. DOE-HDBK-1216-2015 48 The site's meteorological monitoring program should be documented in the site’s ERPP or other appropriate document and in the ASER (per DOE O 458.1 and DOE O 231.1B). 5.1 Key Requirements The following DOE directives apply to meteorological monitoring: • DOE O 458.1, Radiation Protection of the Public and the Environment, requires environmental monitoring, including meteorological monitoring, as part of demonstrating compliance with the Public Dose Limit. According to DOE O 458.1, meteorological monitoring must be commensurate with the level of site radiological activities, the site topographical characteristics, and the distance to critical receptors, and the scope of the monitoring must be sufficient to characterize atmospheric dispersion and model the dose to members of the public. The meteorological monitoring program can be integrated into the Environmental Radiological Protection Program. • DOE O 151.1C, Comprehensive Emergency Management System, requires that DOE facility/site meteorological data be available to support timely (real-time) assessments of

the onsite and offsite consequences of an unplanned radiological release. Additionally, these data should be made available to the National Atmospheric Release Advisory Center (NARAC) in a timely manner to facilitate near real-time computations. 5.2 Meteorological Monitoring Program Design Meteorological monitoring program design requires the proper siting of meteorological towers and equipment, the collection of valid meaningful data, the appropriate analysis and application of the data, and the archiving of the data. Meteorological data are essential to characterize transport, diffusion, deposition, and re-suspension of radiological material released to the atmosphere at DOE facilities and sites, and to represent other meteorological conditions (e.g., precipitation, temperature, and atmospheric moisture) that are important to environmental surveillance activities, such as air quality and radiological monitoring. Such characterization is necessary to assess the following: • Potential consequences of radiological releases from projected new or modified facilities; • Consequences of actual routine radiological releases from existing facilities to demonstrate compliance with applicable regulations and standards; and • Consequences to the worker and public from actual accidental radiological releases. DOE-HDBK-1216-2015 49 Meteorological information also is important to consider in the design of environmental monitoring networks. In general, DOE sites should have onsite measurements of meteorological data. These include, but are not limited to wind direction (transport), wind speed (transport and dilution), turbulence (diffusion). Turbulence may be determined explicitly using sonic anemometers that are used to measure fluctuations in the three components of wind (u, v, and w) and temperature or inferred from a measurement of atmospheric stability (e.g., solar radiation plus temperature lapse rate over a vertical distance of at least 50 meters). Large DOE sites with multiple facilities and the potential for complex terrain flow characteristics should establish meteorological measurements at more than one location since spatial variations in meteorological conditions need to be considered in evaluating atmospheric dispersion among facilities and to points of public access. At some sites additional monitoring may be needed to provide supplemental information, to support safety aspects of operational programs (e.g., lightning protection, protection from cold and hot weather). It may not be necessary to establish a meteorological monitoring program for each individual facility. Some smaller sites with limited potential for the atmospheric release of radiological materials may choose to establish a meteorological program that makes use of meteorological measurements obtained from offsite sources such as a first-order National Weather Service station or cooperative stations. For data from an offsite source to be an acceptable substitute for onsite data, the offsite data should be spatially representative of conditions at the DOE facility where material may be released and subsequently transported and provide statistically valid data consistent with onsite monitoring requirements. A documented determination of offsite data source(s) that is (are) acceptable and spatially representative should be established and ensure the analysis will achieve data quality objectives. Additional guidance can be found in ANSI/ANS-3.11-2005

(R2010) and EPA (2000a). 5.3 Meteorological Monitoring Program Models and Data Atmospheric models, used to determine consequences of airborne dispersion of material, simulate winds for bulk transport and turbulence for diffusion. Sometimes these two functions, transport and diffusion, are handled by separate models, and sometimes they are incorporated in the same model. The complexity of the models needed depends upon the application and DOE-HDBK-1216-2015 50 the complexity of the atmospheric conditions, as well as the complexity of the mechanisms resulting in the release of material to the atmosphere. Transport models may vary from being as simple as using a constant single wind speed and direction, to complex time-dependent three-dimensional models which explicitly treat divergence, vorticity, deformation, rotation and strain. The transport model may generate wind fields that: • Represent the wind fields in one, two or three dimensions; • Are time dependent or time independent (i.e., constant); • Employ diagnostic wind fields, which may be generated by interpolation/extrapolation routines, mass conservation, or varying degrees of dynamic complexity and parameterization; • Include radiation (i.e., non-ionizing long wave and visible), hydrostatic or non-hydrostatic effects, etc.; and • Employ diagnostic and prognostic wind fields. Diffusion models may also be very simple, with an assumed statistical distribution, or utilize varying degrees of complexity. The diffusion models may: • Employ simple or complex turbulent closure methods; • Employ Eulerian, Lagrangian, or hybrid Eulerian-Lagrangian methods; • Include wet and/or dry deposition, with or without re-suspension; • Include airborne plume chemistry; and • Include health effects. These models may also include or utilize a source characterization model. Meteorological data required to drive the atmospheric transport and dispersion calculations range from wind speed, wind direction, and a direct or inferential measure of atmospheric turbulence at one location and one measurement height for spatially-invariant Gaussian models to extensive network of monitoring locations with in situ or remote measurements (i.e., SOund Detection and Ranging (SODAR) or Light Detection and Ranging (LIDAR)) taken at multiple levels for some of the computer-intensive Lagrangian complex terrain flow modeling techniques. Use of simple screening compliance assessment techniques (NCRP 1993; NCRP 1996), which are based on conservative assumptions and use selected meteorological conditions (i.e., wind DOE-HDBK-1216-2015 51 speed and a Pasquill stability class), could be sufficient for some DOE sites, especially those with limited radiological hazards. DOE sites that have completed their essential missions and that are presently in decontamination and decommissioning programs will have reduced hazards. For this situation, these sites may consider the use of simpler modeling techniques, commensurate with the remaining emergency management consequence assessment element requirements. For sites where onsite meteorological measurements are not required, programs should include a description of the climatology in the vicinity of the site. Data from offsite sources, such as the National Weather Service, the Federal Aviation Administration (FAA), or military installations may be used in these situations if the meteorological instruments are well maintained and the

data are readily available and representative of conditions at the site. It should be noted that some airport data (specifically ASOS/AWOS) may not meet criteria for dispersion modeling due to high wind speed thresholds for calm conditions and/or variable wind parameterizations. Data from other offsite sources also need to be examined for their quality and applicability prior to application. As an example, the use of the CAP88-PC or an EPA-approved alternative per 40 CFR 61.93 is required to demonstrate compliance with 40 CFR Part 61 Subpart H. The meteorological input to the CAP88-PC model includes the joint-frequency distribution of wind speed, wind direction and a Pasquill stability class. This model also requires an average mixing-layer depth, an average absolute humidity, and an average temperature. As the maximum magnitude of potential releases from a facility increases, the use of more realistic, and therefore complex, models may be necessary to either assess the consequences of the releases or to demonstrate compliance with applicable laws, regulations, and DOE Orders. Complex terrain environments may require a comprehensive onsite meteorological monitoring program to provide sufficient meteorological data to allow complex terrain models to be employed. Computational techniques based on straight-line Gaussian models (e.g., CAP88- PC) are appropriate for facilities that are located in simple topographic settings. Straight-line Gaussian models are described in detail in many reports (e.g., Slade 1968 and Randerson 1984). At a minimum, these models require specification of wind direction, wind speed, and an indicator of atmospheric turbulence such as a Pasquill stability class. Some models may require the specification of mixing-layer height to account for plume reflection from the capping layer. Remote sensing instrumentation (e.g., Radio Acoustic Sounding System [RASS], DOE-HDBK-1216-2015 52 SODAR, LIDAR) is now available to assist in mixing height determinations as indicated in ANSI/ANS-3.11-2005(R2010). If the models estimate wet deposition (i.e., precipitation scavenging), they could require information on precipitation rates, and if the models compute mechanical and buoyant plume rise for stack releases, the ambient air temperature could be required to compare to the temperature of the effluent. For the evaluation of chemical accidents, especially with respect to pressurized liquid and gas releases, or releases of deliquescent chemicals, both the temperature and the relative humidity could be required to accurately assess the time-varying source term. Estimation of plume rise requires air temperature and wind speed at release height, direct or inferential measure of turbulence, and, in some cases, an estimate of the mixing-layer thickness. Mixing layer thickness is only required to determine if the plume rise will be capped by the inversion, or if the plume is emitted above the inversion, in which case it will be lofted and prevented from reaching the ground level. When it is necessary to evaluate the consequences of a release on receptors near the release point, the basic models should be modified to account for deviations from this assumption. For new DOE sites with complex terrain or buildings with low stacks where wake effects3 may be significant, onsite measurements (e.g., field tracer gas studies, wind tunnel experiments) could be used to help model atmospheric transport and dispersion and could also aid in model

selection. For emergency response applications, which require real-time meteorological measurements for diagnostic consequence assessment evaluations, and weather forecasting information for prognostic consequence assessment determinations, straight-line Gaussian transport and dispersion models are not appropriate for facilities that are located in valleys, near coastlines or mountains, and on large sites with varying terrain. In these settings, strictly applied straight-line Gaussian models could not only underestimate the consequences of a release, but also can incorrectly identify locations where higher concentrations can occur, sometimes by more than 3 Building wake effects can cause a plume from a stack source located within a few times the height of a nearby building to be forced down to the ground much sooner than it would if a building were not present, thereby increasing the concentration nearer the source than might otherwise be expected. DOE-HDBK-1216-2015 53 one order of magnitude. This can lead to the selection of inappropriate measurement locations or have undesirable effects on subsequent protective actions. Complex terrain trajectory models provide more realistic assessments in these settings, as they more accurately account for temporal and spatial variations in atmospheric conditions and release rates. Complex terrain airflow trajectory models (NRC 1979; NRC 1983; NRC 1986) treat atmospheric transport and dispersion as separate processes. This additional complexity is necessary to consider spatial and temporal variations of the atmosphere. These models generally require the same types of meteorological data as the straight-line models. However, to make full use of their capabilities to characterize three-dimensional spatial variations, use of meteorological data from more than one location and at more than one height above the surface is necessary. In addition, input to complex terrain trajectory models is a series of meteorological observations at different levels in the atmosphere that include wind direction and speed, a direct or inferential measure of turbulence indicator of stability class, temperature, and other important variables, rather than sets of frequency distributions. 5.4 Meteorological Data Requirements for Other Applications Meteorological data and site-specific forecast services may also be needed to support daily operations and responses to actual hazardous conditions. These include weather conditions that may: • Produce a threat or challenge to personnel safety and health; • Damage or destroy property and facilities; • Lead to a variety of accidents that could result in injury or loss of life; and, • Facilitate optimum plant operations. 5.5 Meteorological Data Requirements for Quantifying Turbulent Diffusion Atmospheric dispersion models require data characterizing turbulence in the atmospheric boundary layer to determine the diffusion of a contaminant as it is transported downwind. Many of the contemporary advanced models use or calculate horizontal and vertical velocity variances (or turbulence kinetic energy) directly and apply the resulting statistics in a Lagrangian particle or Gaussian diffusion model (e.g., EPA’s AERMOD). Sonic anemometers can be used to determine these velocity variances and other required boundary layer scaling parameters such as friction velocity (u*), convective velocity scale (w*), and Obukov length (L), as described by

DOE-HDBK-1216-2015 54 Monin-Obukov similarity theory. The use of these direct turbulence measurements in atmospheric dispersion modeling is preferred, whenever possible. For sites that do not use sonic anemometers, or where traditional instruments are used as a backup data source, average values of wind speed and temperature from two levels on a tower can be used to calculate the Bulk Richardson number (Rb). The value of Rb can be used to determine L, which in turn can be used with wind speed and surface roughness length, zo to calculate the appropriate scaling parameters. Gaussian straight-line and complex terrain trajectory transport and dispersion models make use of dispersion coefficients (e.g., the terms σy and σz in the Gaussian plume equation) to describe the lateral and vertical spread of the contaminant, respectively. Values for these coefficients are determined using well-established empirical expressions, which couple turbulent diffusion with the distance the material has traveled since released. Most of the commonly applied Gaussian models, such as CAP-88, utilize expressions for σy and σz that are dependent on discrete categories of atmospheric turbulence such as Pasquill stability class. Gifford (1976) discusses various sets of stability dependent expression for σy and σz including those derived by Briggs (1984) and Pasquill-Gifford (Gifford, 1976). Acceptable methods for determining Pasquill stability class from typical onsite meteorological measurements are: Method 1. Solar radiation coupled with the temperature difference between two levels in the vertical (∆T). Method 2. The standard deviation in fluctuations in the elevation angle of the wind (σφ) coupled with wind speed and time of day. Method 3. The standard deviation in fluctuations of wind direction azimuth (σθ) coupled with wind speed and time of day. EPA (2000a) provides appropriate criteria for determining Pasquill stability using each of these methods. Methods 2 and 3 have the appeal of utilizing direct measurement of turbulence, whereas method 1 is similar conceptually to Pasquill’s original method. Use of ∆T data alone for stability classification, as outlined in Nuclear Regulatory Commission Regulatory Guide 1.23, Rev. 1 (2007b) is not recommended for use in stability classification since there is only a weak relationship between turbulence intensity and lapse rate in unstable conditions. DOE-HDBK-1216-2015 55 For sites utilizing meteorological data from the National Weather Service or other private and public sector organizations, the use of Pasquill’s original scheme, as modified by Turner (1970) (summarized in Table 5-1) is appropriate. Classification criteria for Turner’s method is summarized in Table 5-1 and described in EPA (2000a). TABLE 5-1. Key to Pasquill Stability Categories A: Extremely Unstable Conditions B: Moderately Unstable Conditions C: Slightly Unstable Conditions D: Neutral Conditions E: Slightly Stable Conditions F: Moderately Stable Conditions Daytime Insolation Nighttime Conditions Surface Wind Speed (m/s) Strong Moderate Slight Thin overcast or ≥ 4/8 low cloud ≤ 3/8 < 2 A A-B B - - 2-3 A-B B C E F 3-5 B B-C C D E 5-6 C C-D D D D >6 C D D D D Note: Neutral category D should be used regardless of wind speed, for overcast conditions during day or night For some models, the dispersion coefficients consist of continuous functions of atmospheric turbulence intensity and downwind distance (Hanna et al. 1977; Irwin 1983; Pasquill 1979;

Ramsdell et al. 1982). Pasquill strongly advocated the explicit use of turbulence data to evaluate dispersion coefficients, and models with continuous functions for σy and σz should be used when possible. One advantage is that lateral and vertical diffusion can be calculated independently rather than depend on one single characterization of turbulence. 5.6 Criteria for Meteorological Measurements The meteorological monitoring system design should be based on the needs and objectives of the facility and the guiding principles for making accurate and valid meteorological measurements. Meteorological measurements should be made in locations that, to the extent feasible, provide data representative of the atmospheric conditions into which material will be released and subsequently transported. A qualified professional meteorologist or atmospheric scientist with experience in atmospheric dispersion and with meteorological instrumentation should be consulted in selecting measurement locations and in the design and installation of the meteorological monitoring system. DOE-HDBK-1216-2015 56 Factors to be considered in selecting the appropriate measurement locations and for the determination of the installation of the instruments should include the prevailing wind direction, the topography, and the location of man-made and natural obstructions. Any special meteorological monitoring requirements imposed by other agencies (i.e., outside of DOE) should be taken into consideration when designing meteorological measurement systems and establishing measurement locations (e.g., a DOE-owned facility that is licensed by the NRC). The instruments used in a meteorological monitoring program should be capable of continuous operation within the expected range of atmospheric conditions at the DOE facility. An uninterruptible power supply should be included in the system, and an alternate source of power should be available for longer duration outages. 5.6.1 Criteria for Siting and Locating Meteorological Measurements Wind speed and wind direction measurements should be able to adequately characterize the wind and turbulence (if being directly measured) at potential release heights. If a vertical temperature difference (i.e., ∆T/∆z) is used along with solar radiation to determine atmospheric stability, the temperature difference should be determined over an interval of sufficient thickness to avoid undue influence of the ground (typically at least 50 meters). The temperature monitoring levels should be selected and spaced such that the profile is representative and characterizes the magnitude of atmospheric turbulence at the potential release height(s). EPA (2000a) and ANSI/ANS-3.11-2005 (R2010) provide information on siting and exposure of meteorological towers and sensors for the in situ measurement of the primary meteorological variables. EPA (2000a) includes information on siting in simple terrain, complex terrain, coastal locations and urban locations. Other necessary meteorological measurements should be made using appropriate instrumentation in accordance with accepted procedures. Standard meteorological measurement techniques for the basic meteorological measurements (i.e., wind speed, wind direction, temperature, and precipitation) and site-specific supplemental meteorological measurements (i.e., atmospheric moisture, solar and net radiation, barometric pressure, mixing

height, soil temperature, soil moisture) are outlined in ANSI/ANS-3.11-2005(R2010) and EPA (2000a). Meteorological measurement techniques applicable to complex terrain features, coastal locations, and urban locations are outlined in EPA (2000a). DOE-HDBK-1216-2015 57 Additional information on meteorological monitoring to characterize turbulence can be found in ANSI/ANS-3.11-2005 (R2010), and EPA (2000a). Other necessary meteorological measurements should be made using standard instrumentation in accordance with accepted procedures and manufacturers’ recommendations. 5.6.2 Instrument Mounting Criteria Monitoring site locations need to be selected to reduce aerodynamic influences of obstructions and external influences that may adversely affect the measurements. Wind measurements should be made at locations and heights where airflow modification by obstructions such as large structures, trees, or nearby terrain with heights exceeding one-half of the height of the wind measuring device is minimized. Air temperature and relative humidity measurements should be made in a way to avoid modification by heat and moisture sources (e.g., heating ventilation and air conditioning sources, cooling towers, nearby water bodies, large paved parking lots). The meteorological tower should be sited in an accessible location and the accessibility should be maintained. The meteorological monitoring tower should not be located on or near man-made surfaces such as concrete or asphalt. Mounted wind instruments may be placed on top of the towers or on booms extending to the side of the towers to avoid confounding effects of tower-generated turbulence. Instruments mounted above a tower should be mounted on a mast extending at least one tower diameter above the tower. Instruments mounted on booms extending to the side of a tower should be at least two tower diameters from the tower. Furthermore, the booms should be oriented in directions that minimize the potential aerodynamic effects of the tower on the wind measurements. The orientation of booms for wind instruments should be determined after considering the frequencies of all wind directions. Orientation of the booms on the basis of only the prevailing direction might not minimize tower effects. In some locations, placement of wind instruments on opposite sides of the tower could be necessary to obtain reliable wind data for all wind directions. For locations with two distinct prevailing wind directions, the sensors should be mounted in a direction perpendicular to the primary two directions. Temperature sensors should be mounted and placed in fan-aspirated radiation shields, and the shields should be oriented to minimize effects of direct and reflected solar radiation. The shield should provide ventilation of the sensor at appropriate flow velocities recommended by the vendor. The shield inlet should be at a distance at least 1.5 times the tower horizontal width away from the nearest point on the tower. DOE-HDBK-1216-2015 58 5.6.3 Measurement Recording Systems Criteria The onsite meteorological monitoring system should use an electronic digital data acquisition system housed in a climatically controlled environment as a primary data recording system. A backup recording system for the meteorological monitoring system is recommended, particularly for DOE sites that require a high assurance and availability of valid data. The current

generation of data loggers is so well temperature compensated that environmental control is only required in very extreme conditions. The output of the instruments should be displayed in a location where instrument performance can be monitored on a regular basis. Digitally recorded data used to determine averages for storage into the archive database should consist of, except for σΘ, σφ and precipitation, at least 30 samples taken at intervals not to exceed 60 seconds. The time period represented by the averages should generally be 15 minutes. A minimum of 180 equally spaced wind direction samples is required for estimation of σΘ and σφ. For turbulence measurements with sonic anemometers, a 10 Hz sampling rate should be used. Fifteen-minute averages should be stored in a permanent archive. Additional information on sampling frequency and statistical considerations, such as determining 15- minute and hourly averages, as well as on the standard deviation of wind direction for turbulence characterization is detailed in ANSI/ANS-3.11-2005 (R2010) and EPA (2000a). 5.7 Measurement System Accuracy Criteria The accuracies of the monitoring measurements should be consistent with the specifications set forth in either ANSI/ANS-3.11-2005 (R2010), or EPA (2000a). The specifications in the EPA guidance are usually similar to or more stringent to those found in ANSI/ANS-3.11-2005(R2010). The minimum system accuracy and resolution requirements for digitally recorded data and instrument specifications identified in ANSI/ANS-3.11-2005 (R2010), and EPA (2000a) are presented in Table 5-2. System accuracy should be estimated by calculation of the root-mean- square of the accuracy of the individual components of the system. DOE-HDBK-1216-2015 59 TABLE 5-2. Standards of Accuracy of Meteorological Criteria Criterion Standard of accuracy Horizontal and vertical wind direction ±5º in azimuth with a starting threshold of 0.45 m/sec (1 mph). If a wind vane is to be used to determine σφ, the damping ratio needs to be between 0.4 and 0.6, and the delay distance should not exceed 2 m Wind speed ±0.22 m/sec (0.5 mph) for speeds less than 2.2 m/sec (5 mph); within 5% for speeds of 2.2 m/sec (5 mph) or greater, starting speed of less than 0.45 m/sec (1 mph) Air temperature ±0.5ºC Vertical air temperature difference ±0.1ºC/50m* Dew point temperature ±1.5ºC Relative humidity ±4% Solar/Terrestrial radiation ±5 watts/m2 for <100 watts/ m2 Barometric pressure ±3 mb (0.3kPa) Soil temperature ±1ºC Soil moisture ±10% of actual Precipitation ±10% of volume Time ±5 min * The vertical air temperature difference accuracy requirement is more precise since this parameter is generally used in turbulence typing where very small differences may result in different stability class determinations. 5.8 Inspection, Maintenance, Protection, and Calibration Criteria The meteorological monitoring program should include routine inspection of the measured data for validity. Scheduled maintenance and calibration of the meteorological instrumentation and data-acquisition system should be performed semi-annually at a minimum, or at another appropriate interval based on the calibration recommendations of the manufacturers. Inspections, maintenance, and calibrations should be conducted in accordance with written controlled procedures. Logs of the inspections, maintenance, and calibrations should be kept and maintained as permanent records within the site’s records management system.

ANSI/ANS-3.11-2005 (R2010) provides guidance on recommended calibration practices and on field calibration checks for meteorological instrumentation. DOE-HDBK-1216-2015 60 The meteorological monitoring system should be capable of providing data recovery of at least 90 percent which is quality assured on an annual basis for the combination of wind direction, wind speed, and those data necessary to classify atmospheric stability. All elements of the monitoring and data recording systems should be protected from lightning- induced electrical surges and severe environmental conditions. Functional checks of instrumentation, including recalibration, should be performed after exposure to damaging meteorological conditions or other events with the potential to compromise system integrity. 5.9 Criteria Associated with Supplementary Meteorological Instrumentation Supplementary meteorological data may be needed to support site-specific programs, including, but not limited to, flows in complex terrain over large distances. The topographic setting around a DOE facility, especially with regard to the types of air flow encouraged by the local topography, and the distances from the facility to points of public access should be considered when evaluating the need for any supplementary meteorological instrumentation. Supplementary measurements should be made if meteorological measurements at a single location cannot adequately represent atmospheric conditions for transport and diffusion computations (that is, spatial representativeness). Additional meteorological data may be necessary for making estimates of atmospheric transport and dispersion for large distances. Data from spatially representative meteorological stations (e.g., military, National Weather Service, cooperative stations) can be useful for these applications. The determination of the number of additional data sources and their location(s) is dependent on the heterogeneity of the terrain, the possibility of the presence of three- dimensional atmospheric flow phenomena, and the complexity of the application for which the data will be applied. These judgments require an extensive knowledge of atmospheric transport and dispersion principles. Accordingly, qualified meteorologists should be consulted with respect to these judgments. In some instances, in situ measurements may be augmented by measurements from remote sensing technologies. These include various widely deployed (i.e., commonly used) systems, and less widely deployed systems. 5.10 Meteorological Data Processing Criteria Designing environmental surveillance programs, establishing compliance with applicable regulations and DOE directives, and analyzing the consequences of potential or actual releases DOE-HDBK-1216-2015 61 require information on a common set of meteorological elements. Typically, these elements are wind direction, wind speed, a direct or inferential measure of turbulence, air temperature, and mixing layer thickness. Data should be averaged over a period not to exceed 15 minutes for archival in the permanent database. Although the individual applications could require data for a common set of meteorological elements, the format in which the data are required will vary by application and assessment procedure. Many of these applications will need an averaging interval of one-hour for construction of a time series of data over a defined period of record, or

to develop a data set consisting of the joint frequency of occurrence of wind direction sectors and wind speed categories by Pasquill stability. 5.11 Data Summarization and Archiving Criteria It is important that every facility have a valid and accurate meteorological database, which can be utilized to evaluate environmental impacts and consequence assessments. For licensing and other regulatory purposes, five years of meteorological data are recommended. For future facilities, there should be at least a one-year period of pre-construction data and one- to two- years operational data that meet the aforementioned 90 percent quality assured data recovery requirements. These data should be examined and entered into the permanent archive at least monthly. Meteorological data, raw and quality-assured, should be retained for the life of the facility. 5.12 QA and Documentation Criteria As they apply to meteorological monitoring, the general QA program provisions described in Chapter 11 should be followed. Guidance in quality assurance related to meteorological measurements and meteorological data processing may also be found in Finkelstein et al. (1983) and ANSI/ANS-3.2-1994. DOE-HDBK-1216-2015 62 INTENTIONALLY BLANK DOE-HDBK-1216-2015 63 6 ENVIRONMENTAL SURVEILLANCE The purpose of the environmental surveillance program is to characterize the radiological conditions of the DOE facility environs and, if appropriate, estimate public doses related to these conditions, and confirm predictions of public doses based on effluent monitoring data. Environmental surveillance data also may be useful in evaluating doses to the biota consistent with DOE O 458.1 and DOE-STD-1153-2019. The environmental surveillance program should be conducted in accordance with the requirements of DOE O 458.1 and other applicable regulations and DOE directives. Media routinely monitored in environmental surveillance include air, water, terrestrial foodstuffs, aquatic foodstuffs, soil and sediment. The responsible DOE field organization needs to determine the scope of the environmental surveillance program by considering the following factors: • Applicable regulations; • Hazard potential of the effluents; • Expected quantities and concentrations of effluents; • Nature of potential or actual impacts on air, land, biota, and water; • Extent to which facility operations are routine and unchanging; • Need for supplementing and complementing effluent monitoring; • Size and distribution of the exposed population; • Cost effectiveness of modifications to environmental surveillance; and • Availability of measurement techniques that provide sufficiently sensitive comparisons with the applicable standard and “ambient” measurements. A lines of inquiry approach is provided to conduct self-assessments; to verify that the program is effective and in compliance with appropriate requirements; and to ensure the existence of continuous improvement of the program. Lines of inquiry are identified in Appendix B of this Handbook. 6.1 Key Requirements DOE O 458.1, Radiation Protection of the Public and the Environment, requires that environmental monitoring conducted as part of demonstrating compliance with the Public Dose Limit include environmental surveillance. DOE-HDBK-1216-2015 64 6.2 Summary of General Criteria The criteria listed in Table 6-1 can be used to establish environmental surveillance program

elements for DOE sites. Any additional site-specific criteria should be documented in the site Environmental Monitoring Plan (EMP) or other supporting documentation. An evaluation (e.g., critical pathway analysis) should be conducted and used as the basis for establishing environmental surveillance for DOE sites. The results of this evaluation should be documented in appropriate records to show the following: • Environmental measurement and sampling locations used for determining ambient environmental levels resulting from facility operations; • Procedures and equipment needed to perform the measurement and sampling; • Frequency and analyses required for each measurement and sampling location; • Minimum detection level and accuracy; • QA components; and • Investigation and alarm levels. DOE-HDBK-1216-2015 65 TABLE 6-1: Minimum Criteria for Determining Need for Environmental Surveillance Topic Criteria Routine Surveillance of All Pathways (Ingestion, Inhalation, and Immersion and Submersion Doses) When feasible, all environmental media that, as determined by site- specific radiation exposure pathway analysis, might lead to a measurable annual dose of site origin at the location of the MEI (or a representative location) should be routinely sampled and analyzed for the radionuclides important to dose estimation, and routine measurements of penetrating radiation should be performed at those sites that, as determined by site- specific exposure pathway analysis, might result in an annual dose of site origin at the site boundary, if the total exceeds: a) 5 mrem effective dose, or b) 100 person-rem collective effective dose to the affected population (e.g., within a radius of 80 kilometers (km) of a central point in the site). Periodic Confirmation Environmental surveillance measurements may be performed occasionally when potential dose is low, but should be performed at least every five years even when the projected annual effective dose to the public is less than 0.1 mrem. The frequency and magnitude of environmental surveillance should be proportional to the potential annual dose. Where potential annual dose represents a significant fraction of the reference dose for routine surveillance, environmental sampling should be more frequent. At 20 percent of the reference dose (e.g., 1 mrem effective dose from emissions during a year), annual surveillance for confirmation should be considered. Similarly, more frequent measurements may be warranted if the biota screening levels are challenged. Pathway Measurements Actual measurements on two media for each critical radionuclide/pathway combination, one of which might be the effluent stream, should be performed as part of the site routine environmental monitoring and surveillance program. Characterization of Background Use of data should be based on statistically significant differences between the point of measurement and background data. Unplanned Releases Provisions should be made, as appropriate, for the detection and quantification of unplanned releases of radionuclides to the environment. DOE-HDBK-1216-2015 66 6.2.1 Evaluation of Need for Sampling The need for environmental sampling and analysis should be evaluated, by exposure pathway analysis, for each site radionuclide effluent or emission (liquid or airborne). This analysis with appropriate data, references, and site-specific assumptions, along with site-specific criteria for

selection of samples, measurements, instrumentation, equipment, and sampling or measurement locations, should be adequately and appropriately documented as part of the ERPP. If actual releases are significantly greater than expected, or if unplanned or accidental releases occur, re-evaluate the environmental surveillance needs based on the actual releases. A critical pathway analysis (radionuclide/media) should be performed, documented, and referenced in appropriate documentation (e.g., ERPP-related documents, ASER). If the projected dose equivalent from inhalation of particulates exceeds the criteria of Table 6-1, a particle-size analysis of the sample should be conducted at least annually. In addition, the lung solubility class that is assumed for the particulates in question should be justified and re- substantiated on an annual basis if it is likely to vary with changing facility operations. If environmental surveillance data are to be used with (or in place of) effluent monitoring and modeling to support the assessment and demonstration of compliance with such regulations as 40 CFR Part 61, consider the special requirements of those regulations in the planning and implementation of the environmental surveillance system. The radionuclides of interest are site specific and should be identified based on process knowledge, previous sampling results, and other pertinent information. Radionuclides of interest discussed in this document are provided as a general guide only. While it is tempting to include every suggestion, excessively long lists of radionuclides may lead to: • Extra expense; • Spectral interference; and • False positives. Expense: depending on the procedure, the analytical laboratory may charge more for extra analytes. Spectral interference: occurs when the alpha-particle or photon energies for different radionuclides are too close. Peaks may overlap, or one peak can affect the estimated background of another, or unwanted data from one radionuclide may be within the region of interest of another. This is a frequent problem, and becomes more frequent with a long list of analytes. DOE-HDBK-1216-2015 67 False positives: typically, a few percent of the peaks reported by a computer program are false positives, and the more peaks the computer is asked to look for, the more false positives it will find. The problem of false positives is aggravated by the common practice of reporting the number of counts in a “region of interest” regardless of whether there is a well-defined peak in the right place and with the right shape. The human eye is good at pattern recognition; if a peak does not look real to a human eye, it probably is not real. If there are serious ramifications with a false positive, health-physics staff should examine the shapes and locations of the peaks, and consider whether all the expected peaks are credible, and have areas consistent with expectations. Health physics staff should help to develop a list of radionuclides with a credible chance of being observed. Legacy materials are likely to predominate at most DOE sites. In this case, materials with short half-lives are unlikely unless there is a long-lived parent. When determining radionuclides of interest, staff should consider each category: transuranics, uranium, fission products, and activation products. Transuranics: the most common transuranics are: Pu-238, Pu-239, and Am-241. Transuranics

should be measured by alpha spectrometry or elemental analysis techniques. Detection of transuranics by gamma spectrometry is unreliable because of the spectral interference between the low-energy gammas emitted by transuranics and the K-shell and L-shell x-rays emitted by many radioactive materials. Uranium: may be categorized as natural uranium, uranium tailings, refined uranium, enriched uranium, and depleted uranium. Uranium should be measured by alpha spectrometry or elemental analysis techniques. The first two categories include Pb-214 and Bi-214, the other three do not. Refined uranium does not include measurable amounts of Pb-214 and Bi-214, because Th-230 and Ra-226 were removed during the refinement process and they take thousands of years to grow in. Therefore, at facilities that use only refined uranium, the presence of Pb-214 and Bi-214 indicate natural uranium. On the other hand, facilities that processed uranium ore will have Th-230, Ra-226, Pb-214, and Bi-214 in the tailings. The isotopic ratios of U-234:U-235:U-238 are useful, though staff should be aware that water is usually enriched in U-234 because the decay process causes the U-234 to become dislodged, and so makes it more soluble. Fission products: normally occur together in a mixture known as “mixed fission products.” At reactor facilities or re-processing facilities, the list of fission products will be long. In legacy DOE-HDBK-1216-2015 68 material, only two fission products are normally measurable: Sr-90 and Cs-137. However, Cs- 134 is easy to detect by gamma spectrometry when sampling shortly after fission product accident events (e.g., Fukushima-Daiichi). Iodine isotopes are potentially important, though most have short half-lives; iodine-129 is naturally occurring and is very difficult to detect. Activation products: Co-60 is easy to detect by gamma spectrometry. Na-22 is also easily detected by gamma spectrometry and may be measurable in more recently activated materials. Tritium is widespread and requires specialized detection techniques. At accelerators, the list of activation products will be long. Radionuclides in sealed sources are unlikely to be found in the environment. Also, small quantities of radionuclides used in a well-managed modern facility are unlikely to be found in the environment unless there is a leak or spill. Discharges from a permitted outfall are monitored and the data should guide the environmental staff. Measurement of background/ambient and near-site naturally-occurring radionuclides (e.g., Be- 7, K-40, Tl-208, Pb-212, Pb-214, Bi-214, and Ac-228) may be useful as a reality check and to confirm that systems are behaving as expected. The mobility of radionuclides and the likelihood of uptake into biota should also be considered. Tritium is the most mobile and is readily taken up by biota. Iodine is mobile, readily taken up by mammals, and concentrates in the thyroid, so it should be monitored if recent fission products are credible; several iodine isotopes are readily detected by gamma spectrometry when sampled shortly after fission product accident events (e.g., Fukushima-Daiichi). Strontium behaves like calcium and it is moderately mobile. Uptake of strontium into biota depends on the availability of calcium in the environment, though some plants do not easily discriminate between strontium and calcium. Cesium cations attach strongly to the soil matrix and are less

mobile than strontium. Most biota can discriminate between cesium and potassium, so uptake of cesium is dependent on the availability of potassium. For example, cesium uptake is common near Savannah River where the soil is deficient in potassium, and less common where potassium is abundant. Transuranics are generally less mobile and not easily taken up by biota. 6.2.2 Emergency Monitoring Provisions Emergency monitoring is beyond the scope of this document. However, provisions for monitoring during an emergency situation should be considered when planning for environmental monitoring and determining routine program needs. Further provisions should be DOE-HDBK-1216-2015 69 made, as appropriate, for the detection and quantification of unplanned releases to the environment of radioactive materials, including radionuclides that may be transported by storm water runoff, flooding, or re-suspension of ground-deposited material. It is important to establish an environmental surveillance program that will provide adequate data to compare to measurements taken to support a response should an emergency occur. 6.3 Performance Requirements for Environmental Surveillance Programs For all new or modified DOE facilities, a pre-operational assessment should be made and documented to determine the types and quantities of effluents to be expected from the facility and to establish associated environmental surveillance programs. Calibration of dosimeters and exposure-rate instruments should be based on NIST traceable standards. Where significant variations in effluent releases are observed or expected, obtain environmental samples or perform measurements either continuously or at an interval less than one-half the expected peak-to-peak interval. Gross radioactivity analyses should be used only as trend indicators, unless documented supporting analyses provide a reliable relationship to specific radionuclide concentrations or doses. The overall precision (± percent uncertainty) of all measurements should be estimated, and the LLD at specified confidence levels for appropriate radionuclides should be determined and documented. Sample preservation methods used to assure integrity should be consistent with the analytical procedures used. All environmental surveillance programs and procedures should be designed to ensure representative samples or measurements of the radiation exposure pathway media are obtained. 6.3.1 Specific Performance Requirements Sampling or measurement frequencies for each significant radionuclide - environmental medium combination (e.g., those contributing greater than 0.1 mrem effective dose or greater than or equal to 10 percent of the annual offsite dose from all emissions) should take into account the half-life of the radionuclides to be measured and should be documented in the site environmental surveillance description. When considering short-half-life radionuclides, ensure that the sampling and measurement intervals do not exceed twice the half-life of the radionuclide. “Background” or “control” location measurements should be made for every significant radionuclide and pathway combination for which environmental measurements are used in the dose calculations. An annual review of the radionuclide composition of effluents or emissions should be conducted and compared with those used to establish the site environmental surveillance monitoring program plan or other document that describes the DOE-HDBK-1216-2015

70 environmental surveillance. Deviations from established environmental surveillance requirements, including sampling or measurement station placement, should be documented. 6.3.2 Air Sampling System Air sampling equipment calibrations should be performed by either a primary measurement device or a calibrated secondary measurement device at the field location. Recalibration should be performed on a pre-determined schedule. The air sampling rate should not vary by more than ± 20 percent, and total air flow or total running time should be indicated or recorded; air sampling systems should be leak-tested, flow-calibrated, tested, and inspected on a routine basis. At a minimum, the manufacturer’s recommended calibration frequency should be followed. 6.3.3 Consultation with Game Officials If protected species are selected through the critical pathway analysis to sample, analogous species should be selected and sampled in their place whenever possible. State and local game officials should be consulted when selecting appropriate protected species to sample. 6.3.4 Consultation with Local, State and Regional EPA Representatives DOE field elements and contractor staff should ensure that ground water monitoring plans are consistent with applicable State and regional EPA ground water monitoring requirements. DOE Federal and contractor staff should consult as needed, with local, and State representatives and regional EPA offices, to ensure that applicable requirements are incorporated into environmental surveillance program documentation. 6.4 Design Criteria It is important that overall objectives for environmental monitoring programs be established and documented. It is also important that the environmental surveillance program be reviewed periodically and modified as program needs change. The general design criteria for establishing an environmental surveillance program for radioactive materials released in the effluents or emissions from DOE-controlled facilities are discussed in the following sections. DOE-HDBK-1216-2015 71 6.4.1 Environmental Surveillance Program Objectives Environmental surveillance programs conducted at all DOE sites should enable the following to be determined: • Compliance with all applicable environmental quality standards and public exposure limits; and the requirements of DOE O 458.1; • Background levels and site contributions of radioactive materials in the environment; • Effectiveness of effluent treatment and controls in reducing effluents and emissions; • Validity and effectiveness of models to predict the concentration of contaminants in the environment; • Quantification of contaminant transport into the environment; • Long-term buildup and prediction of environmental trends from site-released radioactive material; and • Detection and quantification of unplanned releases. In addition to determining the need for an environmental surveillance program based on the objectives noted above, certain subsidiary objectives should also be considered. For example, site history and current public interests might indicate the need for an environmental surveillance program that examines specific aspects of a site’s environmental impact, even when no other need is indicated. The following is a partial list of subsidiary objectives (as provided in ICRP 1985) that should be considered when establishing environmental surveillance program objectives:

• The environmental surveillance should provide information that is available to the public; • The environmental surveillance program should provide data that enable distinguishing site radiation contributions from other local sources (natural or manufactured); • The environmental surveillance program should be capable of obtaining data that may be needed to assess the consequences of an accident; and • Elements of the environmental surveillance program should be capable of determining site-specific values for transfer parameters where appropriate. Information on transfer parameters is provided in IAEA (2010a), ICRP (2009), and Staven et al. (2003). DOE-HDBK-1216-2015 72 6.4.2 Program Planning and Design Factors that affect the relative level of environmental surveillance and to some extent the points at which measurements are to be made, include: 1) The potential hazard of the materials released, considering both expected quantities (including unplanned releases) and relative radiotoxicities; 2) The extent to which facility operations are routine and unchanging; 3) The need for supplementing and complementing effluent monitoring; 4) The size and distribution of the exposed population; 5) The cost effectiveness of modifications to the environmental surveillance program; and 6) The availability of measurement techniques that provide sufficiently sensitive comparisons with the applicable standard and “background” measurements. The environmental surveillance media sampled or radiation measurements made should represent, as much as possible, the actual exposure vectors to people. Selection of locations, frequency, media and radionuclides to be measured, and measurement techniques are the basis of an environmental surveillance program. This program also should include any special monitoring required, such as trend indicators and additional samples/measurements required for quality assurance. The effort devoted to the environmental surveillance program should reflect the significance of the projected radiation doses. Once the critical pathways and nuclides are identified (i.e., a critical pathway analysis is carried out), an annual review comparing reported effluent releases with those considered in the original analysis should be conducted and changes in the environmental surveillance program noted in a revised version of the appropriate program document and discussed in the ASER. The effluents and the environment into which they are dispersed are dynamic, exhibiting both spatial and temporal variations of nearly all constituents. The importance of each individual radionuclide depends on its physical and chemical form, which determines its movement in the environment and eventual uptake, deposition, and retention by humans, and on the differential metabolism of the radionuclide by humans. Providing site-specific tables of the environmental sampling/measurement locations per site as a function of calculated annual total effective dose (TED) to the representative person or to the MEI or collective dose is recommended. Any changes in site-specific factors (e.g., location of samples, type of samples, average temperatures, wind direction or velocities) and the basis for DOE-HDBK-1216-2015 73 the change(s) should be indicated in environmental surveillance program documentation. Information previously used should be preserved in historical records. 6.5 External Exposure Monitoring

A primary objective of external exposure monitoring is to assess and limit the actual or potential radiation dose to persons in the site environs. External exposure monitoring considerations include: (1) external exposure in air; (2) external exposure in water; (3) external radiation measurement locations and frequency; (4) factors in selection of indicator locations; (5) locations of background measurement stations; (6) onsite and offsite locations needed to characterize discharges or confirm effluent monitoring and modeling projections; (7) shoreline locations; and (8) height and frequency of measurements. For most DOE facilities, the whole-body exposure is limited, and penetrating radiation measurements are satisfactory. Exceptions could include the atmospheric release of beta emitters such as uranium decay products or krypton from fuel manufacturing or reprocessing facilities, respectively. For DOE sites, the gamma (and, where applicable, neutron) exposure (or exposure rate) should be measured or calculated; any significant skin dose from airborne beta emitters should be calculated from effluent data. If external beta doses from deposition are considered to be significant, they should be estimated from effluent data, from beta-sensitive dosimeters, or by soil or vegetation sampling and laboratory analysis. 6.5.1 External Exposure in Air One of the “critical pathways” of exposure for population groups living within the vicinity of DOE facilities is exposure to external radiation from those sites (Denham 1979). Exposure of population groups to external radiation from DOE operations includes: (1) cloud passage of airborne effluents; (2) previously released and deposited radionuclides on soil, vegetation, or sediments; (3) radiation-generating facilities, especially high-energy accelerators or industrial x- ray equipment, and large isotopic radiation sources; and (4) the storage, disposal, or movement of large sources of radioactive waste. 6.5.2 External Exposure in Water External exposures from radionuclides in water generally are insignificant. However, unique situations could arise where recreational, commercial, or industrial use of a receiving body of water might cause exposure to certain individuals. Appropriate environmental measurements should be included in the routine program to better define an unusual “source” if the site-specific DOE-HDBK-1216-2015 74 pathway analysis shows this to be a significant (greater than 10 percent of the total offsite dose) source of exposure. 6.5.3 External Radiation Measurement Locations and Frequency Considerable judgment needs to be used in locating environmental radiation measurement stations. Before final placement of any environmental radiation measurement station (background or control and indicator locations), an initial on-the-spot survey should be performed and documented to determine the absence of possible naturally occurring anomalies that could affect interpretation of later measurements. The recommended technique for making these pre-surveys is to use a low-level radiation survey instrument (e.g., micro-R meter) followed up with a pressurized ion chamber (PIC) measurement at those geographic locations selected on the basis of the preliminary screening by portable instrument survey. If desired, an in situ gamma- ray spectrometer (e.g., NaI, IGe (Intrinsic Germanium detector), or Ge(Li)) can be used to determine which terrestrial nuclides are contributing to the observed exposure rate.

Examples of dosimeter placement locations to be avoided, if at all possible, include the following: • Locations of unique or different geology (i.e., reflecting changes in the terrestrial background); • Locations where the altitude differs significantly (e.g., altitudinal differences between “background” or control locations and those indicator locations to be used around a given DOE site should not exceed 150 m (reflecting changes in the cosmic-ray background)); • Locations where the proximity of structures could alter the measurement results (reflecting changes from shielding or high background radiation levels due to naturally occurring radionuclides in building materials (e.g., thorium, uranium, radium)); and • Valleys or hollows (where puddles of precipitation or runoff could accumulate, or where local topography could shield the dosimeters from the possible passage of airborne effluents). DOE-HDBK-1216-2015 75 6.5.4 Factors in Selection of Indicator Locations Selection of the indicator locations4 for external exposure monitoring should be based on expected sources of external radiation – noble gas plumes, soil-deposited atmospheric particulates released from the site, onsite radiation-generating facilities or large radiation sources, or potential routes of waste transport from the site – and the local population distribution and prevailing wind directions. The technique described by Waite (1973a, 1973b) for placement of air samplers, based on average meteorological conditions and existing population distributions should be considered for determining external radiation measurement locations. 6.5.5 Location of Background Measurement Stations Background or control measurement stations should be located a minimum distance of 15 to 20 kilometers (km) from the larger sites and 10 to 15 km from the smaller sites in the least prevalent wind direction. Control stations should also be placed in areas typical of local geology, away from buildings (which can shield the detectors), and at similar elevations to those for indicator stations. The emphasis here is on the placement of dosimeter stations such that the difference between background/control or pre-operational data and the data from those stations expected to be affected by site effluents/activities can be assessed accurately. 6.5.6 Offsite Locations Offsite radiation measurement locations should be monitored for each DOE site where predicted external radiation doses exceed the 0.1 mrem effective dose criterion in Table 6-1. These offsite measurement locations include a background or control location, site perimeter or boundary locations, and locations in nearby communities (within a pre-determined distance from the site to include communities in the predominant transport regions). The site perimeter or boundary locations should include locations directly upwind from the maximum predicted 4 Indicator locations are monitoring locations intended for measuring radioactive material or radiation that has or may be present as a result of a DOE activity or operation. Background or ambient background locations are those monitored or sampled to establish to establish radiation or radioactive material levels that are not associated with DOE activities. Indicator locations also are used to verify or validate modeling projections and in such cases may indicate nothing above background. DOE-HDBK-1216-2015 76 ground-level concentration from atmospheric releases averaged over a period of 1 year. Offsite

measurement locations should coincide with locations where maximum predicted levels occur and where any member of the public resides or abides. For those sites larger than a few kilometers in radius, the maximum predicted concentrations may actually be onsite. In this case, radiation measurements may be made at the onsite location of predicted maximum air concentration(s), as well as other locations that may be helpful in the interpretation of offsite results. 6.5.7 Shoreline Locations If exposure measurements are to be made at shoreline locations, dosimeters should also be placed to correspond to key water sampling locations (including the site boundary), as well as locations important for recreational, commercial, or industrial use. However, changes in water elevation caused by tides or fluctuating releases from dams may make this impractical, in which case intermittent exposure-rate measurements need to be used during the seasons in which recreational use of the shoreline (for hunting, fishing, sun-bathing) actually occurs. 6.5.8 Height and Frequency of Measurements The recommended height for external radiation measurement is 1 m above the surface. If another height is used, the relationship to the 1 m height should be established and documented for the site. The frequency should be based on predicted exposure rates from site operations at the measurement locations. Integrating devices (e.g., dosimeters) should be exposed long enough (typically 1 calendar quarter) to produce a readily detectable dose (e.g., 10 × the minimum sensitivity of the dosimeter). If intermittent external radiation measurements are made, their frequency should be timed to coincide with batch atmospheric releases or the intermittent use of large sources or the operation of radiation-generating facilities. 6.6 Direct Radiation Measurement (Pressurized Ion Chamber-Type Instrumentation) Factors for direct radiation measurement that need to be considered include: (1) continuous exposure monitoring; (2) neutron monitoring; and (3) instruments and methods to use. 6.6.1 Continuous Exposure Monitoring Continuous environmental gamma-ray monitoring is available (Jackson et al. 1985; Urabe and Katsurayama 1984) and highly desirable, yet it cannot always be justified on the basis of initial DOE-HDBK-1216-2015 77 system cost or long-term maintenance. However, in situ gamma spectrometry should be used as a method of documenting environmental mixtures of radionuclides resulting from natural and manufactured sources (e.g., for dosimeter placement). Historical monitoring information also should be considered. The deployment of at least one continuously recording exposure-rate instrument is recommended, preferably near the site boundary in the expected direction of a potential plume. An array of continuously recording exposure-rate instruments should be considered if there is a potential for release of large inventories of gamma emitters. 6.6.2 Neutron Monitoring For some sites, especially in the vicinity of high-energy facilities, neutron monitoring also may be necessary. Application of detection techniques to measure environmental levels of neutrons is limited. Commonly used materials for detection of slow or thermal neutrons include using a Bonner multisphere, etched track detectors, silicon diodes, and ionization detectors such as boron trifluoride proportional counters. Monitoring for fast neutrons will require use of Columbia Resin #39 (CR-39) detector material. When neutron monitoring is necessary, the method of measurement should be based on the anticipated flux and energy spectrum. A fixed monitor (moderated boron trifluoride (BF3) counter or rem counter) is recommended, yet site-specific conditions may warrant the use of intermittent portable instrument surveys only during the infrequent periods of machine operation