DOE-HDBK-3010-94 Volume I (Reaffirmed 2013), Airborne Release Fractions/Rates and Respirable Fractions for Nonreactor Nuclear Facilities, Volume I, Analysis of Experimental Data (Part 1 of 2, links to all Parts)

TS NOT MEASUREMENT SENSITIVE DOE-HDBK-3010-94 December 1994 Reaffirmed 2013 DOE HANDBOOK AIRBORNE RELEASE FRACTIONS/RATES AND RESPIRABLE FRACTIONS FOR NONREACTOR NUCLEAR FACILITIES Volume I - Analysis of Experimental Data U.S. Department of Energy AREA SAFT Washington, D.C. 20585 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. This document has been reproduced directly from the best available copy. Available to DOE and DOE contractors from the Office of Scientific and Technical Information, P.O. Box 62, Oak Ridge, TN 37831; (615) 576-8401. Available to the public from the U.S. Department of Commerce, Technology Administration, National Technical Information Service, Springfield, VA 22161; (703) 487-4650. Order No. DE95004712 DOE-HDBK-3010-94 FOREWORD 1. This Department of Energy (DOE) Handbook is approved for use by the DOE and its contractors as an information source. 2. Beneficial comments (recommendations, additions, deletions) and any pertinent data that may be of use in improving this document should be addressed to: Director, Office of Engineering, Operations, Security and Transition Support (DP-31, GTN), U.S. Department of Energy, Washington, D.C., 20585. 3. The issue of airborne releases of radioactive material from nonreactor nuclear facilities has been a subject of investigation for almost four decades, during which time a large number of individuals have contributed to the current knowledge base. Beginning in the 1960’s, a number of experiments were conducted in the United States and other countries to develop actual data on release potentials. In the late 1970s, the United States Nuclear Regulatory Commission (NRC) sponsored a research program to develop improved methods for realistically evaluating the consequences of major accidents in nuclear fuel cycle facilities. This program culminated in the development of NUREG-1320 (5/88), "Nuclear Fuel Cycle Facility Accident Analysis Handbook." The U.S. DOE began placing an increased emphasis on environmental, health, and safety issues in the mid- to late-1980s. In response to these efforts, the DOE Office of Defense Programs (DP) sponsored the Defense Programs Safety Survey (11/93). One of the objectives of this study was to build upon previous work to "develop consistent data and methodologies for making conservative estimates of basic consequence derivation parameters." As part of this effort, experimental data for airborne release fractions and respirable fractions were summarized and evaluated to estimate reasonably bounding values for physical stresses associated with the experiments. The unique and valuable nature of that compilation has been judged to merit further development as a handbook that can be directly used by technical analysts. 4. This handbook contains (1) a systematic compilation of airborne release and respirable fraction experimental data for nonreactor nuclear facilities, (2) assessments of the data, and (3) values derived from assessing the data that may be used in safety analyses when the data are applicable. To assist in consistent and effective use of this information, the handbook provides: Identification of a consequence determination methodology in which the information can be used; Page i DOE-HDBK-3010-94 Discussion of the applicability of the information and its general technical limits; Identification of specific accident phenomena of interest for which the information is applicable;

Examples of use of the consequence determination methodology and airborne release and respirable fraction information. It is acknowledged that the data examined in this handbook is limited to that available during the preparation process. Other data may exist or be developed, and individuals are invited to submit such material for consideration for any future revisions. Page ii DOE-HDBK-3010-94 ACKNOWLEDGEMENTS This Department of Energy Handbook was prepared by Mr. Jofu Mishima and Mr. David Pinkston of SAIC under the technical direction of Mr. Dae Chung, DOE Office of Defense Programs. No one group of individuals, however, can appropriately take sole credit or responsibility for an undertaking of this magnitude. The preparers would like to gratefully acknowledge the specific authors whose works are referenced in this document and analysts, operators, scientists, and managers throughout the Department of Energy weapons complex and NRC fuel cycle licensee process who have labored for decades to define a context in which this information is meaningful. This broad thanks extends likewise to the large number of individuals who have provided comments on the handbook. Additional individuals involved in the development and refinement of this document merit special mention. Mr. Roger Blond of SAIC was the initiator of this effort under the sponsorship of Mr. Jeff Woody and Mr. Gerald Gears, DOE-DP. The task of editing and word processing this document was performed by William Benton, Collise Bohney, Sandra Marks, Carla Merrill, Elizabeth Owczarski, and Dawn Standley. Beyond the formal comment process used for documents of this type, the following individuals provided valuable technical insights and/or specific reviews of this document in its various stages of development: Dr. Chris Amos, SAIC Mr. John Joyce, WHC Ms. Marcel Ballinger, PNL Mr. Randy Kircher, H&R Tech. Assoc. Dr. Sanford Bloom, MMES-OR Dr. Bob Luna, SNL Dr. Bruce Boughton, SNL Ms. Lenna Mahonney, PNL Dr. Sandra Brereton, LLNL Mr. Bob Marusich, PNL Dr. Donald Chung, Scientech Dr. Louis Muhlenstein, WHC Mr. Chris Everett, SAIC Dr. Louis Restrepo, SNL Dr. Roland Felt, WINCO Mr. Fred Stetson, SAIC Mr. Terri Foppe, EG&G-Rocky Flats Dr. Doug Stevens, LLNL Mr. Abel Garcia, LLNL Mr. Ray Sullivan, SAIC Dr. Norman Grandjean, SNL Ms. Wendy Ting, SAIC Dr. John Haschke, LANL Mr. John Van Kieren, WHC Mr. Hans Jordan, EG&G-Rocky Flats Dr. David Wilson, WSRC One additional special effort merits final mention. In precursor efforts to this document, the DOE Office of Nuclear Safety provided the services of a review panel organized and directed by Dr. Vinod Mubayi, BNL, whose members were Dr. Brian Bowsher, AEA Tech. UK, Dr. Bob Einzinger, PNL, Dr. Jim Gieseke, BCL, and Dr. Dana Powers, SNL. This group reviewed draft versions of this document as well. Page iii DOE-HDBK-3010-94 Page iv DOE-HDBK-3010-94 TABLE OF CONTENTS VOLUME 1: MAIN TEXT List of Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xii List of Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiv List of Acronyms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xviii 1.0 INTRODUCTION 1.1 Purpose of Handbook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 1.2 Source Term Formula . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

1.3 Applicability of Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7 1.4 Accident Stresses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10 1.5 Handbook Organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-12 2.0 MATERIALS IN THE GASEOUS STATE 2.1 Noncondensible Gases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 2.1.1 Summary of Analysis of Data . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 2.1.2 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 2.2 Vapors (Condensible Gases) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2 2.2.1 Summary of Analysis of Data . . . . . . . . . . . . . . . . . . . . . . . . . 2-2 2.2.2 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2 3.0 LIQUIDS 3.1 Summary of Analysis of Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1 3.2 Aqueous Solutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7 3.2.1 Thermal Stress: Evaporation and Boiling . . . . . . . . . . . . . . . . . 3-7 3.2.1.1 Heating Of Shallow Pools . . . . . . . . . . . . . . . . . . . . . 3-10 3.2.1.2 Heating of Pools . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-13 3.2.1.3 Additional Evaporation and Bubbling Release Studies . . 3-15 3.2.2 Explosive Stress: Shock, Blast, and Venting . . . . . . . . . . . . . . 3-18 3.2.2.1 Shock Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-18 3.2.2.2 Blast Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-19 3.2.2.3 Venting of Pressurized Liquids . . . . . . . . . . . . . . . . . 3-19 3.2.2.3.1 Venting Below the Liquid Level . . . . . . . . 3-20 3.2.2.3.2 Venting Above the Liquid Level or Overall Containment Failure . . . . . . . . . . . . . . . . . 3-22 3.2.2.3.3 Flashing Spray . . . . . . . . . . . . . . . . . . . . 3-26 3.2.3 Free-Fall Spill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-33 Page v DOE-HDBK-3010-94 3.2.3.1 Solutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-33 3.2.3.2 Slurries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-35 3.2.3.3 Viscous Solutions . . . . . . . . . . . . . . . . . . . . . . . . . . 3-36 3.2.4 Aerodynamic Entrainment and Resuspension . . . . . . . . . . . . . . 3-37 3.2.4.1 Spray Release From Large Outdoor Pond . . . . . . . . . . 3-37 3.2.4.2 Suspension of Liquids From Shallow Pools of Concentrated Heavy Metal Solutions on Stainless Steel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-40 3.2.4.3 Estimate of the Resuspension of Liquids From Soil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-40 3.2.4.4 Suspension From Soil at Higher Windspeeds . . . . . . . . 3-41 3.2.4.5 Bounding Assessments . . . . . . . . . . . . . . . . . . . . . . . 3-41 3.3 Organic, Combustible Liquids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-42 3.3.1 Burning of Small Volume/Surface Area 30% TBP-Kerosine Solutions, No Vigorous Boiloff . . . . . . . . . . . . . . . . . . . . . . . 3-43 3.3.2 Pool Fires of 30% TBP-Kerosine . . . . . . . . . . . . . . . . . . . . . . 3-44 3.3.3 Combustion of TBP-Kerosine Solutions Over Pools of Acid,

Vigorous Boiloff . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-44 3.3.4 Airborne Release of Uranium During the Burning of Process Solvent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-46 3.3.5 Airborne Release During Combustion of TBP-Kerosine . . . . . . . 3-46 3.3.6 UNH and Air-Dried UNH on Various Surfaces During a Shallow Pool Gasoline Fire . . . . . . . . . . . . . . . . . . . . . . . . . . 3-48 3.3.7 Thermal Stress Bounding Recommendations . . . . . . . . . . . . . . . 3-49 4.0 SOLIDS 4.1 Summary of Analysis of Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1 4.2 Metals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-11 4.2.1 Thermal Stress . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-11 4.2.1.1 Plutonium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-11 4.2.1.1.1 . . . 4 Room Temperature Oxidation/Corrosion 4-12 4.2.1.1.2 Oxidation at Elevated Temperatures Below Ignition Temperature . . . . . . . . . . . . . . . . 4-19 4.2.1.1.3 Self-sustained Oxidation Above the Ignition Temperature . . . . . . . . . . . . . . . . . . . . . . 4-21 4.2.1.1.4 Turbulence . . . . . . . . . . . . . . . . . . . . . . . 4-25 4 Disturbed Molten Metal Surface With High 4.2.1.1.5 Small Molten Metal Drops Hurled Through Air or Explosion of Entire Metal Mass . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-31 4.2.1.2 Uranium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-33 Page vi DOE-HDBK-3010-94 4.2.1.2.1 Oxidation at Elevated Temperatures . . . . . . 4-37 4.2.1.2.2 Disturbed Molten Metal Surface With High Turbulence . . . . . . . . . . . . . . . . . . . . . . . 4-42 4.2.1.2.3 Small Molten Metal Drops Hurled Through Air or Explosion of Entire Metal Mass . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-44 4.2.2 Explosive Stress: Shock, Blast, and Venting . . . . . . . . . . . . . . 4-44 4.2.2.1 Shock Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-45 4.2.2.2 Blast Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-45 4.2.2.3 Venting of Pressurized Gases Over Metals . . . . . . . . . 4-45 4.2.3 Free-Fall Spill and Impaction Stress . . . . . . . . . . . . . . . . . . . . 4-45 4.2.4 Aerodynamic Entrainment and Resuspension . . . . . . . . . . . . . . 4-46 4.3 Nonmetallic or Composite Solids . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-46 4.3.1 Thermal Stress . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-46 4.3.1.1 Vitrified Waste . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-47 4.3.1.2 Aggregate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-48 4.3.1.3 Encased Nuclear Material . . . . . . . . . . . . . . . . . . . . . 4-48 4 Spent Nuclear Fuel 4-484.3.1.3.1 . . . . . . . . . . . . . . . . . 4.3.1.3.2 Metal Targets . . . . . . . . . . . . . . . . . . . . . 4-50 4.3.1.3.3 Metal Alloy and Cermet Targets . . . . . . . . 4-50 4.3.2 Explosive Stress: Shock, Blast, and Venting . . . . . . . . . . . . . . 4-51 4.3.2.1 Shock Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-51 4.3.2.2 Blast Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-51 4.3.2.3 Venting of Pressurized Gases Over Solids . . . . . . . . . . 4-52

4.3.3 Free-Fall Spill and Impaction Stress . . . . . . . . . . . . . . . . . . . . 4-52 4.3.4 Aerodynamic Entrainment and Resuspension . . . . . . . . . . . . . . 4-52 4.4 Powders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-55 4.4.1 Thermal Stress . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-55 4.4.1.1 Chemically Nonreactive Compounds . . . . . . . . . . . . . . 4-56 4.4.1.2 Chemically Reactive Compounds . . . . . . . . . . . . . . . 4-57 4.4.2 Explosive Stress: Shock, Blast, and Venting . . . . . . . . . . . . . . 4-61 4.4.2.1 Shock Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-61 4.4.2.2 Blast Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-63 4.4.2.2.1 and Large Volume, Confined Deflagrations . . . . . . . . . . . . . . . . . . . . . . 4-63 4 Unshielded Blast Effects From Detonations 4.4.2.2.2 Shielded Blast Effects From Detonations and Large Volume, Confined Deflagrations . . . . . . . . . . . . . . . . . . . . . . 4-65 4.4.2.3 Venting of Pressurized Powder . . . . . . . . . . . . . . . . . 4-69 Page vii DOE-HDBK-3010-94 4 Venting of Pressurized Powders or 4.4.2.3.1 Pressurized Gases Through a Powder, Pressure > 0.17 MPag . . . . . . . . . . . . . . . . 4-70 4 Venting of Pressurized Powders or 4.4.2.3.2 Pressurized Gases Through a Powders, Pressure < 0.17 MPag . . . . . . . . . . . . . . . . 4-73 4.4.3 Free-Fall Spill and Impaction Stress . . . . . . . . . . . . . . . . . . . . 4-74 4.4.3.1 Free-Fall Spill of Powder with Air Velocity Normal to the Direction of Fall . . . . . . . . . . . . . . . . . . . . . . . . . 4-74 4.4.3.1.1 . . . . .4 Factors That Affect Dust Generation 4-74 4.4.3.1.2 Free-Fall Spill Experiments . . . . . . . . . . . . 4-77 4.4.3.1.3 Free-Fall Spill of Powder Model . . . . . . . . 4-81 4.4.3.2 Free-Fall Spill with Enhanced Velocity Effects Normal to the Direction of Fall . . . . . . . . . . . . . . . . . 4-82 4.4.3.3 Impact . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-83 44.4.3.3.1 Vibration Shock . . . . . . . . . . . . . . . . . . . . 4-84 4.4.3.3.2 Air Turbulence . . . . . . . . . . . . . . . . . . . . 4-85 4 Large Falling Object Impact or Induced 4.4.4 Aerodynamic Entrainment and Resuspension . . . . . . . . . . . . . . 4-88 4.4.4.1 Entrainment From the Surface of a Homogenous Powder Layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-88 4.4.4.1.1 Phenomena, Factors, and Rates . . . . . . . . . 4-88 4 Review Of Literature on Resuspension 4.4.4.1.2 Experimentally Measured Resuspension Rates . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-96 4.4.4.2 Suspension of Material by Vehicular Traffic . . . . . . . . 4-101 5.0 SURFACE CONTAMINATION 5.1 Summary of Analysis of Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1 5.2 Contaminated, Combustible Solids . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-9 5.2.1 Thermal Stress . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-9 5.2.1.1 Packaged Waste . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-10 5.2.1.2 Uncontained, Cellulosic Waste or Largely Cellulosic Mixed Waste . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-13 5.2.1.3 Dispersed Ash Dropped into Airstream or Exposed to Forced Draft Air . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15

5.2.1.4 Uncontained Plastics/Elastomers . . . . . . . . . . . . . . . . 5-16 5.2.1.4.1 Polychloropene (Elastomer, Rubber) . . . . . . 5-17 5.2.1.4.2 Polymethylmethacrylate (Lucite/Perspex, Windows) . . . . . . . . . . . . . . . . . . . . . . . . 5-17 Page viii DOE-HDBK-3010-94 5.2.1.4.3 Polystyrene (Molded Plastic, Containers, Ion Exchange Resin) . . . . . . . . . . . . . . . . 5-18 5.2.2 Explosive Stress: Shock, Blast, and Venting . . . . . . . . . . . . . . 5-18 5.2.2.1 Shock Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-19 5.2.2.2 Blast Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-19 5.2.2.3 Venting of Pressurized Gases Over Solids . . . . . . . . . . 5-20 5.2.3 Free-Fall Spill and Impaction Stress . . . . . . . . . . . . . . . . . . . . 5-20 5.2.3.1 Free-Fall Spill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-20 5.2.3.2 Impact . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-20 5.2.4 Aerodynamic Entrainment and Resuspension . . . . . . . . . . . . . . 5-21 5.3 Solid, Noncombustible Unyielding Surfaces . . . . . . . . . . . . . . . . . . . . 5-21 5.3.1 Thermal Stress . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-21 5.3.2 Explosive Stress: Shock, Blast, and Venting . . . . . . . . . . . . . . 5-21 5.3.2.1 Shock Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-21 5.3.2.1.1 Contaminated Solids as Monoliths . . . . . . . 5-21 5.3.2.1.2 Contaminated Soil . . . . . . . . . . . . . . . . . . 5-22 5.3.2.2 Blast Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-22 5.3.2.3 Venting of Pressurized Gases Over Solids . . . . . . . . . . 5-22 5.3.3 Free-Fall Spill and Impaction Stress . . . . . . . . . . . . . . . . . . . . 5-23 5.3.3.1 Free-Fall Spill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-23 5.3.3.2 Impact . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-23 5.3.3.2.1 Solids That Undergo Brittle Fracture . . . . . 5-23 5.3.3.2.2 Solids That Do Not Brittle Fracture . . . . . . 5-23 5.3.4 Aerodynamic Entrainment and Resuspension . . . . . . . . . . . . . . 5-24 5.4 HEPA Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-30 5.4.1 Thermal Stress . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-30 5.4.2 Explosive Stresses: Shock, Blast, and Venting . . . . . . . . . . . . . 5-31 5.4.2.1 Shock Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-31 5.4.2.2 Blast Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-31 5.4.2.3 Venting of Pressurized Gases Through Filters . . . . . . . 5-31 5.4.4 Free-Fall Spill and Impaction Stress . . . . . . . . . . . . . . . . . . . . 5-32 5.4.4.1 Enclosed Filter Media . . . . . . . . . . . . . . . . . . . . . . . 5-33 5.4.4.2 Unenclosed Filter Media . . . . . . . . . . . . . . . . . . . . . . 5-35 6.0 INADVERTENT NUCLEAR CRITICALITY 6.1 Summary of Bounding Release Estimates . . . . . . . . . . . . . . . . . . . . . . . 6-1 6.2 Total Fission Yield . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5 6.2.1 Historical Excursions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5 6.2.2 Analytical Models for Solution Criticalities . . . . . . . . . . . . . . . . 6-5 6.2.3 Assessment of Fission Yields . . . . . . . . . . . . . . . . . . . . . . . . . 6-12

6.2.3.1 Solutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-13 Page ix DOE-HDBK-3010-94 6.2.3.2 Fully Moderated and Reflected Solids . . . . . . . . . . . . . 6-15 6.2.3.3 Dry Powder and Metal . . . . . . . . . . . . . . . . . . . . . . . 6-15 6.2.3.4 Large Storage Arrays . . . . . . . . . . . . . . . . . . . . . . . . 6-16 6.3 Material Release in Criticality Excursions . . . . . . . . . . . . . . . . . . . . . 6-16 6.3.1 Solutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-17 6.3.2 Fully Moderated and Reflected Solids . . . . . . . . . . . . . . . . . . . 6-21 6.3.3 Dry Powder and Metal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-24 6.3.4 Large Storage Arrays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-24 7.0 APPLICATION EXAMPLES 7.1 Application Methodology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1 7.2 Example Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2 7.3 Mock Operation Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-5 7.3.1 Feed Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-5 7.3.1.1 Hazard Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-5 7.3.1.2 Release Estimation . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-6 7.3.1.3 Feed Preparation Example Assessment . . . . . . . . . . . . 7-12 7.3.2 Oxide Dissolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-14 7.3.2.1 Hazard Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-14 7.3.2.2 Release Estimation . . . . . . . . . . . . . . . . . . . . . . . . . . 7-14 7.3.2.3 Oxide Dissolution Example Assessment . . . . . . . . . . . 7-18 7.3.3 Residue Dissolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-19 7.3.3.1 Hazard Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-19 7.3.3.2 Release Estimation . . . . . . . . . . . . . . . . . . . . . . . . . . 7-19 7.3.3.3 Residue Dissolution Example Assessment . . . . . . . . . . 7-20 7.3.4 Metal Dissolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-20 7.3.4.1 Hazard Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-20 7.3.4.2 Release Estimation . . . . . . . . . . . . . . . . . . . . . . . . . . 7-21 7.3.4.3 Metal Dissolution Example Assessment . . . . . . . . . . . 7-26 7.3.5 Liquid Sampling and Tank Farm . . . . . . . . . . . . . . . . . . . . . . 7-28 7.3.5.1 Hazard Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-28 7.3.5.2 Release Estimation . . . . . . . . . . . . . . . . . . . . . . . . . . 7-29 7.3.5.3 Liquid Sampling and Tank Farm Example Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-32 7.3.6 Ion Exchange . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-34 7.3.6.1 Hazard Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-34 7.3.6.2 Release Estimation . . . . . . . . . . . . . . . . . . . . . . . . . . 7-36 7.3.6.3 Ion Exchange Example Assessment . . . . . . . . . . . . . . 7-45 7.3.7 Calcination and Hydrofluorination . . . . . . . . . . . . . . . . . . . . . . 7-48 7.3.7.1 Hazard Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-48 7.3.7.2 Release Estimation . . . . . . . . . . . . . . . . . . . . . . . . . . 7-49

Page x DOE-HDBK-3010-94 7.3.7.3 Calcination and Hydrofluorination Example Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-51 7.3.8 Reduction Line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-53 7.3.8.1 Hazard Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-53 7.3.8.2 Release Estimation . . . . . . . . . . . . . . . . . . . . . . . . . . 7-55 7.3.8.3 Reduction Line Example Assessment . . . . . . . . . . . . . 7-59 7.3.9 Solid Waste Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-60 7.3.9.1 Hazard Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-60 7.3.9.2 Release Estimation . . . . . . . . . . . . . . . . . . . . . . . . . . 7-61 7.3.9.3 Solid Waste Handling Example Assessment . . . . . . . . . 7-66 7.3.10 Seismic Release . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-66 7.3.10.1 Hazard Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-66 7.3.10.2 Release Estimation . . . . . . . . . . . . . . . . . . . . . . . . . . 7-67 7.3.10.3 Seismic Release Example Assessment . . . . . . . . . . . . . 7-73 7.3.11 Production Support Lab . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-74 7.3.11.1 Hazard Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-74 7.3.11.2 Release Estimation . . . . . . . . . . . . . . . . . . . . . . . . . . 7-75 7.3.11.3 Production Support Lab Example Assessment . . . . . . . 7-81 7.3.12 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-81 8.0 REFERENCES Page xi DOE-HDBK-3010-94 LIST OF FIGURES Figure 3-1 Size Distribution of Bubble Induced Droplets . . . . . . . . . . . . . . . . . . . 3-11 Figure 3-2 Entrainment Data Obtained at Small Gas Velocity . . . . . . . . . . . . . . . . 3-16 Figure 3-3 Weight Percent Airborne as a Function of Mole Fraction of Pressurizing Gas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-17 Figure 3-4 Mass Fraction vs. Droplet Diameters for Sprays as a Function of Orifice Diameter and Upstream Pressure . . . . . . . . . . . . . . . . . . . . . . 3-21 Figure 3-5 Average Weight Percent of Liquid Airborne as a Function of Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-24 Figure 3-6 Measured and Predicted Temperatures for Flashing-Spray Releases . . . . 3-30 Figure 3-7 Weight Percent Airborne Versus Viscosity for Sucrose, Slurry, and Low Surface Tension Spills . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-38 Figure 3-8 Mass Release Rate vs. Fetch, 200 by 200 Meter Pond . . . . . . . . . . . . . 3-39 Figure 4-1 What Affects the Aerosolization Fraction in Plutonium Burning? . . . . . . 4-13 Figure 4-2 Dependence of Rate of Removal of Oxide Particulate from the Metal Surface on Humidity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14 Figure 4-3 Particle Size Distributions Produced by the Oxidation of Plutonium Under a Variety of Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-16 Figure 4-4 Release of Particulate Oxide Less Than 10 µm Diameter from Plutonium into Saturated Air . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-17 Figure 4-5 Release of Particulate Oxide Less Than 10 µm Diameter from

Plutonium into Dry Air . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-18 Figure 4-6 Representative Particle Size Distributions Obtained with Cascade Impactors for PuO2 Aerosols Formed in Static and Dynamic Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-22 Figure 4-7 Mass-Size Distribution of Sodium-Plutonium Aerosol . . . . . . . . . . . . . 4-34 Figure 4-8 Dependence of Uranium Ignition on Specific Area . . . . . . . . . . . . . . . 4-36 Figure 4-9 Aerosol Mass of Uranium Airborne during Oxidation as a Function of Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-39 Figure 4-10 Respirable Mass of Uranium Airborne during Oxidation as a Function of Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-41 Figure 4-11 Uranium Metal Burning in Air; The Distributions of the Measurements of the Respirable Aerosol Fractions in the Static and Dynamic Experiments . . . . . . . . . . . . . . . . . . . . . . . 4-43 Figure 4-12 Particle Size Distribution Resulting from UO2-2 Pellet Impact Test Data for UO2 Specimen #2 Including Mean Grain Size of Original Crystalline UO2 Particles. (Size Distribution 3 pellets 13.7-mm diameter x 13.6-mm long; drop-weight 1.2 J/cm3) . . . . . . . . . 4-53 Page xii DOE-HDBK-3010-94 Figure 4-13 Variation of Respirable Size for Impact Tests of Pyrex and SRL-131 Glass Specimens as a Function of Impact Test Energy Density . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-54 Figure 4-14 Equivalent Diameter PuO2 Particle Lifted by Various Air Velocities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-60 Figure 4-15 Removal of ThO2 from Stainless Steel . . . . . . . . . . . . . . . . . . . . . . . . 4-64 Figure 4-16 Aerodynamic Entrainment of Uranium Dioxide Powder from a Stainless Steel Surface at an Air Velocity of 20 mph . . . . . . . . . . . . . . 4-68 Figure 4-17 Average Weight Percent of Powder Airborne as a Function of Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-72 Figure 4-18 Measured Size-Specific Dust Generation Rate Versus Predicted Size- Specific Generation Rate from Equations 8-11 . . . . . . . . . . . . . . . . . . 4-78 Figure 4-19 Titanium Dioxide and Uranium Dioxide Particle-Size Distribution . . . . . 4-79 Figure 4-20 Percent of Soil Airborne as a Function of Wind Speed . . . . . . . . . . . . 4-84 Figure 4-21 Particulate Threshold Friction Speed . . . . . . . . . . . . . . . . . . . . . . . . . 4-90 Figure 4-22 Resuspension Factor Ranges from Mechanical and Wind Resuspension Stresses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-99 Figure 4-23 Particle Resuspension Rates from an Asphalt Road Caused by Vehicle Passage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-103 Figure 4-24 Particle Resuspension Rates from an Asphalt Road Caused by Vehicular Traffic Passage Four Days After Particle Deposition . . . . . . . 4-104 Figure 4-25 Particle Resuspension Rates from an Asphalt Road as a Function of Weathering Time (Car Driven Through Tracer) . . . . . . . . . . . . . . . . 4-105 Figure 5-1 Results from Burning Contaminated Combustibles . . . . . . . . . . . . . . . 5-11

Figure 5-2 Variation in Adhesive Forces Observed for Various Size Particles . . . . . 5-25 Figure 5-3 Resuspension Flux Fr Air Flow Velocity for Particles Smaller Than 10 Micrometer Diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-26 Figure 5-4 Schematic Diagram of Turbulent Burst in the Wall Region . . . . . . . . . . 5-27 Page xiii DOE-HDBK-3010-94 LIST OF TABLES Table 3-1 Fractional Airborne Releases During the Heating with Flowing Air of Concentrated Plutonium Nitrate Solution . . . . . . . . . . . . . . . . . . . . . . 3-12 Table 3-2 Fractional Airborne Release During Heating of Pools of Dilute Plutonium Nitrate Solution - 90% Volume Reduction . . . . . . . . . . . . . 3-14 Table 3-3 Measured ARFs from Venting Pressurized Aqueous Solutions . . . . . . . 3-23 Table 3-4 Average Weight Percent Airborne from Pressurized Liquid Release . . . . 3-23 Table 3-5 Measured ARFs and RFs During the Venting of Superheated Aqueous Solutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-29 Table 3-6 Measured ARFs and RFs From the Free-Fall Spill of Aqueous Solutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-34 Table 3-7 Statistical Summary of Drop Size Parameters for Lognormal Distributions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-35 Table 3-8 Measured ARFs and RFs for Free-Fall Spill of Slurries (1 liter source, 3 meter fall distance) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-36 Table 3-9 Measured ARFs and RFs for Free-Fall Spill of Viscous Solutions (1 liter source volume, 3 meter fall height) . . . . . . . . . . . . . . . . . . . . 3-36 Table 3-10 Measured ARFs from Shallow Pools of Concentrated Heavy Metal Salt Solution (0.72 g to 0.82 g Pu, 24-hr sampling period) . . . . . . . . . . 3-40 Table 3-11 Measured ARFs and RFs of Uranium (UNH) From Soil at 2.5 mph and ~ 20 mph . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-41 Table 3-12 Measured ARFs From Burning Small Volumes of 30% TBP-Kerosine Traced with Selected Radionuclides . . . . . . . . . . . . . . . . . . . . . . . . . 3-44 Table 3-13 Measured Uranium ARFs During the Burning of TBP-Kerosine Over Aqueous Phase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-45 Table 3-14 Measured Transfer Coefficients and Decontamination Factors During the Burning of TBP-Kerosine Solvent . . . . . . . . . . . . . . . . . . . . . . . . 3-47 Table 3-15 Measured ARFs and RFs for Uranium Airborne During Gasoline Fires on Various Surfaces Involving UNH and Air-Dried UNH . . . . . . . . . . . 3-48 Table 4-1 Measured ARFs During Oxidation of Unalloyed and Delta-Phase Plutonium at Elevated Temperatures in Air . . . . . . . . . . . . . . . . . . . . 4-19 Table 4-2 Summary of Oxidation Rates for Plutonium at Temperatures Below 100°C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-20 Table 4-3 Measured ARFs During Self-Sustained Oxidation of Unalloyed and Delta-Phase Plutonium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-21 Table 4-4 Measured ARFs During Self-Sustained Oxidation of Unalloyed Plutonium Metal in Flowing Air . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-23 Page xiv DOE-HDBK-3010-94

Table 4-5 Measured ARFs During the Self-Sustained Air Oxidation of Large Specimens of Unalloyed and Delta Plutonium Metal . . . . . . . . . . . . . . 4-24 Table 4-6 Measured ARFs for Heating Small Specimens of Delta Phase Pu Metal in Various Atmospheres . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-28 Table 4-7 ARFs From Heating Small Pieces Delta-Phase Plutonium Metal Under Specific Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-29 Table 4-8 Airborne Release of Pu From Pu-Na Mixtures During Self-Sustained Oxidation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-30 Table 4-9 Possible Factors Influencing Uranium Oxidation . . . . . . . . . . . . . . . . . 4-35 Table 4-10 Airborne Release from Nonreactive Powder During Heating in Flowing Air . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-56 Table 4-11 ARFs and RFs During the Heating of Reactive Compounds in Flowing Air . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-58 Table 4-12 ARFs and RFs from the Venting of Pressurized Powders . . . . . . . . . . . 4-73 Table 4-13 Measured ARFs and RFs from the Free-Fall Spill of Powders . . . . . . . 4-80 Table 4-14 Airborne Soil Particle Size Distribution . . . . . . . . . . . . . . . . . . . . . . . . 4-83 Table 4-15 Measured ARFs and RFs from the Impact of Structural Debris on Powders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-86 Table 4-16 Resuspension Factors from Wind Resuspension Stresses . . . . . . . . . . . 4-91 Table 4-17 Resuspension Factors from Mechanical Resuspension Stresses . . . . . . . 4-92 Table 4-18 Resuspension Rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-95 Table 4-19 Variables Which Influence Resuspension . . . . . . . . . . . . . . . . . . . . . . 4-97 Table 5-1 ARFs from Burning of Packaged, Contaminated, Mixed, Combustible Wastes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-12 Table 5-2 Measured ARFs and RFs from the Burning of Contaminated Cellulosic Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-14 Table 5-3 Measured ARFs from Burning Contaminated PC . . . . . . . . . . . . . . . . . 5-17 Table 5-4 Measured ARFs and RFs from Burning of Contaminated PMMA . . . . . 5-18 Table 5-5 Measured ARFs and RF from Burning of Contaminated PS . . . . . . . . . 5-18 Table 5-6 Fractions of Media Mass as Particles 10 µm and Less Generated by HEPA Filters Under Shock/Vibration Stresses . . . . . . . . . . . . . . . . . . 5-34 Table 6-1 Summary of Known Accidental Criticality Excursions (1945 to 1974): (a) Solution Systems, (b) Metal Systems, and (c) Moderated Foil and Powder Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6 Table 6-2 Destructive Power Excursion Summary . . . . . . . . . . . . . . . . . . . . . . . . 6-9 Table 6-3 Inhomogeneous Water-Moderated Systems . . . . . . . . . . . . . . . . . . . . . 6-10 Table 6-4 Miscellaneous Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-11 Table 6-5 Theoretical Criticality Accident Fission Yields . . . . . . . . . . . . . . . . . . 6-13 Table 6-6 Accidents in Processing Plants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-14

Page xv DOE-HDBK-3010-94 Table 6-7 Curies of Important Nuclides Released During Nuclear Excursion Involving Spent Fuel Solution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-18 Table 6-8 Curies of Important Nuclides Released During Nuclear Excursion Involving Unirradiated, Unenriched Uranium Solution (400 g U/liter) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-19 Table 6-9 Curies of Important Nuclides Released During Nuclear Excursion Involving Plutonium Solutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-20 Table 6-10 Release Fraction for Various Chemical Classes from Heated Spent Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-23 Table 7-1 Site Boundary Doses Associated with Release . . . . . . . . . . . . . . . . . . . 7-4 Table 7-2 Feed Preparation Example Topics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-5 Table 7-3 Important Nuclides Released from Powder Plutonium Criticality . . . . . . 7-12 Table 7-4 Oxide Dissolution Example Topics . . . . . . . . . . . . . . . . . . . . . . . . . . 7-14 Table 7-5 Important Nuclides Released from Plutonium Solution Criticality . . . . . 7-17 Table 7-6 Residue Dissolution Example Topics . . . . . . . . . . . . . . . . . . . . . . . . . 7-19 Table 7-7 Metal Dissolution Example Topics . . . . . . . . . . . . . . . . . . . . . . . . . . 7-20 Table 7-8 Liquid Sampling and Tank Farm Example Topics . . . . . . . . . . . . . . . . 7-28 Table 7-9 Ion Exchange Example Topics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-34 Table 7-10 Calcination and Hydrofluorination Example Topics . . . . . . . . . . . . . . . 7-48 Table 7-11 Reduction Line Example Topics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-53 Table 7-12 Solid Waste Handling Example Topics . . . . . . . . . . . . . . . . . . . . . . . 7-60 Table 7-13 Seismic Release Example Topics . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-66 Table 7-14 Production Support Lab Example Topics . . . . . . . . . . . . . . . . . . . . . . 7-74 Page xvi DOE-HDBK-3010-94 VOLUME II: APPENDICES APPENDIX A APPENDIX B Tables and Figures from Source Documents with Data Used in this Study Example Facilities Page xvii DOE-HDBK-3010-94 LIST OF ACRONYMS The terminology used in this handbook is commonly used in DOE management or technical communities, and is therefore not defined. A number of acronyms are used constantly throughout this large document, however, and brief definitions are provided for important acronyms to assist the reader. AED Aerodynamic Equivalent Diameter: the diameter of a sphere of density 1 g/cm3 that exhibits the same terminal velocity as the particle in question. AMAD Activity Median Aerodynamic Diameter: the diameter of the particle for which half the activity is associated with particles larger than and half the activity associated with particles smaller than this size particle. AMMD Aerodynamic Mass Median Diameter: the aerodynamic diameter of the particle for which half the mass is associated with particles greater than and half the mass the mass is associated with particles less than the stated size. ARF Airborne Release Fraction: the coefficient used to estimate the amount of a radioactive material that can be suspended in air and made available for airborne transport under a specific set of induced physical stresses. Applicable to events and situations that are completed during the course of the event.

ARR Airborne Release Rate: the coefficient used to estimate the amount of material that can be suspended in air and made available for airborne transport under a specific set of induced physical stresses as a function of time. The rates are often longer-term averages due to the non-discrete nature of the release. Applicable to events that are relatively continuous over some time span. CRAC Consequences Radiologiques d'un Accident de Criticite: experimental criticality study. DOE U.S. Department of Energy. DR Damage Ratio: the fraction of MAR impacted by the actual accident-generated conditions under evaluation. FP Fission Products. Page xviii DOE-HDBK-3010-94 GSD Geometric Standard Deviation: standard deviation of the logarithms. For any normal distribution, one standard deviation represents the difference between the size associated with the cumulative mass of 84.1% and the median (50% cumulative mass) size (or between the 50% cumulative size and the 15.9% cumulative size). For lognormal distributions, ratios between sizes are as follows: GSD = sigmag = d84%/d50% = d50%/d16% =[d84%/d16%]1/2 HEPA High Efficiency Particulate Air. IHE Insensitive High Explosives: high explosives that are less sensitive to ordinary initiators such as shock, heat, etc. than conventional high explosives such as TNT, dynamite. LLD Least Linear Diameter: the size distributions determined by sieving. The fractions are categorized by the particles that can pass through the openings of a sieve and, if not spherical, represent the small dimension of that particle. LPF LeakPath Factor: the fraction of airborne materials transported from containment or confinement deposition or filtration mechanism (e.g., fraction of airborne material in a glovebox leaving the glovebox under static conditions, fraction of material passing through a HEPA filter.) MAR Material-at-Risk: the amount of radioactive materials (in grams or curies of activity for each radionuclide) available to be acted on by a given physical stress. MMD Mass Median Diameter: the geometric diameter of the particle for which half the mass is associated with particles greater and half the mass associated with particles less than the stated size. MR Mass Ratio: the ratio mass of inert material impacted to mass of TNT equivalent of an explosion. NRC U.S. Nuclear Regulatory Commission. PC Polychloropene. PMMA Polymethylmethacrylate. Page xix DOE-HDBK-3010-94 PS Polystyrene. PSPILL Powder Spill computer code: See subsection 4.4.3.1.3. PULF Pulverization Fragments calculation: See section 4.3.3. RF Respirable Fraction: the fraction of airborne radionuclides as particles that can be transported through air and inhaled into the human respiratory system and is commonly assumed to include particles 10-µm Aerodynamic Equivalent Diameter (AED) and less. SAR Safety Analysis Report. TBP Tri-normal Butyl Phosphate. UNH Uranyl Nitrate Hexahydrate: The uranium solution form generally associated with recovered uranium from the PUREX (plutonium uranium extraction, a liquid-liquid extraction) process for reprocessing spent nuclear fuel or irradiated product targets. Page xx DOE-HDBK-3010-94 1.0 INTRODUCTION 1.1 PURPOSE OF HANDBOOK

The purpose of this document is to provide a compendium and analysis of experimental data from which airborne release fractions (ARFs) and respirable fractions (RFs) may be derived. Such values are needed to determine quantities of radioactive material driven airborne for the purpose of estimating the scope of the potential release spectrum and potential downwind consequences from a given facility or activity. The information provided in this handbook aids in making such estimates. This introduction discusses the following major topics: • Source term formula - Provides a computational formula for using this information. • Applicability of data - Distinguishes proper use of information. • Accident stresses - Identifies the types of accident conditions for which this information is applicable. • Handbook organization - Explains presentation of information and use of examples. The data in this handbook can be used in a variety of applications, such as safety and environmental analyses, and to provide information relevant to system and experiment design. However, these data and the analyses of the data contained herein need to be critically evaluated for applicability in each situation in which they are used, and represent only one source of information in a complete safety analysis or design process. 1.2 SOURCE TERM FORMULA The source term is the amount of radioactive material, in grams or curies, released to the air. The initial source term is the amount of radioactive material driven airborne at the accident source. The initial respirable source term, a subset of the initial source term, is the amount of radioactive material driven airborne at the accident source that is effectively inhalable. Lesser source terms are determined by applying filtration or deposition factors to the initial source term. The airborne pathway is of primary interest for nonreactor nuclear facilities. DOE-STD­ 1027-92 quotes observations of the NRC to the effect that "for all materials of greatest interest for fuel cycle and other radioactive material licenses, the dose from the inhalation Page 1-1 DOE-HDBK-3010-94 1.0 Introduction pathway will dominate the (overall) dose" (NUREG-1140). The airborne source term is typically estimated by the following five-component linear equation: Source Term = MAR x DR x ARF x RF x LPF (1-1) where: MAR = Material-at-Risk (curies or grams), DR = Damage Ratio, ARF = Airborne Release Fraction (or Airborne Release Rate for continuous release), RF = Respirable Fraction, and LPF = Leakpath Factor. The initial source term and initial respirable source term are products of the first three factors and first four factors respectively. A depleted source term after a subsequent stage of deposition or filtration is a product of the initial source term multiplied by the leakpath factor of the specific stage. This handbook assesses ARF and RF values separately for sources of airborne material generated from accidents involving gases, liquids, solids, and surface contamination. All of the above factors may need to be determined for particulate releases. Some of them, however, will collapse to values of one for special cases (e.g., gaseous releases). Material-at-Risk (MAR)

The material-at-risk is the amount of radionuclides (in grams or curies of activity for each radionuclide) available to be acted on by a given physical stress. For facilities, processes, and activities, the MAR is a value representing some maximum quantity of radionuclide present or reasonably anticipated for the process or structure being analyzed. Different MARs may be assigned for different accidents as it is only necessary to define the material in those discrete physical locations that are exposed to a given stress. For example, a spill may involve only the contents of a tank in one glovebox. Conversely, a seismic event may involve all of the material in a building. Damage Ratio (DR) The damage ratio is the fraction of the MAR actually impacted by the accident-generated conditions. A degree of interdependence exists between the definitions of MAR and DR. If it is predetermined that certain types of material would not be affected by a given accident, some analysts will exclude this material from the MAR. Page 1-2 DOE-HDBK-3010-94 1.0 Introduction As an example, assume 600 g from a total of 1000 g of material X are in a form that would not be affected by an explosion. Of the remaining 400 g, 200 g have a high release fraction and 200 g have a low release fraction. If the 600 g is included in the MAR, specific DRs for the MAR of 1000 g are 0 for the unaffected material, 0.2 for the high release fraction material, and 0.2 for the low release fraction material. If the 600 g is not included, specific DRs for the MAR of 400 grams are 0.5 for the high release fraction material and 0.5 for the low release fraction material. The basic distinction is whether or not DRs of 0 are officially designated. Neither convention cited in the example is necessarily correct. What is important is that one convention is used consistently to avoid an obvious potential for assigning incorrect DR values. The DR is estimated based upon engineering analysis of the response of structural materials and materials-of-construction for containment to the type and level of stress/force generated by the event. Standard engineering approximations are typically used. These approximations often include a degree of conservatism due to simplification of phenomena to obtain a useable model, but the purpose of the approximation is to obtain, to the degree possible, a realistic understanding of potential effects. Airborne Release Fraction (ARF) The ARF is the coefficient used to estimate the amount of a radioactive material suspended in air as an aerosol and thus available for transport due to a physical stresses from a specific accident. For discrete events, the ARF is a fraction of the material affected. For mechanisms that continuously act to suspend radionuclides (e.g., aerodynamic entrainment/resuspension), a release rate is required to estimate the potential airborne release from postulated accident conditions. Generally, accident release rates (ARRs) are based upon measurements over some extended period to encompass most release situations for a particular mechanism. The rates are average rates for the broad spectrum of situations and, as such, the most typically meaningful time unit to reflect average conditions is 1 hour. There is evidence (discussed later in the subsection on the aerodynamic entrainment of surface contamination) that in some situations (e.g., aerodynamic entrainment of sparse powder deposits on a heterogeneous surface), the rate of release is not uniform with time. Even in the situations where the rates are relatively uniform, the source is depleted by the removal of particles from the surface by aerodynamic forces, and the amount of material airborne decreases with time unless the source is continuously replenished.

This handbook specifically deals with ARFs and ARRs, although ARF will connote both concepts in generic discussions for the sake of simplicity. The ARFs are based primarily upon experimentally measured values for the specific material (e.g., plutonium, uranium, mixed fission products) or surrogates subjected to the particular type of stress under Page 1-3 DOE-HDBK-3010-94 1.0 Introduction controlled conditions. Attention is given to the parameters, if known, that may have a significant influence upon suspension by the specific mechanism and the uncertainty in the measurement as indicated by the variability of the results. Those applying the data must be aware of the range of stress represented by the measured ARFs, and seek to define the accident conditions to determine, in a gross sense, whether or not the stresses induced by the postulated events are bounded by the experimental parameters as evaluated in this document. It is important to note that the experiments discussed evaluate release phenomena holistically. No attempt is made to precisely characterize total airborne material in terms of individual mechanisms acting within an overall given release. To obtain useful data outside the immediate physical chaos of the stress-inducing event itself, the experimental apparatus cited almost uniformly relied upon designs to channel air to some contamination collection mechanism a short distance from the point of generation. The need to keep this distance small to avoid introducing new distortion in the form of aerosol deposition effects is one of the reasons for the relatively small scale of many experiments. In keeping with this experimental design, the interpretation of experimental data does not consider material momentarily airborne from substrate mass ejection due to physical stresses acting on the substrate mass as an aerosol suspended in air. For example, in fire and boiling experiments, fuel mass and volumes of solution were observed to splatter or launch from the experimental substrate and land on surfaces in the local vicinity. The radioactive contamination carried with this material that deposits and is measured on the adjacent surfaces is not an aerosol suspended in air, and does not travel on air currents. It represents a source of highly localized migration that is not amenable to meaningful prediction and is not relevant to the issue of how much material might be expected to escape the immediate area and disperse in air. Respirable Fraction (RF) The RF is the fraction of airborne radionuclides as particles that can be transported through air and inhaled into the human respiratory system and is commonly assumed to include particles 10-µm Aerodynamic Equivalent Diameter (AED) and less. Other definitions of "respirable particles" have been presented by various groups at different times. The British Medical Research Council adopted a definition in 1952 classifying particles with a terminal velocity equal to that of a 5-µm diameter as "respirable dust." The U. S. Atomic Energy Commission defined "respirable dust" as insoluble particles that are part of inhaled dust which penetrate to the non-ciliated portions of the gas exchange region, and with a 50% respirable cut-size of 3.5-µm AED. The American Conference of Governmental Industrial Hygienists has adopted a definition that is almost identical, differing only in the 2 µm fraction allowed. The U. S. Environmental Protection Agency defines "inhalable dust" Page 1-4

DOE-HDBK-3010-94 1.0 Introduction (particles penetrating the upper respiratory airway and entering the thorax) with a 50% cut­ off at 15-µm AED. The International Standards Organization - Europe defines "inhalable dust" as particles entering the nasal or oral passages with a 50% cut-size of 10-µm AED. Accordingly, use of a 10-µm AED cut-size for respirable particles is considered conservative, and may even be overly conservative since the mass is a cube function of particle diameter. The size of a particle is a function of the measurement technique used. If the method used is optical/electron microscopy or spectrometry, particle size is a projected diameter measured by the plane that intercepts the light/electron beam or reflection from light scattered by the particle. The size represents the two-dimensional area intercepting the beam and, as with all projections of three dimensions into two, can result in considerable distortion. Projected diameter approximates the Geometric Diameter (Dg). Dg is also approximated by sieving where the size measurement is termed geometric/linear/least linear diameter. The measurement represents the smallest dimension of the particle that will pass through the openings in the sieve. Liquid and air sedimentation techniques of inertial impaction by a cascade impactor measure the settling velocity of a particle and report size as an aerodynamic characteristic. Size is reported as an equivalent sphere with an equivalent settling velocity, or Stoke Diameter (DStk). The Aerodynamic Diameter (DAED) specifically refers to an equivalent sphere with a density of 1 g/cm3. DAED is the parameter of interest for defining respirable particles (i.e., ≤ 10-µm AED) as it normalizes materials of differing density. Other size units include Ferret's diameter (the relationship between the maximum and minimum diameters) or Sauter's mean diameter (the surface to volume ratio most representative of the distribution of a group of liquid drops), but these are of little use for the purposes of this document. Dg is related to DAED by the equation: DAED = (Dg[ρp] 0.5[CC,e/CC,a] 0.5)/α (1-2) where: ρp = Particle density (g/cm3), CC,e = Cunningham slip factor corresponding to the volume equivalent diameter, CC,a = Cunningham slip factor corresponding to the aerodynamic equivalent diameter, and α = Aerodynamic shape factor. The Cunningham slip factor is related to the potential for particle impact with the mean free path of air molecules. Above the sub-micron size range, all particles impact with air Page 1-5 DOE-HDBK-3010-94 1.0 Introduction molecules, and the ratio of Cunningham factors can be ignored. The aerodynamic shape factor is not typically known and is assumed to be 1. Therefore, DAED may be estimated from Dg by simply multiplying Dg by the square root of the particle density. More discussion of this subject can be found in available references (e.g., Fry, T.M., 1980). Although the principal emphasis in this document is directed toward the potential downwind hazard to the populations at some distance from the point of source term generation, airborne particles larger than 10-µm AED released from the facility may constitute an onsite hazard (direct radiation) and may (if the larger particles are agglomerates that deagglomerate with time or can be subdivided by local conditions) be subject to re-dispersal. If direct shine can be a significant contributor to doses (e.g., fission product release from a criticality excursion), the respirable factor should not be accounted for in evaluating that pathway contributor.

This handbook specifically addresses RFs. RFs for particles made airborne under accident- induced stresses are dependent upon a variety of factors, such as the bulk density (i.e., how well the powder at rest compacts), the presence of moisture, how effectively the type and level of stress deagglomerates the powder or subdivides the solid/liquid, the efficiency with which the stress suspends the powder/fragments of solid over varying size ranges, and the degree of immediate proximity of surfaces on which airborne particles may impact/settle. Data to evaluate these factors individually for all cases are not found in the literature. Measured RF data from the experimental studies are applied where available. Measured experimental data for RFs are much more limited but are from the same general sources used for the ARFs. To keep RFs at a reasonable bounding rather than an ultraconservative level, the RF associated with the measured bounding ARF is generally selected rather than the highest RF value measured. The highest RF values are often associated with the smallest ARFs, and when used in conjunction with the bounding ARF, result in ultraconservative estimates of the respirable fraction released. When no measured RF is associated with the maximum measured ARF, but other measured RFs are available for the experimental set, the greatest RFs are generally used. In some cases where significant uncertainty may exist, RFs are arbitrarily set to a value of 1.0 for conservatism. Leakpath Factor (LPF) The LPF is the fraction of the radionuclides in the aerosol transported through some confinement deposition of filtration mechanism. There can be many LPFs for some accident conditions (e.g., the fraction transported from the package, such as a shipping container, to the cell or enclosure; the fraction leaked from the enclosure, cell, or glovebox to the operating area around the enclosure or room; the fraction leaked from the room to the Page 1-6 DOE-HDBK-3010-94 1.0 Introduction building-atmosphere interface). Where multiple leakpaths are involved, their cumulative effect is often expressed as one value that is the product of all leakpath multiples. The LPF is a calculated or standard value based upon (1) established relationships between size of the particulate material, airborne transport mechanisms, and losses by deposition mechanisms, or (2) specified filtration efficiencies. 1.3 APPLICABILITY OF DATA In most cases, the ARFs and RFs for conditions bounded by the experimental parameters can be defined to one significant digit. The parameter definition process has focused on estimating reasonable bounding values because of the limited quantity and variability of the data. The use of the word "reasonable" is an acknowledgement that the only definitive bounds are ARFs and RFs of 1.0, which can always be postulated if enough synchronous, extreme localized conditions are assumed. Such extreme synchronicity is neither an expected condition nor a practically useful model of reality. The NRC has commented on this subject in a survey of nonreactor nuclear facility release potential and historical experience (NUREG-1140) as follows:

Operating experience may be more relevant for these [fuel cycle] licensees than for nuclear power plants because of the nature of the accident driving force. In nuclear power plants the driving force is the enormous amount of heat in the reactor. The available energy is so large that some unique occurrences are conceivable, such as molten cores, large-scale metal-water reactions, and rupturing of the containment by overpressurization. Because these events have never happened, they can only be studied theoretically. The dominant driving force for accidents at nonreactor licensees are common industrial accidents--fires, chemical explosions, leaks, and the like. A great deal of industrial accident experience can be drawn upon in analyzing these potential accidents. The experiments used as a basis for this document were specifically focusing on general characterization of suspension phenomena in an industrial environment. A key element in defining bounding values from the data is understanding the physical entrainment mechanisms at work, their potential variability, and the inherent limits of such mechanisms. Accordingly, this document provides detailed discussion of entrainment mechanisms wherever possible. Median and average values are estimated for some data. These estimates are made solely for the purpose of providing perspective on potential conservatism and should not be used as a basis for an ARF statistical distribution. It is generally not productive to attempt to use the experimental data cited in this handbook to develop assumed statistical distributions of values Page 1-7 DOE-HDBK-3010-94 1.0 Introduction for probabilistic assessments. The overall collection of data available for a wide variety of stresses will not support fine statistical resolution as a technically meaningful activity, and this handbook specifically rejects citation as a defensible basis for such attempts. The generation and suspension of particles is the result of the interaction of multiple physiochemical variables that have not been completely characterized as the majority of the experiments performed were designed in an attempt to reflect reasonably bounding conditions for specific industrial situations of concern. Accordingly, the data obtained are more accurately characterized as selected points from multiple distributions against multiple parameters than as different values from a common distribution. Even if this point is neglected, there are still practically intractable problems in attempting to generate statistical distributions. While the data are presumed to be bounding for the purpose intended, it is largely unknown whether the data values are truly 90th percentile, 99th percentile, 99.9th percentile, etc. Further, in many cases it is considered likely that accident specific ARFs are actually distributed in a highly irregular manner (i.e., multi-modal or truncated distributions). Assuming a typical distribution (i.e., log-normal, Poisson) using standard deviations will produce seriously distorted values that may have little or nothing to do with reality.

The available data do, however, cover a range of conditions that typify the energy sources associated with nonreactor nuclear facilities. The data cover a more complete range of phenomenological concerns than the data upon which nuclear reactor source terms have been estimated. They are at least the equal of reactor source term data in overall quality, and a number of the experiments performed were very close to actual scale for the type of operations conducted at nonreactor nuclear facilities. In general, scaling effects, while not to be trivialized, are less of an issue with this data than with comparable reactor source term estimation data. The NRC has already accepted a considerable amount of this information as a basis for source term estimation in NUREG-1320, "Nuclear Fuel Cycle Facility Accident Analysis Handbook." DOE-HDBK-3010-94 serves a similar function for DOE. The values for ARFs and RFs taken from experimental measurements are reasonably well defined. It is noted, however, that they are dependent upon the types and levels of stress imposed, the initial state (physical form, chemical composition, particle size distribution, degree of dispersion of the material-of-concern), and the response of the material-of-concern and other materials present. In most cases, the materials chosen for the experiments were selected to bound the behavior of materials under accident conditions for a specific location or process. The applicability of the experimental conditions to the complete spectrum of processes and potential accident conditions is, however, uncertain. For this reason, the discussions of the data have tried to indicate where typical industrial accident phenomena (e.g., fires, explosions, spills) are considered covered by the data. Page 1-8 DOE-HDBK-3010-94 1.0 Introduction The estimates of ARFs and RFs applicable to various accident-generated mechanisms for the suspension of radioactive materials are based upon experimental data for specific types and levels of stresses/force. Care must be used in applying the ARFs/ARRs to ensure that the values chosen truly reflect the type and level of stress/force postulated for the event. For instance, the suspension of powder from a surface (commonly termed resuspension) is not applicable to situations where the powder is dropped into flowing gas in a dispersed fashion. Before the ARFs and RFs presented can be properly applied, the conditions imposed and the response of critical items must be evaluated. The calculational methods to perform the engineering analysis are not part of the scope of this document. Many standard methods are applicable (e.g., the rupture pressure of tanks and piping based upon the material of construction, the thickness, the temperature and pressure). In other cases (e.g., the blast energy from the deflagration of flammable gas and oxidant mixtures in the free volume above the materials), however, standard engineering calculational methods are not available and interpretation of information and data (e.g., the fraction of the heat of combustion of reactants that translates into the shock wave) is required.

Once the forces and conditions imposed upon the material for dispersion/fragmentation and suspension are identified, the applicable ARF and RF can be selected. In most cases, precise correspondence between the event conditions and experimental conditions during the measurement of the ARFs and RFs is not found. For conservative analysis, the data are applicable if the measurement conditions exceed those calculated for the event (e.g., if the fall distances for spilled powders or liquids with characteristics like the materials used in the experiments are equal to or less than the experimental distance of 3 m). In most cases, extrapolation beyond the experimental data is valid for a limited range beyond the maximum (a factor of 2 to 5 dependent on the slope of the experimental data and the range of conditions covered in the experimental study) imposed in the experimental study. Models are available for the calculation of ARFs and RFs for some phenomena (e.g., free-fall spill of powders and liquids - Ballinger et. al., 1988; PULF formula for fragmentation by brittle fracture - Sandia, 1987). Care should be used in any extrapolation, however, to avoid producing obviously inappropriate answers. This caution is particularly apt if calculations are being used to influence facility or process design. A final emphasis is necessary regarding application of this data. As developed for the NRC and DOE, it has never been intended to be used as absolute proof of anything. Special attention has been given to understanding suspension phenomena, ranges of relevant parameters covered in experimental studies, artifacts or limitations of the data that may have been induced by experimental conditions, and possible effects of relevant parameters that may not have been controlled or monitored. As noted, this has resulted in development of Page 1-9 DOE-HDBK-3010-94 1.0 Introduction bounding ARFs and RFs. The purpose of developing these values was (1) to better understand the potential bounding hazards presented by nonreactor nuclear facilities, and (2) to provide information to support general bases of decisionmaking. The first purpose has been fulfilled by use of this information in the Defense Programs Safety Survey Report (Pinkston, et al., 1993). This use has supported previous NRC estimates that the bounding consequence potential for nonreactor nuclear facilities is significantly less than commercial nuclear power plants, or large commercial chemical plants as well. In domino fashion, this conclusion has reemphasized the use of the term "general bases" in the second purpose. The information in this handbook can be used to indicate relative significance of unmitigated releases and to verify the effectiveness of mitigative measures, such as HEPA filtration. It is a misuse of information in this handbook to focus on ARF "pencil-sharpening" at the expense of objective, performance based evaluation, particularly to attempt subtle judgements of consequence potential to support fine distinctions such as testing HEPA filters to only 90% efficiency, or to claim that meeting a dose guideline alone using this data constitutes a complete safety basis. 1.4 ACCIDENT STRESSES

In developing this handbook, literature and historical experience on the major types of accidents in nonreactor nuclear facilities were reviewed. The evaluation of experimental data was then focused on identifying applicability for those accidents. High-energy insertion-type events that are of concern for nuclear reactors are not covered by this document, nor are some accident conditions peculiar to high-level waste tanks (e.g., response of salt or moist salts to accident-generated conditions). Some responses of materials found in high-level waste vitrification plants to accident stresses are directly covered (e.g., brittle fracture of glasses due to crush-impact, free-fall spill of liquids and slurries), but others (e.g., behavior of molten salts and glass) are not. In some cases, attempts can be made to bound such materials by using data for more limiting materials. As with extrapolation, care should be used in any such attempt. The main types of accidents of common concern in nonreactor nuclear facilities are: • Spill: Material experiences instability/shear stress at the surface of the mass resulting in sub-division of the overall mass. Airflow patterns around and through the material mass, including induced turbulence, accelerate overall sub-division. Mass breakup is further enhanced by impact with ground surface. The material sub-division can generate particles sufficiently small that they remain airborne for a significant period of time. Page 1-10 DOE-HDBK-3010-94 1.0 Introduction • Fire: Generates heat and combustion gases that may destroy/stress the radioactive material and/or the substrate upon which radioactive materials may be deposited, compromise barriers, and/or pressurize containers/enclosure that may lead to the airborne release of contained radioactive materials. Mass flux of vapors from the reacting surfaces suspend material in air. This material is then entrained in general convective currents that provide transport for particulate materials. • Explosion: Generates shock and blast effects with potential for gas flow subsequent to the explosive event that may subdivide/deagglomerate and entrain material. Explosive reactions may result from chemical (e.g., oxidations involving branch-chain products, oxidations of gas-oxidant mixtures) or physical (overpressurization to failure of tanks or vessel, vapor explosions) reactions. Shock waves are supersonic pressure waves (pulses) that can transmit an impulse to materials and the surrounding structures resulting in shattering of solid items. Shock waves are a true wave phenomenon and involve little gross motion of propagating medium. The potential for damage from shock waves has been extensively characterized. Blast effects are typically subsonic and involve material entrained in the gas flow. Blast effects are often more damaging. Blast effects are not subject to the same reflection/amplification phenomena as shock waves because they have significant momentum and inertia. The gas expanding from the explosion zone carries material from the explosion site. If the explosion is adjacent to the MARs, then blast effects can cause damage above and beyond the initial impulse loading. Some explosive reactions may be followed by chemical reactions, material vaporization, or fires that lead to substantial gas flows following the explosive event. These gas flows may also entrain material. Deflagrations do not involve shock, but can simulate blast effects. Under proper conditions (e.g., confinement, structural features that enhance turbulence), deflagrations can transition to detonations and produce shock waves.

• Criticality: Major hazard is unshielded radiation produced. Generates fission products that may become airborne as well. Fission product gases are released from liquid criticalities and from solid criticalities to the extent the underlying critical mass is degraded. Solid fission products typically have small release fractions determined by the degree of physical stress placed on the critical mass itself. At large fission yields, solid critical masses may experience some degree of melting or oxidation. Page 1-11 DOE-HDBK-3010-94 1.0 Introduction • Earthquake: Typically bounds other natural phenomena. Generates severe lateral and vertical stresses upon the structure and equipment that may result in confinement failure, breach, or collapse. The response of the materials-of­ construction may dislodge materials-of-concern by vibration, impact of debris, and fragmentation. Seismic forces may cause material spills but do not generate gas flow to transport particulate materials, although flows are generated by falling debris or any fires/explosion caused by the seismic event. The information presented in this document is directed toward evaluation of the radiological consequences of these events and the suspension phenomena that they generate. Unless otherwise noted, the release from material affected by multiple phenomena can be calculated individually and summed to obtain the overall release. 1.5 HANDBOOK ORGANIZATION The evaluation of data is given by the physical form of the material affected (e.g., gas, liquid, solid, surface contamination) and suspension stresses (e.g., spill, thermal stress, shock wave, and blast stress) in chapters 2 through 5. Because of its unique nature, criticality is treated as a phenomenon for all materials in chapter 6. Examples of application of the release fraction recommendations are given in chapter 7. Each chapter begins with a summary of the results of data analyses, which are followed by discussions of specific data analyses in the remainder of the chapter. Bounding values for parameters and, in some cases, median values derived from the data analyses are presented in these summaries. As previously noted, where median values are presented, they are for the purpose of providing perspective on the potential conservatism of the bounding values as the available data do not generally support the derivation of data distributions. When using these data, care must be taken to assure the experimental data are applicable to the situation being analyzed. A summary table of the individual chapter summaries has not been provided in this chapter due to the sheer amount and variety of information in this document. A summary table is not considered an efficient vehicle for communication in a document of this nature as it would be either too large and unwieldy to satisfy the purpose of a table or too superficial to adequately represent the document. Data tables in the body of individual chapters are summations from raw data, which is typically provided in Appendix A. Original graphs are presented both in the chapters and in Appendix A, while figures of experimental apparatus, where available, are presented exclusively in Appendix A. Metric units are used in most instances, but some old documents and figures cited are in English units. It is noted that many of the source reports used are difficult to obtain, and copies available are old and fading. This significantly reduces the Page 1-12 DOE-HDBK-3010-94

1.0 Introduction legibility of reproductions. Accordingly, the notation "reproduced from" indicates where raw data and figures from original source reports have been retyped or traced to enhance legibility. Chapter 7 is designed to assist users of this document. It contains examples of application of the information for accidents that have occurred or are considered physically credible at DOE nonreactor nuclear facilities. These examples are based on example facilities detailed in Appendix B. Simple analyses of a defined facility were considered to be particularly helpful in demonstrating the use of ARFs and RFs in relation to the overall analysis process. This example also underscores previous cautions by indicating how excessive reliance on mathematical models using this data can lead to overlooking obviously inappropriate design or operational practices. Page 1-13 DOE-HDBK-3010-94 Page 1-14 DOE-HDBK-3010-94 2.0 MATERIALS IN THE GASEOUS STATE 2.1 NONCONDENSIBLE GASES 2.1.1 Summary of Analysis of Data Loss of Physical Containment. For noncondensible gases, the recommended ARF is 1.0. All materials in the gaseous state can be transported and inhaled; therefore, a value for RF of 1.0 is assumed for the purposes of these analyses. 2.1.2 Discussion In DOE nonreactor nuclear facilities, radionuclides in the form of noncondensible gases are only found under a few circumstances: as stored tritium, encased in a stored spent fuel matrix, generated by physical or chemical reaction, and generated by inadvertent nuclear criticalities (see Chapter 6). The radiological impact on the human body varies greatly between radionuclides. The noble gases (krypton, xenon) primarily expose the individual to an immersion dose during the passage of the cloud of gases. Their impact, in terms of total effective dose equivalent (TEDE), is from 5 to 10 orders of magnitude less than for the same level of activity of 239Pu or other actinides as particles in the respirable size fraction. However, the noble gas dose will be prompt as opposed to the fifty-year cumulative dose associated with alpha-emitting actinides. Accordingly, such gases may represent a greater threat for acute health effects than the higher specific activity alpha-emitting actinides. The most significant gaseous radionuclide handled outside of cladding matrices is tritium. Tritium is a special case where factors in addition to ARFs and RFs are especially significant. These other factors are the form of the tritium (i.e., elemental tritium or tritium oxidized to a molecular form), which significantly affects the potential dose from exposure, and the exposure modes, which include transpiration. These other factors relevant to tritium are not addressed in this document. Page 2-1 DOE-HDBK-3010-94 2.0 Materials in the Gaseous State 2.2 VAPORS (CONDENSIBLE GASES) 2.2.1 Summary of Analysis of Data For generation of vapors plus release from physical containment, the recommended ARF is 1.0. All materials in the gaseous state can be transported and inhaled; therefore, an RF of 1.0 is assumed for the purposes of these analyses. 2.2.2 Discussion

Vapors (materials in gaseous form due to local conditions) may result from two phenomena: chemical reaction and heating. Some vapors result from chemical reactions that generate a volatile compound (e.g., halogens in an oxidizing, acidic environment). Other vapors can be generated when the local temperature exceeds the boiling point of the element or compound (e.g., evaporation of water). Under most conditions, the ARF (the fraction of vapor formed initially airborne) assumed for vapors is 1.0. If the local conditions are not adequate for quantitative vaporization of all the material (e.g., inadequate chemical reactants, inadequate temperature), the ARF is the fraction of the material converted to vapor form. Release of vapors generated during inadvertent nuclear criticalities is covered in Chapter 6. Loss for chemically reactive materials is difficult to quantify due to the uncertainty of the materials encountered along the pathway, the kinetics of these reactions, and the transport of the vapors to the surfaces. A conservative value is to assume all the material released is transported to the facility/environment interface without loss unless engineered emission control devices (e.g., for radioiodine - impregnated charcoal filters, silver substituted zeolite filters, silver nitrate coated ceramic saddles; HEPA or other filtration devices for condensed vapors or vapors adsorbed onto pre-existing particles) are present for removal of the specific material. In many cases, an assumption of complete transport of the airborne material without significant loss is very conservative but transport losses must be substantiated for the specific configurations associated with an event. Many chemically volatile compounds are reactive and can be lost in transit by reaction with materials encountered along their path to the facility/environment interface or adsorption on pre-existing airborne particles. Temperature sensitive materials can condense homogeneously (particles formed directly from the vapor have been observed to be in the sub-micron range) or on pre-existing particles. Aerosols form rapidly since entrainment of cooler air invariably accompanies the formation process. Various natural processes act to attenuate transport of particles (e.g., agglomeration, gravitational settling, turbulent diffusion) and filtration or other engineered devices such as water sprays have varying removal efficiencies for particles. Page 2-2 DOE-HDBK-3010-94 2.0 Materials in the Gaseous State For temperature-sensitive vapors (e.g., metal vapors generated at high temperatures, tritiated water vapors), the amount of material volatilized can be estimated by the amount of heat energy present and/or generated by the event. Similarly, condensation may also be calculated by heat transfer at the surfaces or by homo- or heterogenous condensation in air. The mass flux of vapors to a cool surface (diffusiophoresis) can be an effective mechanism to sweep small diameter (i.e., submicron) particles from the air. Page 2-3 DOE-HDBK-3010-94 Page 2-4 DOE-HDBK-3010-94 3.0 LIQUIDS In order for a liquid to be made airborne, in most realistic situations, the bulk liquid must be subdivided into particles/droplets small enough to be entrained in the local airflow. In some cases, it may be possible for the activity coefficient of the solute to be adequately reduced so that some material may be made airborne by vaporization.

This section describes mechanisms by which two types of liquids (aqueous solutions and organic, combustible solvents) become airborne; the descriptions are based on experiments. The mechanisms discussed for aqueous solutions include thermal stress, explosive release (i.e., shock, blast, and pressurized venting effects), free-fall spills, and aerodynamic entrainment (resuspension). Organic liquids are specifically discussed in relation to thermal effects. 3.1 SUMMARY OF ANALYSIS OF DATA Aqueous Solutions Thermal Stress • Heating of aqueous solution in flowing air without surface rupture of bubbles. For the airborne release of bulk liquid during heating of aqueous solutions in flowing air without noticeable bubbles breaking on the surface of the bulk liquid, conservative values are based upon the experimental data available. Median ARF 6E-7/RF 1.0 Bounding ARF 3E-5/RF 1.0 • Boiling (bubbles continuously breaking the surface of the bulk liquid with <30% of the volume of the liquid as bubbles) of aqueous solutions in flowing air. A bounding ARF for the airborne release from the bubble-burst at the surface for aqueous solutions exceeds all measured values. In the absence of a measured size distribution for the airborne droplets, a conservative value of 1.0 is assumed for the RF bound. Median ARF 1E-3/RF 1.0 Bounding ARF 2E-3/RF 1.0 Page 3-1 DOE-HDBK-3010-94 3.0 Liquids; Summary Explosive Stress Releases are discussed for detonation shock effects, detonation or deflagration blast effects, deflagration pressurized venting effects, and general pressurized venting. The effect most closely resembling stresses in a given explosive-type accident scenario is chosen. There is no need to assume cumulative releases for all effects cited. • Shock Effects. For detonations in or immediately contiguous to a pool of liquid, a bounding respirable release is assessed to be the mass of inert material equal to the calculated TNT equivalent. At low mass ratios, the respirable release is comparable to the total material release. As mass ratios increase, the respirable fraction becomes significantly less than the total amount of material released, which decreases with increasing mass ratio as well. • Blast Effects. For detonations and deflagration at a distance where the pressure impulse is essentially equal to a flow parallel to the surface of the liquid, an ARF of 4E-3/hour (1E-6/second) for the time the pressure pulse is over the liquid and an RF of 1.0 are conservatively assumed. • Venting of Pressurized Liquids. There are three main regimes of pressurized venting of liquids: (1) venting below liquid level, (2) venting above liquid level, and (3) venting of superheated liquid (i.e., flashing spray). This phenomena covers general pressurized venting, including deflagration induced pressurized venting effects. — Depressurization of liquid via a failure under the liquid surface level. Liquids covered are those at or below their boiling points. Bounding ARF and RF are estimated using the mass fraction of droplets 10-µm and less in diameter formed by commercial spray nozzles (device designed to produce small drops) under conditions that will exceed those anticipated for most accident situation (3.25-mm diameter orifice at 200 psig upstream pressure). Bounding ARF 1E-4/RF 1.0 — Depressurization of containment via a failure above the liquid level or overall containment failure. Values are determined for elevated levels of dissolved gases and gas pressure pulses above liquids. Liquids covered are those at or below their boiling points.

Page 3-2 DOE-HDBK-3010-94 3.0 Liquids; Summary The ARF and RF values depend on the maximum liquid or vessel failure pressure and the density of solution. Two regimes are defined for liquid venting or vessel failure pressure. The first regime is pressure equal to or less than 0.35 MPag (~ 50 psig). This value is independent of solution density. The second regime is for pressures greater than 0.35 MPag up to 3.45 MPag (~ 500 psig). In this regime a distinction is made between general aqueous solutions and concentrated heavy metal nitrate solutions such as uranium nitrate hexahydrate (UNH) or plutonium nitrate. The distinction is gross, with any solution having a density > ~ 1.2 g/cm3 being considered a concentrated heavy metal solution. The highest release fraction is for aqueous solutions. Low Pressure (0.35 MPag or less) Bounding (all solutions) ARF 5E-5/RF 0.8 High Pressure (> 0.35 MPag) Median (aqueous solution, density ~ 1 g/cm3) ARF 3E-4/RF 0.9 Median (conc. heavy metal solution, density > ~ 1.2 g/cm3) ARF 2E-4/RF 0.3 Bounding (aqueous solution) ARF 2E-3/RF 1.0 Bounding (conc. heavy metal solution) ARF 1E-3/RF 0.4 If the containment failure is located above the critical freeboard height, allowing rapid pressurization and depressurization, the ARF and RF values may be significantly less than those noted above. For failures below the critical freeboard height, a potential method for estimating release fractions is discussed in subsection 3.2.2.3.2.B. However, difficulty in defining a critical parameter, density of gas released, precludes clear use of the method at this time. The values noted above will be conservative for such cases. — Depressurization of liquid above boiling point. Three different values are defined for flashing spray release based on the degree of superheat: liquids with less than 50 oC superheat above the boiling point of the liquid; liquids with superheats between 50 and 100 oC above the boiling point of the liquid; and liquids with greater than 100 oC superheat. The ARF appears to increase with decreasing source size and volume. The values used in the experiments for these parameters are much below Page 3-3 DOE-HDBK-3010-94 3.0 Liquids; Summary those anticipated under most accident situation (100 ml), and therefore may be very conservative for many applications. ≤ 50 oC Superheat Bounding ARF 1E-2/RF 0.6 50 to 100 oC Superheat Median ARF 2E-2/RF 0.7 Bounding ARF 1E-1/RF 0.7 For superheats greater than 100 oC above the boiling point of the liquid, the ARF value is 0.33 (MFg) 0.91 (where MFg is the mole fraction of pressurizing gas/water vapor flashed) with an RF of 0.3 if the calculated respirable release exceeds the 50 to 100 oC superheat value. Free-Fall Spill • Free-fall spill of aqueous solutions, 3-m fall distance. A distinction is made between general aqueous solutions and concentrated heavy metal nitrate solutions such as uranium nitrate hexahydrate (UNH) or plutonium nitrate. The distinction is gross, with any solution having a density > ~ 1.2 g/cm3 being considered a concentrated heavy metal solution. The highest release fraction is for aqueous solutions. Median (aqueous solution, density ~ 1.0 g/cm3) ARF 4E-5/RF 0.7 Median (conc. heavy metal solution, density > ~1.2 g/cm3) ARF 1E-6/RF 0.3 Bounding (aqueous solution) ARF 2E-4/RF 0.5 Bounding (conc. heavy metal solution) ARF 2E-5/RF 1.0 • Free-fall spills of slurries, 3-m fall distance, <40% solids. Median ARF 2E-5/RF 0.7 Bounding ARF 5E-5/RF 0.8

• Free-fall spills of viscous solutions, viscosity >8 centipoise. Median ARF 3E-6/RF 0.8 Bounding ARF 7E-6/RF 0.8 Page 3-4 http:MFg)0.91 DOE-HDBK-3010-94 3.0 Liquids; Summary • Free-fall spills of aqueous solutions, slurries and viscous solutions, fall distances >3 m. The empirical correlations for ARF and drop size distribution parameter presented by Ballinger et al. (January 1988) are assessed to be adequate provided ARF x RF value exceeds bounding 3-m values. Aerodynamic Entrainment and Resuspension There appear to be very large differences in suspension rates under experimental test conditions as well as an order of magnitude uncertainty in measurements for individual conditions. On this basis, conservative values are applied. • Indoors, on heterogeneous surface (stainless steel, concrete), low airspeeds up to normal facility ventilation flow; Outdoors, pool for low windspeeds. Bounding ARR 4E-7/hr; RF 1.0 • Indoors, on heterogeneous surfaces, covered with debris or under static conditions. Bounding ARR 4E-8/hr; RF 1.0 • Outdoors, from large pools/ponds, higher windspeeds to 30 mph. Bounding ARR 4E-6/hr; RF 1.0 • Outdoors, absorbed on soil, no lengthy pooling, windspeeds to 50 mph. Bounding ARR 9E-5/hr; RF 1.0 Use of the above values for short time frames (<100 hours) would not introduce serious error due to the severe depletion of the source. For time periods exceeding 100 hours, the reduction of the source can be accounted for from the entrainment of material. In general, these values are intended for immediate post-accident conditions and freshly deposited material. They would overestimate cumulative releases from long-term contamination of surfaces (i.e., months to years) and are not appropriate for such use. Organic Combustible Liquids This section specifically addresses potential releases of radioactive contaminant due to thermal stress for organic solutions or organic and aqueous solutions present together. Page 3-5 DOE-HDBK-3010-94 3.0 Liquids; Summary Thermal Stress • Volatiles (i.e., iodine) under all conditions. Bounding ARF 1.0/RF 1.0 • Quiescent burning, small surface area pools, or small solvent layer over large aqueous layer burning to self-extinguishment. Median ARF 6E-3/RF 1.0 Bounding ARF 1E-2/RF 1.0 • Vigorous burning large pools, or solvent layer burning over limited aqueous layer with sufficient turbulence to disrupt bulk of aqueous layer. Bounding ARF 3E-2/RF 1.0 • Large, vigorously burning organic fire that burns to complete dryness or burning solvent over aqueous phase burning to complete dryness for both phases (typically requires external heat source). Median ARF 1E-2/RF 1.0 Bounding ARF 1E-1/RF 1.0 • Aqueous solution or air-dried salts under gasoline fire on a porous or otherwise absorbing (i.e, cracks, depressions) surface. Bounding ARF 5E-3/RF 0.4 • Aqueous solution or air-dried salt under gasoline fire on heat conducting surface (i.e., metal). Bounding ARF 2E-1/RF 0.3 No experimental data on the behavior of organic, combustible liquids in response to explosive release, venting of pressurized liquid, free-fall spills, or aerodynamic entrainment were found. In general, the values provided for aqueous solutions can be used for the types of organic solvents used in material extraction operation. However, extreme thermal effects, such as explosions, require subsequent consideration of solvent fires. Page 3-6 DOE-HDBK-3010-94 3.0 Liquids; Aqueous Solutions

3.2 AQUEOUS SOLUTIONS 3.2.1 Thermal Stress: Evaporation and Boiling Under most realistic scenarios involving the heating of aqueous solutions during postulated accidents in nonreactor fuel cycle facilities, the relative vapor pressures of the solvent (water) and the solute (various compounds of radionuclides, generally acidic nitrate) preclude evaporation of the solute as a viable mechanism for the airborne release of the solute. Instead, the airborne release is postulated to result from the entrainment of minute drops of the bulk liquid formed by the mechanical disintegration of the surface of the bulk liquid. Mechanical disintegration mechanisms include bubble breakup during boiling, jet drops formed from the collapse of the crater remaining after bubble breakup, and secondary drops from the reentry of jet drops. Drops are carried to the bulk flow by convective and vapor flow away from the heated liquid. An increase in surface disruption would increase the airborne release, although capture of secondary drops by the large number of primary particles may place a limit on the release. Kataoka and Ishii (April 1983) reviewed the literature and data on the entrainment of liquid droplets from the surface of a bubbling or boiling pool. Droplets are generated by bubble bursting, splashing or foaming. Some of the entrained droplets fall back into the pool and some are carried away by the streaming gas. Entrainment, Efg, is defined as: Efg = droplet upward mass flux/ the gas mass flux = (ρf jfe)/(ρg jg) (3-1) where: ρf = fluid density jfe = superficial velocity of liquid flowing upward as droplets ρg = gas density jg = superficial gas velocity. Two levels of the gas flow through the liquid upon the surface were noted: 1. bubbly flow (condition postulated for nonreactor facility accidents): small gas flow (<0.1 m/s); droplets generated by discrete bubbles rising to surface of pool and collapsing; initial velocity of entrained droplets is a function of bubble burst time, bubble diameter, density of liquid and pressure around bubble; transition to next level at ~0.1 m/s and liquid void fraction 0.3. 2. churn turbulent flow: may be dominant mechanism for post-Loss of Coolant accident in light water reactor accident conditions; initial velocity of droplets determined by momentum exchange mechanism (during breakup of liquid Page 3-7 DOE-HDBK-3010-94 3.0 Liquids; Aqueous Solutions ligaments formed from surface disruption); droplets generated by all three droplet generation mechanisms (i.e., bubble bursting, splashing, or foaming). Three regions as a function of axial distance from the pool surface were identified: 1. near-surface region: immediate vicinity of surface; entrainment dependent on height and gas velocity; entrainment consists of all droplets entrained. 2. momentum-controlled region: intermediate axial distances above pool surface; entrainment consists of droplets with initial momentum to reach height and droplets whose terminal velocity is equal to or less than the superficial gas velocity; three regimes as a function of superficial gas velocity in region: • low gas flux: entrainment small and consists of very fine droplets; Efg approximately proportional to gas flux. • intermediate gas flux: larger drops ejected from pool; Efg increases with the 3rd or 4th power of the superficial gas velocity. • high gas flux: large gas slugs form and pool surface highly agitated; considerable droplets formed by splashing; Efg increases with the 7th to 20th power of the superficial gas velocity.

3. deposition-controlled region: entrained droplets of size whose terminal velocity is equal to or less than the superficial gas velocity. A simple mechanistic model was developed based on the concepts presented above. Due to the enormous number of droplets generated, the motion of individual droplets could not be followed individually, and so droplet motion was handled statistically. Important physical parameters and distribution functions essential to the modeling and calculations were developed or assumed. Correlations for the height criteria and entrainment in each region were developed as a function of: * 2]1/4dimensionless gas velocity, jg = ~ jg/[σg Δρ/ρg (3-2) dimensionless height above surface, h* = h/[σ/g Δρ] 1/2 (3-3) gas viscosity number, Nµg = µg/[ρg σ (σ/g Δρ) 1/2]1/2 (3-4) dimensionless vessel diameter, D* H = DH/ [σ/g Δρ] 1/2 (3-5) Page 3-8 DOE-HDBK-3010-94 3.0 Liquids; Aqueous Solutions where: = liquid surface tension jg = superficial gas velocity g = acceleration due to gravity g = surface tension of gas g = gas density h = height above pool surface µg = viscosity of gas = density difference between gas and liquid DH = diameter of vessel. All correlations agreed well with the published data and could be applied to estimate ARF for specific scenarios. The correlations are relatively straightforward although the values depend upon parameters that are not readily quantifiable for many practical situations and vary with temperature. Methods to determine the temperature or the values for the parameters as a function of temperature were not presented. Use of the correlations for this study would require the definition of a range of accident scenarios (not done as of this time) to determine a bounding ARF and RF. The results indicate that large variations may be observed in measured data dependent upon the location and configuration of the sampling system. Four important observations arise from review of literature on entrainment of liquid droplets from bubbling or boiling pools performed by Borkowski, Bunz and Schoeck (May 1986): 1. the influence of surface effects on the amount and composition of the generated aerosols; 2. the possibility of chemical enrichment and depletion of substances in aerosols; 3. the existence of two groups of droplets with different mean sizes and amounts of airborne mass; 4. the limited range of ejected jet droplets due to initial velocity; Droplet formation during boiling is dependent upon conditions of boiling and bubble characteristics. There appear to be at least two and possibly three boiling regimes that affect bubble and droplet formation. The first regime occurs at lower rates where the volume fraction of the bubbles is less than 30%, when discrete bubbles rise through the liquid and grow due to decreasing hydrostatic head. Bubbles may coalesce or divide during ascent. Droplets are formed from three mechanisms (bubble film disintegration, jet drops from crater collapse, and secondary droplets from jet drop reentry into bulk liquid). This regime is the predominant concern for nonreactor facility accident scenarios. A second regime occurs at Page 3-9 DOE-HDBK-3010-94 3.0 Liquids; Aqueous Solutions higher boiling rates; the liquid is turbulently mixed and progressively disintegrates at the surface forming drops from both mechanisms. A possible third regime occurs at very high boiling rates when splashing and foaming dominate the surface (Borkowski, Bunz and Schoeck, May 1986).

Gas flow conditions and material characteristics are important parameters in bubble-induced droplet formation. Bubble size determines the number and size of the droplets formed. Bubble size is determined by the volume of vapor, surface characteristics such as surface tension, and bubble contact angle. Contact angle changes due to local turbulence during bubble formation resulting in a distribution of bubble sizes. Many bubbles are unstable and coalesce and break up during ascent. Steam bubbles are in the range of 0.5 to 5 cm diameter at low pressure and nucleate boiling (presence of rough surface, suspended particles). The formation and detachment of macro-bubbles is a function of contact angle of the liquid and the degree of superheat. Bubble shape at the surface may range from spherical to hemispherical depending on size. The liquid in the dome of the bubble runs down the sides and thins the film. The bubble bursts when the internal pressure exceeds the external pressure and surface tension of the film. Droplets are formed by the film breakup. The crater remaining from the bubble rupture itself collapses forming an ascending liquid jet that decays into droplets after some critical length. Jets ascend up to 20 cm from the surface of the bulk liquid. Jet drops are only formed from bubbles <5 to 6 mm in diameter. Droplets from film breakup are only formed for bubbles >0.2 mm in diameter. Therefore, by inference, only jet drops are formed from bubbles <0.2 mm in diameter and only film breakup droplets are formed from bubbles >6 mm in diameter. The number and size distribution of droplets formed from film breakup correlates with the size of the bubble and may number into the hundreds for the upper limit of bubble diameter. Figure 3-1, reproduced from the reference document, shows a number distribution from the burst of two bubbles of 0.1% NaCl in water. Only one jet drop ejected from collapse of a bubble ~2-mm in diameter with up to 6 ejected from very small diameter bubbles (high internal pressure). The diameter of the drop is ~20% of the bubble diameter (100- to 1000-µm for the conditions covered here) (Borkowski, Bunz and Schoeck, May 1986). 3.2.1.1 Heating of Shallow Pools The airborne release during heating of aqueous solution was measured and reported by Mishima, Schwendiman and Radasch (November 1968). This study involved the collection and measurement of airborne Pu during drying of shallow pools of concentrated acidic plutonium nitrate solution at three air velocities and the evaporation of 90% of the volume of a dilute acidic plutonium nitrate solution. Table 3-1 displays measurements extracted from Page 3-10 D O E -H D B K -3010-94 3.0 L iquids; A queous S olutions P age 3-11 DOE-HDBK-3010-94 3.0 Liquids; Aqueous Solutions Table 3-1. Fractional Airborne Releases During the Heating with Flowing Air of Concentrated Plutonium Nitrate Solution (Table 1 from Mishima, Schwendiman, and Radasch, November 1968) Temp, °° C Air Velocity, m/s Sampling Time, hr ARF 50 1.0 2 1.3E-7 75 0.5 5 <1.0E-8 90 0.5 2 5.3E-7 90 1.0 1.5 5.7E-7 100 0.1 2 1.0E-5 100 0.5 2 3.0E-5 the study reference document (reproduced as Table A.1 in Appendix A) and shows the ARFs from evaporation of concentrated plutonium nitrate solutions under three air velocities (0.1, 0.5, and 1.0 m/s).

A schematic diagram of the experimental apparatus is shown in Figure A.1 (Appendix A). Approximately 2.5 to 3 ml of a concentrated Pu(NO3)4 solution containing from 0.72 to 0.86 g Pu were placed in a shallow depression (~25.4-mm diameter x ~2.4-mm deep) in a 31.8-mm diameter x 6.35-mm deep stainless steel dish. The dish was placed in a teflon retainer that filled half of the diameter of a 38.1-mm diameter borosilicate glass tube. Filtered room air was drawn through the tube at three nominal velocities (0.1, 0.5, and 1.0 m/s) over the solution and through a water-cooled condenser to remove excess moisture; the airborne particles were then collected on an in-line glass fiber filter. The liquids were heated to various temperatures by heat lamps positioned over the liquid. The evaporation times ranged from 1.5 to 24 hours. None of the solutions were observed to boil during any of the experiments and the airborne release is most probably due to the aerodynamic breakup of the surface, with release increasing as temperature increases due to reduced surface tension. The airborne fractional releases measured are shown in Table 3-1; ARFs range from <1E-8 to 3E-5. The highest ARFs were measured at the highest temperature (1E-5 and 3E-5 at 100 oC). The limited data also tend to indicate some increase in airborne release with increasing air velocity. The surfaces during the drying were relatively undisturbed (no visible surface disturbance). The upper bound release is 3E-5, and, in as much as the size distribution of the airborne materials was not measured, a conservative value of 1.0 is selected for the RF. The median value is 6E-7 (5.5E-7 rounded upward) with an average value of 7E-6. Page 3-12 DOE-HDBK-3010-94 3.0 Liquids; Aqueous Solutions The data are limited but do appear to consistently indicate a gradual increase in airborne release with temperature until boiling or near boiling temperatures. The air velocity range is very limited although the air velocity probably represents a much greater aerodynamic stress on the surface than the nominal velocity indicates. Air velocity measurements are usually at much greater distances from the surface than in the experimental apparatus, and, air being a fluid, the velocity decreases with distance from the surface due to frictional forces. The extremely small liquid sample sizes would also enhance effective stress as well. The concentrated plutonium nitrate solution used represents a very important class of liquids found in DOE facilities but its fluid characteristics (higher density, surface tension) may not make it bounding for other aqueous solutions. 3.2.1.2 Heating of Pools ARFs were also measured during the evaporation of 90% of the volume of aqueous solutions at three surface disturbance levels: simmering, disturbed surface, and boiling (Mishima, Schwendiman and Radasch, November 1968). The results from the source document are reproduced in Table A.2, and the experimental apparatus is shown in Figure A.2, both in Appendix A. In the experiments, 100 ml of a dilute Pu(NO3)4 solution (0.25 M HNO3) containing 0.7 mg Pu was placed in a 180 ml borosilicate beaker. The surface area of the liquid was 11.5 cm2. The beaker was held in the center of a transite support ring that positioned the beaker in a aluminum plate set upon a hot plate. A screen supporting a glass fiber filter filled the annular area between the support ring and beaker and allowed air to be drawn through the 4-liter borosilicate glass bell jar to entrain particulate material escaping from the beaker. The velocity through the annular filter was estimated to be 3 cm/s. The air was drawn out of the top of the bell jar via a water-cooled condenser to remove moisture. The condensate was collected. Airborne material was collected on an in-line glass fiber filter.

The pertinent results are shown in Table 3-2. The ARFs for the four runs at boiling ranged from 4.5E-7 to 1.8E-3. Three of the four values ranged from 3E-4 to 1.8E-3. The two highest values (1.1E-3 and 1.8E-3) were estimated by the sum of the filter acid leach and from acid washes of the equipment downstream of the filter position due to loss of the filter. These values include solution splattered from the vessel onto the glassware. The values are almost certainly high, but it is not known how high. Two of the runs (ARFs 4.5E-7 and 1.1E-3) used a 0.70 mg Pu source without an airflow. The two runs performed at simmering (no surface breaking) resulted in ARFs of 1.3E-6 and 4.5E-6 that are bounded by the evaporation value of 3E-5 quoted in subsection 3.2.1.1. The four experiments with heating rates resulting in disturbed surfaces generated ARFs ranging from 5.8E-5 to 8.4E-4: an order of magnitude variation in estimates. A bounding value for boiling of aqueous solutions of 2E-3 is selected, and, in the absence of a measured particle size distribution, a Page 3-13 DOE-HDBK-3010-94 3.0 Liquids; Aqueous Solutions Table 3-2. Fractional Airborne Release During Heating of Pools of Dilute Plutonium Nitrate Solution - 90% Volume Reduction (Table II, Mishima, Schwendiman, and Radasch, November 1968) Average Hot Plate Temperature, °° F Average Boil-Off Rate, ml/min Minutes Heated Appearance Surface ARF 150 150 164 175 188 190 200 218 218 220 0.6 0.5 0.66 0.73 1.2 0.9 1.4 1.4 1.4 2.1 151 150 121 124 64 80 66 63 59 42 Simmering Simmering Disturbed Disturbed Disturbed Disturbed Boiling Boiling Boiling Boiling 4.5E-6 1.3E-6 5.8E-5 2.4E-4 8.0E-5 8.4E-4 1.1E-3a,b 1.8E-3a 3.0E-4 4.5E-7b a Filter ruptured, estimate based on activity collected in acid washes of equipment downstream of filter position. b Only 0.07 mg Pu used as source. No air sweep used during these experiments. ARF estimate from activity collected in condensate. conservative value for an RF of 1.0 is selected. The median value for the range of surface disturbance levels is 6E-5 (6.4E-5 rounded off) with an average value of 7E-4. The fraction of source material exiting the container and depositing nearby (fallout) ranged from ~3E-8 during simmering to 1.7E-2 during boiling. This material is considered generally indicative of the liquid ejected from the container but not airborne during such event. As with the airborne materials, the fraction ejected will increase with the increase in surface disturbance. The data are limited for each type of heated liquid. The loss of the filters coupled with not using air sweeps in two of the boiling experiments makes the data for that type of heating especially uncertain. The surface of the heated liquid is recessed from the airflow and may reduce the airborne material due to losses to the sides of the beaker prior to escape. The configuration may be indicative of airborne release from heated liquids from the tops of vessels. These types of considerations are why the higher values obtained are selected, even though they represent overestimates to some degree due to equipment failure and are considered excessive for the experimental configuration. The liquids are very dilute aqueous solutions and should bound other more viscous liquids or those with greater surface tension. Page 3-14 DOE-HDBK-3010-94 3.0 Liquids; Aqueous Solutions 3.2.1.3 Additional Evaporation and Bubbling Release Studies

Borkowski, Bunz, and Schoeck (May 1986) reviewed 12 experimental studies that examined the airborne release of dissolved matter from bubble-burst at the surface of aqueous solutions. The slope of the rate change for fraction entrained as a function of gas velocity changes at a gas velocity of 15 cm/s. The experimental data reported in this region are reproduced in Figure 3-2. Data generated by the venting of pressurized liquids is also presented as Figure 3-3 to assist in overall phenomena assessment. The data by Mishima, Schwendiman, and Radasch (November 1968) covered in subsection 3.2.1.2 are plotted along with data from six other studies under reasonably comparable conditions. Manowitz et al. (1955) measured the DF (decontamination factor, the ratio between the radioactivity retained in the liquid in the vessel to that boiled off) during evaporation of waste solution using a de-entrainment device (not specified). The DFs ranged from 1E-4 to 1E-5 depending upon the boiling rate and contents suspended in solution. Garner et al. (1959) performed experiments at reduced pressures and equilibrium conditions to identify the main parameters for liquid entrainment during evaporation. Entrainment increased with evaporation rate and decreasing solute concentration. Entrainment rates ranged from 1E-5 to 1E-4. Garner et al. (1954) measured the drop size distribution and total entrainment during evaporation in vessels of various diameters (4-in. and 12-in. diameter tubes). Entrainment rates were in the 1E-5 range. Although ~95% of the drops were in the < 20-µm diameter range, the total mass entrained was primarily due to the drops > 100-µm in diameter. Shor et al. (1957) measured the radioactivity carried over in boilers by continuous monitoring of trace 137CsCl driven airborne at elevated pressures (0.93 to 1.0 Mpa). Entrainment (1E-6 to 1E-4) correlated with boiling rate and had an initial high burst of activity released. Heger et al. (1982, 1983) conducted bubbling experiments to simulate reprocessing plant components. Stirring air flow velocity was ~10 m/h (2.8 cm/s). Entrainment values ranged from 1E-7 to 1E-4. The presence of tributyl phosphate (TBP) reduced the surface tension and increased entrainment by a factor of 5 to 10. The drops airborne were bimodally distributed with maxima at 0.3 and 0.8-µm diameter. Addition of the TBP increased the generation of larger diameter drops. It is evident that the ARF of 2E-3 measured by Mishima, Schwendiman and Radasch (November 1968) bounds the value measured by the other reported studies by approximately an order of magnitude. Data generated by the venting of pressurized liquids shown in Figure 3-3 indicate that short of flashing spray conditions (superheating of the liquid by pressurization), a release value in the range of 1E-3 will bound the airborne release of liquids during boiling at normal atmospheric pressures. Thus, a bounding ARF of 2E-3 with an RF of 1.0 is considered a very conservative bound for the airborne release of respirable size drops during accident condition resulting in the boiling of aqueous solutions. Page 3-15 DOE-HDBK-3010-94 Page 3-16 D O E -H D B K -3010-94 3.0 L iquids; A queous S olutions P age 3-17 DOE-HDBK-3010-94 3.0 Liquids; Aqueous Solutions 3.2.2 Explosive Stress: Shock, Blast, and Venting Liquids may be subdivided by the shock generated by detonation-like reactions or by shear stress at the surface generated by the accelerated airflow from the blast. Venting of pressurized liquid phenomena is related to explosions as well.

3.2.2.1 Shock Effects Steindler and Seefeldt (1980) provide an empirical correlation to experimental data on the fragmentation of metals and aqueous solution by detonations [energy releases in microseconds with brisance (shattering effect)] (Ayer, et al., May 1988). The experiments performed by others were used to relate releases to mass ratios (i.e., ratio mass of inert material to TNT equivalent) of 1 to 15. The experiments were conducted with the condensed phase explosive embedded or contiguous to the material affected. Estimates of the ARF and size distribution for various mass ratios up to 1000 are provided in Appendix C of Ayer, et al. (May 1988) for a GSD (Geometric Standard Deviation, the slope of the line on log probability plot) of 8. The GSD is much greater than normally assumed (GSD 2) due to potential uncertainties regarding actual energy distribution. The fragmentation of only a portion of the inert material occurs when MRs are large, and the fraction of shock energy absorbed by this unknown portion of material is likewise unknown. All inert material is driven airborne as particulates in the respirable size range for an MR of one. The volume of material exposed to the shock effects of the explosion is essentially constant for an explosive charge of a given size as the surface area in proximity to the charge is fixed. However, as the amount of inert material increases, the fraction of the total mass exposed to significant shock effects in that volume decreases. Given the potential uncertainties of the data, this simple relationship will be used to extrapolate respirable releases from the point of maximum release (i.e., MR = 1). A respirable release of inert mass equal to the TNT equivalent for the detonation (to a maximum of 100% release) is considered to bound the Steindler and Seefeldt (1980) correlation. This assumption is supported by numerical comparison. For MRs of 5, 10, and 15, the combined ARF x RF values predicted by the correlation for a GSD of 2 are 4E-3, 6E-4, and 3E-4 respectively. For MRs of 5, 10, and 15, the combined ARF x RF values predicted by the correlation for a limiting GSD of 8 are 2E-1, 9E-2, and 7E-2 respectively. The simple method used by this handbook would predict combined ARF x RF values of 2E-1, 1E-1, and 7E-2, which correlate with the values for a GSD of 8 that are believed to be very conservative. Page 3-18 DOE-HDBK-3010-94 3.0 Liquids; Aqueous Solutions 3.2.2.2 Blast Effects The blast effect of interest is accelerated gas velocities passing over the surface of the liquid. Mishima and Schwendiman (August 1973) reported the results of measurements of the airborne release of uranium from various surfaces (soil, vegetated soil, stainless steel, asphalt with UO2 powder or UNH solution) before, during and after gasoline fires in a wind tunnel at air velocities of ~1 m/s and ~10 m/s. The flame speed in flammable vapor mixtures is also on the order of 10 m/s, although flame speed may propagate to sonic velocities under turbulent conditions. The results are reproduced in Table A.3 and the experimental apparatus is shown in Figure A.3 in Appendix A. The only experiments involving UNH solution were performed on a substrate of loose, sandy soil at air velocities of~1 & 10 m/s. The ARF measured at 10 m/s from soil during a 28-hour sampling period was 3.9E-4 with an RF of 0.68. The value is comparable to other experiments involving UNH residues from the fire except for one result from stainless steel at 10 m/s (ARF 2.6E-2 in 6 hours/RF 0.3; linear rate 4E-3/hr). Therefore, the rapid passage of air at an accelerated velocity from the deflagration of a flammable vapor mixture does not appear to have the potential to release large amounts of material from aqueous liquids. The ARF is assessed to be 4E-3/hr for the time duration of impulse passage over the liquid (generally on the order of 1 second).

3.2.2.3 Venting of Pressurized Liquids Liquids, contained in a vessel or containment, can be pressurized by external sources (e.g., deflagration in a free volume above the liquid, pressurized gases from an external source) or by vapor generated by the heating of liquid. If the pressure exceeds the strength of the vessel/containment, the vessel/containment will fail and, under the proper circumstances, can release the liquid to the atmosphere as liquid drops. Droplets of an aqueous solution under pressure can be generated by spray if the pressure is relieved by venting a cold liquid through a small opening in the wall of the vessel, by the bubbling action on the surface of the liquid resulting from the release of gases absorbed/trapped in the cold liquid, and by fragmentation of the liquid by bulk vaporization when the pressure over a superheated solution is relieved (i.e., flashing spray). The characteristic of the liquid, the source of the pressure, and the location of the failure all have an effect on drop formation and release. Pressure driving the release is estimated by the strength of the external source, temperature/vapor pressure of the liquid, the temperature/volume expansion of the gases, etc., depending on the scenario described. The point of venting is determined by the design, construction and strength of material of the vessel/containment. If the vent is located below the level of the liquid, spray formation is the mechanism for drop formation. If the vent is Page 3-19 DOE-HDBK-3010-94 3.0 Liquids; Aqueous Solutions above the liquid level, whether or not the liquid can release gases or vapors upon depressurization influences the drop formation mechanism. If the liquid has come to equilibrium with the free volume atmosphere, liquids under pressure will generate drops by bubble breakup at the surface from release of trapped/dissolved gases. For heated liquids, drops are generated by bubble breakup at the surface of the liquid from vapor generation. For liquids that have not come to equilibrium with a pressurized free volume atmosphere, the bubbling action from release of absorbed/trapped gases can be minimal. Drop formation is more accurately described as a function of shear stress on the liquid surface and stratified two-phase flow. If the vent is greater than the Critical Freeboard Height above the surface of the liquid, the flow pattern tends to be vertical and does not exert significant shear stress across the liquid surface to create drops, and the relatively great distance from the point of origin of the drops to the vent does not create conditions favorable to release. For vents that are less than the Critical Freeboard Height from the liquid surface, drop formation is by shear stress exerted due to the induced, high velocity flow parallel to the liquid surface. While this release mechanism can result in significantly smaller release fractions than the three mechanisms cited in the preceding paragraph, it requires data that is not practically attainable in most cases. As a result, this mechanism, while discussed, will be represented by the more conservative case of release of absorbed/trapped gases. 3.2.2.3.1 Venting Below the Liquid Level. If the container or pipe holding an ambient-temperature liquid under pressure is breached, the liquid can escape in a variety of ways. Breaches venting pressurized liquids can range from pinhole leaks in pipes (generating a mist) to drips from very slow leaks to large jets of liquids that may gush from large holes. The amount and aerodynamic size distribution of the spray generated are a function of the size and characteristics of the breach, the upstream pressure, and the liquid characteristics (e.g., viscosity, density, volatility).

For the purposes of airborne suspension, a conservative assumption would be the pressurized release of the liquid via a very fine hole as occurs in a commercial spray nozzle. The size distribution of some commercial spray nozzles as a function of orifice diameter and upstream pressure were shown by Mishima, Schwendiman and Ayer (October 1978). The size distribution of the liquid drops decreases with orifice diameter and increasing upstream pressure. It is not anticipated that drops formed from breaches, cracks, leaks would generate finer drop size distributions than equipment specifically designed for that purpose. Therefore, the respirable fraction of the coarsest distribution generated by commercial spray nozzles shown in Figure 3-4 is selected as the bounding ARF, 1E-4, with a RF of 1.0. For other size fractions, the values can be inferred from the 0.128-inch (3.25-mm) diameter spray nozzle values at 200 psig (1.38 MPag) upstream pressure. Page 3-20 DOE-HDBK-3010-94 3.0 Liquids; Aqueous Solutions Page 3-21 DOE-HDBK-3010-94 3.0 Liquids; Aqueous Solutions Other recent investigations (Leach, 1993; Gieseke, Kogan and Shaw, September 1993) using an analytical model suggest that, under some conditions, the fraction of drops in the finer size fractions (i.e., 10-µm and less) are greater for fine orifices (and possibly slot-type breaches) at high pressures and that the evaporation of the liquid prior to deposition may reduce the size of the larger diameter drops to some extent. There is considerable uncertainty as to the value to assign the critical factor (Q, a drop size fitting parameter) and the analytical model, though useful in understanding the phenomenon, cannot presently be used to predict the size distribution of sprays. 3.2.2.3.2 Venting Above the Liquid Level or Overall Containment Failure. The amount of liquid entrained as droplets in depressurization flow depends on several factors. The effect of dissolved gases, surface turbulence and stratified two-phase flow are considered below. A. Elevated Levels of Dissolved Gases. Sudden depressurization of a liquid allows the release of dissolved/trapped gases. This sudden release of gases may result in bubble formation that can create very small drops upon collapse. The drops formed can be carried with the venting gases. Figure 3-3 previously presented illustrated the relationship between the amount of gas/vapor released and the fraction airborne. Experiments were performed to measure the ARF due to venting pressurized volumes of aqueous solutions in quasi-equilibrium with their pressurizing gases (Sutter, August 1983). Data from the referenced document (reproduced as Tables A.4 through A.7 in Appendix A) describing airborne release of aqueous solutions are tabulated in Table 3-3. The experimental apparatus is shown in Figures A.4 & A.5 of Appendix A. The average ARF as a function of pressure, solution density and source size are shown in Table 3-4 (tabulated as weight percent, 0.05 wt/o = 5E-4 fraction) from the reference and plotted in Figure 3-5. ARF increases with pressure and decreases with density and source size. Due to the pressures employed, there appears to be a significant difference between bounding ARF and RF for pressure less than 0.345 MPa (50 psig) and between 0.352 MPa (51 psig) and 3.45 MPa (500 psig). g g g Bounding values for each pressure range are given. For the venting of liquids with elevated levels of dissolved gases or overall vessel failure/blowout to 0.345 MPag, the ARF and RF values range from 3E-6/0.8 to 5E-5/0.8. The bounding ARF and RF are assessed to be 5E-5 and 0.8.

For the venting of liquids with elevated levels of dissolved gases or overall vessel failure/blowout in a range of 0.352 MPag to 3.45 MPag, the data appears to show some dependency on experimental parameters. For the uranine solution (lower density liquid, ~1 g/cm3), a bounding ARF of 2E-3 with a fraction of airborne Page 3-22 DOE-HDBK-3010-94 3.0 Liquids; Aqueous Solutions Table 3-3. Measured ARFs from Venting Pressurized Aqueous Solutions (Tables A.4, A.5, B.4 and B.5 - Sutter, August 1983) Source Volume, ml Pressure, psig Material ARF RF ARF x RF 350 500 uranine 6.0E-4 0.86 5.0E-4 500 uranine 4.0E-4 0.85 3.0E-4 500 UNH 2.0E-4 0.34 7.0E-4 500 UNH 3.0E-4 0.37 1.0E-4 250 uranine 7.0E-5 0.98 7.0E-5 250 uranine 1.0E-4 0.84 1.0E-4 250 UNH 1.0E-4 0.20 2.0E-5 250 UNH 9.0E-5 0.45 4.0E-5 50 uranine 4.0E-6 0.83 3.0E-6 50 uranine 1.0E-5 0.87 1.0E-5 50 UNH 3.0E-6 0.76 2.0E-6 50 UNH 4.0E-6 0.70 3.0E-6 100 500 uranine 2.0E-3 0.90 2.0E-3 500 uranine 1.0E-3 0.70 8.0E-4 500 UNH 7.0E-4 0.46 3.0E-4 500 UNH 1.0E-3 0.38 4.0E-4 250 uranine 4.0E-4 0.78 3.0E-4 250 uranine 7.0E-4 0.77 5.0E-4 250 UNH 4.0E-4 0.36 2.0E-4 250 UNH 6.0E-4 0.45 3.0E-4 50 uranine 4.0E-5 NM 50 uranine 5.0E-5 0.80 4.0E-5 50 UNH 2.0E-5 0.61 1.0E-5 50 UNH 2.0E-5 0.60 1.0E-5 Table 3-4. Average Weight Percent Airborne from Pressurized Liquid Release Pressure, psig 350 cm3 Source 100 cm3 Source Uranine UNH Uranine UNH 500 250 50 0.05 0.01 0.0008 0.025 0.01 0.0004 0.15 0.06 0.005 0.08 0.05 0.002 Page 3-23 DOE-HDBK-3010-94 3.0 Liquids; Aqueous Solutions Page 3-24 DOE-HDBK-3010-94 3.0 Liquids; Aqueous Solutions material in the respirable size range of 1.0 appears conservative. For the UNH (higher density liquid, ~1.3 g/cm3), a bounding ARF of 1E-3 (100 ml UNH at 500 psi) with a fraction of the airborne material in the respirable size fraction of 0.4 appears conservative. The "median" values for the uranine ARF and RF are 3E-4 and 0.9 and 2E-4 and 0.3 for UNH. The average values for uranine are ARF and RF of 5E-4 and 0.9 and 3E-4 and 0.5 for UNH. For the sake of simplicity, a gross density distinction is made for determining which ARF and RF values to use. Any solution containing heavy metal salts where the liquid alone has a density in excess of ~ 1.2 g/cm3 is considered a "concentrated heavy metal solution" for assigning ARF and RF values (i.e., 1E-3 and 0.4). Any solution containing heavy metal salts where the solution alone has a density less than ~ 1.2 g/cm3 is considered an "aqueous solution" for assigning ARF and RF values (i.e, 2E-3 and 1.0). B. Rapid Pressurization That Does Not Allow Gas Absorption by Liquid. If a pressurized vessel vents, liquid contents can be suspended as droplets formed by turbulent shear stress on the liquid surface. If flow across the liquid is perpendicular to the liquid surface (i.e., entire crown of vessel is lost), the gases pass directly to the atmosphere and has little impact on the surface. Some small fraction of liquid may be suspended by the negative phase of the impulse due to the release of normally dissolved gases in the liquid. If vent diameter is small and flow is low, little stress is created on the liquid surface. If the vent size is adequate to generate flows resulting in turbulence on the liquid surface, liquid can be suspended by drop formation. In the experimental study of stratified two-phase flow reported by Shrock et al. (August 1987), a determinant parameter for the release of airborne droplets was Critical Freeboard Height. This is the height from the gas-liquid interface to the break center where gas or liquid pull through begins. Equation 5.7 in the study report is:

/ΔP) 0.5][V/gD][(dg = 0.395(hb/D)2.5 (3-6) where: V = gas velocity g = gravitational acceleration, 980 cm/s2 D = diameter of vent dg = density of gas at saturation ΔP = pressure differential hb = Critical Freeboard Height. Page 3-25 DOE-HDBK-3010-94 3.0 Liquids; Aqueous Solutions For liquids that only contain dissolved/trapped gases at normal pressure and have a surface level greater than the critical freeboard height from the venting point, an undefined but insignificant fraction may be released depending on the size of the drops, the velocity of the gas to carry the drops (most of the gas has been vented prior to the formation of the drops), and the distance to the vent. Greater releases would be expected if the liquid surface level was less than the critical freeboard height from the venting point. A possible technique to estimate the fraction of these liquids released is as follows: • Estimate the pressure based on increase in volume of the combustion product and air components raise to a temperature based on the heat generated by the deflagration. • Estimate the volume of the combustion products and air components at standard and temperature vented. • Estimate fraction of gas in volume vented using Equation 5.11 in Schrock et al. (August 1987). • Estimate the mass of liquid in the gas estimated above by subtraction. Unfortunately, the equation for estimating the Critical Freeboard Height requires estimating the gas density at the moment of pressurized release. There is no simple or recognized means other than experimentation to estimate gas density at release. The only gas density known at this point is the initial gas density at saturation, which is less than the gas density with the liquid droplets. Accordingly, the more conservative bounding estimates for the release of absorbed/trapped gases are assessed as most applicable for general use. 3.2.2.3.3 Flashing Spray. Liquids heated above the boiling temperature of the liquid/solvent/diluent "flash" upon release; that is, the excess heat above the boiling point of the liquid is expended in the bulk vaporization of the liquid and the remaining liquid is fragmented into fine droplets. The phenomenon has been investigated in experimental studies and through empirical correlations and models, as summarized below. A. Experimental Studies. Brockman (February 1985) reviewed the literature on the possible flashing of condensed moisture during the depressurization of a LWR post- accident containment vessel. The event postulated was the vigorous boiling of water during depressurization with droplets entrained in the vapor generated. A simplified model was used to calculate the amount of water entrained. Entrainment is defined as Page 3-26 DOE-HDBK-3010-94 3.0 Liquids; Aqueous Solutions the ratio between mass of liquid entrained/mass of vapor generated and was calculated by the correlation developed by Rozen et al. (1970). The correlation as shown in Kataoka and Ishii (April 1983) is limited to the deposition controlled region with different correlations for the low and high superficial gas velocity regimes. The correlation used here is the general correlation for the entire region. The size distribution of droplets formed is based upon the suspension velocity and Weber breakup of liquid masses. Initial conditions for scoping calculations were as follows: • Vessel volume: 50,000 m3 • Pool area: 500 m2 • Initial pressures: 0.3 MPa (43.5 psi), 0.5 MPa (72.5 psi), and 0.7 MPa (101.5 psi)

• Vent hole sizes: 1, 10, 100 and 1000 m2 • Total water inventory: 2.71 X 105 kg. The following assumptions were made: • System instantly comes to equilibrium. • Fluid temperature instantly comes to saturation temperature. • Vapor generation in bulk liquid instantly produces vapor flux at surface. • Liquid vaporization does not contribute to the containment pressure. Blowdown is calculated without vapor source. • Blowdown is calculated by choked flow through orifice while containment pressure is above 0.18 MPa (26.1 psi). Below 0.18 MPa, blowdown is calculated by an orifice-pressure-drop/flow-rate relationship. • Containment temperature at failure is at saturation temperature at the initial pressure and does not change throughout the calculation. • Values of liquid specific heat and heat of vaporization are constant. Page 3-27 DOE-HDBK-3010-94 3.0 Liquids; Aqueous Solutions • The liquid water at the start of the calculation is the total water inventory less the amount of water necessary to pressurize the containment to the initial pressure. • The liquid water is depleted throughout the calculation by vaporization and entrainment. The removed water is not returned to the pool. • The liquid water is assumed to reside in a pool of constant surface in a large single volume. Kataoka and Ishii tabulated (April 1983; Table G-11, "Entrained Water and Droplet Size") the mass of water entrained, mass geometric mean diameter and GSD of the droplet size distribution as a function of initial pressure and vent hole area. The largest mass entrained at each pressure was associated with the largest vent hole area due to the rate of release. The ARF and RF values for the largest sized vent hole for each pressure listed are: 0.3 MPa: 2.4E-1 and 3E-3 to 1.0E+0 and 6E-7 0.5 MPa: 3.4E-1 and 2E-3 to 1.0E+0 and 4E-7 0.7 MPa: 3.9E-1 and 6E-7 to 7.4E-1 and 4E-7. Not all the water was entrained at the highest pressure, because the liquid volume in the pool reduces by vaporization, thus reducing the superficial gas velocity under these conditions. The possible effect of secondary flashing by the droplets was assessed and found not to be a serious concern but the possible reduction of the droplets due to evaporation of the solvent after release was not evaluated. Thus, although the author stated that the model tends to overestimate the entrainment, the possible increase in the fraction of dissolved FPs entrained due to the reduction of droplet size could result in significant underestimation. Nonetheless, the values for droplets in the respirable fraction from flashing sprays under these conditions do not appear to result in a significant fraction of the material as droplets in the respirable fraction (range of 7E-4 to 3E-7). The values for the many of the variable parameters are temperature dependent and methods for determining temperature or change in temperature and values for parameters as a function of temperature are not provided. Experiments have been performed to measure the airborne release and size distribution of aqueous solution over a limited range of conditions. Table 3-5 lists the experimental results obtained (Ballinger, Sutter and Hodgson, May 1987). Aqueous Page 3-28 DOE-HDBK-3010-94 3.0 Liquids; Aqueous Solutions Table 3-5. Measured ARFs and RFs During the Venting of Superheated Aqueous Solutions (Tables A.3 and A.4 - Ballinger, Sutter and Hodgson, May 1987) Source Volume, ml Pressure, psig ARF RF ARF x RF

700 350 100 125 240 125 60 125 1.0E-2 5.0E-2 2.0E-2 9.0E-3 9.0E-2 0.78 0.73 0.66 0.62 0.69 1.0E-2 4.0E-2 1.0E-2 6.0E-3 6.0E-2 solutions were heated to pressures of 0.39 MPa (57 psig at ~134 oC), 0.85 MPa (124 psig at ~161 oC) and 1.65 MPa (240 psig at ~202 oC) using source volumes of 700 cm3, 350 cm3 and 100 cm3. Figure 3-6 reproduced from Ballinger, Sutter and Hodgson (May 1987) indicates the temperature of the aqueous solution at the stated pressures although the extrapolation to the lower temperature/pressure is questionable given datum point #5. The uncertainty at these lower values, however, does not pose any significant concern. The liquid was released from the open top of the ~4-in. diameter apparatus via a double rupture disk arrangement. The experimental apparatus is shown schematically in Figures A.5 and A.6 in Appendix A. The fraction airborne increased with initial pressure and decreasing source size. The highest ARF, 9E-2, was measured at 0.85 MPa using a 100 cm3 source and 69% of the airborne material was in the respirable size fraction. The ARF and RF depend upon the amount of heat (sensible heat in the liquid plus in the container) available and the heat needed to vaporize the solvent. The greater the fraction of solvent that can be flashed, the larger the ARF and RF. The ARFs and RFs measured are tabulated in Tables A.8 and A.9 in Appendix A. Two bounding values are selected. For relatively low energy liquids with temperatures greater than the boiling point but less than 50 oC superheat, bounding ARF and RF values are assessed to be 1E-2 and 0.6 based on the 60 psig experimental run in Table 3-5. For more severe conditions between 50 and 100 oC superheat, bounding values for ARF and RF are assessed to be 1E-1 and 0.7. Median values for these conditions are 2E-2 and 0.7 with average values of 4E-2 and 0.7. B. Empirical Correlations/Models. For situations where the temperature of the liquid released exceeds 100 oC superheat, an empirical correlation was presented by Ayer et al. (May 1988) for the evaporation/settling corrected data for the flashing spray experiments performed by Ballinger, Sutter and Hodgson (May 1987): Page 3-29 DOE-HDBK-3010-94 3.0 Liquids; Aqueous Solutions Page 3-30 DOE-HDBK-3010-94 3.0 Liquids; Aqueous Solutions )0.91ARF = 0.33 (MFg (3-7) where: MFg = mole fraction of pressurizing gas or water vapor flashed. The mole fraction of pressurizing gas is computed using the method described in Appendix B of Ballinger, Sutter and Hodgson (May 1987) and is equal to the fraction of liquid flashed at release. The enthalpy and volume of vapor and liquid before and directly at release are used to calculate the fraction flashed. The mass of vapor "flashed" at release is determined by an energy balance for the two phases after the initial pressure is vented. As an initial step, nomenclature must be defined. Temperature T1 and pressure P1 are the liquid temperature and pressure before release (i.e., superheated, pressurized liquid). Temperature T2 is the saturation temperature of the remaining liquid and generated vapor immediately after release to a lower pressure (P2, typically atmospheric pressure). A simple, conservative energy balance can equate the enthalpies of the saturated vapor and liquid directly after the release to the enthalpy of the superheated liquid just before release. This energy balance, where the total mass, volume of container, and initial time are known, is as follows:

masssh(Hsh) = massv(Hv) + massl(Hl) (3-8) where: masssh = mass of superheated liquid present (g), Hsh = enthalpy of superheated liquid at T1 and P1 (cal/g), massv = mass of saturated vapor generated by flashing during depressurization (g), Hv = enthalpy of saturated vapor (e.g., vapor at saturation temperature T2 for pressure P2 ) (cal/g), massl = mass of saturated liquid remaining after depressurization (g), and Hl = enthalpy of saturated liquid (e.g., liquid at saturation temperature T2 for pressure P2 ) (cal/g). The simple mass balance for the flashing system would be: masssh = massv + massl (3-9) The mass balance can be rearranged to Page 3-31 DOE-HDBK-3010-94 3.0 Liquids; Aqueous Solutions massl = masssh - massv (3-10) and substituted into the energy balance to develop an equation for the flashing fraction (massv/masssh) as follows: massv/masssh = (Hsh - Hl)/(Hv - Hl) (3-11) The RF for the airborne material is assessed to be 0.3 based on an aerodynamic mass median diameter (AMMD) of 21 µm and a GSD of 3 recommended by the original authors for the liquid droplets. If the combined ARF x RF calculated using the correlation is less than the 7E-2 bounding value from experimental data for less than 100 oC superheat, the 7E-2 value is considered bounding. Models also exist for the size distribution of the droplets formed (Gido and Koestel, November 1978, Brown and York, 1962). Gido and Koestel (November 1978) base their model upon the fact that drops with center-to-surface temperature differences of <5o K do not fragment. Their model requires evaluation of many parameters such as drop density, drop surface tension, vapor density, thermal diffusion, or residence time. Brown and York (1962) present a much simpler model: D10 = (1840 - 5.18) T/NWe (3-12) where: D10 = linear mean diameter of the droplet, µm (for water or aqueous solutions of low solute concentration, the linear diameter is roughly equivalent to the AED) T = temperature of the jet, ° F NWe = Weber number = densitygas X velocity of jet X diameter of jet/2 surface tension of liquid. A conservative assumption is to assume all the excess heat is used to evaporate as much liquid as is required to reduce the temperature to less than boiling. The non­ volatile radionuclides are assumed to remain in the liquid and the fraction of droplets in the respirable range (droplets 10 µm AED or less) determined by Brown and York's (1962) formula is the ARF with the RF set to a value of 1.0. In as much as the liquid temperature is just at boiling, any additional heat could reduce the size of the liquid droplet (although it is more difficult to evaporate water from concentrated solutions) or even generate solid salt particles with the addition of sufficient heat. This correlation is not assessed to be suitable for most uses due to the complexity of parameter determination. Page 3-32 DOE-HDBK-3010-94 3.0 Liquids; Aqueous Solutions 3.2.3 Free-Fall Spill Aqueous solution, slurries, and viscous liquids (non-Newtonian fluids) spilled onto a hard, unyielding surface can be subdivided into drops by the instability/shear stress at the surface of the liquid during the fall and by impact upon striking the surface (splashing). The passage of the falling material through the air space creates airflow patterns and turbulence that aids in suspension. 3.2.3.1 Solutions

Experiments have been performed to determine the airborne release from the free-fall spill of aqueous solutions with densities of ~ 1.0 (uranine) and ~ 1.3 g/cc (UNH). Materials that may represent airborne material deposited on the walls were measured in some experiments. The fall distance was limited, less than 3 m, and the initial dispersion of the material was uncontrolled; material was released by inverting a glass beaker holding the liquid. The experimental apparatus is shown schematically in Figure A.7 and the measured results reproduced in Tables A.10 through A.13 in Appendix A. Measured ARFs and RFs are tabulated in Table 3-6. The ARFs for the uranine solution under these conditions ranged from 4E-6 to 2E-4 and 1E-6 to 2E-5 for the UNH. The fraction of the source airborne as particles 10 µm AED and less ranged from 2E-6 to 1E-4 for the uranine solution and from 2E-7 to 1E-5 for UNH. Both the fraction airborne and the fraction in the respirable size range appear to vary with fall distance and source size. A conservative bounding value for the ARF for aqueous solution with a density near 1 would be 2E-4 with an RF of 0.5. For TRU solutions with greater densities, a bounding ARF of 2E-5 with an RF of 1.0 (based on a high value that may be anomalous) is considered conservative. The median ARF and RF for aqueous solutions are 4E-5 and 0.7 and 1E-6 and 0.3 for the concentrated heavy metal solutions. As previously noted in subsection 3.2.2.3.2, for the sake of simplicity a gross density distinction is made for determining which ARF and RF values to use for solutions. Any solution containing heavy metal salts where the liquid alone has a density in excess of ~ 1.2 g/cm3 is considered a "concentrated heavy metal solution" for assigning ARF and RF values. Any solution containing heavy metal salts where the solution alone has a density less than ~ 1.2 g/cm3 is considered an "aqueous solution" for assigning ARF and RF values. An empirical model of ARF and droplet size distribution from free-fall spills of liquids beyond the fall distance range encompassed in the experiments has been developed by Ballinger, et al. (January 1988). In this model, the ARF value is defined by the following equation: Page 3-33 DOE-HDBK-3010-94 3.0 Liquids; Aqueous Solutions Table 3-6. Measured ARFs and RFs From the Free-Fall Spill of Aqueous Solutions (Tables A.2, A.4, B.2 and B.4 - Sutter, Johnston, and Mishima, December 1981) Source Volume, ml uranine or uranium, g Spill Height, m ARF RF ARF x RF Uranine Solution 1000 10 3 1.0E-4 0.45 6.0E-5 8.0E-5 0.50 4.0E-5 500 5 3 4.0E-5 0.56 2.0E-5 3.0E-5 0.44 1.0E-5 3.0E-5 0.80 3.0E-5 6.0E-6 0.82 5.0E-5 5.0E-5 0.74 4.0E-5 3.0E-5 0.70 2.0E-5 4.0E-5 0.59 2.0E-5 4.0E-5 0.64 2.0E-5 125 1.25 3 2.0E-4 0.52 8.0E-5 3.0E-5 0.63 2.0E-5 1000 10 1 3.0E-5 0.53 2.0E-5 500 5 1 4.0E-6 0.62 2.0E-6 125 1.25 1 6.0E-6 0.72 4.0E-6 UNH Solution 1000 208.7 U 3 1.0E-5 0.23 2.0E-6 1.0E-5 0.19 3.0E-6 500 104.4 U 3 1.0E-5 1.0 1.0E-5 2.0E-5 0.30 6.0E-6 1.0E-5 0.16 2.0E-6 125 26.1 U 3 1.0E-5 0.36 5.0E-6 2.0E-5 0.26 5.0E-6 1000 208.7 U 1 1.0E-6 0.51 5.0E-7 1.0E-6 0.24 2.0E-7 500 104.U 1 1.0E-6 0.85 9.0E-7 125 26.1 U 1 4.0E-6 0.61 2.0E-6 5.0E-6 0.62 3.0E-6 ARF = 8.9E-10 Arch0.55 (3-13) where: Arch = Archimedes Number = (densityair) 2 * (spill height)3 * g/(solution viscosity)2. Densityair is in g/cc, spill height is in cm, solution viscosity is in poise, and g is a gravitational constant, 981 cm/s2. Page 3-34 http:Arch0.55

DOE-HDBK-3010-94 3.0 Liquids; Aqueous Solutions This correlation covers all of the spill data, including slurries and viscous solutions. This results in it being potentially nonconservative for low-density aqueous solutions modelled on the uranine data. In order to determine a bounding ARF for this subset of solutions, the ARF value calculated from the model are multiplied by a factor of 3 (empirical observation). This factor does not apply to the other types of solutions. No regression analysis produced a satisfactory correlation with AMMD and a simple statistical correlation representation of lognormal drop size parameters is substituted. They are presented in Table 3-7. Table 3-7. Statistical Summary of Drop Size Parameters for Lognormal Distributions (Table 3.4 - Ballinger, et al., January 1988) AMMD, µµm GSDa RF All data 21.5 7.3 0.4 UNH spill 27.2 6.0 0.3 Uranine Spill 27.1 3.0 0.2 Sucrose spill 12.5 12.3 0.5 Slurry spill 15.8 10.1 0.4 a GSD = Geometric Standard Deviation. The values listed in Table 3-7 should be applied to the appropriate liquids assumed involved in the event. For example, if the liquid can not be specified, the values assumed for all data would apply. The UNH represents heavy metal, aqueous solutions with densities 1.2 g/cm3 or greater. For other aqueous solutions, the uranine values apply. The sucrose values are applicable to liquid with viscosities greater than 50 centipoise (the ARF decreases with viscosity but the AMAD appears to remain relatively constant for the limited data set available). Slurry values are applied to aqueous slurries. 3.2.3.2 Slurries Experiments have been performed to measure the ARF and RF from the free-fall spill of slurries (Ballinger and Hodgson, December 1986). The apparatus (see Figure A.7, Appendix A) and procedures were as used in the free-fall spill experiments involving aqueous solutions. The pertinent data extracted from the reference document (Ballinger and Hodgson, December 1986) are shown in Table 3-8 (original data tables reproduced as Tables A.14 and A.15 in Appendix A). The bounding ARF and RF values are 5E-5 and 0.8 with median and average values of 2E-5 and 0.7 and 2E-5 and 0.8, respectively. The empirical model for calculation of ARFs and drop size characteristics was discussed in subsection 3.2.3.1. Page 3-35 DOE-HDBK-3010-94 3.0 Liquids; Aqueous Solutions Table 3-8. Measured ARFs and Rfs for Free-Fall Spill of Slurries (1 liter source, 3 meter fall distance) (Tables B.3 and B.4 - Ballinger and Hodgson, December 1986) TiO2, Glass Uranine, Sucrose, Viscosity, Surface g/l Frit, g/l g/l g/l centipoise Tension, SpG ARF RF ARF x RF dyne/cm 10 0 20 250 3.2 58.2 1.12 9.0E-7 0.73 7.0E-6 100 0 20 200 NM 54.5 1.16 1.0E-5 0.64 7.0E-6 40 60 20 335 4.9 64.6 1.19 9.0E-6 0.77 7.0E-6 40 60 20 335 3.1 68.6 1.20 2.0E-5 0.76 1.0E-5 200 300 20 0 1.3 63.1 1.33 5.0E-5 0.78 4.0E-5 200 300 20 0 1.3 63.4 1.35 3.0E-5 0.81 2.0E-5 200 300 20 100 1.3 64.9 1.29 3.0E-5 0.78 2.0E-5 200 300 20 100 2.9 62.8 1.41 2.0E-5 0.72 1.0E-5 3.2.3.3 Viscous Solutions Experiments were also performed to measure the ARFs and Rfs from the free-fall spill of viscous solutions (Ballinger and Hodgson, December 1986). The experimental apparatus is essentially the same as used for the free-fall spill experiments involving aqueous solution and slurries and is shown in Figure A.7 in Appendix A. Table 3-9 is a tabulation of pertinent data taken from the reference source (original data tables reproduced as Tables A.16 and A.17 in Appendix A).

Table 3-9. Measured ARFs and Rfs for Free-Fall Spill of Viscous Solutions (1 liter source volume, 3 meter fall height) (Tables B.1 and B.2 - Ballinger and Hodgson, December 1986) Viscosity, centipoise Surface Tension, dyne/cm SpG ARF RF ARF x RF 1.3 2.6 7.9 17.5 46.0 65.2 68.9 70.9 77.4 74.5 1.01 1.10 1.19 1.23 1.28 3.0E-5 3.0E-5 7.0E-6 1.0E-5 5.0E-6 7.0E-6 3.0E-6 3.0E-6 2.0E-6 3.0E-6 0.59 0.74 0.70 0.76 0.80 0.83 0.78 0.90 0.84 0.89 2.0E-5 2.0E-5 5.0E-6 8.0E-6 3.0E-6 5.0E-6 2.0E-6 2.0E-6 1.0E-6 2.0E-6 Page 3-36 DOE-HDBK-3010-94 3.0 Liquids; Aqueous Solutions Figure 3-7 reproduced from that reference shows the ARF tends to decrease with viscosity. For solutions that have a viscosity >8 cp, the ARFs are less than 7E-6 with a maximum RF of 0.9. For the range of viscosity >8 cp (surface tension >65 dyne/cm, specific gravity >1.2) the ARF and RF are bounded by 7E-6 and 0.8 with median values of 3E-6 and 0.8. The average ARF and RF values were 4E-6 and 0.8. Solutions with viscosities less than 8 cp are considered bounded by the values in subsection 3.2.3.1. 3.2.4 Aerodynamic Entrainment and Resuspension Liquid can be made airborne by the passage of air over its surfaces through either parallel airflow or airflow directed into the surface, i.e., via whitecaps, spume, and film breakup due to capillary action of the liquid up the sides of its container. The latter effect may only be important for situations where the ratio of perimeter distance is a significant fraction of the surface area as in small pools used in experimental studies. Only a thin layer at the surface of the liquid can be involved in droplet formation since the droplets are formed by the film fragments that would not suspend if the film were too thick or the fragments too large. The airborne release fraction for this type of situation has been studied theoretically and measured under two sets of conditions. Calculations indicate that particles held to heterogeneous surfaces by a layer of water greater than 5 molecules thick cannot be resuspended at superficial gas velocities <5000 m/s (greater than sonic velocities) (Brockman, February 1985). Other calculations performed in the paper indicate that the aerodynamic flow profile at the surface may not be properly estimated; particles 10-µm in diameter were entrained at the lowest superficial velocity, 1.8 m/s, although most calculations indicate that the minimum velocities are required for particles an order of magnitude larger. Nonetheless, the calculations indicate the force necessary to suspend shallow pools of liquid probably requires substantial superficial velocities for suspension and that release of liquid droplets under most ordinary conditions are very low. 3.2.4.1 Spray Release From Large Outdoor Pond A model, SPRAYMASS, was developed from empirical formulas representing ocean sprays (Roblyer and Owczarski, April 1992). Correlations between wind velocity and fetch (distance from the lee shore where turbulence begins) were developed from sea-salt aerosols (principally during surface breakup of bubbles formed in wave action) in the open sea, finite ponds and diffusion in atmosphere-surface boundary layers. The concentration of aerosol above ocean waves with finite fetch as a function of windspeed has been measured and is represented by: Page 3-37 DOE-HDBK-3010-94 3.0 Liquids; Aqueous Solutions Page 3-38 DOE-HDBK-3010-94 3.0 Liquids; Aqueous Solutions Page 3-39 DOE-HDBK-3010-94

3.0 Liquids; Aqueous Solutions 3.2.4.2 Suspension of Liquids From Shallow Pools of Concentrated Heavy Metal Solutions on Stainless Steel An indication of the ARF for this type of condition at low velocities can be gained from the entrainment of plutonium solution in air at velocities from 10 to 100 cm/s passing over the surface (Mishima, Schwendiman and Radasch, November 1968). The entrainment was from a very shallow pool (~2 to 4 mm) of limited diameter (~2.5 cm) using a dense solution. Evaporation periods lasted from 2 h to 24 h with temperatures from ambient (~21 oC) to 100 oC. For entrainment at ambient temperature with an evaporation period of 24 h, the ARF ranged from <2E-10 to 2.5E-9. The ARFs measured are listed in Table 3-10 taken from Table I in the reference document and found in Appendix A (Table A.1). The experimental apparatus is shown in Figure A.1. Table 3-10. Measured ARFs from Shallow Pools of Concentrated Heavy Metal Salt Solution (0.72 g to 0.82 g Pu, 24-hr sampling period) (Table I - Mishima, Schwendiman and Radasch, November 1968) Temperature, Air Velocity, ARF Rate °° C m/s ambient 0.1 <1.0E-9 <1.0E-14/s ambient 0.5 2.5E-9 3.0E-14/s ambient 1.0 <2.0E-10 <2.0E-15/s Although the nominal velocities used in these experiments appear to be much lower than those quoted in subsection 3.2.4.1, the values represent velocities much closer to the surface (i.e., within cm) than the usual height for meteorological windspeed measurements of 10 m. For turbulent to laminar flow, the nominal 10 meter windspeed would be a factor of 2 to 10 higher than the values quoted in Table 3-10. The ARRs measured range from 7E-12/hr to 1E-10/hr. 3.2.4.3 Estimate of the Resuspension of Liquids From Soil As will be discussed in Chapter 4, Sehmel and Lloyd (1976a,b) measured resuspension rates of a powder deposited on a soil surface and deduced that a reasonable value for resuspension rate was 1E-8/s to 1E-10/s. These values correspond to 4E-5/hr and 4E-7/hr. Liquids are significantly less susceptible to entrainment than powders. Page 3-40 DOE-HDBK-3010-94 3.0 Liquids; Aqueous Solutions 3.2.4.4 Suspension From Soil at Higher Windspeeds Aerodynamic entrainment (resuspension) at higher air velocities for UNH solution from various surfaces was measured in wind tunnel experiments (Mishima and Schwendiman, August 1973). Measurements were made at velocities of 2.5 mph and 20 to 23 mph at 1 ft above the surface of smooth, sandy soil. The experimental apparatus and measured values are shown in Figure A.3 and Table A.3 in Appendix A. The pertinent data are listed in Table 3-11. Table 3-11. Measured ARFs and Rfs of Uranium (UNH) From Soil at 2.5 mph and ~20 mph (Table III - Mishima and Schwendiman, August 1973) Substrate Windspeed, mph Sampling Time, hr ARF RF Rate Fraction/hr Soil 2.5 20 6 24 28 5.0E-4 1.0E-4 4.0E-4 0.76 0.84 0.63 9.0E-5 4.0E-6 1.0E-5 The ARF for 1 m/s (5E-4 in 6-hr, airborne suspension rate of 9E-5/hr) bounds the measured ARFs. The suspension rates from soil at both windspeeds for the remaining two datapoints appear to be approximately the same value (4E-6/hr vice 1E-5/hr). The two measurements at 1.0 m/s show more variation than the measurements for the two different windspeeds. In keeping with typical resuspension assumptions, the RF of the airborne material is conservatively assumed to be 1.0. 3.2.4.5 Bounding Assessments

For liquids inside buildings or other confinements, the effective airflows experienced are not considered comparable to extremes such as high external wind. The experiment involving suspension of liquids from shallow pools of concentrated heavy metal salt solutions on stainless steel (Mishima, Schwendiman, and Radasch, November 1986) produced extremely low estimates of aerodynamic entrainment in the range of 1E-11/hr to 1E-10/hr. Even the spray release from large outdoor pond values would not exceed a value of 4E-7/hr for 5m/s windspeed, and would be expected to be considerably less. Examining the results of Sehmal and Lloyd (1976 a,b), this study would expect a resuspension rate for liquids to be 4E-7/hr or less. Based on the above considerations, a conservative ARR of 4E-7/hr is assigned for: (1) liquids indoors on heterogenous surfaces (e.g., stainless steel, concrete) exposed to forced Page 3-41 DOE-HDBK-3010-94 3.0 Liquids; Aqueous Solutions building ventilation; or (2) liquids indoors exposed to other significant overall structural airflow, such as intrusion of external winds due to localized damage in various areas of the structure. No experimental data for the effects of large debris over deposited powder on aerodynamic entrainment were found. Due to the decrease in aerodynamic stress if liquid is shielded by remnants and debris of a structure or confinement, an order of magnitude decrease in ARR is assigned. The bounding ARR for liquid covered with debris or exposed to largely static conditions in a structure that has lost forced airflow is 4E-8/hr. For liquids spilled outside, three values are provided. For large pools (even if depth is shallow) and relatively high windspeeds (~ 30 mph), the maximum ARR estimate from the SPRAYMASS correlation of 4E-6/hr is assessed to be bounding. If only small external windspeeds are involved, the 4E-7/hr value for forced ventilation flow is more appropriate. For liquid spilled on and being absorbed by soil (i.e., rapidly depleting small puddles), however, special circumstances are involved. The contaminant is being deposited on the soil in a manner that makes it more conducive to airborne release. A bounding ARR of 9E-5/hr is assumed based on the experimental work of Mishima and Schwendiman (August, 1973). This same phenomena would not apply to very large spills with pooling as the ground would remain damp for a significant period of time and the surface would be less susceptible to aerodynamic stress. The values assessed in this section apply only to freshly deposited contaminant that is not heavily intermingled with the overall soil or waste matrix. They are to be used for estimating releases for the short term only. It is incorrect to multiply the values cited by large time periods and assume the resulting large fractions represent real release potential from long term environmental contamination sites. 3.3 ORGANIC, COMBUSTIBLE LIQUIDS Radionuclides are present in combustible liquids during liquid-liquid extraction processes and during decontamination procedures. In some cases, the radionuclides can be in an aqueous solution under a burning organic layer (e.g., process liquids, solvents, fuels). The combustion of a liquid is a heterogenous reaction - heat from the flame radiates back to the liquid surface resulting in the evaporation of more fuel vapor that entrains air until a combustible mixture is attained and is ignited. The suspension of non-volatile materials appears to result from formation of drops of the bulk liquid. If the conditions are such that the surface film of the liquid is minimally disturbed, very little of the non-volatile components will be suspended from the bulk liquid. As the surface of the liquid is disturbed

Page 3-42 DOE-HDBK-3010-94 3.0 Liquids; Organic, Combustible Liquids by turbulence of the vapor generation, the capillary action at the edge of the liquid, and the evolution of water vapors from the aqueous solution trapped beneath the organic layer, the suspension of non-volatile components increases. If the evolution of water vapors is very rapid, a large volume of the aqueous layer may be ejected and quench the fire. Flaming combustion (smoldering combustion is observed in some solid fuels such as cellulosics) may also be quenched when the oxygen concentration diminishes to the range of 11% to 17.5% (generally flaming combustion ceases at ~ 16%) (Malet et al., 1983, Jordan and Lindner, 1983, 1985). 3.3.1. Burning of Small Volume/Surface Area 30% TBP-Kerosine Solutions, No Vigorous Boiloff For quiescent fire (relatively undisturbed liquid surfaces), the ARFs measured by Mishima and Schwendiman (June 1973) for the combustion of 30% TBP in a kerosine-type diluent traced with various radionuclides (U, Cs, Ce, Zr, I) are applicable. The measured values are reproduced in Table A.18 and the experimental apparatus is shown in Figures A.8a and b in Appendix A. Twenty-five ml of 30% TBP-kerosine were placed in a 50-ml borosilicate beaker. Air (1- and 2-cfm) was drawn through a 2.7-in.-diameter stainless steel chimney around and over the beaker. Iodine (during the experiments using iodine tracer) was collected in a charcoal trap at the top of the chimney and airborne particulates in a glass fiber filter. The liquid was ignited and the liquid gently heated by a hand-held propane torch. Experiments were performed to self-extinguishment (no heating after initiation of flaming combustion) and supplemental heating to complete dryness. No aqueous phase in contact with the combustible organic was used in these experiments. The pertinent data are tabulated in Table 3-12. Under the experimental conditions, the ARFs for all non-volatile materials appear to be less than 1E-2. Uranium ARFs range from 2E-4 to 3E-3, an uncertainty of approximately an order of magnitude. Cesium ARFs also show an order of magnitude uncertainty ranging from 2E-3 to 1E-2. ARFs for both cerium and zirconium are more consistent for the limited number of measurements made. The ARFs for iodine range from 7E-1 to 8E-1 and are assumed to be essentially 1E+0. In the absence of any measured airborne particle size distribution, all the airborne material is conservatively assumed to be in the respirable fraction. The volatile materials are considered to remain in the gaseous state although the volatile materials (generally iodine but may include other halogens and possibly some cesium compounds) may condense on various surfaces contacted or on pre-existing airborne particles and behave like the host particle thereafter. The effect cannot be readily characterized and the conservative assumption is that all the material is respirable. For the more industrial types of stresses encountered in nonreactor nuclear facilities, as opposed to LWR and BWR core melt conditions, semi-volatiles such as cesium and ruthenium are not expected to behave Page 3-43 DOE-HDBK-3010-94 3.0 Liquids; Organic, Combustible Liquids Table 3-12. Measured ARFs From Burning Small Volumes of 30% TBP-Kerosine Traced with Selected Radionuclides (Table I - Mishima and Schwendiman, June 1973) ARFs Self-Extinguishment ARFs Complete Dryness 1-cfm 2-cfm 1-cfm 2-cfm Uranium Cesium Cerium Zirconium Iodine 2.7E-4

2.2E-3 7.4E-3 6.5E-3 6.57E-1 2.3E-4 2.5E-3 5.6E-3 ND 6.53E-1 ----­ 1.9E-3 7.7E-3 5.5E-3 8.17E-1 3.0E-3 1.0E-2 7.1E-3 2.4E-3 8.43E-1 8.28E-1 8.33E-1 as volatiles. Volatiles of interest for phenomenological stresses in nonreactor nuclear facilities are typically limited to iodine (NUREG-1320, NUREG-1140). 3.3.2 Pool Fires of 30% TBP-Kerosine The ARFs for strontium from a large-scale 30% TBP-kerosine burn were reported by Sutter, Mishima and Schwendiman (June 1974). One hundred and fifty liters (150 l) traced with 25 g of strontium nitrate were burned in ten 17-in. x 23-in. x 3-in. deep stainless steel pans placed on concrete block above an 8-in. pool of water on the floor of a 12-ft x 12-ft cell of insulating board held in a sheet steel silo. The combustible organic phase was not in contact with an aqueous phase. Kerosine was floated on the surface of the water pool to aid in the burning of the 30% TBP-kerosine PUREX-type solvent. The organic liquids were ignited and the airborne materials carried to the exhaust gas treatment/sampling train apparatus shown in Figure A.9 in Appendix A taken from the reference document (Figure 1 - Sutter, Mishima and Schwendiman, June 1974). Two of the three burns generated usable data with ARFs of 2.2E-3 and 1.9E-3. The values are generally consistent with those generated in the small volume/surface area experiments in subsection 3.3.1.1. 3.3.3 Combustion of TBP-Kerosine Solutions Over Pools of Acid, Vigorous Boiloff Halverson, Ballinger, and Dennis (February 1987) reported measurements of airborne uranium during the burning of combustible organic liquid over aqueous solutions. Small volumes of liquid were placed in metal beakers (except in one case where a borosilicate glass beaker was used to minimize the heat transfer through the beaker) on a load cell as shown in Page 3-44 DOE-HDBK-3010-94 3.0 Liquids; Organic, Combustible Liquids Figure A.10 of Appendix A. The liquids were heated by heating tapes wrapped around the metal beaker except in the single case where a borosilicate glass beaker was used. In this case, radiant heat panels were used. The organic liquid ignited and air (27.5-cfm) was drawn up the 25.4-cm diameter chimney. Airborne particles were collected on glass fiber filters as a function of time. The pertinent data taken from Table A.6 in the reference document (original data tables reproduces as Table A.19 in Appendix A) are tabulated in Table 3-13. Table 3-13. Measured Uranium ARFs During the Burning of TBP-Kerosine Over Aqueous Phase (Table A.6 - Halverson, Ballinger and Dennis, February 1987) Solutions Tested Burn Duration, min ARF Remarks 100 ml 30% TBP-kerosine (U) + 100 ml acid 27.5 34.8 53.3 4.04E-3 5.57E-3 4.34E-3 Aqueous boiled over and quenched fire, 40% to 60% organic unburned 100 ml 30% TBP-kerosine (U) + 100 ml acid (FP) 24.8 34.0 2.52E-2 2.70E-2 Aqueous boiled over and quenched fire, 40% to 60% organic unburned 100 ml 40% TBP-kerosine + 100 ml acid (U + FP) 61.3 65.0 5.98E-2 7.09E-2 Burned to dry residue Burned to dry residue 50 ml 40% TBP-kerosine + 150 ml acid (U + FP) 40.0 1.7E-3 ~40% organic unburned 50 ml 30% TBP-kerosine (U) + 150 ml acid (U + FP) 57.3 1.56E-2 Unburned organic residue 50 ml 30% TBP-kerosine (U) + 100 ml acid (U + FP) 51.0 8.09E-3 Unburned organic residue

The measured values for ARF appear to have two orders of magnitude variation. The conservative upper bound ARF is 1E-1. The RF was only measured for one experiment [50 ml 30% TBP-kerosine (U) + 150 ml acid (U + FP)] with a value of 0.99. In most cases, heat transferred through the metal solution holder resulted in a boilover that terminated the burning. Use of glass holders or no external heat addition after ignition delayed boilover. Only in experiments #52 and #53 (40% TBP in normal paraffin hydrocarbon) using heating tape to heat the liquid did the burning proceed to complete dryness. It appears that burning the liquids to dryness increases the ARF; the two highest measured ARFs are from this configuration (6.0E-2 and 7.1E-2). The variation found for the other experimental configurations may be partially due to the vigor in boiloff and composition of the aqueous phase. The presence of salts in the aqueous phase may result in a slightly greater heat Page 3-45 DOE-HDBK-3010-94 3.0 Liquids; Organic, Combustible Liquids capacity for the aqueous phase resulting in a more violent eruption upon boiling. Violent eruption of the aqueous phase could cause the generation and entrainment of organic droplets. Based on the results of this experiment, it is considered appropriate to make distinctions between fires that burn to a completely dried residue and fires where, for example, the presence of a large amount of aqueous solution precludes such an outcome. 3.3.4 Airborne Release of Uranium During the Burning of Process Solvent Jordan and Lindner (October 1983) performed small-scale burning experiments using TBP­ kerosine mixtures without an aqueous phase. The experimental apparatus is shown in Figure A.13 and the uranium release as a function of the uranium concentration in the solvent is reproduced as Figure A.14 in Appendix A. The decomposition of nitric acid or nitrates extracted into the solvent resulted in additional surface disturbance during burning. The ARF for uranium dissolved in the combustible liquid increased with uranium concentration and appears to range from 2E-3 to 2E-2. A bounding value of 1.5E-2 was selected by the authors and is generally consistent with the range of uranium releases reported above in the previous section. 3.3.5 Airborne Release During Combustion of TBP-Kerosine The airborne release of cesium, thorium and cerium was measured in tests using both small (78.5 cm2) and large (0.4 to 5 m2) surface areas for combustion of TBP-kerosine process solvent (Malet et al. April 1983). The experimental apparatus is shown in Figures A.11 and A.12 in Appendix A. In both cases, the solvent traced with materials to represent the behavior of heavy metal and fission product elements was held in metal trays and heated by electric heaters. Air was drawn through the test vessel to exhaust systems that collected the airborne materials. The transfer coefficient in air was determined by: [initial mass element] - [final mass element]/initial mass element. The decontamination factor was determined by: [initial concentration element] x [volume]/mass collected on filter. The pertinent results taken from the referenced documents (original data tables reproduced as Tables A.20 and A.21 in Appendix A) are presented in Table 3-14. Page 3-46 DOE-HDBK-3010-94 3.0 Liquids; Organic, Combustible Liquids Table 3-14. Measured Transfer Coefficients and Decontamination Factors During the Burning of TBP-Kerosine Solvent

(Table I - Malet et al., April 1983) Trace Element Transfer Coefficient Decontamination Factor Fraction Reaching Filter (Small Scale Experiments) Cs 0.47 0.32 0.27 0.49 1310 >5270 >4890 >3760 3.6E-4 <6.0E-5 <5.5E-5 <1.3E-4 Th 0.45 0.23 0.12 112 159 137 4.0E-3 1.4E-3 8.8E-4 (Large Scale Experiments) Ce 0.23 0.42 0.92 0.89 0.47 4260 1110 ----­ ----­ 5620 5.4E-5 3.8E-4 ----­ ----­ 5.4E-5 The transfer coefficient appears to be the fraction of the trace element not recovered from the test apparatus after the run. Others have experienced difficulties with recovering/detecting various elements in the residues from the combustion of TBP-kerosine solvents. The decontamination factor is the fraction of airborne material carried to the collection filters, although it appears that only the initial airborne concentration was used for the estimates. The actual concentration may have varied during the run. The ARFs reported from other studies are generally the fraction of the material used in the experiment that is carried to the collection filters that are within a few feet and the exhaust gases relatively contained from the point of origin to the collector. The fraction reaching filter is the transfer coefficient multiplied by the reciprocal of the decontamination factor. Thus, ARFs reported from other studies should be smaller than the transfer coefficient but greater than the fraction reaching filter. The values are within an order of magnitude or two for the cesium and cerium used for the small scale and large scale experiments and are considered to corroborate those values. Page 3-47 DOE-HDBK-3010-94 3.0 Liquids; Organic, Combustible Liquids 3.3.6 UNH and Air-Dried UNH on Various Surfaces During a Shallow Pool Gasoline Fire Experiments were performed by Mishima and Schwendiman (1973) in a wind tunnel to measure the ARF and RF of uranium from various surfaces (sandy soil, sandy soil with vegetation cover, stainless steel and asphalt) at windspeeds of 1.0 m/s and 10 m/s. Windspeed measurements were made at the centerline of the 2-ft x 2-ft wind tunnel and therefore represent much higher windspeeds (50 mph to 60 mph) at a standard 10-m height. UNH was placed upon the surface held in a 22-inch diameter flange in the floor of the wind tunnel. In some experiments with sandy soil, the UNH was allowed to air-dry for several days prior to testing. One gallon of gasoline was poured over the surface, ignited and the air drawn over the burning surface. In some cases, the airborne particles were only sampled during the actual burning; in other cases, the airborne particles were collected for much longer periods. The ARFs and Rfs measured are reproduced in Table A.3 and the apparatus shown in Figure A.3 in Appendix A. The relevant data are listed in Table 3-15. Table 3-15. Measured ARFs and Rfs for Uranium Airborne During Gasoline Fires on Various Surfaces Involving UNH and Air-Dried UNH (Table III - Mishima and Schwendiman, August 1973) Substrate Uranium Form Air Velocity, m/s ARF Rate Fraction/hr RF Sandy soil Vegetation on sandy soil Asphalt Stainless steel liq. UNH air-dried UNH liq. UNH liq. UNH 1.0 10 1.0 10 1.0 10 1.0 10 1.0 10 1.7E-5 5.4E-3 9.6E-4 2.0E-3 7.4E-5 4.0E-4 1.2E-3 4.1E-4 2.4E-3 1.4E-2 1.14E-1 3.0E-6 4.0E-2* 2.0E-4 4.0E-4 1.0E-5 6.0E-5 2.0E-4 1.0E-3* 6.0E-3 6.0E-2 6.0E-1 0.75 0.40 0.78 0.86 0.64 0.18 0.32 0.70 0.68 0.40 0.34 * Calculated based on actual burn time for gasoline fire.

The ARFs range from 1.7E-5 (soil, 1.0 m/s) to 1.14E-1 (stainless steel, 10.0 m/s). The data are extremely limited with single values at some sets of conditions (surface, windspeed). The type of surface may have some effect in that the liquid can be absorbed into the substrate or the substrate can conduct heat. If the substrate conducts heat well, the liquid can be boiled rapidly generating conditions much more favorable to generation of airborne liquid droplets. In extreme cases for any surface, a possible mechanism for suspension of liquids Page 3-48 DOE-HDBK-3010-94 3.0 Liquids; Organic, Combustible Liquids and salts is explosive release of moisture trapped under the salt during rapid heating of the material. The ARFs for soil and vegetation covered soil are lower than the ARFs for stainless steel under comparable conditions but are consistent with the ARFs for asphalt, which does not conduct heat but may become plastic due to the heat and retain salts from the evaporation of solution. 3.3.7 Thermal Stress Bounding Assessments Based on the experimental results summarized in the preceding sections, a distinction will be made between volatiles (i.e., iodine) and other radionuclides and between various burning environments. For volatiles, the bounding ARF and RF are 1.0 and 1.0. For other radionuclides, the ARF and RF are a function of the burning characteristics. The experiments summarized in sections 3.3.1 and 3.3.2 (with additional insight obtained from section 3.3.3) represent a reasonable approximation of quiescent burning, small-scale pool burning, or the burning of a relatively thin layer, as compared to the underlying layer of aqueous solution, of organic solvent. A bounding ARF and RF of 1E-2 and 1.0 are believed to appropriately characterize these conditions. The median ARF and RF are estimated to be 6E-3 and 1.0. The experiments summarized in sections 3.3.3 and 3.3.4 represent a reasonable approximation of vigorously burning large pools or solvent burning over aqueous layers, where the relative sizes of the two layers support significant turbulent disruption of the aqueous layer. The main distinction is whether the burning proceeds to complete dryness. When it does not, a bounding ARF and RF are assessed to be 3E-2 and 1.0. When complete dryness results, a conservative bounding value of ARF is assessed to be 1E-1 (7E-2 rounded upward), with an RF, in the absence of a measured value, of 1.0. The median ARF is 1E-2 with an average value of 2E-2. The ARF (1.5E-2) reported by Jordan and Lindner (February 1985) agrees with the median ARF for the other experimental conditions. Two other conditions relating to large organic fires over specific types of base surfaces are discussed based on section 3.3.6. The first condition is aqueous solutions or air-dried salts on a surface that absorbs or holds liquid. Candidate surfaces include those that are porous or are significantly cracked or pitted. The bounding ARF and RF are 5E-3 and 0.4 respectively (liquid UNH on sandy soil, 10 m/s) for the actual combustion period. The median values of ARF and RF are 1E-3 and 0.8 (liquid UNH on vegetation covered sandy soil at 1 m/s) with average ARF and RF values of 1E-3 and 0.5. The second condition is aqueous solutions or air-dried salts on a surface that is a strong conductor of heat (i.e., metal). The bounding ARF and RF are 2E-1 and 0.3 (stainless steel, 10 m/s) for the actual combustion period. Page 3-49 DOE-HDBK-3010-94 Page 3-50

DOE-HDBK-3010-94 4.0 SOLIDS 4.1 SUMMARY OF ANALYSIS OF DATA In assessing release fractions for solid materials, the materials cannot be treated in the more generic sense applicable to most liquids of interest. Specific distinctions must be made in terms of types of solid material. This chapter provides information1 for three categories of solids: (1) metals (Note: release from energetic hydride reactions also covered under topic of metals in subsection 4.2.1.1.4); (2) nonmetallic or composite solids; and (3) powders. Metal Thermal Stress: Plutonium • Airborne Release of particulates formed by room temperature oxidation (corrosion). Based upon the experimental measured values, the bounding ARRs and RFs for the four situations covered are: Bounding (unalloyed Pu) ARR (dry air) 2 x 10-6 µg Pu/cm2-hr; RF 0.7 ARR (100% RH) 7 x 10-3 µg Pu/cm2-hr; RF 0.7 (delta-phase metal) ARR (dry air) 7 x 10-8 µg Pu/cm2-hr; RF 0.7 ARR (100% RH) 6 x 10-4 µg Pu/cm2-hr; RF 0.7 Use of the above values are generally intended for short timeframes (i.e., < 100 hours). They are not appropriate for long-term estimation (i.e., months to years) as rate is controlled by issues such as oxide coat coherence. • Airborne release of particulates formed by oxidation at elevated temperature, greater than room temperature but less than self-sustained oxidation (ignition). The bounding values apply to static oxidation at elevated temperatures less than ignition temperatures. The MAR is the amount of oxide present under specific conditions. If oxidation is not complete, experimental data cited can provide a basis for such estimations if desired. Bounding ARF 3E-5/RF 0.04 It is noted that there are some special issues associated with Pu-238 in compacted forms used in thermoelectric power devices as material behavior of Pu-238 is different from that of Pu-239 and power devices can be subjected to unique high-energy stresses. Specific information on this subject can be obtained from the DOE radioisotope thermal generator program. Page 4-1 1 DOE-HDBK-3010-94 4.0 Solids; Summary • Airborne release of particulates formed by self-sustained oxidation (molten metal with oxide coat), self-induced convection. The phenomena applies to the self-sustained oxidation in air of metal pieces under self-induced convection. Mishima's (1965, 1966) values exceed the combined value (ARF x RF) for all other measurements and are assessed to be bounding for this situation. Bounding ARF 5E-4/RF 0.5 • Airborne release of particulates from disturbed molten metal surfaces (i.e., flowing metal, actions resulting in continual surface renewal), high turbulence at surface. Without continuous surface renewal, maximum release phenomena is self-sustained oxidation as described previously. The bounding value applies to situations where ignited-molten plutonium is disturbed by direct impact of high air velocities such as during free-fall, induced high turbulence on molten surface, etc. The 95% confidence limit ARF and RF values recommended by Carter and Stewart (September 1970) are assessed to bound the experimentally measured values reported. Bounding ARF 1E-2/RF 1.0 This value is also considered applicable to highly energetic surface reaction as, for example, the conversion of a significant mass of fine hydride to oxide. It is not, however, applicable to oxidation of trace quantities of hydride as metal or powder contamination exposed to air.

• Airborne release of particulates from oxidation of small (hundreds of µm in diameter) molten metal drops passing through air or explosive reaction of entire metal mass. For the violent ejection of molten metal and vapor formation from droplets, Raabe et al. measured an ARF of 1.0 with an RF of 0.4 (estimated from MMD reported) from exploding wire experiments and Carter and Stewart (September 1970) measured an ARF of 0.5 with an RF of 1.0 for small molten metal drops falling through air. Bounding ARF 1E+0/RF 0.5 Thermal Stress: Uranium • Airborne release of particulates during complete oxidation of metal mass, >500 oC, gas flow 0 - 2 m/s. Based upon the experiments performed by Carter and Stewart (September 1970) heating uranium in an upflow of air with oxide generated allowed to sluff away during the oxidation process, the mean Page 4-2 DOE-HDBK-3010-94 4.0 Solids; Summary value as designated by the authors is chosen. The measured values were only for airborne particles <10 µm AED. The values for solubility class in simulated lung fluids are assumed to be >95% "Y" class with remainder in "D" class, based on the solubilities of sintered oxides recovered from the burn tests performed as part of the hazard classification tests on armor-defeating munitions. The 95% confidence level airborne release value for oxidation of uranium metal at flow velocities <100 cm/s reported by Carter and Stewart (September 1970) is exceeded by the value reported by Elder and Tinkle (December 1980) during the oxidation of staballoy penetrators in laboratory experiments. The ARF x RF values obtained for experiments at temperatures less than 900 oC were less than 1E-3. ARF and RF values of 1E-3 and 1.0 are assessed to be bounding for this category with the solubility classification for the oxides formed given above. Median ARF 1E-4/RF 1.0 Bounding ARF 1E-3/RF 1.0 • Airborne release during free-fall of molten metal drops. The median ARF x RF values for free-fall of molten uranium metal droplets in air are as given by Carter and Stewart (1970). The ARF x RF value assessed to be bounding is an arbitrary increase of the 95% confidence level value assigned by Carter and Stewart (to 1E-2) to be consistent with the comparable value for plutonium. Since the airborne material is cooled rapidly after formation, the solubility of the airborne oxides formed from plastic deformation and ignition of the thin film of metal generated by the impact of penetrators against hard targets is assessed to be 50% "Y" class and 50% "D" class. Median ARF 2E-3/RF 1.0 Bounding ARF 1E-2/RF 1.0 • Airborne release from explosive dispersal of molten uranium. The values for explosive release of molten uranium indicate that, if the uranium is molten and subdivided in very small drops (as by the exploding wire technique) and ejected into air at sonic velocities (as by the electrodynamic thruster technique described), all the uranium could be made airborne as a very fine particulate material with all particles or aggregates 10 µm AED and less (Rader and Benson, June 1988). The solubility class of the airborne material is anticipated to be like the airborne material formed during impact of staballoy Page 4-3 DOE-HDBK-3010-94 4.0 Solids; Summary penetrators against hard targets such as armor (i.e., thin film formed by plastic deformation of the metal in passage through armor is ignited by frictional heat and rapidly cooled in the air). The maximum solubility values reported for the type of situation are 50% "D" class + 50% "Y" class.

Bounding ARF 1E+0/RF 1.0 Explosive Stress The effect most closely resembling stresses in a given explosive-type accident scenario is chosen. There is no need to assume cumulative releases for all effects cited. • Shock Effects. For detonations in or contiguous to solid metal, a respirable release of a mass of inert material equal to the TNT equivalent is assessed to be bounding. At low mass ratios (mass inert material/mass TNT equivalent), the respirable release is comparable to the total material release. As mass ratios increase, the respirable fraction becomes significantly less than the total amount of material released, which decreases with increasing mass ratio as well2. • Blast Effects. No significant airborne release is postulated. For effects on metal surface contamination, see Chapter 5. • Venting of Pressurized Gases Over Metal. No significant airborne release is postulated. For effects on metal surface contamination, see Chapter 5. Free-Fall Spill and Impaction Stress No significant airborne release is postulated for this accident configuration. For effects on surface contamination, see Chapter 5. The release estimation methodology presented here is not intended to cover high explosive detonations involving nuclear weapons or associated assemblies, which can involve mass ratios much less than 1. Extensive investigation into such events has been conducted and actual releases depend on highly sensitive configuration information. An estimate of 20% of weapon metal released as respirable particles has precedent as a general upper bound for such events. However, specific configuration studies also support respirable releases in the range