Radiological Risk Assessment and Environmental Analysis

Contents......Page 12
Contributors......Page 26
1 The Radiological Assessment Process......Page 28
Radiological Assessment Process......Page 29
Source Term......Page 30
Environmental Transport......Page 32
Exposure Factors......Page 35
Conversion to Dose......Page 39
Conversion of Dose to Risk......Page 40
Uncertainty Analysis......Page 42
Validation......Page 45
Communication of Dose and Risk and Stakeholder Participation......Page 48
References......Page 55
2 Radionuclide Source Terms......Page 58
Radionuclides of Interest and Their Properties......Page 59
Situations That Do Not Require Source Terms......Page 64
Human Activities Producing Releases of Radionuclides......Page 65
Uranium Milling......Page 66
Uranium Enrichment......Page 67
Weapon Component and Fuel Fabrication......Page 68
Reactors......Page 69
Fuel Processing Plants......Page 85
Solid Waste Disposal......Page 88
Source Terms for Prospective Analyses......Page 89
Source Terms for Retrospective Analyses......Page 91
Problems......Page 93
References......Page 96
3 Atmospheric Transport of Radionuclides......Page 106
Vertical Extent Important for Atmospheric Releases......Page 107
Scales of Motion......Page 108
Source......Page 116
Winds......Page 117
Turbulence and Stability......Page 120
Atmospheric Stability Categories......Page 121
Modeling of Transport and Diffusion......Page 135
Gaussian Diffusion Models......Page 136
Puff-Transport and Diffusion Models......Page 147
Multibox Models......Page 152
Particle-in-Cell Models......Page 153
Screening Models......Page 154
Atmospheric Removal Processes......Page 155
Model Validation......Page 159
Guidelines for Selecting Models......Page 163
Regulatory Models......Page 164
Problems......Page 166
References......Page 167
4 Surface Water Transport of Radionuclides......Page 174
Transport......Page 176
Intermedia Transfer......Page 178
Transformation......Page 180
Radionuclide Transport Models......Page 181
Accidental Radionuclide Releases......Page 182
Routine Long-Term Radionuclide Releases......Page 183
Rivers......Page 186
Estuaries......Page 194
Coastal Waters and Oceans......Page 203
Lakes......Page 208
Sediment Effects......Page 214
Numerical Modeling......Page 217
Chernobyl Nuclear Accident Aquatic Assessment......Page 219
Radionuclide Transport in Rivers......Page 221
Aquatic Pathways and Their Radiation Dose Contributions......Page 224
Problems......Page 227
References......Page 230
5 Transport of Radionuclides in Groundwater......Page 235
Geologic Isolation of High-Level Waste......Page 236
Uranium Mining and Milling......Page 237
Groundwater Models for High-Level Waste Repositories......Page 238
Groundwater Models for Mill Tailings Waste Migration......Page 242
Groundwater Flow......Page 243
Mass Transport......Page 246
Chain Decay of Radionuclides......Page 247
Percolation of Water into the Ground......Page 248
Diffusion and Dispersion in Porous Media......Page 249
Porosity and Effective Porosity......Page 251
Hydraulic Conductivity for Saturated Flow......Page 253
Sorption, Retardation, and Colloids......Page 255
Numerical Methods......Page 260
Analytical Solutions of the Convective-Dispersive Equations......Page 263
Simplified Analytical Methods for Minimum Dilution......Page 270
Models for Population Doses......Page 273
Source Term Models for Low-Level Waste......Page 277
Model Validation and Calibration......Page 278
Misuse of Models......Page 280
References......Page 281
6 Terrestrial Food Chain Pathways: Concepts and Models......Page 287
Conceptual Model of the Terrestrial Environment......Page 289
Predictive Approaches......Page 295
Concepts and Terminology of Tracer Kinetics......Page 300
Single-Compartment, First-Order Loss Systems......Page 302
Single-Compartment, Non–First-Order Loss Systems......Page 311
Individual Transport Processes: Concepts and Mathematical Formulations......Page 314
Types of Processes......Page 315
Deposition from Air to Soil and Vegetation......Page 316
Transport from Soil to Vegetation......Page 322
Transport from Vegetation to Soil......Page 334
Transport within the Soil Column......Page 336
Transport from Vegetation to Animals......Page 345
Transport from Soil to Animals......Page 347
Transfers to Animal-Derived Human Food Products......Page 348
Ingestion Pathways to Humans......Page 350
Dynamic Multicompartment Models: Putting It All Together......Page 351
Conclusions......Page 358
Problems......Page 360
References......Page 361
7 Aquatic Food Chain Pathways......Page 367
Aquatic Ecosystem Classification......Page 368
Conceptual Model for an Aquatic Environment......Page 369
Physicochemical Processes......Page 370
Radionuclide Uptake and Concentration Factors......Page 371
Examples of Bioconcentration Factors......Page 375
Bioconcentration Factors in Screening-Level Risk Estimations......Page 378
Bioaccumulation Factors in Estimating Exposure......Page 379
Bioaccumulation under Nonequilibrium Conditions: The Chernobyl Cooling Pond Example......Page 381
Case Studies in Exposure and Bioaccumulation......Page 391
Discussion of the Chernobyl Modeling Results......Page 395
Problems......Page 398
References......Page 399
8 Site Conceptual Exposure Models......Page 403
Interested Party Input......Page 404
Exposure Pathways......Page 405
Sources and Source Areas......Page 406
Radionuclides......Page 407
Exposure Areas......Page 408
Potentially Exposed Persons......Page 409
Exposure Routes......Page 410
Transport Mechanisms......Page 411
Exposure Scenarios......Page 412
Exposure Factors......Page 413
Problems......Page 414
References......Page 415
External versus Internal Exposure......Page 416
Internal Dose Control......Page 419
ICRP Publication 26 Techniques......Page 421
ICRP Publication 30 Techniques......Page 426
Calculation of the Committed Dose Equivalent......Page 429
Dosimetric Models Used in the ICRP 30 Calculations......Page 436
ICRP Publication 60......Page 449
Age-Dependent Doses to the Public (ICRP Publications 56, 67, 69, 71, and 72)......Page 457
ICRP Publication 89......Page 470
Summary......Page 471
References......Page 472
10 External Dosimetry......Page 474
Dose Coefficients for External Exposure......Page 475
Compilation of External Dose Coefficients......Page 476
Description of Dose Coefficients in Current Federal Guidance......Page 477
Applicability of Dose Coefficients......Page 479
Effective Dose Coefficients......Page 480
Corrections to Dose Coefficients for Photons......Page 481
Effects of Ground Roughness......Page 482
Exposure to Contaminated Shorelines......Page 483
Description of the Point-Kernel Method......Page 484
Applications of the Point-Kernel Method for Photons......Page 486
Problems......Page 488
References......Page 489
11 Estimating and Applying Uncertainty in Assessment Models......Page 492
Why Perform an Uncertainty Analysis?......Page 495
Describing Uncertainty......Page 496
Descriptive Statistics......Page 498
Statistical Intervals......Page 503
Typical Distributions......Page 510
Correlations and Multivariate Distributions......Page 512
Assigning Distributions......Page 514
Deriving Distributions from Data......Page 517
Analytical Methods......Page 524
Formulas for Normal and Lognormal Distributions......Page 528
Mathematical Approximation Techniques......Page 529
Propagation Using Interval Estimates......Page 531
Covariance and the Order of Operations......Page 532
Monte Carlo Methods......Page 533
Potential Problems with Monte Carlo Methods......Page 535
Sampling Designs......Page 536
Number of Simulations......Page 538
Interpretation of the Output Distributions......Page 540
Sensitivity Analysis......Page 544
Local Sensitivity Analysis......Page 545
Global Sensitivity Analysis......Page 547
Statistics for Ranking Parameters......Page 548
Uncertainty and Model Validation......Page 549
Summary......Page 551
Problems......Page 552
References......Page 553
12 The Risks from Exposure to Ionizing Radiation......Page 558
Biophysical Aspects of Radiation Action on Cells......Page 560
Epigenetic Responses to Radiation......Page 562
Effects at Low Doses of Radiation......Page 564
Genetic Susceptibility to Cancer......Page 565
Heritable Diseases......Page 566
Cancer Epidemiology......Page 567
Japanese A-Bomb Survivors......Page 568
Other Cohorts......Page 569
In Utero Exposures......Page 570
Uncertainties in Risk Estimates Based on Mortality Data......Page 571
Cancer Risk Coefficients......Page 572
Hereditary Risk......Page 573
Overall Conclusions on Biological Effects at Low Doses......Page 574
References......Page 576
13 The Role of Epidemiology in Estimating Radiation Risk: Basic Methods and Applications......Page 578
Estimating Disease Risk......Page 579
Estimating Disease Rate......Page 581
Estimating Disease Prevalence......Page 582
Risk Ratio......Page 584
Exposure Odds Ratio......Page 586
Cohort Designs......Page 590
Case–Control Designs......Page 592
Assessing the Observed Level of Association between Disease and Exposure......Page 593
Interpreting Estimates of Disease Exposure Association......Page 594
Confidence Intervals......Page 597
Issues in Radiation Epidemiology......Page 607
Problems......Page 611
References......Page 614
14 Model Validation......Page 616
Validation Process......Page 617
Model Composition......Page 618
Model Performance......Page 620
Calibration......Page 621
Testing for Bias......Page 623
Measures of Scatter......Page 625
Visual Display of Information......Page 626
Reasons for Poor Model Performance......Page 630
User Error......Page 631
The Model......Page 632
The Assessment Question......Page 634
Problems......Page 635
References......Page 636
15 Regulations for Radionuclides in the Environment......Page 640
Principal Laws for Regulating Exposures to Radionuclides and Hazardous Chemicals in the Environment......Page 641
Responsibilities of U.S. Governmental Institutions......Page 644
Basic Approaches to Regulating Exposure to Radionuclides in the Environment......Page 646
Radiation Protection Standards for the Public......Page 647
Standards for Specific Practices or Sources......Page 656
Concepts of Exemption......Page 698
Recommendations of Advisory Organizations......Page 699
Exemptions Established by the U.S. Nuclear Regulatory Commission......Page 700
Protective Action Guides for Accidents......Page 701
Time Phases for Defining Protective Actions......Page 702
Protective Action Guides Established by Federal Agencies......Page 703
Proposed Recommendations of the U.S. Department of Homeland Security......Page 704
U.S. Nuclear Regulatory Commission’s Reactor Siting Criteria......Page 706
ICRP Recommendations on Responses to Accidents......Page 707
IAEA Guidelines for Intervention Levels in Emergency Exposure Situations......Page 708
Conclusions......Page 709
References......Page 710
A......Page 716
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E......Page 720
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H......Page 722
L......Page 723
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P......Page 725
R......Page 726
S......Page 727
T......Page 728
Z......Page 729