13
_James E. Martin Physics for Radiation Protection A Handbook Second Edition, Completely Revised and Enlarged WILEY- VCH WILEY-VCH Verlag GmbH & Co. KGaA
_James E. Martin
Physics for Radiation ProtectionA Handbook
Second Edition, Completely Revised and Enlarged
WILEY-VCH
WILEY-VCH Verlag GmbH & Co. KGaA
Co ntents
Preface XIX
1 Atoms and Energy 11.1 Structure of Atoms 21.1.1 Two-proton Atoms 61.1.2 Three-proton Atoms 71.2 Nuclide Chart 71.3 Atom Measures 91.3.1 Avogadro's Number 10
1.3.2 Atomic Mass Unit (u) 10
1.4 Energy Concepts for Atoms 11
Checkpoints 141.5 Relativistic Energy 15
1.5.1 Momentum and Energy 181.5.2 Effects of Velocity 181.5.3 A Natural Limit 191.5.4 Mass-energy 20
Checkpoints 211.6 Electron Volt (eV) 221.7 Binding Energy of Nuclei 23
1.7.1 Calculation of Binding Energy 24
1.7.2 Q-value Calculations 241.8 Summary and Checkpoints 26
Other Suggested Sources 28Problems — Chapter 1 28
2 Major Discoveries in Radiation Physics 292.1 Great Discoveries from Simple Tools 302.1.1 Discovery of X-rays (1895) 31
2.1.2 Discovery of Radioactivity 322.1.3 Discovery of the Electron 342.1.4 The Electron's Charge 35
2.2 First Concept of the Atom 37
Physics for Radiation Protection: A Handbook. James E. MartinCopyright © 2006 WILEY-VCH Verlag GmbH & Co. KGaA, WeinheimISBN: 3-527-40611-5
Ivn
VIII I Contents
Checkpoint 39
2.3 Theory of Electromagnetic Radiation: the Quantum 39
2.3.1 Wein's Law 41
2.3.2 Rayleigh—Jeans Law 42
2.3.3 Planck's Qantum Theory of Radiation 43
Checkpoint 45
2.3.4 Quantum Theory and the Photoelectric Effect 46
2.3.5 Electromagnetic Spectrum 48
2.3.6 The Photon 49
2.3.7 Compton Effect 50Checkpoint: Quantized Energy 53
2.4 Discovery of the Atom's Structure 54
2.4.1 Rutherford' s Alpha Scattering Experiments 55
2.4.2 Bohr Model of the Atom 57
2.4.3 Emission and Absorption Spectra 58
2.5 Wave Mechanics: a Necessary Theory 63
2.5.1 De Broglie Waves 63
2.5.2 Confirmation of de Broglie's Hypothesis 64
2.5.3 De Broglie Waves and the Bohr Model 66
2.5.4 Wave Mechanics 67
2.5.5 Exclusion Principle 70
2.5.6 Uncertainty Principle 72
2.6 Atom Systems 73
2.6.1 The Neutron 73
2.6.2 Nudear Shell Model 74
2.7 Summary 76Other Suggested Sources 77
Problems — Chapter 2 77
3 Radioactive Transformation 79
3.1 Processes of Radioactive Transformation 79
3.1.1 Transformation of Neutron-rich Radioactive Nuclei 813.1.2 Double Beta (ßß) Transformation 85
3.1.3 Transformation of Proton-rich Nuclei 853.1.4 Positron Emission 87
3.1.5 Average Energy of Negatron and Positron Emitters 903.1.6 Electron Capture (EC) 91
3.1.7 Radioactive Transformation of Heavy Nuclei by Alpha ParticleEmission 93
3.1.8 Theory of Alpha Particle Transformation 96
3.1.9 Transuranic (TRU) Radionuclides 98
3.1.10 Gamma Emission 99
3.1.11 Internal Transition (Metastable or Isomeric States) 100
3.1.12 Internal Conversion 101
3.1.13 Multiple Modes of Radioactive Transformation 107
Contents IIX
3.1.14 Transformation by Delayed Neutron Emission 1093.1.15 Transformation by Spontaneous Fission 1093.1.16 Proton Emission 1113.2 Decay Schemes 112
3.3 Rate of Radioactive Transformation 1153.3.1 Activity 1163.3.2 Units of Radioactive Transformation 1163.3.3 Mathematics of Radioactive Transformation 1183.3.4 Half-Life 120
3.3.5 Mean Life 121
3.3.6 Effective Half-life 122
3.4 Radioactivity Calculations 123
3.4.1 Half-life Determination 126
3.5 Activity—mass Relationships 128
3.5.1 Specific Activity 128
3.6 Radioactive Series Transformation 131
3.6.1 Series Decay Calculations 131
3.6.2 Recursive Kinetics: the Bateman Equations 134
3.7 Radioactive Equilibrium 135
3.7.1 Secular Equilibrium 136
3.7.2 Transient Equilibrium 138
3.7.3 Radionuclide Generators 139
3.8 Total Number of Transformations (Uses of z and .1 E ff) 142
3.9 Discovery of the Neutrino 144
Acknowledgments 145
Other Suggested Sources 145
Problems — Chapter 3 146
4 Interactions 149
4.1 Production of X-rays 149
4.2 Characteristic X-rays 151
4.2.1 X-rays and Atomic Structure 153
4.2.2 Auger Electrons 154
4.3 Nuclear Interactions 156
4.3.1 Cross-Section 158
4.3.2 Q-values for Nuclear Reactions 160
4.4 Alpha Particle Interactions 162
4.4.1 Alpha—Neutron Reactions 1634.5 Transmutation by Protons and Deuterons 164
4.5.1 Proton—Alpha Particle (p,a) Reactions 166
4.5.2 Proton—Neutron (p,n) Reactions 167
4.5.3 Proton—Gamma (p,y) Reactions 168
4.5.4 Proton—Deuteron Reactions 168
4.5.5 Deuteron—Alpha (d,a) Reactions 1694.5.6 Deuteron—Proton (d,p) and Deuteron—Neutron (d,n) Reactions 169
X I1 Contents
4.6 Neutron Interactions 172
4.6.1 Radiative Capture (n,y) Reactions 172
4.6.2 Charged Partide Emission (CPE) 173
4.6.3 Neutron–Proton (n,p) Reactions 174
4.6.4 Neutron–Neutron (n,2n) Reactions 174
4.7 Activation Product Calculations 175
4.7.1 Neutron Activation Product Calculations 177
4.7.2 Charged Particles Calculations 182
4.8 Medical Isotope Reactions 184
4.9 Transuranium Elements 186
4.10 Photon Interactions 188
4.10.1 Activation by Photons 188
4.11 Fission and Fusion Reactions 191
4.11.1 Fission 191
4.11.2 Fusion 192
4.12 Summary 196Other Suggested Sources 197
Problems – Chapter 4 197
5 Nuclear Fission and its Products 201
5.1 Fission Energy 2035.2 Physics of Sustained Nudear Fission 2055.3 Neutron Economy and Reactivity 210
5.4 Nuclear Power Reactors 212
5.4.1 Reactor Design: Basic Systems 2135.5 Light Water Reactors (LWRs) 2155.5.1 Pressurized Water Reactor (PWR) 2155.5.2 Boiling Water Reactor (BWR) 2175.5.3 Inherent Safety Features of LWRs 2195.5.4 Decay Heat in Power Reactors 2215.5.5 Uranium Enrichment 2225.6 Heavy Water Reactors (HWRs) 2235.6.1 HWR Safety Systems 2265.7 Breeder Reactors 2275.7.1 Liquid Metal Fast Breeder Reactor (LMFBR) 2295.8 Gas-cooled Reactors 2325.8.1 High-temperature Gas Reactor (HTGR) 2335.9 Reactor Radioactivity 2345.9.1 Fuel Cladding 2355.9.2 Radioactive Products of Fission 2365.9.3 Production of Individual Fission Products 2405.9.4 Fission Products in Spent Fuel 2425.9.5 Fission Product Poisons 2435.10 Radioactivity in Reactors 2465.10.1 Activation Products in Nuclear Reactors 246
Contents IXI
5.10.2 Tritium Production in Reactors 2495.10.3 Low-level Radioactive Waste 2505.11 Summary 251
Acknowledgments 252
Other Suggested Sources 253
Problems – Chapter 5 253
6 Naturally Occuring Radiation and Radioactivity 255
6.1 Discovery and Interpretation 256
6.2 Background Radiation 259
6.3 Cosmic Radiation 260
6.4 Cosmogenic Radionuclides 263
6.5 Naturally Radioacitve Series 267
6.5.1 Neptunium Series Radionuclides 274
6.6 Singly Occuring Primordial Radionuclides 274
6.7 Radioactive Ores and Byproducts 276
6.7.1 Resource Recovery 278
6.7.2 Uranium Ores 278
6.7.3 Water Treatment Sludge 279
6.7.4 Phosphate Industry Wastes 2796.7.5 Elemental Phosphorus 280
6.7.6 Manhattan Project Wastes 281
6.7.7 Thorium Ores 283
6.8 Radioactivity Dating 284
6.8.1 Carbon Dating 284
6.8.2 Dating by Primordial Radionuclides 2856.8.3 Potassium–Argon Dating 286
6.8.4 Ionium ( 230Th) Method 287
6.8.5 Lead-210 Dating 287
6.9 Radon and its Progeny 288
6.9.1 Radon Subseries 289
6.9.2 Working Level for Radon Progeny 292
6.9.3 Measurement of Radon 296
6.10 Summary 300Acknowledgements 301
Other Suggested Sources 301
Problems – Chapter 6 302
7 Interactions of Radiation with Matter 305
7.1 Radiation Dose and Units 3057.1.1 Radiation Absorbed Dose 306
7.1.2 Radiation Dose Equivalent 3067.1.3 Radiation Exposure 3077.2 Radiation Dose Calculations 3097.2.1 Inverse Square Law 309
XII
1 Contents
7.3 Interaction Processes 310
7.4 Interactions of Alpha Particles and Heavy Nuclei 312
7.4.1 Recoil Nuclei and Fission Fragments 314
7.4.2 Range of Alpha Particles 314
7.5 Beta Particle Interactions and Dose 317
7.5.1 Energy Loss by Ionization 318
7.5.2 Energy Losses by Bremsstrahlung 318
7.5.3 Cerenkov Radiation 319
7.5.4 Attenuation of Beta Particles 321
7.5.5 Range Versus Energy of Beta Particles 322
7.5.6 Radiation Dose from Beta Particles 324
7.5.7 Beta Dose from Contaminated Surfaces 327
7.5.8 Beta Contamination on Skin or Clothing 328
7.5.9 Beta Dose from Hot Particles 329
7.6 Photon Interactions 330
7.6.1 Photoelectric Interactions 331
7.6.2 Compton Interactions 332
7.6.3 Pair Production 334
7.6.4 Photodisintegration 336
7.7 Photon Attenuation and Absorption 337
7.7.1 Attenuation (,u) and Energy Absorption (g En) Coefficients 340
7.7.2 Effect of E and Z on Photon Attenuation/Absorption 344
7.7.3 Absorption Edges 346
Checkpoints 348
7.8 Energy Transfer and Absorption by Photons 348
7.8.1 Electronic Equilibrium 353
7.8.2 Bragg—Gray Theory 355
7.9 Exposure/Dose Calculations 356
7.9.1 Point Sources 357
7.9.2 Gamma Ray Constant, F 358
7.9.3 Exposure and Absorbed Dose 360
7.9.4 Exposure, Kerma, and Absorbed Dose 3617.10 Summary 363
Acknowledgments 363Other Suggested Sources 364Problems — Chapter 7 364
8 Radiation Shielding 367
8.1 Shielding of Alpha-Emitting Sources 367
8.2 Shielding of Beta-Emitting Sources 368
8.2.1 Attenuation of Beta Particles 368
8.2.2 Bremsstrahlung Effects for Beta Shielding 371
8.3 Shielding of Photon Sources 374
8.3.1 Shielding of Good Geometry Photon Sources 375
8.3.2 Half-Value and Tenth-Value Layers 382
Contents 'XIII
8.3.3 Shielding of Poor Geometry Photon Sources 3848.3.4 Use of Buildup Factors 3908.3.5 Effect of Buildup an Shield Thickness 391
8.3.6 Mathematical Formulations of the Buildup Factor 3938.4 Gamma Flux for Distributed Sources 398
8.4.1 Line Sources 3998.4.2 Ring Sources 401
8.4.3 Disc and Planar Sources 402
8.4.4 Shield Designs for Area Sources 4038.4.5 Gamma Exposure from Thick Stabs 410
8.4.6 Volume Sources 415
8.4.7 Buildup Factors for Layered Absorbers 416
8.5 Shielding of Protons and Light Ions 4178.6 Summary 420
Acknowledgments 420
Other Suggested Sources 421
Problems – Chapter 8 421
9 Internat Radiation Dose 425
9.1 Absorbed Dose in Tissue 425
9.2 Accumulated Dose 426
9.2.1 Internal Dose: Medical Uses 429
Checkpoints 429
9.3 Factors In The Internal Dose Equation 430
9.3.1 The Dose Reciprocity Theorem 437
9.3.2 Deposition and Clearance Data 438
9.3.3 Multicompartment Retention 438
9.4 Radiation Dose from Radionuclide Intakes 443
9.4.1 Risk-Based Radiation Standards 4449.4.2 Committed Effective Dose Equivalent (CEDE) 445
9.4.3 Biokinetic Models: Risk-Based Internal Dosimetry 446
9.4.4 Radiation Doses Due to Inhaled Radionuclides 448
9.4.5 Radiation Doses Due to Ingested Radionuclides 458
9.5 Operational Determinations of Internal Dose 4659.5.1 Submersion Dose 466
Checkpoints 4669.6 Bioassay Determination Of Intake 4689.6.1 Weighted Estimate Of Intake 4749.6.2 Tritium: a Special Case 4759.6.3 Bioassay of Tritium: a Special Case 4779.7 Summary 479
Other Suggested Sources 479Problems – Chapter 9 480
XIV I Contents
1 0 Environmental Dispersion 48310.1 Atmospheric Dispersion 48510.1.1 Atmospheric Stability Effects on Dispersion 488
10.1.2 Atmospheric Stability Classes 49010.1.3 Calculational Procedure: Uniform Stability Conditions 492
10.1.4 Distance xmax of Maximum Concentration (xmax) 494
10.1.5 Stack Effects 495Checkpoints 497
10.2 Nonuniform turbulence: Fumigation, Building Effects 49710.2.1 Fumigation 497
10.2.2 Dispersion for an Elevated Receptor 49910.2.3 Building Wake Effects: Mechanical Turbulence 50010.2.4 Concentrations of Effluents in Building Wakes 501
10.2.5 Ground-level Area Sources 503
10.2.6 Effect of Mechanical Turbulence on Far-field Diffusion 50410.3 Puff Releases 50610.4 Sector-Averaged x/Q Values 50710.5 Deposition/Depletion: Guassian Plumes 51110.5.1 Dry Deposition 51110.5.2 Air Concentration Due to Resuspension 51510.5.3 Wet Deposition 51710.6 Summary 520
Other Suggested Sources 520Problems – Chapter 10 521
11 Nuclear Criticality 52311.1 Nuclear Reactors and Criticality 52411.1.1 Three Mile Island Accident 52411.1.2 Chernobyl Accident 52611.1.3 NRX Reactor: Chalk River, Ontario, December 1952 52911.1.4 S L-1 Accident 52911.1.5 K-reactor, Savannah River Site, 1988 53011.1.6 Special Reactor Experiments 53111.2 Nuclear Explosions 53211.2.1 Fission Weapons 53211.2.2 Fusion Weapons 53311.2.3 Products of Nuclear Explosions 53411.2.4 Fission Product Activity and Exposure 535
Checkpoints 53711.3 Criticality Accidents 53811.3.1 Y-12 Plant, Oak Ridge National Laboratory, TN: June 16, 1958 53811.3.2 Los Alamos Scientific Laboratory, NM: December 30, 1958 53911.3.3 Idaho Chemical Processing Plant: October 16, 1959, January 25, 1961,
and October 17, 1978 54011.3.4 Hanford Recuplex Plant: April 7, 1962 541
Contents IXV
11.3.5 Wood River Junction RI: July 24, 1964 541
11.3.6 UKAEA Windscale Works, UK: August 24, 1970 542
11.3.7 Bare and Reflected Metal Assemblies 542
11.4 Radiation Exposures in Criticality Events 54311.5 Criticality Safety 54411.5.1 Criticality Safety Parameters 54611.6 Fission Product Release in Criticality Events 55011.6.1 Fast Fission in Criticality Events 551
11.7 Summary 553Acknowledgments 554
Other Suggested Sources 554Problems – Chapter 11 554
12 Radiation Detection and Measurement 55712.1 Gas-Filled Detectors 55712.2 Crystalline Detectors/Spectrometers 561
12.3 Semiconducting Detectors 562
12.4 Gamma Spectroscopy 56312.4.1 Gamma-Ray Spectra: hv � 1.022 MeV 56312.4.2 Gamma-Ray Spectra: hv � 1.022 MeV 56812.4.3 Escape Peaks and Sum Peaks 57012.4.4 Gamma Spectroscopy of Positron Emitters 571
12.5 Portable Field Instruments 572
12.5.1 Geiger Counters 572
12.5.2 Ion Chambers 57312.5.3 Microrem Meters 57412.5.4 Alpha Radiation Monitoring 57412.5.5 Beta Radiation Surveys 57512.5.6 Removable Radioactive Surface Contamination 576
12.5.7 Instrument Calibration 57712.6 Personnel Dosimeters 57712.6.1 Film Badges 57712.6.2 Thermoluminescence Dosimeters (TLDs) 57812.6.3 Pocket Dosimeters 57912.7 Laboratory Instruments 579
12.7.1 Liquid Scintillation Analysis 57912.7.2 Proportional Counters 58312.7.3 End-window GM Counters 58512.7.4 Surface Barrier Detectors 58612.7.5 Range Versus Energy of Beta Particles 587
Other Suggested Sources 588
Problems – Chapter 12 589
XVI I Contents
13 Statistics in Radiation Physics 59113.1 Nature of Counting Distributions 591
13.1.1 Binomial Distribution 59313.1.2 Poisson Distribution 59313.1.3 Normal Distribution 59513.1.4 Mean and Standard Deviation of a Set of Measurements 598
13.1.5 Uncertainty in the Activity of a Radioactive Source 59913.1.6 Uncertainty in a Single Measurement 601
Checkpoints 60113.2 Propagation of Error 60213.2.1 Statistical Subtraction of a Background Count or Count Rate 603
13.2.2 Error Propagation of Several Uncertain Parameters 60513.3 Comparison of Data Sets 60613.3.1 Are Two Measurements Different? 606
13.4 Statistics for the Counting Laboratory 60913.4.1 Uncertainty of a Radioactivity Measurement 60913.4.2 Determining a Count Time 61013.4.3 Efficient Distribution of Counting Time 612
13.4.4 Detection and Uncertainty for Gamma Spectroscopy 61313.4.5 Testing the Distribution of a Series of Counts
(the Chi-square Statistic) 61513.4.6 Weighted Sample Mean 61613.4.7 Rejection of Data 617
13.5 Levels of Detection 619
13.5.1 Critical Level 620
13.5.2 Detection Limit (Ld) or Lower Level of Detection (LLD) 62213.6 Minimum Detectable Concentration or Contamination 62613.6.1 Minimum Detectable Concentration (MDConc.) 62613.6.2 Minimum Detectable Contamination (MDCont.) 62813.6.3 Less-than Level (Lt) 62913.6.4 Interpretations and Restrictions 62913.7 Log Normal Data Distributions 63013.7.1 Particle Size Analysis 633
Acknowledgment 637Other Suggested Sources 637Chapter 13 — Problems 637
14 Neutrons 63914.1 Neutron Sources 63914.2 Neutron Parameters 64114.3 Neutron Interactions 64314.3.1 Neutron Attenuation and Absorption 64414.4 Neutron Dosimetry 64614.4.1 Dosimetry for Fast Neutrons 64914.4.2 Dose from Thermal Neutrons 651
Contents IXVII
14.4.3 Monte Carlo Calculations of Neutron Dose 653
14.4.4 Kerma for Neutrons 65614.4.5 Dose Equivalent Versus Neutron Flux 65614.4.6 Boron Neutron Capture Therapy (BNCT) 65914.5 Neutron Shielding 65914.5.1 Neutron Shielding Materials 65914.5.2 Neutron Shielding Calculations 661
14.5.3 Neutron Removal Coefficients 66214.5.4 Neutron Attenuation in Concrete 66514.6 Neutron Detection 66614.6.1 Measurement of Thermal Neutrons 66714.6.2 Measurement of Intermediate and Fast Neutrons 668
14.6.3 Neutron Foils 67014.6.4 Albedo Dosimeters 67214.6.5 Flux Depression of Neutrons 672
14.7 Summary 673Acknowledgment 673Other Suggested Sources 673Problems – Chapter 14 674
15 X-rays 67515.1 Producing and Shaping the X-ray Beam 67715.1.1 X-ray Yield (Bremsstrahlung Production Fraction) 67915.1.2 X-ray Tubes 682
15.1.3 Focal Spot 68415.1.4 Rotating Anodes 68615.1.5 Equipment Techniques 687
15.1.6 Intensity of X-ray Beams 688
15.1.7 X-ray Filters 69115.2 X-ray Image Information 69715.2.1 X-ray Imaging Dosimetry 69915.3 Capture of the X-ray Image 702
15.3.1 Air Gaps and Grids 70315.3.2 X-ray Film/Screen Systems 70715.3.3 Intensifying Screens 70915.4 Image Processing 710
15.4.1 Optimization of Film Processing 714
15.5 Radiation Protection from X-rays 71715.5.1 Ensuring Patient Protection in X-ray Diagnosis 717
15.5.2 Radiation Exposure from X-rays 718
15.5.3 Good Practice 724
15.6 X-ray Shielding 726
15.6.1 Shielding Calculations 726
XVIII I Contents
15.7 Summary 733Acknowledgments 734Other Suggested Sources 734Problems — Chapter 15 735
Answers to Selected Problems 737
Appendix A 743
Appendix B 745
Appendix C 755
Appendix D 763
Appendix E 791
Appendix F 813
Index 815
