Nuclear safety

Cover......Page 1
Nuclear Safety......Page 3
Copyright......Page 4
Contents......Page 5
Preface......Page 13
 References......Page 15
 1.1 Objectives......Page 16
  1.2.1 The Early Years......Page 17
  1.2.2 From the Late 1950s to the Three Mile Island Accident......Page 18
  1.2.3 From the Three Mile Island Accident to the Chernobyl Accident......Page 24
  1.2.4 The Chernobyl Accident and After......Page 26
  1.2.5 Fukushima Accident and its Lessons......Page 28
 EndNotes......Page 29
 Further Reading......Page 32
2 Inventory and Localization of Radioactive Products in the Plant......Page 33
 References......Page 36
 3.1 Plant Systems......Page 37
 3.2 Safety Systems and Accidents......Page 38
  3.3.1 General Remarks......Page 45
  3.3.2 Some Passive Safety Systems for Nuclear Plants......Page 48
  3.3.3 Inherently Safe Systems in the Process Industries......Page 52
 References......Page 56
 Further Reading......Page 57
   4.2.1.1 Initial Conditions......Page 58
   4.2.1.2 Doppler Coefficient......Page 59
   4.2.1.4 Reactivity of the Boron Content......Page 61
   4.2.1.5 Reactivity of the Control Rods......Page 62
  4.2.2 Example of a Category 2 Accident: Spurious Opening of a Pressurizer Safety Valve......Page 64
  4.2.3 Example of a Category 3 Accident: Instantaneous Power Loss to All the Primary Pumps......Page 66
  4.2.4 Example of a Category 4 Accident: Main Steam Line Break......Page 67
  4.2.5 Example of a Category 4 Accident: Sudden Expulsion of a Control Rod From the Core......Page 69
  4.2.6 Example of a Category 4 Accident: Break of the Largest Pipe of the Primary System (Large LOCA)......Page 72
  4.2.7 Example of a Category 4 Accident: Fuel Handling Accident......Page 74
  4.2.8 Area Accidents......Page 75
 4.3 Beyond Design Basis Accidents......Page 76
  4.3.2 Accidents Due to Human Voluntary Actions......Page 77
 4.4 External Accidents of Natural Origin......Page 78
 EndNote......Page 79
 References......Page 80
 Further Reading......Page 81
 5.1 Existing Plants......Page 82
 5.2 Future Plants: Extreme and Practicable Solutions......Page 84
 5.3 Severe Accident Management: The Present State of Studies and Implementations......Page 88
  5.5.1 Loss of Station Electric Power Supply (TE=Transient+Loss of Electrical Supply)......Page 89
  5.5.3 Interfacing Systems LOCA (V)......Page 92
  5.5.4 Large LOCA With Failure of the Recirculation (ALFC)......Page 93
 5.6 “Source Terms” for Severe Accidents......Page 94
 References......Page 96
 Further Reading......Page 97
 6.1 The Most Interesting Releases for Safety Evaluations......Page 98
 6.2 Dispersion of Releases: Phenomena......Page 100
 6.3 Release Dispersion: Simple Evaluation Techniques......Page 104
 6.4 Formulae and Diagrams for the Evaluation of Atmospheric Dispersion......Page 106
 6.5 Calculation of Atmospheric Dispersion by Computer Fluid Dynamics Codes......Page 112
 EndNotes......Page 114
 References......Page 115
 7.2 Some Quantities, Terms, and Units of Measure of Health Physics......Page 116
 7.3 Types of Effects of Radiation Doses and Limits......Page 118
  7.4.2 Evaluation of Doses Due to Submersion in a Radioactive Cloud......Page 119
  7.4.6 Direct Radiation Doses......Page 120
 References......Page 123
  8.2.1 The Objectives and Limits of Release/Dose......Page 124
 8.3 Some Plant Characteristics for the Prevention and Mitigation of Accidents......Page 125
 8.5 Site Characteristics......Page 126
 9.1 Definition, Objectives, Levels, and Barriers......Page 128
 9.2 Additional Considerations on the Levels of Defence in Depth......Page 129
 References......Page 131
 10.1 General Remarks and Requirements......Page 132
 Further Reading......Page 133
 11.2 Deterministic Safety Analysis......Page 134
 11.3 Probabilistic Safety Analysis......Page 137
  11.3.2 Fault Trees......Page 139
 References......Page 148
 12.2 The Reference Points......Page 150
 12.3 Foreseeing Possible Issues for Discussion......Page 151
 12.5 Clarification Is Not Disrespectful......Page 152
   12.6.3.1 Flow Distribution in Lower Plenum......Page 154
  12.6.6 Vibration Analysis......Page 155
   12.6.6.1 Cross Flow......Page 156
   12.6.6.2 Parallel Flow......Page 157
   12.6.6.3 Fatigue Analysis......Page 158
 12.7 Discussion......Page 159
 EndNote......Page 160
 References......Page 161
13 Classification of Plant Components......Page 162
 References......Page 163
  14.1.1 Problems Highlighted by Operating Experience......Page 164
  14.1.2 Rupture Probability of Nonnuclear Vessels......Page 165
   14.1.3.1 Normal Conditions, Transients, and Design Accidents......Page 166
  14.1.4 Vessel Material Embrittlement due to Neutron Irradiation......Page 171
  14.1.6 The Reactor Pressure Vessel of Three Mile Island 2......Page 173
  14.1.7 General Perspective on the Effect of Severe Accidents on the Pressure Vessel......Page 174
   14.1.8.1 Materials......Page 176
   14.1.8.3 Fabrication and Inspection......Page 177
  14.2.1 Evolution of the Regulatory Positions......Page 178
   14.2.2.1 Cracks in Primary System (see USNRC, 1997a)......Page 179
   14.2.3.1 Requirements......Page 181
  14.2.4 Research Programs on Piping......Page 182
  14.3.1 General Remarks......Page 183
  14.3.2 Relevant Data From Operating Experience......Page 184
  14.3.3 The Most Commonly Used Types of Valve......Page 185
  14.3.4 Types of Valve: Critical Areas, Design, and Operation......Page 186
   14.3.4.1 Compatibility of the Motor Operator With the Valve and Associated Control Circuits......Page 187
   14.3.4.2 Seals on the Stem (Seal Packs, Bellows, etc.)......Page 188
   14.3.4.4 Fluid Tightness Across the Valve Seats......Page 190
   14.3.4.5 Misuse of Valves for the Intended Service......Page 191
  14.3.5 Valve Standards......Page 192
 14.4 Containment Systems......Page 193
 References......Page 195
 15.1 General Aspects, Criteria, and Starting Data......Page 197
 15.2 Reference Ground Motion......Page 201
  15.3.1 Foundation Soil Resistance......Page 211
   15.3.1.1 Soil Bearing Capacity (Soil Stability)......Page 214
   15.3.1.2 Mononobe–Okabe Method......Page 216
   15.3.2.1 One Degree of Freedom Systems......Page 217
   15.3.2.2 Multidegree of Freedom Systems......Page 222
   15.3.2.3 Continuous Systems......Page 226
   15.3.2.4 Tanks......Page 227
   15.3.2.5 Resistance and Functionality of Mechanical, Electrical, and Electronic Components......Page 229
   15.3.2.6 Soil–Structure Interaction......Page 232
   15.3.2.7 Bridge Cranes......Page 235
   15.3.2.8 Buried Structures and Caverns......Page 236
   15.3.2.9 Towers and Chimneys......Page 237
    15.3.2.11.2 Sequence of Actions and Methods......Page 238
    15.3.2.11.3 Typical Weak Points and Ameliorating Provisions......Page 239
 References......Page 243
 Further Reading......Page 245
 16.1 The Physical Phenomenon......Page 246
 16.2 Scale of Severity of the Phenomenon......Page 248
 References......Page 249
  17.2.1 Effects of an Aircraft Impact......Page 250
  17.2.2 Overall Load on a Structure......Page 251
  17.2.4 Local Perforation of Structures......Page 253
  17.2.6 Temporary Incapacity of the Operating Personnel......Page 254
 17.3 Pressure Wave......Page 255
 17.4 Other Impacts......Page 256
 References......Page 257
 18.1 General Characteristics......Page 259
 18.2 The US General Design Criteria......Page 260
 18.4 EUR Criteria......Page 261
 18.5 Other General Criteria Compilations......Page 262
  18.6.2 Possible Evolution in Safety Evaluation Methods (Mistakes and Limits in Probability Evaluations) and in Safety Criteria......Page 263
 References......Page 269
 Further Reading......Page 270
19 Nuclear Safety Research......Page 271
 Reference......Page 272
 20.3 Some Significant Events......Page 273
  20.3.1 Mechanical Events......Page 274
  20.3.3 System Events......Page 275
  20.3.4 Area Events......Page 276
  20.3.6 Possible Future Accidents......Page 277
 20.4 The International Nuclear Event Scale......Page 278
 References......Page 282
21 Underground Location of Nuclear Power Plants......Page 283
 References......Page 286
 22.2 Types of Nuclear Bomb......Page 288
 22.3 The Consequences of a Nuclear Explosion......Page 289
 22.4 Initial Nuclear Radiation......Page 290
 22.5 Shock Wave......Page 291
 22.6 Initial Thermal Radiation......Page 292
 22.7 Initial Radioactive Contamination (“Fallout”)......Page 293
  22.8.2 The Possible Effects of an Underground Nuclear Explosion......Page 294
 References......Page 295
 23.1 Types and Indicative Amounts of Radioactive Waste......Page 296
 Further Reading......Page 299
24 Fusion Safety......Page 300
 Further Reading......Page 305
 25.1 Boiling Water Reactors......Page 306
 25.2 Pressure Tube Reactors......Page 308
 25.3 Gas Reactors......Page 309
 25.4 Research Reactors......Page 310
 25.6 Generation III/III+ Reactors......Page 311
  25.7.1 Small–Medium Size Reactor......Page 312
  25.7.2 Molten Salt Fast Reactor......Page 313
 25.8 Fuel Plants......Page 315
 25.10 VVER Plants......Page 316
 25.12 Safe Transport of Radioactive Substances......Page 317
 References......Page 320
 Further Reading......Page 321
 26.2 Possible Accidents and Their Consequences......Page 322
 Further Reading......Page 324
27 Erroneous Beliefs About Nuclear Safety......Page 325
 References......Page 327
28 When Can We Say That a Particular Plant Is Safe?......Page 328
  29.2.1 Tolerable Risk......Page 329
  29.2.2 Risk-informed Decisions......Page 331
 29.4 Risk From Various Energy Sources......Page 332
 29.6 Are the Risk Analyses of Nuclear Power Plants Credible?......Page 333
 References......Page 335
  Nuclear Safety Standards Series......Page 336
 MISC, Other References......Page 337
 A1.2 The Reactor......Page 339
 A1.3 The Event......Page 342
 Further Reading......Page 345
 A2.2 Initial Overpressure......Page 346
 A2.3 Containment Pressure Versus Time......Page 348
  A2.3.3 Heat Exchanged With the Outside Through the Metal Container......Page 349
  A2.3.5 Heat Exchanged With Cold Metals......Page 351
  A2.3.6 Heat Exchanged With Concrete Layers......Page 352
  A2.3.7 Decay Heat......Page 353
  A2.3.9 Solar Heat......Page 355
  A2.3.11 Considerations on the Performance of the Calculation and on the Choice of the Input Data......Page 356
   A2.3.11.2 Choice of the Length of the Time Step and of the Thickness of the Concrete Layers, ΔX......Page 357
  A2.3.12 Example Calculation......Page 358
 References......Page 362
Appendix 3 Table of Safety Criteria......Page 364
  A4.2.2 Source Term at Three Days (I, Cs, Xe)......Page 375
  A4.2.4 Ground Shine Long-term Dose......Page 376
  A4.3.2 Reference Impact......Page 377
  A4.3.3 Fragmentation and Dispersion of Material......Page 378
   A4.3.3.1 Alternative Source Term......Page 379
  A4.3.4 Doses......Page 380
  A4.4.2 Reference Impact......Page 381
  A4.4.3 Amount of Significant Fission Products in the Internal Atmosphere of the Cask and External Release in One Day......Page 382
   A4.4.4.1 Cesium Doses......Page 383
 References......Page 385
 A5.1 Analysis of the Core Without Refrigeration......Page 386
 References......Page 389
 A6.2 Sample of Notable Concepts Adopted in Revision E......Page 390
 A6.3 Extracts from EUR Criteria Revision E (2016) (Pressurized Water Reactors)......Page 392
 Reference......Page 413
 A7.1 Introduction......Page 414
 A7.2 Current Practice......Page 415
 References......Page 421
Appendix 8 US General Design Criteria......Page 422
 A8.1 Introduction......Page 424
  A8.3.1 Overall Requirements......Page 425
  A8.3.2 Protection by Multiple Fission Product Barriers......Page 426
  A8.3.3 Protection and Reactivity Control Systems......Page 428
  A8.3.4 Fluid Systems......Page 430
  A8.3.5 Reactor Containment......Page 432
  A8.3.6 Fuel and Radioactivity Control......Page 434
Appendix 9 IAEA Criteria......Page 436
 A10.1 Initial Studies......Page 437
 References......Page 444
 A11.1 General Remarks......Page 445
  A11.3.1 Macro Stampa Dati......Page 446
  A11.3.2 Macro Copia_dati......Page 448
  A11.3.4 Macro HFG......Page 449
  A11.3.6 Macro VFG......Page 450
  A11.3.8 Macro GU......Page 451
  A11.3.9 Macro GE......Page 452
  A11.3.10 Macro DT......Page 453
  A11.3.11 Macro PS......Page 454
  A11.5.1 Anticipated Transients Without Scram......Page 458
 References......Page 459
Appendix 12 The Atmospheric Dispersion of Releases......Page 461
 A13.1 Regulatory Framework......Page 467
  A13.2.1 The Safety Report......Page 468
  A13.2.3 The Environmental Impact Assessment......Page 471
  A13.2.5 The Operation Manual, Including the Emergency Procedures......Page 472
  A13.2.7 The Preoperational Test Program......Page 473
  A13.2.8 The Technical Specifications for Operation......Page 474
 References......Page 475
 A14.1 Extracts From a Regulatory Guide......Page 476
 A14.2 List of Contents and Extracts From a Sample Chapter of the Standard Review Plan......Page 480
 A14.3 Sample Chapter......Page 487
 A15.3 Mechanical Energy Which Can be Released......Page 492
  A15.4.1 Verification of the Tendons......Page 493
 A15.5 Experimental Tests on Steel Cages for the Containment of Vessel Explosions......Page 495
 Reference......Page 496
 A16.1 Population and Land Use......Page 497
 A16.4 Extreme Events from Human Activities......Page 498
 A16.5 Extreme Natural Events......Page 499
 A17.1 Summary Description of the Three Mile Island No. 2 Plant......Page 500
 A17.2 The Accident......Page 502
 A17.3 The Consequences of the Accident on the Outside Environment......Page 510
 A17.4 The Actions Initiated After the Accident......Page 513
 References......Page 515
  A18.1.3 The Safety Objectives and Limits of Release/Dose, Key Aspect 1: External Releases......Page 516
  A18.1.4 The Safety Objectives and Limits of Release/Dose, Key Aspect 2: External Doses......Page 520
  A18.1.5 Key Aspect 3: Possible Not Considered Accidents......Page 523
   A18.1.6.5 Key Aspect 8: Leak Before Break......Page 524
   A18.1.6.11 Key Aspect 14: Consideration of Plant Decommissioning......Page 525
  A18.2.2 The PS Code (Microsoft Excel Work Sheet)......Page 526
  A18.2.4 RELAP Case and Model......Page 528
  A18.2.5 PS Code Tuned Case......Page 529
  A18.2.6Comparison of the Calculated Variation With Time of Some Quantities......Page 531
  A18.3.3 Dynamic Analysis (Explicit and Matrix Treatment)......Page 532
   A18.3.3.1 Two Degrees of Freedom, Excitation Along y Axis: Classical (nonmatrix) Notation......Page 534
   A18.3.3.2 Two Degrees of Freedom, Excitation Along x Axis: Matrix Notation......Page 539
   A18.3.3.3 Static Analysis of Some Elements......Page 540
   A18.3.3.4 Three Degrees of Freedom, Nonstructural Walls Considered, Matrix Notation......Page 543
   A18.3.3.5 Static Analysis of Some Elements......Page 549
  A18.3.4 Modal Analysis Performed by an Integrated Structural Program......Page 552
 References......Page 558
Websites......Page 559
Index......Page 560
Back Cover......Page 565