Engineering design of a fission converter-based epithermal beam for neutron capture therapy

3 ACKNOWLEDGMENTS 5 TABLE OF CONTENTS 7 LIST OF FIGURES 10 LIST OF TABLES 15 CHAPTER ONE 17 INTRODUCTION 1.0 OBJECTIVE 17 2.0 BORON NEUTRON CAPTURE THERAPY 18 3.0 CURRENT EPITHERMAL NEUTRON BEAM FACILITY FOR BNCT 20 4.0 DESIGN GOALS 25 5.0 DESCRIPTION OF THE MITR-II AND THERMAL COLUMN AREA 26 5.1 MITR-II reactor 27 5.2 MITR-II thermal column area 35 6.0 REFERENCES 45 CHAPTER TWO 49 FISSION CONVERTER BEAM OVERALL FACILITY DESIGN 1.0 OVERALL DESIGN OF FISSION CONVERTER BEAM FACILITY 49 2.0 SUMMARY OF NEUTRONIC STUDY 52 3.0 FISSION CONVERTER TANK DESIGN 59 3.1 Thermal Column Cavity 59 3.2 New Cadmium Shutter and Frame 63 3.3 New Shield Blocks in the Thermal Column Cavity 69 3.3.1 Permanent Lower Shield Blocks 69 3.3.2 Removable Lower Shield Block 71 3.3.3 Removable Upper Shield Block 71 3.4 Dose Calculation in the Thermal Column Cavity 74 3.5 Equipment in the Thermal Column Cavity 82 3.6 Fission Converter Fuel Lower Grid Structure 84 3.7 Fission Converter Tank 90 3.8 Fission Converter Tank Lid 95 3.9 Structural Analysis of Fission Converter Tank Plates 97 3.9.1 Numerical Analysis 97 3.9.2 Analytical Analysis 120 4.0 FISSION CONVERTER FUEL HANDLING 123 4.1 Fuel Element Self-Protection 124 4.2 Fuel Loading and Unloading 125 4.2.1 Fuel Transfer Cask 127 4.2.2 Fuel Transfer Cask Support 130 4.2.3 Fuel Loading and Unloading Procedures 130 5.0 REFERENCES 134 CHAPTER THREE 135 THERMAL HYDRALIC ANALYSIS 1.0 INTRODUCTION 135 2.0 THERMAL HYDRAULICS DESIGN LIMITS 139 3.0 NATURAL CONVECTION DESIGN (DESIGN I) 140 3.1 Description of Cooling System 140 3.2 Thermal Hydraulic Analysis of Natural Convection Design (Design I) 143 3.3 Fission Converter Input Model for TEMPEST 145 3.4 Results from the TEMPEST 153 3.5 Validity of the Calculated Results 164 4.0 FORCED CONVECTION WITH BYPASS CHANNEL (DESIGN II) 167 4.1 Description of Forced Convection with Bypass Channel Design 167 4.2 Optimization of Bypass Channel Width 170 4.2.1 Instant at Which the Primary Forced Flow is Lost 175 4.2.2 Hydro Dynamic Steady State Condition 179 5.0 SIMPLE FORCED CONVECTION DESIGN (DESIGN II) 183 6.0 SUMMARY OF STEADY STATE RESULTS 184 7.0 ANTICIPATED ACCIDENTS ANALYSIS 187 7.1 Loss of Flow with Cadmium Shutter Closure 187 7.1.1 Pump Failure 189 7.1.1.1 Design I 189 7.1.1.2 Design II 201 7.1.1.3 Design III 205 7.1.2 Outlet Pipe Break 208 7.1.3 Inlet Pipe Break 208 7.2 Loss of Flow with Cadmium Shutter Failure 210 7.3 Loss of Flow and Converter Power at Full Power 212 7.4 Description of the Program Used for LOF Analysis 212 7.5 Loss of Coolant Accident (Bounding Analysis) 219 7.5.1 Initial Heat Up of Fuel Plate 223 7.5.2 Calculation of Temperature History After Initial Heat Up 225 7.5.3 Alternative Simple Calculation Approach 229 7.5.4 Effect of Emissivity Value Uncertainties 233 7.5.5 Conclusions 234 8.0 CONCLUSION 236 9.0 REFERENCES 237 SHUTTERS AND MEDICAL ROOM DESIGN STUDIES 1.0 INTRODUCTION 239 2.0 DESIGN STUDIES OF SHUTTERS 240 2.1 Optimization of Shutters 245 2.1.1 Geometric Configuration of the Shutters 246 2.1.1.1 Classic Slab Shielded Door 246 2.1.1.2 Rotating Collimator 249 2.1.1.3 Water Shutter Plus Fast Shutter 249 2.1.2 Material Selection 252 2.2 Analytical Calculation 254 3.0 COMPUTATIONAL METHOD 260 3.1 Reactor Model 265 3.2 Fission Converter Model 269 3.3 Variance Reduction 274 3.4 MCNP Calculations for Shutter Studies 281 4.0 MECHANICAL DESIGN OF WATER SHUTTER 297 5.0 MECHANICAL DESIGN OF FAST SHUTTER 303 6.0 MEDICAL ROOM SHIELDING DESIGN 307 7.0 REFERENCES 318 APPENDIX 319 MATHCAD PROGRAMS USED FOR THERMAL-HYDRAULIC ANALYSIS A3.1 ANALYTICAL CALCULATION OF NATURAL CONVECTION FLOW RATE AND THE TEMPERATURE DIFFERENCE ACROSS THE FUEL ELEMENT IN THE FISSION CONVERTER 319 A3.2 FORCED CONVECTION WITH BYPASS CHANNEL ANALYSIS 324 A3.3 CALCULATION OF COOLANT EXIT TEMPERATURE AS A FUNCTION OF INLET PRIMARY FLOW RATE FOR DIFFERENT BYPASS CHANNEL WIDTHS 328 A3.4 CALCULATION OF NATURAL CONVECTION FLOW RATE FOR THE FORCED CONVECTION WITH BYPASS CHANNEL DESIGN DURING LOSS OF FLOW ACCIDENT 332 A3.5 CALCULATION OF NATURAL CONVECTION FLOW RATE FOR THE FORCED CONVECTION WITH BYPASS CHANNEL DESIGN DURING LOSS OF FLOW ACCIDENT 336 239 CHAPTER FOUR