Table of contents : Title-page_2021_High-Temperature-Gas-Cooled-Reactors High Temperature Gas-cooled Reactors Copyright_2021_High-Temperature-Gas-Cooled-Reactors Copyright Contents_2021_High-Temperature-Gas-Cooled-Reactors Contents List-of-contributors_2021_High-Temperature-Gas-Cooled-Reactors List of contributors About-the-authors_2021_High-Temperature-Gas-Cooled-Reactors About the authors Preface-of-JSME-Series-in-Thermal-and-Nuclear_2021_High-Temperature-Gas-Cool Preface of JSME Series in Thermal and Nuclear Power Generation Preface-to-Volume-5--High-Temperature-Gas-C_2021_High-Temperature-Gas-Cooled Preface to Volume 5: High-Temperature Gas-Cooled Reactors 1---Overview-of-high-temperature-gas-coole_2021_High-Temperature-Gas-Cooled- 1 Overview of high temperature gas-cooled reactor 1.1 Features of high temperature gas-cooled reactor 1.1.1 Structure and materials 1.1.1.1 Fuel 1.1.1.2 Coolant 1.1.1.3 Moderator 1.1.2 Heat application 1.1.3 Safety 1.1.4 Adaptability to environment 1.2 History of research and development in world 1.3 History of research and development in Japan References 2---Design-of-High-Temperature-Engineering-Te_2021_High-Temperature-Gas-Cool 2 Design of High Temperature Engineering Test Reactor (HTTR) 2.1 Overview of HTTR design features 2.1.1 Introduction 2.1.2 History and future plan of HTTR project 2.1.2.1 Evaluation of reactor performance 2.1.2.2 Safety demonstration test 2.1.2.3 Development of process heat application system 2.1.3 Major design features of HTTR 2.1.3.1 Reactor core 2.1.3.1.1 Core components 2.1.3.1.2 Reactor internals 2.1.3.1.3 Reactivity control system 2.1.3.1.4 Reactor pressure vessel 2.1.3.2 Reactor cooling system 2.1.3.3 Engineered safety systems 2.1.3.3.1 Auxiliary cooling system 2.1.3.3.2 Vessel cooling system 2.1.3.3.3 Containment structure 2.1.3.4 Instrumentation and control system 2.1.3.4.1 Instrumentation system 2.1.3.4.2 Control system 2.1.3.4.3 Safety protection system 2.1.4 R&D programs for HTTR 2.1.4.1 Fuel 2.1.4.2 Graphite 2.1.4.3 Metallic materials 2.1.4.4 Reactor physics 2.1.4.5 Reactor instrumentation 2.1.4.6 Heat transfer and fluid dynamics 2.1.4.6.1 Air ingress process following primary-pipe rupture 2.1.4.6.2 Graphite oxidation in case of air ingress into reactor core 2.1.4.7 Components and structures at high temperature 2.2 Nuclear design 2.2.1 Introduction 2.2.2 Design requirement 2.2.2.1 Excess reactivity 2.2.2.2 Reactor shutdown margin 2.2.2.3 Reactivity addition rate 2.2.2.4 Reactivity coefficient 2.2.2.5 Power distribution 2.2.2.6 Burnup 2.2.3 Analytical method 2.2.3.1 Design codes 2.2.3.2 Validation of design code using very high temperature reactor critical assembly 2.2.4 Evaluation of nuclear characteristics 2.2.4.1 Excess reactivity and nuclear shutdown margin 2.2.4.1.1 Excess reactivity Reactivity losses Excess reactivity 2.2.4.1.2 Burnable poison rods 2.2.4.1.3 Controllable reactivity and shutdown margin Control rod Reserved shutdown system 2.2.4.2 Reactivity addition rate and reactivity coefficient 2.2.4.2.1 Reactivity addition rate 2.2.4.2.2 Reactivity coefficient 2.2.4.3 Power distribution and burnup 2.2.4.3.1 Power distribution Radial power distribution Axial power distribution 2.2.4.3.2 Burnup 2.3 Core thermal-hydraulics 2.3.1 Introduction 2.3.2 Design requirements 2.3.3 Design details 2.3.4 Evaluation results of design 2.3.5 Reevaluation of maximum fuel temperature with operational data 2.3.5.1 Revision of calculation condition 2.3.5.2 Reevaluation result by operational data 2.4 Graphite components 2.4.1 Introduction 2.4.2 In-core graphite and carbon structure in high temperature engineering test reactor 2.4.2.1 Core graphite components 2.4.2.2 Core support graphite components 2.4.3 Concepts of graphite design criteria 2.4.3.1 Component classification 2.4.3.2 Fracture theory 2.4.3.3 Stress classification 2.4.3.4 Stress limit 2.4.3.5 Buckling limit 2.4.3.6 Stress analysis 2.4.3.7 Specified minimum ultimate strength 2.4.3.8 Oxidation effect 2.4.4 Quality control 2.5 Metallic components 2.5.1 Introduction 2.5.2 Development of Hastelloy XR 2.5.3 Identification of failure modes 2.5.4 Developments of design limits and rules 2.5.4.1 Hastelloy XR 2.5.4.1.1 Material characterization 2.5.4.1.2 Tensile property 2.5.4.1.3 Creep property 2.5.4.1.4 Creep–fatigue interaction 2.5.4.1.5 Applicability of the fast breeder reactor code 2.5.4.1.6 Structural mechanics behavior 2.5.4.1.7 Multiaxiality of creep rupture strength and creep–fatigue damage 2.5.4.1.8 Creep buckling 2.5.4.1.9 Creep analysis method 2.5.4.2 2¼ Cr–1Mo steel 2.5.4.3 Austenitic stainless steels SUS321TB and SUS316 2.5.4.4 1Cr–0.5Mo–V steel 2.6 Core components and reactor internals 2.6.1 Introduction 2.6.2 Fuel 2.6.2.1 Design requirement 2.6.2.2 Design details 2.6.2.3 Evaluation 2.6.3 Hexagonal graphite blocks 2.6.3.1 Design requirement 2.6.3.2 Design details 2.6.3.3 Evaluation 2.6.4 Core support structures 2.6.4.1 Design requirement 2.6.4.2 Design details 2.6.4.3 In-service inspection and surveillance test 2.6.4.3.1 In-service inspection using TV camera 2.6.4.3.2 Results of preservice inspection 2.6.4.3.3 Surveillance test 2.6.5 Core support metallic structures 2.6.5.1 Design requirement 2.6.5.2 Design details 2.6.5.3 In-service inspection and surveillance test 2.6.6 Shielding blocks 2.6.6.1 Design requirement 2.6.6.2 Design details 2.7 Seismic design 2.7.1 Introduction 2.7.2 Seismic design 2.7.2.1 Basic guideline of seismic design 2.7.2.2 Seismic classification 2.7.2.3 Basic design earthquake ground motion 2.7.3 Geological composition and seismometry 2.7.3.1 Geological composition 2.7.3.2 Seismometry 2.7.4 Structure of core components 2.7.5 Development of evaluation method 2.7.5.1 Vibration characteristics of core components 2.7.5.2 Validation of SONATINA-2V code 2.7.6 Structural integrity of graphite components 2.7.6.1 Core components 2.7.6.2 Core bottom structure 2.8 Cooling system 2.8.1 Introduction 2.8.2 Primary cooling system 2.8.2.1 Primary pressurized water cooler 2.8.2.2 Intermediate heat exchanger 2.8.2.3 Primary gas circulator 2.8.2.4 Primary concentric hot gas duct 2.8.3 Secondary helium cooling system 2.8.3.1 Secondary pressurized water cooler 2.8.3.2 Secondary gas circulator 2.8.3.3 Secondary helium piping 2.8.4 Pressurized water-cooling system 2.8.4.1 Pressurized water pump 2.8.4.2 Air cooler 2.8.5 Residual heat removal system 2.8.5.1 Auxiliary cooling system 2.8.5.2 Vessel cooling system 2.9 Reactivity control system 2.9.1 Introduction 2.9.2 Control rod system 2.9.2.1 Design requirement 2.9.2.2 Design details 2.9.2.2.1 Control rod 2.9.2.2.2 Control rod drive mechanism 2.9.2.3 High temperature structural design guideline of control rod 2.9.2.4 Design material data on Alloy 800H 2.9.2.5 Results of R&D 2.9.2.5.1 Scram tests of the control rod system under seismic conditions 2.9.2.5.2 Reliability test of control rods in the HENDEL loop 2.9.2.5.3 Verification tests of the control rods 2.9.2.6 Temperature analysis 2.9.2.7 Stress analysis 2.9.3 Reserve shutdown system 2.9.3.1 Design 2.9.3.2 Results of R&D 2.10 Instrumentation and control system 2.10.1 Introduction 2.10.2 Instrumentation system 2.10.2.1 Reactor instrumentation 2.10.2.1.1 Nuclear instrumentation 2.10.2.1.2 Control rods position instrumentation 2.10.2.1.3 Three core differential pressure instrumentation 2.10.2.1.4 Fuel failure detection system 2.10.2.1.5 In-core temperature monitoring system 2.10.3 Process instrumentation 2.10.4 Control system 2.10.4.1 Operational mode selector 2.10.4.2 Reactor power control device 2.10.4.2.1 Reactor power control system 2.10.4.2.2 Reactor outlet coolant temperature control system 2.10.4.3 Plant control device 2.10.4.3.1 Reactor inlet coolant temperature control system 2.10.4.3.2 Intermediate heat exchanger primary coolant flow rate control system 2.10.4.3.3 Primary-pressurized water cooler primary coolant flow rate control system 2.10.4.3.4 Primary helium pressure control system 2.10.4.3.5 Primary–secondary helium differential pressure control system 2.10.4.3.6 Primary-pressurized water differential pressure control system 2.10.4.3.7 Pressurized water temperature control system 2.10.5 Safety protection system 2.10.5.1 Reactor protection system 2.10.5.2 Engineered safety features actuating system 2.10.5.2.1 Signal isolating containment vessel 2.10.5.2.2 Signal starting up auxiliary cooling system 2.10.5.2.3 Signal isolating auxiliary cooling water line 2.10.6 Performance test results 2.10.6.1 Characteristics of the neutron flux monitoring system 2.10.6.2 Primary-pressurized water cooler primary coolant flow rate control system 2.10.6.3 Reactor outlet coolant temperature control system 2.11 Containment structures 2.11.1 Introduction 2.11.2 Reactor containment vessel 2.11.2.1 Design and construction 2.11.2.2 Leakage-rate test 2.11.2.2.1 Partial leakage-rate test 2.11.2.2.2 Whole leakage-rate test 2.11.3 Service area 2.11.3.1 Design 2.11.3.2 Commissioning tests 2.11.4 Emergency air purification system 2.11.4.1 Design 2.11.4.2 Commissioning tests 2.11.4.2.1 Start-up test 2.11.4.2.2 Filter efficiency measurement 2.12 Other systems 2.12.1 Introduction 2.12.2 Auxiliary helium systems 2.12.2.1 Helium purification system 2.12.2.2 Helium sampling system 2.12.2.3 Helium storage and supply system 2.12.3 Fuel system 2.12.3.1 Fuel handling system 2.12.3.2 Fuel storage system 2.13 Safety design 2.13.1 Introduction 2.13.2 Basic safety design philosophy 2.13.3 Safety classification 2.13.4 Fundamental safety functions unique to HTTR 2.13.4.1 Control of reactivity 2.13.4.2 Removal of heat from core 2.13.4.3 Confinement of fission product release 2.13.5 Acceptance criteria 2.13.6 Selection of events 2.13.7 Safety evaluation technologies 2.13.8 New safety criteria References 3---R-amp-D-on-components_2021_High-Temperature-Gas-Cooled-Reactors 3 R&D on components 3.1 Fuel 3.1.1 Introduction 3.1.2 Related research and development for fuel design 3.1.2.1 Limitation for as-fabricated fuel failure fraction 3.1.2.2 Kernel migration 3.1.2.3 Palladium (Pd)–SiC interaction 3.1.2.4 Confirmation up to maximum burnup 3.1.2.5 Temperature limit of HTTR fuel 3.1.3 Fabrication technologies for HTTR fuel 3.1.3.1 Improvement of fuel fabrication process 3.1.3.2 Quality control 3.1.4 Performance of HTTR fuel during long-term high temperature operation 3.2 Core components and reactor internals 3.2.1 Introduction 3.2.2 Tests on core components 3.2.2.1 Test apparatus 3.2.2.2 Thermal hydraulic characteristics 3.2.2.2.1 Pressure drop 3.2.2.2.2 Heat transfer 3.2.2.3 Effect of power unbalance 3.2.3 Tests on reactor internals 3.2.3.1 Test apparatus 3.2.3.2 Sealing performance of helium gas 3.2.3.3 Mixing performance of helium gas 3.2.3.4 Insulation performance of core bottom structure 3.2.3.5 Thermal performance of a coaxial hot gas duct 3.3 Passive cooling system 3.3.1 Introduction 3.3.2 Experiment 3.3.2.1 Experimental apparatus 3.3.2.2 Measurement 3.3.2.3 Experimental conditions 3.3.3 Numerical method 3.3.3.1 Numerical code 3.3.3.2 Numerical model 3.3.3.3 Empirical correlations for natural convective heat transfer 3.3.4 Evaluation of hot spot by natural convection 3.3.5 Evaluation of local hot spot around standpipes 3.4 Intermediate heat exchanger 3.4.1 Introduction 3.4.2 Creep collapse of the tube against external pressure 3.4.2.1 Objective and test procedure 3.4.2.2 Test results 3.4.3 Creep fatigue of tube against thermal stress 3.4.3.1 Objective and test procedure 3.4.3.2 Test results 3.4.4 Seismic behavior of tube bundle 3.4.4.1 Objective and test procedure 3.4.4.2 Test results 3.4.5 Thermal hydraulic behavior of tube bundle 3.4.5.1 Objective and test procedure 3.4.5.2 Test results 3.4.6 In-service inspection technology of tube 3.4.6.1 Objective and test procedure 3.4.6.2 Test results 3.5 Basic feature of air ingress during primary pipe rupture accident 3.5.1 Introduction 3.5.2 Basic feature of air ingress phenomena in a reverse U-shaped channel 3.5.2.1 Experimental apparatus, method, and results 3.5.2.2 Existence of parallel channels in a reactor core 3.5.2.2.1 Isothermal condition 3.5.2.2.2 Different temperature condition 3.5.3 Basic feature of air ingress phenomena in a simulated reactor apparatus 3.5.3.1 Numerical analysis 3.5.3.2 Comparison with experiments References 4---Operation-of-HTTR_2021_High-Temperature-Gas-Cooled-Reactors 4 Operation of HTTR 4.1 Unexpected incidents under construction and operation 4.1.1 Introduction 4.1.2 Temperature rise of primary upper shielding 4.1.2.1 Outline of incident 4.1.2.2 First countermeasures to reduce temperature 4.1.2.2.1 Countermeasure 4.1.2.2.2 Test result after first countermeasure 4.1.2.3 Second countermeasures to reduce temperature 4.1.2.3.1 Countermeasure 4.1.2.3.2 Test result after installation of second countermeasure 4.1.2.4 Prediction and test results at full power 4.1.3 Temperature rise of core support plate 4.1.3.1 Outline of incident 4.1.3.2 Reevaluation of core support plate temperature 4.2 Characteristic test of initial core 4.2.1 Introduction 4.2.2 General description 4.2.2.1 Test condition 4.2.2.2 Nuclear calculations 4.2.3 Critical approach 4.2.4 Excess reactivity and shutdown margin 4.2.4.1 Excess reactivity 4.2.4.2 Shutdown margin 4.2.5 Control rod characteristics 4.2.5.1 Control rod worth on zero power condition 4.2.5.2 Control rod position versus reactor power 4.2.6 Reactivity coefficient 4.2.6.1 Temperature coefficient 4.2.6.2 Power coefficient 4.2.7 Neutron flux and power distribution 4.2.7.1 Neutron flux distribution 4.2.7.2 Power distribution 4.3 Performance test 4.3.1 Introduction 4.3.2 Major test items 4.3.3 Heat balance of reactor cooling system 4.3.4 Heat exchanger performance 4.3.5 Reactor control system performance 4.3.6 Residual heat removal performance at manual reactor scram 4.3.7 Thermal expansion performance of high temperature components 4.3.8 Fuel and fission product behavior 4.4 High temperature operation 4.4.1 Introduction 4.4.2 Main test results of long-term high temperature operation 4.4.2.1 30-Day continuous operation 4.4.2.2 50-Day continuous operation 4.4.3 Validation using high temperature engineering test reactor burnup data 4.4.3.1 Trend of change in control rod position 4.4.3.2 Effectiveness of rod-type burnable poisons 4.4.3.2.1 Design philosophy of burnable poisons 4.4.3.2.2 Validity of effectiveness of rod-type burnable poisons 4.4.3.3 Whole core burnup calculations 4.4.3.3.1 Calculation method 4.4.3.3.2 Validity of whole core burnup calculations 4.5 Safety demonstration test 4.5.1 Introduction 4.5.2 High temperature engineering test reactor control system 4.5.2.1 Reactivity and reactor power control systems 4.5.2.2 Cooling system and plant control device 4.5.3 Safety demonstration test plan 4.5.4 Analysis code and model 4.5.5 Reactivity insertion test 4.5.5.1 Objective and test procedure 4.5.5.2 Test results 4.5.6 Coolant flow reduction test—gas circulators trip test 4.5.6.1 Objective and test procedure 4.5.6.2 Test results 4.5.7 Loss of forced cooling test 4.5.7.1 Objective and test procedure 4.5.7.2 Test results References 5---R-amp-D-on-commercial-high-temperature-ga_2021_High-Temperature-Gas-Cool 5 R&D on commercial high temperature gas-cooled reactor 5.1 System design for power generation 5.1.1 Introduction 5.1.2 HTR50S: HTGR steam cycle power plant 5.1.3 GTHTR300: HTGR gas turbine power plant 5.2 System design for cogeneration 5.2.1 Introduction 5.2.2 Hydrogen cogeneration 5.2.3 Seawater desalination 5.2.4 HTGR renewable hybrid system 5.3 System design for steelmaking 5.3.1 Introduction 5.3.2 Flow diagram of steelmaking systems 5.3.3 CO2 emission 5.3.4 Steelmaking cost 5.4 Safety design for connection of heat application system and high temperature gas-cooled reactor 5.4.1 Introduction 5.4.2 Roadmap for safety standard establishment 5.4.3 Safety requirements 5.4.3.1 Basic safety approach 5.4.3.2 Safety requirements 5.4.3.2.1 Confinement of radionuclides 5.4.3.2.2 Control reactivity 5.4.3.2.3 Heat removal from core 5.4.3.2.4 Loss-of-offsite power 5.4.3.2.5 Coupling to heat application system 5.4.4 Basic concept of safety guides 5.4.4.1 Evaluation items 5.4.4.2 Licensing basis event selection 5.4.4.2.1 Identification of abnormal events and postulated initiating events 5.4.4.2.2 Definition of safety function and mitigation system 5.4.4.2.3 Grouping of abnormal events 5.4.4.2.4 Licensing basis event selection for single failure events 5.4.4.2.5 Identification of accident sequence 5.4.4.2.6 Grouping of accident sequence 5.4.4.2.7 Identification of significant accident sequence 5.4.4.2.8 Licensing basis event selection 5.4.4.3 Acceptance criteria 5.4.4.3.1 Anticipated operational occurrences 5.4.4.3.2 Accidents 5.4.5 HTTR cogeneration demonstration 5.5 Gas turbine technology for power generation 5.5.1 Introduction 5.5.2 Helium gas compressor 5.5.3 Magnetic bearing 5.6 Iodine–sulfur process technology for hydrogen production 5.6.1 Introduction 5.6.2 Bench-scale test 5.6.3 Elemental technologies 5.6.4 Industrial material component test 5.6.5 Hydrogen production test 5.6.6 Improvement of hydrogen production efficiency 5.6.6.1 Electro-electrodialysis cell 5.6.6.2 Hydrogen iodide decomposer with hydrogen separation membrane 5.6.6.3 Analytical estimation of hydrogen production thermal efficiency 5.6.7 Component materials 5.6.7.1 Corrosion resistance 5.6.7.2 Strength 5.7 System integration technology for connection of heat application system and high temperature gas-cooled reactor 5.7.1 Introduction 5.7.2 Control technology 5.7.3 Tritium permeation 5.7.4 Explosion of combustible gas 5.7.5 High temperature isolation valves 5.8 Prevention technology for air ingress during a primary pipe rupture accident 5.8.1 Introduction 5.8.2 Prevention technology of air ingress in a reverse U-shaped channel 5.8.2.1 Experimental apparatus, method, and results 5.8.2.2 Numerical analysis 5.8.2.3 Onset time of natural circulation flow through the apparatus 5.8.2.4 Onset time of natural circulation 5.8.3 Basic feature of air ingress phenomena during a horizontal pipe break accident 5.8.3.1 Introduction 5.8.3.2 Experimental apparatus 5.8.3.3 Experimental method 5.8.3.4 Experimental results 5.9 Advanced fuel technology for high burnup 5.9.1 Introduction 5.9.2 Design of high burnup fuel 5.9.3 Upgrade technologies for high burnup 5.9.3.1 Fuel design 5.9.3.2 Irradiation test 5.9.4 Future study plan 5.10 Advanced fuel for plutonium burner 5.10.1 Introduction 5.10.2 Fuel fabrication process of Clean Burn 5.10.3 Core design 5.10.4 Future study plan 5.11 Advanced fuel technology for reduction of high-level radioactive waste 5.11.1 Introduction 5.11.2 Calculation for repository design 5.11.3 Evaluation of waste package References Index_2021_High-Temperature-Gas-Cooled-Reactors Index