Conceptual design study of fusion fission hybrid reactor

다국어 초록 (Multilingual Abstract)

The idea of fusion-fission hybrid reactor is very attractive solution of waste burning with evolution of fusion energy. In this study concept of clean nuclear power plant is proposed. The main research objective of the clean nuclear power plant is to burn all high level waste, include transuranic (TRU) isotopes and fission products (FP), in a fusion-fission hybrid reactor. Fusion based TRU burner reactor (FTBR) is proposed which based on a low power tokamak (100 MW max) and annular ring shaped TRU core with metal fuel (TRU 60 w/o, Zr 40 w/o) and FP zone. The TRU and FP compositions are taken as the 1000 MWe PWR spent fuel with 10 years decay. Calculations were performed using MCNPX 2.6 with BURN card. The burn cycle is chosen to be 1100 days (3 years). The power level of TRU core is set to be 2000 MW and to maintain the fission power level the fusion power has to vary with the drop of subcritical level. TBR value more than 1.1 represents self-sufficiency of fusion source fuel. TRU and FP depletion was analyzed by calculating the mass burned per full power year (fpy) (kg/fpy), support ratio and percentage of mass burned per fpy. The toxicity analysis of TRU and FP is also performed by calculating the percentage reduction in toxicity of TRU and FP over the burn cycle. In the end TRU transmutation performance was compared with existing hybrid reactor design. This study is concluded with three major designs of hybrid reactor for waste transmutation (Hyb-WT). First design utilize small tokamak geometry (KSTAR) with a pin type core design and observe to give better TRU transmutation but unsatisfactory FP transmutation. In second design larger hypothetical tokamak geometry is implemented which resulted in improved FP transmutation with a little expense of TRU transmutation performance. Design improvement techniques are applied by different coolant material testing study and reflector optimization study. Hyb-WT with multi material option is observed to be the most optimized design. Third Hyb-WT design is the testing of a novel tube-in-duct core design in place of conventional pin type core design. Hyb-WT with TID core design resulted in best TRU and FP transmutation performance and significant reduction in fusion source neutron utility because of its geometrical advantages.
Hybrid test blanket module study is the future extension of Hyb-WT study. Blanket design will be modified and converted to multiple modules instead of single annular core design. A fusion fission hybrid test blanket module (HTBM) is designed which is presumed to be tested in ITER like fusion source environment. In this preliminary design of HTBM the neutron source and loss factors are computed for the detailed neutronic performance analysis. The neutronic analysis of hybrid blanket module is performed for five different TRU fuel types; TRU-Zr, TRU-Mo, TRU-Oxide, TRU-Carbide and TRU-Nitride. TRU in this module is designed to be burned and transmuted from high-level radioactive waste in PWR used fuels. The effect of TiC reflector on transmutation and tritium breeding performance of HTBM is also quantified. MCNPX is used for neutronic computations. Neutron spectrum, capture to fission ratio and waste transmutation ratio of each fuel type are compared to evaluate their waste transmutation performance. Tritium breeding ratio is also compared for two coolant options: Li and LiPb eutectic.

목차 (Table of Contents)

• Chapter 1 Introduction 1
• 1.1 Nuclear Waste Transmutation 1
• 1.1.1 Nuclear Waste Problem 2
• 1.1.2 Research Activities for Transmutation (fast Reactors, Deep Burn Option, ADSR, etc.) 3
• 1.1.3 Basic physics for transmutation (isotopes, spectrum, fission to capture ratio, etc.) 6
• 1.2 Fusion Fission Hybrid Concept 8
• 1.2.1 What is Fusion power? 8
• 1.2.2 What is ITER and TBM? 9
• 1.2.3 What is Hybrid? 11
• Chapter 2 Preliminary Study 13
• 2.1 Previous Studies of hybrid reactor design (China, USA, EU, Japan, etc.) 13
• 2.1.1 Fusion transmutation waste reactor (FTWR) 13
• 2.1.2 Dual cooled waste transmutation hybrid reactor (DWT) 15
• 2.1.3 Subcritical advance burner hybrid reactor (SABR) 17
• 2.2 Summary of previous study 20
• 2.2.1 Blanket neutronics parameters 22
• 2.2.2 Performance evaluation 25
• Chapter 3 Conceptual Design of Hybrid Reactor for Waste Transmutation 30
• 3.1 Concept and Purpose 30
• 3.2 Fusion Neutron Source – Tokamak 31
• 3.3 Multi-Purpose Blanket 32
• 3.3.1 Tritium Breeding 32
• 3.3.2 Energy Multiplication 33
• 3.3.3 Transmutation of TRU and FP 33
• 3.3.4 Radiation Shielding and Cooling 34
• 3.3.5 Geometrical Design and Material compositions 34
• 3.4 Transmutation performance analysis 37
• 3.4.1 Performance Parameters 37
• 3.4.2 Sub-criticality of TRU Core and Fusion Power level 38
• 3.4.3 TRU and FP mass transmutation analysis 40
• 3.4.4 TRU and FP toxicity analysis 44
• 3.4.5 Thermal Parameters of Core 48
• 3.5 Hypothetical Tokamak Design for Hyb-WT 49
• Chapter 4 Feasibility Assessment of Computational Tools 53
• 4.1 Computational Tools 53
• 4.1.1 MONTEBURNS 53
• 4.1.2 MCNPX 55
• 4.1.3 MCNPX BURN card analysis 56
• 4.1.4 Comparison of MONTEBURNS and MCNPX 58
• 4.2 Cross section libraries 61
• 4.2.1 ENDF-B/VII 61
• 4.2.2 Comparison to JEFF and JENDL 63
• 4.3 Homogenization Effects 66
• 4.3.1 Core design 67
• 4.3.2 Performance analysis 68
• Chapter 5 Special Design Features for Hyb-WT 72
• 5.1 Modification to Tube-In-Duct Fuel Channel in Fission Core 72
• 5.1.1 Tube In Duct core design 72
• 5.1.2 Performance comparison of Hyb-WT with TID and pin type core 74
• 5.2 Choice of Reflector Material 80
• 5.2.1 Reflector materials considered for testing 80
• 5.2.2 Comparison of Hyb-WT performance parameters 81
• 5.3 Effect of Reflector Zone 84
• 5.3.1 Neutronic Analysis 84
• 5.3.2 TRU and FP Transmutation Analysis 86
• 5.4 Choice of Coolant 88
• 5.4.1 FLIBE coolant 89
• 5.4.2 LiPb eutectic coolant 90
• 5.4.3 Li coolant 90
• 5.4.4 Hyb-WT Design based coolant choice 91
• 5.4.5 Comparison of Hyb-WT performance parameters 92
• 5.5 Design Summary of Hyb-WT 95
• 5.6 Preliminary Hybrid Test Blanket Module 98
• 5.6.1 Fuel materials commonly employed in fission reactors 99
• 5.6.2 TRU transmutation performance analysis for different fuel materials 100
• Chapter 6 Conclusions and Future Recommendations 105
• Chapter 7 References 109