110 fm 1 nm10 9 m 1 fm10

原子の構造 1~10 fm 1 nm=10 -9 m 1 fm=10 -15 m 0. 1~1 nm

核反応(nuclear reaction) a b X Y a：入射粒子（incident particle） X：標的核（target nucleus） Y：残留核（residual nucleus） b：放出粒子（emitted particle） 注：aが無いときは崩壊(decay)と呼んでいる

CP-1

-1010 years -4. 5× 109 -3× 109 Big Bang Earth Plant -5× 108 -4× 106 -6. 5× 107 Primates -1. 5× 106 Australopithecus -5× 104 Earth’s Death -2× 108 Mammal -5× 106 0 Homo erectus -5× 104 Homo sapiens sapience -104 Neorithic

Human Energy Consumption Constraint Technology, Living Constraint Environment Chemical Energy Only -4× 106 years Discovery of Fire -104 years 0 New Stone Age Natural Energy Chemical Energy Nuclear Energy

100 Fission Uraniu m Thorium Fusion Lithium Deuteriu m 102 103 104 105 109 Q 101 0 1 Q≒ 1. 056× 1021 J Annual Energy Consumption=0. 3 Q Earth’s Life Fossile Fuel Oil Coa l Nat. Gas 101 Estimated Resources 106 107 108 Oil Sand et al. Thermal Breeder Reactor In the Sea 10 102 103 104 105 106 107 Available Years 108 109 years 1010

B. R. ≒ 1 B. R. ＞ 1 EQUILIBRIUM TRANSIENT

高温ガス炉 PBMR 114 MWe/Md

高温ガス炉 PBMR HP turbo Unit Reactor LP Turbo Unit Power Turbine Generator Core Conditioning System Start-UP Blower System Intercooler Pre-cooler Recuperator

244 Am 10 h 240 Pu 243 Pu 6564 y 239 U 239 Np 23 m 7× 10 y 4 238 U Np 243 2. 1 d 242 m 241 Pu 2. 4× 10 y 238 Pu 9 88 y 237 U 237 Np 6. 8 d Am 5 3. 7× 10 y Pu 4. 5× 10 y Am 5 h 3 Pu 2. 4 d 243 14 y Am 天然に多量に存在 する核種 432 y 核分裂性核種 6 2. 1× 10 y 236 U 236 Np 236 22 h Pu 核分裂性核種とし て重要な存在 7 2. 4× 10 y 2. 9 y 235 U (n, γ)反応 8 α崩壊 7. 0× 10 y ウラン系燃料 β崩壊 (n, 2 n)反応

236 U 7 2. 4× 10 y 235 U 8 7. 0× 10 y 234 Th 天然に多量に存在 Pa する核種 5 233 Th 233 Pa 22 m 233 U 27 d 5 核分裂性核種とし 1. 6× 10 y 232 て重要な存在 232 Pa Th 10 1. 4× 10 y Th α崩壊 β崩壊 231 Pa 1. 06 d 4 3. 3× 10 y 230 Th トリウム系燃料 232 1. 3 d 69 y 231 (n, 2 n)反応 U 1. 2 m 2. 5× 10 y 核分裂性核種 (n, γ)反応 234 m 24 d U

Generation IV Initiative

Nuclide densities in the equilibrium state: ni where = neutron flux = micro. total transmutation cross-section of j’th nuclide = micro. transmutation cross-section of k’th to j’th nuclide = decay constant of k’th to j’th nuclide = discharge constant of j’th nuclide = supply rate of j’th nuclide from external source

Nuclide Densities in Equilibrium State Mn = s M: transmutation matrix n: nuclide densities of HMs and FPs s: fuel supply rates

Uranium cycle Thorium cycle Thermal reactor Fast reactor

Neutron Balance

Neutron Balance Where f and a are nuclide importance given by

h-values of Natural Uranium for Different Neutron Spectrum

h-values of Thorium for Different Neutron Spectrum