Design space and architecture study of Tokamak-based Hybrid Fusion–Fission Power Plants

Fusion–Fission power plants are explored using PROCESS (tokamak systems code) and openmc/Paramak (neutronics simulation code), to determine the trends and achievable design points in a design space of D-T Tokamaks with fissionable material used in the Breeder Blanket. This includes trends effecting plasma configuration and In-Vessel Component design when a plant is optimised for different Breeder Blanket energy multiplication values and a given electrical generating capacity. Due to the additional power produced from fission in a Hybrid Breeder Blanket, lower fusion power can be accepted for a given electrical power output ( < 100 M W t fusion power for a plant at 200 M W e ), which has notable knock-on effects to lower fusion gain ( ∼ 0 . 6 ), and lower power plasma exhaust (estimated Q d i v ′ ′ ≈ 3 . 74 M W / m 2 ). In this design space, Hybrid Breeder Blankets are used to enable energy multiplication (from fission) and increased tritium production, with TBR values greatly exceeding conventional Fusion Power Plant concepts ( T B R > 5 for enriched Lithium, or T B R > 2 with unenriched Lithium). • Fusion–Fission Power Plant Designs explored using PROCESS and openmc/Paramak • Hybrid power plants can be simpler and smaller than comparable fusion power plants • Hybrid Fusion–Fission tokamaks have estimated TBRs of > 2 . 0 • Subcritical Hybrid BB configurations ( k e f f < 0 . 6 ) have TBR estimates of > 2 . 0