Minor actinides transmutation in a molten salt blanket in the fusion-fission hybrid reactor core

Abstract

Abstract Fusion-fission hybrid reactor (FFHR), a representative kind of subcritical nuclear reactor, has the advantage of better safety margin. There are less constraints for the loading of active fuel when burning spent nuclear fuel. A simplified three-dimensional model of tokamak blanket is constructed by the Serpent Monte Carlo Method Code to investigate the MA transmutation characteristics in the Flibe molten salt blanket. Based on the model with one homogenous fuel region, the effect of key design parameters: MA content, plutonium content, Li-6 enrichment in the initial fuel were determined, during which performance characteristics such as MA transmutation amount, keff, tritium breeding ratio (TBR), blanket energy multiplication factor M and conversion ratio were obtained. The results show that it is hard to improve the tritium breeding and meanwhile enhance the MA reducing in one homogenous fuel region. To balance these two functions, a double molten salt fuel regions model with separative MA transmutation zone and tritium breeding zone was proposed.