Influences of 7 Li enrichment on Th–U fuel breeding for an Improved Molten Salt Fast Reactor (IMSFR)

The molten salt fast reactor (MSFR) shows great promise with high breeding ratio (BR), large negative temperature coefficient of reactivity, high thermal–electric conversion efficiency, inherent safety, and online reprocessing. Based on an improved MSFR optimized by adding axial fertile salt and a graphite reflector, the influences of ^7Li enrichment on Th–U breeding are investigated, aiming to provide a feasible selection for the molten salt with high fissile breeding and a relatively low technology requirement for ^7Li concentration. With the self-developed molten salt reactor reprocessing sequence based on SCALE6.1, the burn-up calculations with online reprocessing are carried out. Parameters are explored including BR, ^233U production, double time (DT), spectrum, ^6Li inventory, neutron absorption, and the tritium production. The results show that the ^7Li enrichment of 99.95