Fusion–fission hybrid system for nuclear waste transmutation (I): Characterization of the system and burn-up calculations

Abstract

Generally, a very intensive neutron source is needed for the efficient transmutation process of nuclear waste and minor actinides in particular. A plasma based fusion device is naturally a candidate neutron source. In this paper, we analyze a molten salt (flibe) blanket, driven by a plasma based fusion device, dedicated to burn actinides extracted from the LWR spent fuel. Performance parameters such as k scr, burn-up, fluxes and equilibrium conditions were calculated to assess the characteristics of a flibe based transmutation plant. It seems that nearly 1.1metric ton of spent fuel TRU could be burned annually with an output of 3 GW th fission power. Detailed burn-up calculations show that equilibrium conditions of the fuel concentration in the flibe transmutation blanket could be achieved, provided that fission products were removed at least in part and fresh spent fuel TRU was added during burn-up on-line.