Long-life small modular Sodium-cooled Fast Reactor Core design with breed-and-burn strategy

Abstract

In this paper, a Small Modular Sodium-cooled Fast Reactor (SMSFR) core concept, optimized in terms of core lifetime and reactivity swing, is presented through the analysis of various breed-and-burn (B&B) strategies, and through neutronic analyses in terms of active core movements, isotopic mass balance, and kinetics parameters. The new core aims at a power level of 260MWth, with a core lifetime of 30 years without refueling, and a small reactivity swing by applying the B&B strategy. Starting from five initial candidate cores with various breed-and-burn strategies, an optimum core was selected from a combination of the two candidates which shows a proper breeding behavior with an optimized uranium enrichment in the low enriched uranium (LEU) region and the size of the blanket region. All the SMSFR core models were analyzed by the Argonne National Laboratory (ANL) fast reactor analysis code suite. The depletion calculation analysis of the new core gives various reactor design parameters, such as a core multiplication factor behavior, breeding ratio, heavy metal mass change, power distribution, and a summary of neutron balance. Also, the perturbation analysis provides the reactor kinetics parameters and reactivity feedback coefficients for the inherent safety analysis of the core.