Influence of reprocessing efficiency on fuel cycle performances for molten salt reactor

Abstract

BackgroundChemical post-processing is one of the important characteristics of molten salt reactors (MSR). The post-processing efficiency will affect the neutron performance of core fuel cycle. Therefore, it is necessary to explore the influence of different aftertreatment schemes on fuel cycle performance.PurposeThis study aims to evaluate the neutron characteristics of different post-processing schemes for core fuel cycle of MSR.MethodsBased on the 65 MW MSR core structure with bath fuel post-processing mode, the neutron properties of excess reactivity, low enriched uranium (LEU) feeding inventory, heavy metal mole fraction, and burnup of different reprocessing schemes were analyzed by using self-developed MSR post-processing coupling program.ResultsThe results show that the separation efficiency of fission products has an obvious impact on the neutron performances. When the separation efficiency of fission products is increased from 0 to 100% during 40-a operation of this MSR, the LEU feeding inventory can be saved by about 520 kg whilst the heavy metal mole fraction is reduced by about 9.6% and the burnup is increased by about 10%. Compared with fission products, the removal of transuranium (TRU) has less influence on neutron characteristics due to their fission ability and low inventory.ConclusionsTheoretical simulation calculation in this study provides a reference for the choice of the nuclide removal and its efficiency for chemical post-processing.

Keywords

• chemical post-processing
• msr
• separation efficiency
• fuel cycle