Recent Progress on Removal of Sr/Cs from Molten Salt in Dry Reprocessing

Dry reprocessing technology has advantages of irradiation resistance, proliferation resistance and simplified waste treatment, thereby rendering it the preferred technology for the reprocessing of spent fuel of advanced fast reactors.Molten salt electrolytic refining serves as the core technology of dry reprocessing, primarily capitalizing on the difference in redox potential between actinides such as uranium and plutonium and other fissionable elements within a molten salt system.This technology facilitates the separation and recovery of actinides.During the electrolytic refining process, lanthanide elements and fission elements, such as Sr and Cs, tend to accumulate within the molten salt, which will change the physicochemical properties of the molten salt, thus seriously affecting the efficiency of electrolytic refining.In addition, fission products such as 90 Sr and 137 Cs are water-soluble and long-lived nuclides, posing significant environmental hazards if inadequately managed.Therefore, effective purification of fission elements such as Sr and Cs from molten salt is imperative, not only to improve the efficiency of dry reprocessing of molten salt electrolysis, but also as a crucial strategy to reduce the discharge of radioactive waste.This paper summarizes the current research status of Sr and Cs removal methods in molten salts, comparatively analyzes the separation principles and separation effects of different methods, such as electrolysis, crystallization, decompression distillation, precipitation, and ion exchange.