Separation of Uranium and Fission Products via Reductive Extraction in Fluoride Molten Salt-Bismuth Media

As a core nuclear dry reprocessing technique, reduction extraction is based on liquid/liquid extraction principles and allows for the selective partitioning of target species from a molten salt phase into a liquid metal phase. In this study, the separation behavior of uranium (U) from five representative fission products (Cs, Sr, La, Sm, Nd) was systematically investigated in a 46.5LiF-11.5NaF-42KF (mol%)/Bi molten salt system at 550 °C, with a Bi-Li alloy employed as the reducing agent. The separation factors between U and fission products exceeded 10 4 , enabling efficient U recovery with over 90% with material balance. Separation factors greater than 10 2 were achieved between lanthanides (La, Sm, Nd) and alkali metals (Cs), facilitating group separation and decontamination of fission products, and allowing lanthanides, alkali metals, and alkaline earth metals to be treated as distinct "families" during purification. • For the first time, the 46.5LiF-11.5NaF-42KF (mol%)/Bi two-phase system was employed for the separation of actinides and fission products through the utilization of metal reduction-extraction technology. • The separation factors of fission products relative to uranium and the decontamination factors from uranium were determined in the fluoride molten salt/bismuth two-phase system. • This study analyzed the trends in lanthanide distribution coefficients within the 46.5LiF-11.5NaF-42KF (mol%)/Bi system and investigated the separation factors between actinides and fission products across different molten salt/metal two-phase systems.