Investigation on the electric properties in molten quaternary systems by MD simulation

Abstract For the pyrochemical reprocessing of spent metallic fuels in molten salt, it is of importance to estimate the enrichment degree of Cs. The molecular dynamics simulation has been carried out on molten quaternary systems (Li, Na, K, Cs)Cl at 625K and (Li, Na, K, Cs)F at 727K for the various compositions in order to investigate the electric properties, i.e., the electric conductivity, self-diffusion coefficient, self-exchange velocity and the relative differences in the internal cation mobilities of Cs in molten LiClNaClKCl eutectic mixtures and in the FLINAK melts. These results allow us to conclude that the electric conductivities, self-diffusion coefficients and self-exchange velocities of Li + , Na + , K + and Cs + with reference to Cl − and F − have almost similar tendencies for each composition. We found it possible to enrich at up to χ Cs = 0.38 in molten LiClNaClKCl eutectic as well as LiCl-KCl system and up to χ Cs = 0.42 in the FLINAK melts as well as in molten FLINA system. In addition, the sequence of the simulated electric conductivity in molten quaternary alkali chloride and fluoride systems was in a fair agreement with that of the current simulated self-exchange velocities and self-diffusion coefficients.