Abstract
In the present study, we investigated the thermal transport in two important molten salt mixtures, i.e., LiF-ThF4 and KCl-UCl3. The Born-Mayer-Huggins short-ranged potential was used with LAMMPS and the reverse nonequilibrium molecular dynamics (RNEMD) algorithm to generate a heat flux across the simulation structure. Thermal conductivity was determined by Fourier’s law from the imposed heat flux and induced temperature gradient. The results show that the thermal transport in these molten salt mixtures is readily diffusive, and their thermal conductivities do not depend on temperatures. LiF-ThF4 mixture shows a clear dependency on the density; the thermal conductivity decreases with an increase in its density that results from the ThF4 mole fraction increase. An increase in density is likely to impact phonon transport negatively because of increased viscosity. Unlike LiF-ThF4, the thermal conductivity of KCl-UCl3 increases with an increase in its density that results from UCl3 mole fraction increase. The authors believe that the results obtained in this research will provide a microscopic understanding of the thermal transport properties of molten salt reactor fuels and contribute to the development of more advanced molten salt reactors.
