A molecular dynamics study of the transport properties of LiF-BeF2-ThF4 molten salt

The LiF-BeF2-ThF4 molten salt is designed as the fuel salt mixture in the Thorium Molten Salt Reactor. In the present work, a polarizable force field was used to describe the interionic interactions and the transport properties (such as self-diffusion, electrical conductivity, and viscosity coefficients) of the molten salt have been studied by molecular dynamics simulations within the temperature ranging from 873 K to 1273 K. It is found that the local structure of ThF4 dissociated significantly, the electrical conductivity of the fuel salt melts increased linearly and the viscosity decreased exponentially with the temperature increasing. It is also found viscosity increased slightly and electrical conductivity decreased significantly with mole fractions of ThF4 increasing.