The structure of molten F⁷LiNaK with CeF₃ using neutron diffraction and EPSR

The local structure of eutectic F⁷LiNaK (Li-7 enriched, 0.465 ⁷LiF-0.115NaF-0.42KF) which has potential cooling applications in molten salt reactors (MSR), is studied using neutron diffraction. The nearest neighbor distances and the coordination numbers of constituent ion pairs are derived from the total neutron scattering data using empirical potential structure refinement (EPSR) software. A combination of Lennard-Jones and Coulomb 12-6-1 potential (without empirical adjustments) is used that captures the local structure of F⁷LiNaK from simulated 3D atomic configurations. The effect of adding the actinide surrogate cerium on the F⁷LiNaK local structure is also studied using neutron diffraction and EPSR with the same potential model. By comparing the results with previous experimental and computational findings, the effectiveness of EPSR in analyzing complex molten salt structures is demonstrated. The use of EPSR with simple potential models to describe the physical structures of molten salts can offer a computationally efficient approach, reducing both cost and time.