Behaviors of Ce, Pr, and Nd in liquid cesium by ab initio molecular dynamics simulations

The fuel cladding chemical interaction (FCCI) phenomenon is potentially the main factor restricting the application of metallic fuels in liquid sodium cooled fast reactors. The understanding of the lanthanide (Ln) transport behaviors in liquid Cs filled pores in U-Zr fuel is essential for understanding FCCIs. By using ab initio molecular dynamics, fundamental properties of the metallic system Cs-Ln, such as density of states and coordination number, have been studied. Then, the Ln diffusivities in liquid cesium and the solution viscosity were calculated. For validating the model, the viscosity of the pure liquid Cs which has been well measured is also calculated at three temperatures, which indicates the present model has a high accuracy in calculation of viscosity and self-diffusivity of Cs in liquid Cs.