Kinetic Monte Carlo model of defect transport and irradiation effects in La-doped CeO2

A generalized Kinetic Monte Carlo code was developed to study oxygen mobility in UO2 type nuclear fuels, using lanthanum doped CeO2 as a surrogate material. Molecular Statics simulations were performed using interatomic potentials for CeO2 developed by Gotte, Minervini, and Sayle to calculate local configuration-dependent oxygen vacancy migration energies. Kinetic Monte Carlo simulations of oxygen vacancy diffusion were performed at varying lanthanum dopant concentrations using the developed generalized Kinetic Monte Carlo code and the calculated configuration-dependent migration energies. All three interatomic potentials were found to confirm the lanthanum trapping effect. The results of these simulations were compared with experimental data and the Gotte potential was concluded to yield the most realistic diffusivity curve.