Modeling oxygen self-diffusion in UO2 under pressure

Access to values for oxygen self-diffusion over a range of temperatures and pressures in UO2 is important to nuclear fuel applications. Here, elastic and expansivity data are used in the framework of a thermodynamic model, the cB Omega model, to derive the oxygen self-diffusion coefficient in UO2 over a range of pressures (0-10 GPa) and temperatures (300-1900 K). The significant reduction in oxygen self-diffusion as a function of increasing hydrostatic pressure, and the associated increase in activation energy, is identified. (C) 2015 Elsevier B.V. All rights reserved.