Defects and oxygen diffusion in PuO2−x

A thermochemical model of defects formation is proposed. Using this model, defect species concentrations are determined. The model allows for the calculation of the non-stoichiometry of PuO2−x, as functions of temperature and oxygen pressure. A model of oxygen diffusion is proposed and the oxygen self and chemical diffusivities are calculated for temperatures in the (900–1400 °C) range and partial pressure of oxygen PO2 ∈ (1–10−25 atm). This work shows that, given appropriate parameters, the model is able to describe the non-stoichiometry and oxygen diffusivity in a reasonable way.