Uranium–plutonium–americium cation interdiffusion in polycrystalline (U,Pu,Am)O2±x mixed oxides

Abstract

Diffusion couples made of dense polycrystalline U1−αPuα−βAmβO2±γ/U1−yPuy−zAmzO2±x oxides were annealed in various thermodynamic conditions (temperature, oxygen partial pressure), and for different durations. The associated actinide redistribution was quantified using Electron Probe Micro-Analysis (EPMA). Average diffusion profiles were obtained from elemental U, Pu, and Am X-ray maps and the resulting interdiffusion coefficients were calculated, then analyzed at the light of our model of point defect chemistry.