Chromia doped UO2 fuel: Investigation of the lattice parameter

Chromia doped UO2 fuel was characterised by electron microprobe analysis (EPMA) and X-ray powder diffraction (XRD). The macroscopic distribution of chromium across the fuel pellet (homogeneity, surface evaporation effect) and its microscopic state (extent of atomic scale dissolution in the UO2 matrix versus appearance as precipitates) was investigated. Furthermore, the lattice parameter obtained by X-ray powder diffraction was calculated by the unit cell refinement method and compared to empirical interatomic potential calculations (energy minimisation techniques). Finally, the theoretical density of the chromia doped fuel was calculated.