Determination of oxygen to metal ratio of U-Pu mixed oxides by x-ray diffraction

Abstract

The possibility of measuring the oxygen-metal ratio (O/M) of U-Pu mixed oxides by x-ray diffraction technique has been explored. In single-phase U-Pu mixed oxides, the lattice parameter vs O/M plots for different plutonium concentrations are drawn by interpolation of lattice parameter values between those of UO₂, PuO₂ and Pu₂O₃. These plots are then used for determining the O/Ms of unknown samples against their experimentally measured lattice parameter values. In two-phase mixed oxides, the mole fractions of the two phases are determined from the intensities of their selected diffraction lines. The O/M of the mixed oxide is then given by the mole average of the individual O/Ms of the two phases.