X-ray diffraction analysis of the compositional distribution of U1-yCeyO2 solutions in an UO2-U1-yCeyO2

The composite material UO2-U1-yCeyO2 is used to simulate the MOX nuclear fu el U1-yPuyO2. The characterization of these materials by X-ray diffraction shows a cationic composition distribution of fluorite-type (MO2). Different methods are tested to determine the distribution of cationic composition. The Rietveld method suited to this particular case seems to be the best. Pr ofiles are recorded by diffractometer using monochromatic radiation. They a re refined with the Profile program in several peaks whose parameters are c lose to those of the standard reference material (UO2) to obtain the instru ment resolution function.