High capacity immobilization of U3O8 in Gd2Zr2O7 ceramics via appropriate occupation designs

An optimal occupation of U4+ and U6+ in Gd2Zr2O7 is necessary for a really high immobilization capacity of U3O8 in Gd2Zr2O7 based waste forms. Based on four kinds of occupation methods, a series of U3O8-doped Gd2Zr2O7 compositions have been synthesized. The effects of U3O8 content on the phase and microstructure evolution of Gd2Zr2O7 pyrochlore waste forms were investigated. Detailed XRD analysis show that the four sets of samples exhibit a single defect fluorite structure within the range of 0