A study on the homogenization of simfuel U3O8 powder for spent fuels

There is a difference of burnup between middle position and bottom or up at the same spent fuel rod. The difference effects a produced amount of fissile material, TRU and fission products on the spent nuclear fuel. It may cause not only great errors for accounting of nuclear material but also unstable condition of parameter in the subsequent process. In this study, mixing or milling process for several kinds of oxidized powder is investigate to enhance the homogeneity of mixed powder. - two kinds of UO2 powder having a different size and U-235 content, that is ex-AUC NU(∼20um) and ex-ADU(∼1um) are used to investigate an average and standard deviation of U-235 content according to the mixing time and milling time under a condition of three mixing ratio(NU : DU = 2 : 8, 3 : 7, 4 : 6). - two kinds of CeO2-beared simfuel oxidized powder, that is SS-1(CeO2 : 1.62wt%, 350 .deg. C, 10-hr oxidation) and SS-4(CeO2 : 6.25wt%, 700 .deg. C, 1-hr oxidation), are used to study an average and standard deviation of Ce content according to the mixing time and milling time under a condition of two mixing ratio(SS-1 : SS-4 = 1 : 2, 2 : 1)