PREPARATION BY SPRAY-DRYING OF A FLOWABLE URANIUM DIOXIDE POWDER OBTAINED BY DRY PROCESS CONVERSION OF UF6

摘要

The invention concerns a method for preparing a flowable uranium dioxide UO2 powder, useful for making MOX fuel. Said method comprises the following steps: 1) preparing an aqueous suspension of a UO2 powder obtained by dry process from uranium hexafluoride, said suspension comprising 50 to 80 wt.% of UO2 and at least an additive selected among dispersing agents, organic binders, hydrogen peroxide H2O2 and a U3O8 powder, in an amount such that the viscosity of the suspension does not exceed 250 mPa's; and 2) pulverizing said suspension and drying it in hot gas, at a temperature ranging between 150 and 300 DEG C, to obtain a flowable UO2 powder having an average grain size distribution ranging between 20 and 100 mu m.