Preparation of ceramic grade UO2 powder by atomization from uranyl nitrate solutions

The thermal denitration of a nitrate solution by direct conversion to a ceramic grade uranium dioxide powder, in a furnace that combines atomization nozzle and gas stirred bed, is an attractive method because no liquid waste products are formed and it has relative simplicity. The UO2 powder characteristics, such as size, shape, specific surface area and sinterability as a function of procedural variables were determined. This technique has been developed in the pelleting pilot plant of the IPEN/CNEN-SP and it appears to be practical and economically feasible for wet recovery of rejected UO2 powders and pellets form production process, with the recovered powder being directly mixed to the powder from the AUC reduction process. (orig.)