Process for controlling end-point density of sintered uranium dioxide nuclear fuel bodies and product

A process is described for controlling the end-point density of a sintered uranium dioxide nuclear fuel body and the resulting product. Uranium dioxide powder having a size ranging up to 10 microns is mixed with a precursor to uranium dioxide, such as ammonium diuranate, having an average agglomerated particle size ranging from about 20 microns to 1 millimeter and the mixture is formed into a pressed compact or green body. The precursor to uranium dioxide has a density lower than that of the uranium dioxide powder and is used in an amount which results in discrete low density regions in the green body which range from about 5 percent to 25 percent by volume of the green body. The green body is sintered to decompose the precursor and produce a sintered body having discrete low density porous regions which reduce the end-point density of the sintered body by at least 2 percent. The sintered body has an end-point density ranging from 85 percent to 95 percent of the theoretical. (U.S.)