Nuclear fuel pellets fabricated from gel-derived microspheres

Abstract UO 2 pellets were fabricated from UO 3 gel microspheres by a combined gel-sphere/pellet fabrication process. Desirable sphere properties were established; calcining cycles, pressing conditions, and sintering cycles sufficient to fabricate UO 2 pellets with densities up to 96% TD were determined. The stoichoimetry, activity, density, size and deformability of the spheres had to be within specific ranges for fabrication of high density, crack-free pellets. Preliminary attempts to fabricate ThO 2 and ThO 2 -UO 2 pellets are also described.