Method of making spherical nuclear fuels

Purpose: To improve the productivity of making spherical uranium fuel particles through gel precipitation. Method: Uranyl nitrate is used as the uranium compound and a viscosity improver and an adjusting agent are applied to the aqueous solution of uranyl nitrate. A mixture of hydroxypropylcellulose and hydroxypropylmethylcellulose in 5 : 95 - 95 : 5 ratio is used as the viscosity improver. Further, polyethylene glycol or tetrahydrofurfryl alcohol is used is as the adjusting agent. Spherical particles are formed from the uranyl nitrate solution incorporated with the viscosity improver and the adjusting agent through gel precipitation method. Then, the particles are dried, sintered and then sintered under reduction to form spherical nuclear uranium nuclear fuel particles. By the addition of the viscosity improver and the adjusting agent, the dropping state of the solution can be improved and grains with excellent sphericalness can be obtained. (Moriyama, K.)