A process has been developed for the production of dense fissile fuel kernels for the high-temperature reactor. A method is used whereby a concentrated uranyl nitrate solution with urea and ammonium nitrate as additives is dispersed horizontally into droplets that are hardened by external gelation. The process is very simple and consists of only a few steps, since no organic thickener is necessary and only aqueous solutions are used. The equipment, which has been developed for the special needs of the refabrication of 233U, has a throughput of ∼0.7 kgU/h.