Abstract: A method and an arrangement for producing spherical fuel cores and/or breeder material cores by dripping a pouring solution containing uranyl nitrate and a solution containing at least one auxiliary agent into an ammoniacal precipitation bath to form microspheres, aging, washing, drying, and thermally treating the microspheres.

Abstract: A method for the production of spherical combustible or fertile material particles from an oxide of the group of the heavy metals uranium, plutonium, or mixtures thereof. For this purpose, the process steps of producing a base solution of the nitrates of the heavy metal(s), adding at least one first reagent in order to adjust the viscosity of the solution, dropping the solution to form microspheres, at least superficially solidifying the microspheres in an atmosphere containing ammonia, collecting the microspheres in a solution containing ammonia, and subsequent washing, drying and thermal treatment are carried out, where at least one of urea, ammonium carbonate, ammonium hydrogen carbonate, ammonium cyanate, and biuret are added to the base solution before adding the first reagent. The solution thus prepared is heated to a temperature T where 80° C.?T<Ts and where Ts=boiling temperature of the solution, and is maintained at the temperature over a time period t where 2 h?t?8 h.