Patent Number: 
Section: claims

1. Method for the production of spherical fuel or breeder material particles from an oxide consisting of the heavy metals uranium and plutonium, the method comprising the steps of:producing a starting solution of nitrates of the heavy metals,adding a first reagent from the group of urea and/or ammonium carbonate and/or ammonium hydrogen carbonate and/or ammonium cyanate and/or biuret,adding at least one second reagent comprising PVA and THFA in order to adjust the viscosity of the solution, transforming the solution into droplets to form microspherules,solidifying the microspherules, at least in a surface region, in an atmosphere containing ammonia,collecting the microspherules in a solution containing ammonia and subsequent rinsing, drying and thermal treatment, characterized in that:the first reagent of the starting solution is added at room temperature and the solution thus prepared is heated to a temperature T where 80° C.≦T<Ts, where Ts=boiling temperature of the solution and is maintained at said temperature over a period of time t, where 2 h≦t≦8 h, the solution is subsequently cooled to a temperature TA, where TA=room temperature, and finally, the second reagent is added. 2. Method according to claim 1, characterized in that the solution is cooled to room temperature prior to adding the second reagent. 3. Method according to claim 1, characterized in that the first reagent from the group of urea and/or ammonium carbonate and/or ammonium hydrogen carbonate and/or ammonium cyanate and/or biuret is dissolved in solid form in the starting solution. 4. Method according to claim 1, characterized in that the solution is maintained at a temperature T where T≈90° C. over a period of time t. 5. Method according to claim 1, characterized in that the solution is maintained at a temperature T over a period of time t where 3 h≦t≦6 h. 6. Method according to claim 1, characterized in that a 1 to 2.5 molar nitrate solution is used as the starting solution. 7. Method according to claim 1, characterized in that the rinsed microspherules are subjected to subsequent treatment without using alcohol. 8. Method according to claim 1, characterized in that after rinsing of the microspherules water present in the latter is removed by further treatment in a reduced pressure atmosphere. 9. Method according to claim 1, characterized in that the further treatment for removing water is performed at a pressure p where 0.07 MPa≦p≦0.09 MPa. 10. Method according to claim 1, characterized in that the PVA and THFA are added to the solution in a quantitative ratio of about 1:10.