Abstract: A process for recovering uranium from components contaminated with uranium oxide includes providing a cleaning apparatus with a cleaning solution for dissolving the uranium oxide of the components, carrying out a cleaning process by introducing a batch of components into the cleaning apparatus, and carrying out a measurement for determining the uranium content of the components. The cleaning and the measuring are repeated if a limit value for the uranium content is exceeded. The components are discharged from the process if the uranium content falls below a limit value. The cleaning is carried out on a plurality of successive batches of components until a control measurement indicates an unsatisfactory cleaning action of the cleaning solution. The uranium oxide dissolved in the cleaning solution is recovered after indication of the unsatisfactory cleaning action.

Abstract: A process for recovering uranium from components contaminated with uranium oxide includes providing a cleaning apparatus with a cleaning solution for dissolving the uranium oxide of the components, carrying out a cleaning process by introducing a batch of components into the cleaning apparatus, and carrying out a measurement for determining the uranium content of the components. The cleaning and the measuring are repeated if a limit value for the uranium content is exceeded. The components are discharged from the process if the uranium content falls below a limit value. The cleaning is carried out on a plurality of successive batches of components until a control measurement indicates an unsatisfactory cleaning action of the cleaning solution. The uranium oxide dissolved in the cleaning solution is recovered after indication of the unsatisfactory cleaning action.

Abstract: A control rod for a pressurized-water nuclear reactor contains an absorber rod which is arranged in a casing tube. At least in a lower section, the absorber rod is provided with at least one recess which takes up at most a portion of the circumferential surface of this section. This reduces problems associated with an expansion in the volume of the absorber rod.

Abstract: A control rod for a pressurized-water nuclear reactor contains an absorber rod which is arranged in a casing tube. At least in a lower section, the absorber rod is provided with at least one recess which takes up at most a portion of the circumferential surface of this section. This reduces problems associated with an expansion in the volume of the absorber rod.

Abstract: A nuclear reactor fuel assembly with a high burnup is provided. In order to increase the burnup potential of fuel assemblies, pellets with an impermissibly high level of enrichment are produced on production lines, which are constructed for processing large quantities of normally enriched fuel. The impermissible level of enrichment is compensated for by the fact that, as early as in a powder mixer at an entry to the production line, so much absorber material is mixed with the fuel that the reactivity of the poisoned mixture does not exceed the reactivity of an unpoisoned fuel mixture with a normal level of enrichment. Corresponding fuel assemblies then contain relatively large quantities of these poisoned pellets (or only such poisioned pellets), which can be produced in large numbers (and therefore economically) by using conventional plants.

Abstract: A uranium-containing nuclear-fuel sintered pellet containing UO.sub.2, (U, Pu)O.sub.2, (U, Th)O.sub.2, (U, RE)O.sub.2, (U, Pu, Th)O.sub.2, (U, Pu, RE)O.sub.2, (U, Th, RE)O.sub.2 or (U, Pu, Th, RE)O.sub.2, wherein RE=rare earth, has a sintered-pellet surface layer being formed of at least 80% by volume of a chemical boron compound UB.sub.x or (U, . . . )B.sub.x, wherein x=2;4;6 or 12, and a remainder of the sintered pellet containing at most 5% by volume of the chemical boron compound. A nuclear-reactor fuel assembly has a fuel rod containing such a uranium-containing nuclear-fuel sintered pellet in a cladding tube with the boron as a burnable absorber for thermal neutrons. The surface layer having the chemical boron compound is obtained by treating the nuclear-fuel sintered pellet with boron or a boron-containing chemical compound at an appropriately high treatment temperature.