Coated nuclear particle and procedure and device for its fabrication

The fissionable fuel, e.g. uranium carbide, is surrounded by one or several protective coatings made of pyrolytic carbon. This carbon holds back fission products. In order to increase the tensile strength of the protective coatings, a pyrolytic metal carbide, e.g. the carbides of silicon, germanium, titanium, tantalum, molybdenum or tungsten is added to the graphite carbon in the form of small particles. With multiple coatings, the core is firstly surrounded by an expansion chamber and a coating of pure pyrolytic carbon whilst the remaining coatings exhibit an outward reduction of carbide content. The single protective coatings are produced by means of a device forming a fluidized bed. (DG)