Abstract: A treating process is provided for the separation of coated nuclear fuel particles from a graphitic matrix in which the nuclear fuel particles are embedded, and an installation provides for the conditioning of graphitic fuel elements of high-temperature nuclear reactors. The graphite which encompasses the nuclear fuel particles is conducted away through the action of a brush which isolates the nuclear fuel particles together with their coatings or the nuclear particles themselves. The nuclear fuel particles which are contained in the brushed product are then separated from the comminuted graphite.

Abstract: Component bodies of silicon carbide base material, at least in their surface layers, are welded together without the provision of a binder at finely polished joining surfaces by virtue of the fact that at least one of the joint surfaces is of a silicon carbide material containing an excess of silicon (SiSiC). The component bodies are kept closely fitted together especially by an additional pressing force of at least 0.1 kg/cm.sup.2 during a heating stage at atmospheric or lower pressure at a temperature in the range from 1500.degree. C. to 1800.degree. C. for 15 to 100 minutes in an inert atmosphere, the excess of silicon at the boundary making it possible for silicon carbide crystal growth to take place across the boundary.