[en] Highly active spent cladding sections (hulls) have to be embedded for final disposal in a long-term resistant matrix. Therefore, an extremely corrosion-, leach- and radiation-resistant and mechanically and thermally stable material must be made available. The aim of this research and development program was to find a material suitable for the embedding of spent fuel hulls and for the final disposal in deep salt formations. Three matrix materials -graphite/sulfur, graphite/nickel sulfide, and aluminium- and the corresponding embedding processes were investigated and developed at NUKEM. The physical properties as well as the corrosion and leaching rates (in saturated brine at 90⁰C) of the three materials have been determined. Taking the fabrication process into account the graphite/sulfur matrix seems to be the most promising material. With regard to the physical properties aluminium seems to be of great promise, but the corrosion resistance of pure aluminium does not meet the requirements asked for waste containing bodies in deep salt formations. With respect to this the two graphite based materials are much more suitable for the final disposal of radioactive waste. Compared to the other embedding materials and processes the encapsulation in graphite/sulfur matrix seems to be the most promising method. Advantages are: - low process temperature (<=150⁰C instead of 450⁰C required for graphite/nickel sulfide and aluminium), - low molding pressure, - extremely low leaching and corrosion rates in saturated brine and, - sufficient mechanical and thermal stability (up to 90⁰C)