In accordance with the disposal concept for nuclear power plants, waste from nuclear facilities is to be safely enclosed in repositories with no time limitation. These repositories are not yet available today. Until then the spent fuel elements are either transported to the two central interim storage facilities at Ahaus (North-Rhine Westphalia) and Gorleben (Lower Saxony) or to reprocessing plants abroad. To minimize these transports, the Federal Government requests the additional possibility to place spent fuel elements in interim storage facilities at the power plant site. For this purpose, site interim storage facilities are to be erected which can hold the fuel elements until their ultimate disposal in repositories in 30 to 40 years. The operators of nuclear power plants have filed licensing applications with the Federal Office for Radiation Protection for the erection of site interim storage facilities. For interim storage the fuel elements are packaged in special transport/storage containers (Castorยฎ containers) which are used both for the transport from the nuclear power plant to the interim storage facility and as a storage container. The 40 cm thick wall shields the radiation off, cooling fins at the outside of the container ensure safe heat dissipation of the heat generated by the decay of the fission products to the ambient air.