The erection and operation of nuclear power plants and repositories is regulated in the Atomic Energy Act (AtG) and in the ordinances based on this Act, e. g. the Radiation Protection Ordinance (StrlSchV). According to the stipulations thereof, radioactive waste has to be disposed of "in an orderly manner" in a repository. The same applies to irradiated fuel assemblies which are no longer allowed to be reprocessed. The term "ultimate disposal" describes the maintenance-free and safe disposal of radioactive waste and irradiated fuel assemblies in suitable geological formations for an unlimited period of time.

In Germany, the most favoured way to dispose of radioactive waste is to emplace it in deep geological formations (several hundred metres below the earth's surface). Other countries (France, for example) deem the disposal of low-level waste near the earth's surface (directly underneath the earth's surface) to be sufficiently safe.

3-D-diagramme of storage chambers for fuel assemblies and high-level waste 3-D-diagramme of storage chambers for fuel assemblies and high-level waste

Depending on the existing geological situation, different rock formations are being examined internationally with regard to their suitability as repositories for high-level waste. Concepts for disposal in salt, granite, clay and other host rocks have been developed. Experts from Germany and other countries arrived at the conclusion that the disposal of radioactive waste in rock salt formations is advantageous.

Approximately 65 % of low- and intermediate-level wastes come from nuclear power plants and other plants which are directly linked with the production of electricity. The remaining 35 % is produced by hospitals, industrial companies and research institutes. 98 % of heat-developing medium- and high-level wastes and irradiated fuel assemblies come from power generation and the so-called fuel cycle, the remainder is produced during the operation of research reactors.