Storage buildings for the temporary storage of spent fuel elements for the period between removal from the nuclear power plant and reprocessing or direct ultimate waste disposal. The elements are stored in specially designed cast-iron containers, in particular in so-called Castorยฎ containers which meet all safety functions such as radiation shield, retention of radioactive substances, mechanical integrity even in the event of earthquakes and aircraft crashes. These containers are stored in conventional warehouses. The containers are cooled during interim storage by the natural convection of air. Interim storage facilities for spent fuel elements in Germany are located in Ahaus (North Rhine-Westphalia) with a storage capacity of 3,960 t spent nuclear fuel and in Gorleben (Lower Saxony) with a capacity of 3,800 t. A further modified interim storage facility has been established in Lubmin (Mecklenburg-Western Pommerania), in particular for the storage of dismantled reactor unit components from the former Greifswald Nuclear Power Plant. Further interim storage facilities are to be built at the sites of the nuclear power plants.