Why do we need interim storage facilities?
At our Brokdorf, Grafenrheinfeld, Grohnde, Isar, and Unterweser power plants temporary facilities for the storage of spent nuclear fuel are completed. This is part of E.ON Kernkraft's strategy for compliance with the German government requirement that nuclear power plant sites be equipped with temporary solutions for storing spent fuel elements until such time as a permanent, national storage facility has been built. Each temporary facility will be used exclusively for storing the irradiated fuel elements created on-site until they can be transported to a final disposal site. It may soon be possible to dispense with the current costly practice of transporting spent fuel elements via public roads to external temporary storage sites, such as the Gorleben facility.
Fuel element temporary storage facilities are one link in the nuclear-waste disposal chain employed by German nuclear power plants. In any given maintenance inspection at a nuclear power plant, about a quarter of the fuel elements will be replaced with new ones. The elements removed from the reactor continue to give off heat, so they first need to be kept in water-filled cooling ponds at the plant before they can be reprocessed or put into interim storage. After about five years, the fuel elements are encapsulated in hermetically sealed high-strength containers so that they can be placed into temporary storage. Each storage container is designed to have a maximum storage life of 40 years.
Temporary storage facilities are built to very high strength and resistance specifications. However, in a purely functional sense they are little more than ordinary storehouses. Storing fuel element containers does not require expensive hi-tech cooling systems, nor any sort of complex monitoring system. Storage is low-maintenance, as natural air currents do the task of dissipating the residual heat given off by the containers.