40 Years of CASTOR® - A Success Story from the first Commissioning to Final Defueling

摘要

In early 1978 GNS was commissioned by the German utilities to develop a visionary concept at that time: a dual-purpose cask both for transport and dry storage of spent nuclear fuel. The first-of-its-kind cask family, that was soon christened CASTOR®, revolutionized spent fuel management from the first loading in 1982. Over the years CASTOR® casks became the backbone of spent fuel management in Germany as well as an international benchmark for safe packaging of spent fuel and HLW.To meet highest expectations from its customers and stakeholders, the casks’ fundamental purpose was and still is to provide all the necessary safety functions during transport and storage on its own without additional measures. Due to that, GNS casks can be stored with or even without storage buildings depending on national regulations. A storage building may provide additional protection from environmental influences and reduce radiation exposure to the public. For heat removal from the storage buildings, a passive cooling system by natural convection is sufficient. This makes the interim storage of the casks a completely passive and fail-safe system.By now already more than 1,600 GNS-casks for spent fuel and HLW are in operation worldwide with individual storage periods of up to 35 years. In Germany alone, more than 1,200 CASTOR® casks are stored in 16 interim storage facilities.To provide a comprehensive solution for the final defueling of NPP, GNS recently developed the GNS IQ® Quiver System, to store even damaged fuel rods inside of the standard spent fuel casks. Taking into account the additional casks that have to be loaded and stored during the final years of the German Nuclear Phase Out, there will be over 2,000 GNS casks in operation worldwide within the next couple of years.Unique operational experiences from several hundred loadings mostly carried out by GNS’ own staff result in a cask design which offers easy handling and guarantees minimum turnaround times within the reactor unit. The expertise gained in Germany has been implemented in new cask concepts for the demands of international customers, who e.g. seek casks with higher capacities after longer cooling periods or who need solutions to cope with limited crane capacities.The presentation will give an overview over 40 years of spent fuel management in Germany as well as an outlook on international projects by showing the bandwidth of customized solutions by GNS.