Year
2009
Abstract
Dry storage of spent fuel and high activity waste (HAW) from reprocessing is well established and qualified Type B transport and storage casks are widely used. At present the storage license period in Germany is 40 years accounting for the initial schedule to establish a repository where the radioactive waste can be disposed off finally. As interim cask storage has been started in the 1990’s and significant delays in the national repository project for heat generating waste happened in the meantime an extension of interim storage periods may become a realistic option in future. For that reason and because investigations of ageing effects and long-term stability of materials and components of transport and storage casks are time-consuming, BAM, the Federal Institute for Materials Research and Testing in Germany, just initiated additional investigation programs in that field. Main topics are long-term stability and behavior of polymer components for neutron shielding and of seal systems consisting of metal gaskets. This contribution gives an overview of the most important safety relevant cask ageing effects and of current results of short and long-term experiments with metal gaskets whose seal efficiency depends on mechanical loads, temperature and environmental influences. Moreover, material characteristics of polymer components are discussed as well as results of current investigations and further projects.