Transport and Storage Casks for Long Cooled Spent Fuel Elements

In the past, transport and storage casks such as the TN 1300 /1/ and TN 900 casks, which were suitable for the fuel assembly storage pond with low capacities of the older nuclear power plants, were developed in the Federal Republic of Germany. These casks are capable of housing irradiated fuel elements after a cooling time of 1.3 to 2.5 years. Upon the additional construction and operation of new nuclear power plants in the Federal Republic of Germany, it became necessary to design transport and storage casks which would be optimally suitable for the in many respects modified requirements. These changed boundary conditions include among others - the use of fuel elements with a higher enrichment of U-235 - use of mixed oxide fuel elements - increase of burn-up - increase of fuel element cooling times due to the larger storage pond capacities available at the reactor site. The statements made above apply in Germany both to pressurized water reactors (PWR) and to boiling water reactors ( BWR).