Abstract
Many spent fuels coming out of the nuclear power station are planned to be stored in the special site in Japan until they are reprocessed. In this site, the spent fuels are installed in a cylindrical container called canister. And the canister is installed in the outer cylinder called cask which is a free-standing structure. Therefore, it is very important to reduce the seismic response of the cask at the seismic event. In this study, the sliding and rocking motions of a cask are evaluated analytically. In an analytical model, the cask and the canister are treated as rigid bodies which are connected by a spring, because the cask and canister system is seen as a two-degree-of-freedom coupled system. The equations of motions are derived for sliding and rocking motions when the floor is subjected to the horizontal excitation. The displacement and the rocking angle of the cask are evaluated by numerical simulations. The effects of the canister vibration on the cask motion are discussed.
