Development of Seismic Response Analysis Code of Cask

Since a cask is vertically oriented during loading in cask-storage, it is necessary to investigate the integrity of the cask against tip-over during strong earthquakes. The rocking and sliding behavior of the cask during strong earthquakes can be analyzed as a dynamic vibration problem for a rigid cylinder. (Mochizuki et al. 1948) In this paper, in order to clarify the tip-over characteristics of a cask during strong earthquakes, we applied the Distinct Element Method (DEM) to the seismic response analysis of the cask. (Shirai et al. 1992) DEM was introduced by Cundall P.A. in 1971. It is based on the use of an explicit numerical scheme . The cask was considered to be a rigid polygonal element, which satisfied the equation of motion and the law of action and reaction. We examined the applicability of this code by comparison with experimental results obtained from shaking table tests using scale model casks considering the dimension of a 100 tons class full- scale cask.