Evaluation of the Impact Behavior of the Contents of Reprocessing Radioactive Waste Shipping Cask Subjected to Drop Impact

Reprocessing radioactive wastes, e.g., the vitrified high level radioactive wastes, will be returned from the U.K. and France in 1995 to Japan. According to the IAEA regulations for transport, the waste shipping casks must maintain their integrity against drop impact. As the contents like canisters for the wastes will be spaced in the cask longitudinally, the severest cask drop orientation seems to be vertical. The impact phenomena at drop test is very complicated for the interaction between the contents and the cask body, it is necessary to evaluate the integrity of both of the cask body and contents. In our prior study, we developed the one-dimensional spring-mass computer code to evaluate the impact behavior of the contents (Ito et.al 1988 and Shirai et.al 1988, 1989). In this study, to investigate the impact response characteristics of the contents in the cask precisely, we performed laboratory-scale drop tests, and on the basis of the test results, we proposed the construction of the spring- mass model. Moreover, we confirmed the accuracy of the proposed drop analysis method by comparison with a drop test using a full-scale cask for high level wastes.