Analytical and scale modeling techniques for predicting the response of spent-nuclear-fuel shipping systems involved in severe transportation accidents

This paper describes techniques which can be utilized to predict the response of a spent-nuclear-fuel transportation system in a severe transportation accident involving a high velocity impact into a rigid barrier or a collision with another vehicle. The techniques reviewed include both mathematical analyses and physical (scale) modeling. The mathematical (computer) modeling can be accomplished in two steps. The first models the overall system including the vehicle and the cask with a lumped-parameter model, which predicts the rigid body motion of the cask as the vehicle crushes. The second step utilizes a detailed dynamic finite element computer model of the cask to calculate deformations which the cask sustains when it encounters a rigid target at a high velocity. The second part of the paper discusses scale models of casks and vehicle systems used to analyze two hypothetical accident situations. The results of the scale model tests and the mathematical analyses are then related to the results of full-scale tests conducted as the last step in the research program. It is shown that the techniques described in the paper can give excellent indications of the response of shipping casks and transport systems involved in severe impact situations. 7 figures