The Effects of Simplified Impact Limiter and Lid Arrangement on Decelerations During Cask Drop Scenarios

Reliance solely on full-scale drop testing in partial fulfillment of the requirements to obtain a Certificate of Compliance for a spent fuel transportation package is expensive and no longer common in part due to use of explicit finite element codes. Typically, a combination of finite element modelling, and scale model testing, is part of a benchmarking and validation effort used to support the licensing of the transportation package and to minimize costs and time. Often, certain features of the package are omitted or simplified in a scale model, such as impact limiters, which can be expensive to fabricate, are substituted by a plate, or a single cask lid is used in place of two lids. Such simplifications should be made carefully, however, as there may be distortion in the scaled moment of inertia of the package for a slapdown scenario, which could generate unrealistic g-loads. This paper discusses a sensitivity study of the g-loads experienced by a simplified model with varying lid/impact limiter placement. Recommendations for scale model simplification are provided to compensate for the effects of model distortion when the slapdown configuration is drop tested.