Evaluation of Finite Element Codes for Demonstrating The Performance of Radioactive Material Packages in Hypothetical Accident Drop Scenarios

Drop testing and analysis are the two methods for demonstrating the performance of packages in hypothetical drop accident scenarios. The exact purpose of the tests and the analyses, and the relative prominence of the two in the license application, may depend on the Competent Authority and will vary between countries. The Finite Element Method (FEM) is a powerful analysis tool. A reliable finite element (FE) code when used correctly and appropriately, will allow a package’s behaviour to be simulated reliably. With improvements in computing power, and in sophistication and reliability of FE codes, it is likely that FEM calculations will increasingly be used as evidence of drop test performance when seeking Competent Authority approval. For a FE code to be acceptable it must ideally be shown to be sufficiently reliable in all relevant cases. The code should be able to produce results which are within the band of experimental scatter that might be obtained from physical drop testing. Even if a code were not capable of producing results within the band of experimental scatter, it would be acceptable if the predictions of damage were reliably pessimistic. What is lacking at the moment, however, is a standardised method of assessing a FE code in order to determine whether it is sufficiently reliable or pessimistic.