Computational modelling to predict waste package performance

An important aspect of a safety case for any packaging is its performance under accident conditions. This paper addresses the challenge faced by designers and manufacturers to predict behaviour of waste packages under various transport and emplacement conditions. Previously, performance of waste packages has usually been demonstrated by test. Carrying out a full-scale drop test of a prototype package with the representative simulant wasteform is time consuming, costly, and can lead to variability in the results. Furthermore, these tests are unique for a particular design and cannot be easily applied to other designs. Therefore, predictive modelling based on computational techniques like the finite element analysis (FEA) can be of great benefit. This paper presents an example of how computational modeling can be used to assess free drop and transportation loads. The example presents FEA of a packaging designed to transport a 50 Te steel pot containing radioactive silicate slag to the UK's Low Level Waste Repository site (LLWR) at Drigg in Cumbria in accordance with the relevant UK legislation. The results from FEA are processed to obtain stress and strain levels to show that there is no likelihood of rupture/leakage. Strain energy distribution in the package is assessed to demonstrate that the impact is absorbed by the packaging. (authors)