With the support of the International Atomic Energy Agency, a packaging to transport research reactor irradiated fuel was designed by a trinational team from Argentina, Brazil and Chile. A half-scale model for materials test reactor fuel was constructed and tested according to specifications of regional regulations. Numerical modelling of impact problems played a key role in the cask development. During the design process, it was necessary to improve the performance of the shock absorbers and the containment system. This process was carried out using numerical simulations to predict the behaviour of different shock absorber materials, to consider design improvements and to select the drop orientations. The finite element method was used to simulate the impact problem, and a particular effort was undertaken to model all of the geometrical features with high detail, constitutive equations of different materials and multiple contact problems. © W. S. Maney & Son Ltd 2012.