Investigation of the impact behaviour of wooden impact limiters

Wooden impact limiters are used to reduce the forces acting on packages for irradiated fuel assemblies in hypothetical accident situations. For spruce specimens designed corresponding to the filling of real impact limiters, the dynamic force-compression characteristic has been evaluated in experiments according to the IAEA 9 m drop. Force-compression curves have been obtained, which are compared with those of equivalent static experiments. An analytical and a finite element approach have been used in combination with the dynamic compression curves to calculate the maximum cask deceleration and the maximum impact limiter deformation for a 9 m drop in an end-on, a side and an edge impact. The results are compared with those of 9 m drop experiments performed on original casks. An agreement between calculation and experiment has been found.