Investigation program to assess slug impact consequences on a reactor upper head

Slug impact is considered as a potential risk for PWR power plants in case of a severe accident. The goal of the reduced-scale BERDA tests is to quantify the maximum mechanical energy that the upper head of a PWR is able to withstand. The transfer of the experimental results to reactor dimensions uses scale factors based on similarity laws whose validity is checked with the FLIPPER mock-ups. The influence of the slug material is investigated with the SKIPPY mock-ups. The size, thermal and strain-rate effects are studied in the frame of the LISSAC European program and with the RUPTHER and FASTHER tests. In order to deepen the understanding of the experimental results and to extrapolate them to other combinations of parameters, corresponding theoretical and numerical work is performed.