The Fukushima nuclear accident in Japan resulted from the combination of two correlated extreme external events (earthquake and tsunami). The consequences (flooding in particular) went beyond what was considered in the initial NPP design. Such situations can be identified using PSA methodology that complements the deterministic approach for beyond design accidents. If the performance of a Level 1-Level 2 PSA concludes that such a low probability event can lead to extreme consequences, the industry (system suppliers and utilities) or the Safety Authorities may take appropriate decisions to reinforce the defence-in-depth of the plant. The project ASAMPSA_E aims at identifying good practices for the identification of such situations with the help of Level 1-Level 2 PSA and for the definition of appropriate criteria for decision making in the European context. It offers a new framework to discuss, at a technical level, how extended PSA can be developed efficiently and be used to verify if the robustness of NPPs in their environment is sufficient. It will allow exchanges on the feasibility of “extended PSAs” able to quantify risks induced by NPPs site (multi-units reactors and spent fuel pools, modelling impact of internal initiating events, internal and external hazards on equipment and human recovery actions …).