Guidelines for harmonized hazard assessment for LP-HC events

This report describes the main conclusions of the STREST project (and associated guidelines) to evaluate hazard of Low-Probability High-Consequences (LP-HC) events used to define stress tests for non-nuclear Critical Infrastructures (CIs). Several new approaches have been developed to assess these extreme hazard scenarios and to evaluate the associated uncertainties. This report presents a summary of the developments, results and products issued from Work Package 3 (WP3) of STREST. It is given as a set of "recommendations" for potential users responsible of the estimation of hazard for a particular non-nuclear CI in the European Union and other countries. The methods and guidelines are dedicated to two different target-users: project managers and hazard experts. It poses the main differences with a traditional Probabilistic Hazard Assessment analysis, the benefits and extra challenges, and the particular information requirements for the three selected infrastructure classes covered in STREST. In a simple and understandable manner, it summarizes the principal available tools, the main references and the application examples issued from the project in order to help the users in the realization of theirs studies.