The general principles for the protection of the Nuclear Power Plants against flooding of external origin are defined in the French Basic Safety Rule I.2.e. Nevertheless, the partial flooding of « Le Blayais » Nuclear Power Plant in 1999 has called into question the design bases used for the protection against external flooding and the existing measures, especially the warning systems, the site protection measures, the protection of safety-related equipments, the procedures and the emergency organization.
In addition to the rush through protection measures implemented on the Blayais site, the utility Electricité De France has reassessed the maximum design flood level at all the plants and has launched a wide "review project" of investigations aiming to ensure that the installations would be effectively protected against external flooding.
The "review project" principles were submitted to the judgment of the French Safety Authority in December 2001 after being analyzed by its technical support IRSN (). In general, they were considered as satisfactory. Therefore, the safety analysis of the protection of all French nuclear plants against external flooding should be performed in compliance with both Basic Safety Rule I.2.e and the methodology developed after the incident occurred in Le Blayais.
Following a reminder of the major principles of the BSR 1.2.e and of flooding events that occurred on French coastal sites, the paper presents successively the main safety and technology issues being examined in the framework of this "review project".