Les cahiers de l’ASN #02 - Conditions for the continued operation of EDF’s 900MWe reactors

ASN considers that the measures planned by EDF, supplemented by the replies to the requirements formulated by ASN, will make it possible to achieve the safety review objectives and bring the level of safety of the 900MWe reactors close to that of the most recent reactors (third generation), in particular: • by verifying, over a wide perimeter, the compliance of the reactors with the safety rules applicable to them (see page 10) ; • by improving the way potential hazards (earthquake, flooding, explosion, fire, etc.) are taken into account. The reactors will also be able to withstand more severe hazards than those considered until now (see page 12) ; • by improving the provisions for managing spent fuel pool accident situations (see page 14) ; • by reducing the risk of a core meltdown accident and mitigating the consequences of this type of accident, particularly by limiting situations that would necessitate depressurisation of the containment and by reducing the risk of containment basemat melt-through by the “corium” consisting of molten nuclear fuel, steel and concrete. These measures will thus significantly reduce releases into the environment during this type of accident (see page 16) ; • by mitigating the radiological consequences of the accidents studied in the safety report. This will significantly reduce the occurrence of situations that involve implementing population protection measures (sheltering, evacuation, taking iodine tablets) (see page 18) ; • by identifying the improvements enabling each site to reduce its environmental impacts (see page 19) . At the end of the generic phase of the safety review, ASN considers that all the measures planned by EDF combined with those prescribed by ASN open the prospect of continued operation of the 900MWe reactors for the 10 years following their 4 th periodic safety review. Conditions for the continued operation of EDF’s 900MWe reactors • 9