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

ÉCISION ET PRESCRIPTIONS DE L’ASN A SN underlines the ambitious objectives of the 4 th periodic safety review of the 900MWe reactors and the substantial work carried out by EDF in the generic phase. It also underlines the scale of the modifications planned by EDF, the implementation of which will represent significant safety improvements. These improvements more particularly concern control of the risks associated with hazards (fire, flooding, earthquake, etc.), the safety of the spent fuel storage pool and the management of core meltdown accidents. During the examination, EDF undertook to supplement its technical file to respond to the majority of the points raised by ASN. Finally, ASN prescribes the implementation of the major safety improvements planned by EDF, along with certain additional measures it considers necessary to achieve the safety review objectives. The measures planned at the generic stage of the safety review and those that will be defined in the studies specific to each site, will have to be applied on each reactor with a view to their continued operation. ASN asks EDF to carry out the majority of the safety improvements before submitting the safety review concluding report, which in practice means during the 10-yearly outage of each reactor. The other improvements must be carried out within 5 years at the most after submitting this report. This time frame is increased to 6 years for the first reactors, namely Tricastin1 and 2, Bugey 2, 4 and 5, Gravelines1 and Dampierre1. This staggering is linked to the scale of the works on each reactor, which will moreover be carried out concurrently on several 900MWe reactors. It takes into account the ability of the industrial fabric to conduct the works with the required standard of quality and the associated training necessary for the operators to familiarise themselves with these changes. Given the scale of the modifications envisaged under the safety review, EDF has put in place specific organisational arrangements to improve the activities of modification design and embodiment, production of the operational documentation and capitalising on the lessons learned from experience feedback. ASN requires EDF to report annually on the actions implemented to meet the requirements and their deadlines, and also on the industrial capability of both EDF and its outside contractors to complete the modifications of the facilities within the set time frames. ASN requires that this information be made public. The generic phase of the 4 th periodic safety review of the 900MWe reactors ended late 2020. ASN sets out the inspections and modifications EDF must implement on its reactors to meet the safety review objectives. At the end of the 4 th periodic safety review, what does the ASN resolution stipulate? ASN RESOLUTION AND REQUIREMENTS 8 • Les cahiers de l’ASN • February 2021