The Autorité de Sûreté Nucléaire (ASN) is France’s `nuclear safety regulator. It has stated that it is prepared to provide Électricité de France S.A. (EDF) with more time so that they can implement safety upgrades required at its fleet of nine-hundred-megawatt nuclear power reactors.
EDF is a French multinational electric utility company owned by the French state. Headquartered in Paris, with seventy eight billion dollars in revenues in 2016, EDF operates a diverse portfolio of at least 120 gigawatts of generation capacity in Europe, South America, North America, Asia, the Middle East, and Africa.
EDF’s thirty-two nine-hundred-megawatt reactors were put into commercial operation between 1977 and 1988. They include the oldest operational nuclear reactor in France. Such nine-hundred-megawatt reactors are currently in operation at EDF's Blayais, Bugey, Chinon, Cruas-Meysse, Dampierre, Gravelines, Saint-Laurent and Tricastin plants.
ASN reviews operations at all French reactors every ten years. These reviews are conducted in two steps. First, the ‘generic’ review phase which covers subjects common to the design of all nine-hundred-megawatt reactors. Second, the ‘specific” review phase which deals with each reactor individually. The current review series will end in 2031.
In February 2021, ASN established the conditions for the continued operations of EDF’s reactors beyond forty years. This completed the ‘generic’ phase of the review series. ASN said that it considered the measures planned by the EDF combined with those mandated by the ASN would ensure the safety of all such reactors for a further ten years of operation.
The measures required verifying the conformity of the reactors with their reference system as well as improving their ability to withstand more severe attacks “of internal or external origin.” Modifications will also limit the radiological consequences of accidents or attacks which do not result in a core meltdown. In addition, improvements will be made in the arrangements for managing accidental or aggressive situations which impact the spent nuclear fuel storage at the reactors.
So far, EDF has initiated or completed the fourth ten-year inspection of sixteen of its reactors. The majority of safety improvements have been implemented. In October of last year, EDF requested that ASN postpone deadlines for some of the requirements of this decision, “given the difficulties of being able to meet them.” EDF said that these difficulties included the following problems. The possibility of the occurrence of technical hazards during the implementation of certain requirements. Issues with making changes in the scheduling of outages for fuel renewal, linked in particular to the discovery of stress corrosion on auxiliary lines. There are possibilities of long-term accidental outages and tensions affecting the electrical network. And, finally, the concomitance of other periodic reviews causing strains on its engineering capabilities.
ASN said, “The modifications requested by EDF also aim to standardize the deadlines between the reactors, in order to facilitate the industrial programming of the work, to limit the number of different configurations of the reactors and thus to facilitate the appropriation of safety improvements by the teams responsible for operations. Taking into account the difficulties presented by EDF and the justifications provided regarding the deadline extensions, ASN considers the request acceptable.”
The application file presented by EDF and the ASN’s draft amending decision are now subject to a three-week public consultation.