France’s Autorité de Sûreté Nucléaire (ASN - Nuclear Safety Authority) ruled on 23 February on the conditions for the continued operation of EDF's 900MWe reactors beyond their fourth periodic review. The ruling effectively approves a 10-year life extension for the plants, which were mostly built in the 1980s, giving them an operating life of 50 years. ASN said it “considers that all the measures provided for by EDF, and those it prescribes, open the prospect for continued operation of these reactors for a further 10 years”.
In France, authorisation to establish a nuclear installation is issued by the government, after consultation with ASN. This authorisation is issued without a time limit and an in-depth review of the installation, known as a “periodic review”, is carried out every 10 years to assess the conditions for the continued operation.
EDF's 32 900MWe reactors are the oldest in France. Their fourth periodic review is especially significant as they were designed, for 40 years of operation. Beyond this period their operation requires updating of design studies or material replacements. In its decision (2021-DC-0706), ASN prescribed the completion of the major safety improvements planned by EDF, as well as the additional measures that it considers necessary. This decision closes the so-called “generic” phase of the review, which concerns studies and modifications to installations common to all 900MWe reactors.
These requirements will then be applied reactor by reactor, during their fourth periodic review. The specific features of each of the facilities will then be taken into account. The arrangements planned by EDF for each reactor will be the subject of a public inquiry. ASN has asked EDF to report annually on the actions implemented to meet the requirements and their deadlines, as well as on its industrial capacity and that of external parties to carry out required modifications to the installations on time.
France’s fleet of 56 commercial reactors currently accounts for around 75% of its electricity generation. However, it plans to reduce this to 50% by 2035.