France's Autorité de Sûreté Nucléaire (ASN – Nuclear Safety Authority) has adopted a decision setting the requirements governing the continued operation of unit 1 at the Tricastin NPP in Drôme. This is the first reactor in the French nuclear fleet to receive a positive opinion from ASN following its fourth periodic safety review (PSR), namely after approximately 40 years of operation.

France’s environment code requires the licensee of a basic nuclear installation to carry out a periodic review every 10 years, after which ASN gives its opinion on the conditions for its continued operation. In 2021, ASN stated its position on the generic phase of the fourth PSR for all 900 MWe reactors, focusing on common points. ASN said all the measures planned by EDF and those it had prescribed paved the way for a further 10 years of operation following their fourth PSR.

ASN said the improvements and measures will be applied to each reactor individually during their fourth PSRs, which are scheduled to continue until 2031. These reviews will take into account the particularities of each facility and the measures planned by EDF for each reactor will be subject to a public inquiry.

ASN said, for the PSR of Tricastin 1, EDF took into account the specificities of this reactor, those of its site as well as the results of the inspections carried out, in particular during the reactor’s 10-yearly outage in 2019. The safety improvements planned by EDF as part of this review were the subject of a public inquiry in January and February 2022, resulting in a favourable opinion from the inquiry committee.

ASN considered that the conclusions of the reactor's fourth PSR, the actions planned by EDF and those taken in response to ASN's decision on the generic phase of the safety review “make it possible to achieve the objectives set for this periodic safety review”. However, ASN said it “regulates the continued operation of reactor 1 of the Tricastin nuclear power plant by additional requirements relating to the level of seismic hazard and the heat wave situations that the licensee includes in the safety demonstration”.

Tricastin 1 was connected to the grid in May 1980 and began commercial operation the following December. The French nuclear fleet includes three pressurised water reactor designs – 900 MWe, 1300 MWe and 1450 MWe N4. The 32 900 MWe reactors, which started up between 1977 and 1988 and are the oldest of the country's current nuclear fleetoperate at EDF's Blayais, Bugey, Chinon, Cruas-Meysse, Dampierre, Gravelines, Saint-Laurent and Tricastin NPPs.

Image: Tricastin nuclear power plant (courtesy of EDF)