The 1,650 MWe EPR reactor at unit 3 of France’s Flamanville NPP is “technically ready to start its commissioning,” according to EDF, after teams were mobilised to carry out the required tests. The Nuclear Safety Authority (ASN – Autorité de Sûreté Nucléaire) said that following in-depth exchanges with EDF, it had decided to launch the public consultation from 27 March to 17 April “on its draft decision authorising the commissioning of the EPR reactor of Flamanville 3”.

At the end of this consultation, ASN will be able to authorise the commissioning of the installation, making it possible to proceed with the first loading of nuclear fuel and monitoring of start-up operations. “The connection to the national electricity grid … is planned for summer 2024,” EDF noted.

ASN also listed technical requirements needed to regulate the start-up tests and operation of the reactor. These included:

  • supervising implementation and monitoring of the start-up tests after commissioning;
  • specifying the methods for monitoring feedback from the operation of other EPR-type reactors in the world;
  • specifying define the deadline for replacing the exchangers between the intermediate refrigeration (RRI) and raw water (SEC) circuits in order to ensure, over the entire lifespan of the installation, a sufficient level of performance;
  • defining the deadline for replacing the bodies of two protection valves of the main secondary circuits.

ASN had previously prescribed replacement of the vessel cover, which will take place during the first reactor outage. ASN said it will continue to monitor EDF’s preparation and the performance of activities prior to fuel loading and until commissioning.

Flamanville 3 has suffered a long series of delays and cost increases. Construction began in December 2007 and the reactor was originally expected to start commercial operation in 2013. In December 2022, EDF put the estimated cost of completion at €13.2bn ($14bn), up from a previous estimate of €12.7bn and an original estimate of €3bn.

The first two EPR units came online at Taishan NPP in China in 2018 and 2019, both of which were significantly behind schedule and over-budget. In Europe, Olkiluoto 3 in Finland entered commercial operation in 2023, delayed by more than 10 years and also over budget. Two units are now under construction at Hinkley Point C in the UK.

Image: View of Flamanville 3, 2 and 1 (courtesy of EDF)