Delay in Flamanville 3 attaining full power

Monday, 4 August 2025

The 1630 MWe (net) pressurised water reactor was connected to the grid for the first time on 21 December 2024. At that time, EDF said that "in accordance with the startup operations, the phases of testing and of connection and disconnection to the grid will continue for several months ... until the reactor reaches 100% power". This had been scheduled for summer 2025.

However, EDF has now said: "After its next reconnection to the grid, the Flamanville 3 teams will continue the testing phase before commissioning with an objective to reach full capacity before the end of autumn 2025.

"At the end of this testing period, the unit is expected to be operated at 100% capacity until the first planned outage for maintenance and refuelling, called Visite Complète 1 (VC1). This first planned outage should mainly take place in 2026."

Construction work began in December 2007 on the third unit at the Flamanville site - where two reactors have been operating since 1986 and 1987. The dome of the reactor building was put in place in July 2013 and the reactor vessel was installed in January 2014. The reactor was originally expected to start commercial operation in 2013 but has faced a series of delays.

The first EPR units came online at Taishan in China, where unit 1 became the first EPR to enter commercial operation in 2018 followed by Taishan 2 in September 2019. In Europe, Olkiluoto 3 in Finland entered commercial operation in 2023, and two units are currently under construction at Hinkley Point C in the UK, with two more planned at Sizewell C.