The European Pressurised Reactor (EPR) at Flamanville, located in north-western France, has reached full nuclear power for the first time, according to an announcement by Electricité de France (EDF). The 100% threshold was achieved on December 14 at 11:37, with a gross electrical output of 1,669 MW, the operator stated in a press release, a few days after receiving approval from the Autorité de sûreté nucléaire et de radioprotection (ASNR).
This operational milestone comes more than a year after the reactor was connected to the electrical grid in December 2024. Originally scheduled to enter service in 2012, Flamanville 3 is now 12 years behind schedule. The project’s cost, initially estimated at EUR3.3bn, has now been revised to EUR23.7bn ($25.7bn), according to the latest figures from France’s Cour des comptes, based on 2023 economic conditions.
Start-up programme still underway
EDF stated that reaching full power enables the testing of reactor equipment under maximum operational stress. The current phase involves varying power levels to conduct additional technical readings and assess system stability. The group is also planning a technical intervention on an internal electrical substation, without disconnecting from the grid.
This operation involves the complete replacement of a 400 kV bushing that links overhead lines to underground cables, which supply the auxiliary transformer of the Flamanville 3 reactor. EDF specified that the replacement will be carried out while the reactor remains in operation.
A strategic stake for France’s nuclear sector
Flamanville 3 is the first third-generation reactor to enter service in France in over 25 years. It stands out by its capacity to supply power to approximately two million French households and is currently the most powerful reactor in the national fleet. The development is part of a nuclear revival strategy announced in 2022 by President Emmanuel Macron, which includes the construction of six next-generation EPR2 reactors, with a further eight under consideration.
France’s multiannual energy programme (Programmation pluriannuelle de l’énergie, PPE), the roadmap outlining national energy priorities, remains pending. Political disagreements over the balance between nuclear and renewables are delaying the text’s finalisation, with parties such as the Rassemblement National opposing the expansion of renewable energy sources.
Operational EPR projects abroad
The Flamanville reactor is part of a limited but strategic global fleet of EPRs. Two units are already operating in Taishan, China, and one reactor is in service at Olkiluoto in Finland. The United Kingdom is also building two EPR units at Hinkley Point in the south-west of England. These projects are closely monitored by European industry stakeholders as benchmarks for the technological and financial viability of future civilian nuclear developments.
