Flamanville EPR: 12 years late, the reactor begins operation and produces its first electrons

After 12 years of delay, the Flamanville EPR is coming into operation. The process leading to the first nuclear fission chain reaction has begun, EDF announced on the night of Monday to Tuesday, September 3, 2024, a few hours after indicating that it would be necessary to wait three more months to see its new reactor supplying the electricity network.

The Flamanville EPR is finally waking up. "The divergence phase has begun. This operation will make the reactor's heart beat for the first time", EDF announced in a video posted on X, specifying that “the divergence initiates the nuclear fission chain reaction”.

A la suite de la délivrance de l’autorisation de divergence de l’EPR de Flamanville par l’Autorité de sûreté nucléaire (@ASN), les équipes d’EDF se préparent à faire battre le cœur du réacteur pour la 1ère fois 💗 ⤵️@EDFEPR #Nucléaire #DLDNov

— EDF (@EDFofficiel) September 2, 2024

The energy company had announced earlier that it had received the green light from the Nuclear Safety Authority (ASN) to launch the production of the first electrons of the EPR.

But the "coupling", or the network connection operations that will allow French homes to benefit from the energy of the most powerful reactor (1,600 MW), the 57th in the fleet, will have to wait.

Test program

“A test program to reach a power level of 25% will be implemented”, at which point the EPR “will be connected to the national electricity grid for the first time and will then produce electricity”, a deadline “planned for the end of autumn 2024”, the group specified in a press release.

“To go to coupling, we are talking about the end of fall, because we have a fairly substantial test program ahead of us”, Régis Clément, deputy director of the French group's nuclear production division, previously told the press, who announced a ramp-up "by successive stages", before the nuclear core can "show its credentials".

"Risks"

EDF CEO Luc Rémont had announced that the divergence, a major step in the reactor start-up operations, was “imminent” in early July. If it only started on Monday, it is because the Flamanville teams encountered “hazards”, which led “a certain number of additional operations” to be carried out during the summer, according to Mr. Clément.

As for full power, previously announced by the end of the year, it will take “several months”, according to Mr. Clément, who has not given a new date.

Production of the existing fleet significantly increased

If EDF has nevertheless obtained the "go"of the ASN to launch operations and reach a new crucial milestone, this is yet another setback for a construction site that is already 12 years behind schedule for this new pressurized water reactor, the 4th of this type installed in the world.

While President Emmanuel Macron has decided to relaunch nuclear power, by ordering six EPR2 reactors (and eight additional ones as an option) from the energy company, the start-up of the Flamanville EPR, even though it was decided well before, has a highly symbolic dimension.

In addition to the ASN authorization, the other good news came from the existing fleet: EDF has significantly revised upwards its estimate of nuclear production for the year 2024, now between 340 and 360 TWh, compared to a range of 315 to 345 TWh initially planned, an increase not including the Flamanville EPR.

Numerous setbacks

“The 56 other reactors are performing better than what we had integrated”, declared Mr. Clément, so that the production of "the EPR will arrive in addition".

"The "corrosion" file was less sensitive than expected", he added. “This revision of the estimate of nuclear production for 2024 is based on the improvement in the performance of unit outages, the industrial control of inspections and repair sites related to the stress corrosion file, and the absence of major climatic hazards during the summer”, according to the EDF press release.

The numerous setbacks that have affected the EPR construction site (cracks in the concrete of the slab, anomalies in the steel of the vessel, and welding defects on the containment building penetrations) have caused the bill, now estimated at 13.2 billion euros by EDF, four times the initial estimate of 3.3 billion.

In 2020, the Court of Auditors had estimated it at 19 billion, including in particular the "additional financing costs".