Delays are accumulating around the commissioning of the EPR nuclear reactor in Flamanville, in the English Channel.
EDF announced Friday that six additional months would be necessary.
The reactor must therefore now start up by mid-2024 instead of the end of 2023, with a new additional cost of 500 million euros.
These six additional months, which bring the delay to 12 years in relation to the start date initially planned, result in the total cost of the project, under construction since 2007, rising from 12.7 to 13.2 billion euros.
The new delay is due to the necessary revision of treatment procedures for some 150 “complex” welds, within the main secondary circuit of the reactor, explained to the press the director of the Flamanville 3 project, Alain Morvan.
The problem appeared this summer, when it was necessary to carry out the heat treatment of "stress relief" of welds: the process used revealed a "non-conformity of behavior" of sensitive materials nearby, affected by too high temperatures.
"We had valve temperature behavior that did not conform to what we expected", explained Alain Morvan.
Additional costs related to maintaining staff on site
"We stopped the heat treatment last summer and resumed the studies to define a method, and carried out tests to guarantee the good level of performance of these heat treatments", he specified.
"These files have been presented to Bureau Veritas, which analyzes them, and by the end of the year we will have the authorization to resume the so-called complex heat treatments", affirmed the project director.
EDF adjusts the timetable for the Flamanville 3 project
— EDF (@EDFofficiel) December 16, 2022
These operations should therefore be able to resume at the beginning of 2023, but the entire project schedule is upset: fuel loading is now announced for the 1st quarter of 2024. Then, the reactor will send its first electrons to the network when it has reached nearly of 25% of its power, “about three months later”, therefore by mid-2024, rather than the end of 2023 as previously planned.
The 500 million euros in additional costs are mainly related to maintaining staff and companies on site, said the EDF manager.