The announcement comes in a context of tensions and uncertainties in terms of electricity supply for this winter.
Two nuclear reactors will ultimately not be able to restart before the end of this winter, and six others will have to be shut down in 2023 for repairs related to corrosion problems, we learned in recent days from EDF.
EDF announced in an information note published on its site on Friday that it had decided to systematically replace the pipes of the category of reactors most exposed to these risks of corrosion, on emergency pipes used to cool the reactor in the event of an emergency. .
These reactors must be shut down for the duration of the work.
On these six 1,300 megawatt (MW) reactors, "as we are almost sure to find things
(traces of corrosion),
we go directly to the work", explained an EDF spokesperson on Monday.
Electricity imports at a record level this winter
The winter of 2022-2023 was already the most tense in terms of electricity supply, with a nuclear fleet concerned by numerous maintenance operations but also affected by these corrosion phenomena discovered or suspected on an increasing part of the power plants.
Never before had EDF produced so little nuclear electricity in its history, forcing France to import record volumes of electricity from neighboring countries.
On Friday, 40 nuclear reactors out of the 56 in France were in operation.
After the new repair announcements, the Golfech 1 (Tarn-et-Garonne) and Penly 2 (Seine-Maritime) reactors will only be able to restart on June 11, when they were to return to service on February 18 and January 29, respectively, which would have covered the end of winter.
EDF had already announced two other delays on Friday, with in particular the return to service of Penly 1 on March 20, two months later than planned, for the same reason: the preventive replacement of a portion of piping threatened with cracks.
“Preventive” repairs on 12 reactors
"The analyzes carried out for more than a year have enabled EDF to identify the reactors whose safety injection circuit lines are the most sensitive to the development of the stress corrosion phenomenon" (SCC), indicates EDF in its information note: “these are the 16 most recent reactors”.
Four “N4 level” reactors are Civaux 1 and 2, on which work has been completed, and Chooz 1 and 2, where work is in progress.
There remain 12 1,300 MW reactors known as the "P'4" type, on which EDF has decided on "preventive" repairs, without even going through the examination stage, which implies a shutdown of 160 days, explained the spokesperson.
Of these twelve reactors, one has already been repaired and the other five are in operation.
There will therefore remain six to be repaired automatically during the year 2023 (Belleville 1, Belleville 2, Cattenom 2, Golfech 2, Nogent 1, Nogent 2), while EDF has so far only provided for checks Firstly.
“EDF decided today to adapt its treatment strategy for all reactors in the 1300-P'4 series.
This strategy aims to address the CCS issue for all 1,300-P'4 reactors by the end of 2023,” explains the group.
According to the spokesman, there will be no overall production “lower than expected” so far, the smaller 900 MW reactors, the bulk of the fleet, ultimately being “probably less affected. by this problem.
But the schedules announced by EDF for the restart of its reactors have continued to experience delays in 2022, which augurs for a still complicated winter 2023-2024.
In the immediate future, the manager of the high voltage lines, RTE, will update its forecasts for this winter on Tuesday, in particular for the month of January, where the risk of tensions had been considered high during the previous point, on November 18.