Crack discovered in a nuclear power plant: prolonged shutdowns at several EDF sites

French nuclear sites remain under close surveillance. Discovery of a major crack on a reactor at the Penly power plant (Seine-Maritime) will lead to the extension of shutdowns at other sites, for checks, but there should “be no massive shutdowns”, according to an official from the Nuclear Safety Authority (ASN).
“There will not be massive shutdowns of the reactors for months, but it will have an impact in terms of the duration of the shutdowns,” Julien Collet, deputy director general of ASN, told AFP on Wednesday. A larger than expected crack was detected by EDF at Penly 1 on an emergency pipe used to flood the reactor with water in the event of a nuclear accident. This corrosion-related phenomenon has already been identified since the end of 2021 on several sites, but generated smaller cracks and on other types of pipes.
“Last year, we had a first understanding of the stress corrosion phenomenon. EDF had highlighted a design subject on sensitive lines for 16 reactors”, engaging “a large-scale repair program”, recalls Julien Collet. But “what we have always said” is that this “also required checks on non-sensitive areas. It was within the framework of these checks that this crack was revealed at the start of the year,” he explains.
EDF invited to “review its strategy”
This new damage is “on a line reputed to be non-sensitive but on a weld which was the subject of major repairs at the time of construction” of the reactor. According to Julien Collet, “the fact that a weld has been repaired can in itself generate stress corrosion. However, these repairs can concern all the reactors”.
“We asked EDF to review its strategy, which was centered on reactors known to be sensitive due to the geometry of the lines and we are asking it to reprioritize the checks on repaired welds on all the reactors”, including the 900 MW , the largest and oldest series in the French fleet. On the other hand, new welds are not concerned. The nuclear policeman awaits the revised EDF strategy during the month of March.