PARIS, March 10 (Reuters) – France’s nuclear safety watchdog ASN has ordered energy utility EDF (EDF.PA) to inspect about 200 pipe weldings across its 56-nuclear reactor fleet after discovering three additional cracks this week, the regulator said on Friday.
In addition to a major corrosion-related crack on the Penly 1 reactor in Normandy revealed on Tuesday, which the watchdog attributed to faulty welding, two fissures on EDF’s Penly 2 reactor and the Cattenom 3 reactor in Moselle were disclosed on Thursday.
An EDF spokesperson declined to comment on ASN’s criticism, but said the two newer cracks were due to “thermal fatigue”, which happens when very hot and cold water meet inside pipes, causing the steel to dilate, contract and become more fragile over time.
EDF regularly inspects pipes via ultrasound for this phenomenon during maintenance, the spokesperson added.
The latest defects and watchdog scrutiny come as France and the Britain announced a new energy partnership on Friday to strengthen cooperation on nuclear power, including construction of power stations, innovation and safety.
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Neither French President Emmanuel Macron nor British Prime Minister Rishi Sunak mentioned the nuclear operator’s latest setbacks after a bilateral summit.
“You are helping us secure our supply of nuclear power thanks to EDF’s incredible work,” Sunak told Macron.
EDF is building a new nuclear plant in Britain, Sizewell C, which has suffered from cost overruns and construction delays. A second plant, Hinkley Point C, is also in the works.
The utility’s Penly 2 and Cattenom 3 in France are part of a group of 16 reactors flagged by EDF as being susceptible to corrosion-related cracks due to a design flaw, and prioritised for checks in its inspection and maintenance plan.
That plan is now being updated to accommodate the additional check of 200 weldings, and will be published “in coming days”, EDF has said.
European forward-curve power prices rose sharply on Friday following the announcement of new cracks, after French nuclear output in 2022 fell to a 34-year low while EDF scrambled to fix stress corrosion issues at several sites.
“Some market participants may be worried that the issues with corrosion are trickier than first anticipated, and that EDF will struggle both long- and short-term to fix it and bring generation back to pre-2022 levels,” Rystad analyst Fabian Ronningen said.
Reporting by America Hernandez and Forrest Crellin; Editing by Emelia Sithole-Matarise
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