After discovering fresh "quality variations" in the welding at its troubled Flamanville 3 nuclear project in Normandy, Electricité de France (EDF) has reported the issue as "significant" to the Nuclear Safety Authority, and warns it could lead to yet more delays.
Shares in the company fell 1.6% on the start of trading on the Paris stock exchange.
EDF made the announcement today, saying it discovered the problems during an inspection on 21 March, reports Le Monde.
Already years late, the project is nearly three times over budget.
The state-owned energy company will now carry out further checks on the 150 welds, and has ordered a report by the end of May to examine how the variations happened and what can be done to correct them.
EDF is presently assembling the reactor’s parts and performing pressure tests. It had hoped to begin fuelling the reactor in the fourth quarter of this year with a view to commissioning the reactor next year.
The announcement follows a statement on 22 February that the pressure tests had shown that some welds were below the standard required by the authority, but that this would not affect the construction schedule.
A nuclear power plant south of Cherbourg on the Cotentin Peninsula, Flamanville has two reactors already in operation which supply about 3% of France’s national demand. The five-year project to add a third-generation European Pressurised Water reactor to the plant was begun in 2007 with a budget of €3.5bn. The cost is now put at €10.5bn.
Flamanville was the second EPR reactor to be constructed after Olkiluoto in Finland, which has suffered comparable delays and cost overruns, and which is also due to enter service in 2019.
This means that the first EPR to enter production will probably be at the Taishan nuclear plant in China. Work on Taishan 1 and 2 reactors have also suffered repeated delays, but not on the scale of Flamanville and Olkiluoto. At least one of the reactors is expected to be commissioned this year. Â
The UK’s plans to build two EPRs at Hinkley Point depend on the success of Flamanville: government loan guarantees require the Normandy site to be up and running by 2020. Â
The EPR was developed by Areva, EDF and Siemens.
Image: Flamanville on the Cotentin Peninsula (Manche Tourism)