State-owned power utility Électricité de France (EDF) has deferred its plan to commission the third 1650MW reactor at the nuclear power plant located at Flamanville, Manche, France on the Cotentin Peninsula, to the end of 2018.
The construction of the European Pressurised Reactor (EPR) started in December 2007 with planned completion in 2012.
Commissioning date of the Flamanville 3 nuclear plant was earlier rescheduled to 2017 following discovery of flawed steel in its crucial part, forcing the developer Areva, a government-controlled company, to carry out additional tests.
Areva expects the results of the assessment in October, reported The Wall Street Journal.
EDF also revised the construction cost of the reactor, which is being developed adjacent to two existing pressurized water reactors at the power station, from initially estimate of €3.3bn to €10.5bn ($11.8bn).
The company said that construction of civil structure is 98% complete on the unit as well as 60% of the electromechanical work while the system performance testing is slated to commence in the first quarter of 2017.
EDF chairman and managing director Jean-Bernard Lévy said: "It is a priority for EDF and of critical importance for the French nuclear industry and its success internationally.
"Our teams and those of our partners, particularly AREVA, are working to complete this project together in compliance with the most stringent nuclear and industrial safety standards.
"All of the experience gained at Flamanville will be invaluable for other EPR projects, such as Hinkley Point."
Image: Anamolies were found in crucial part of the EPR. Photo: courtesy of ASN.