LONDON — EDF Energy, the British subsidiary of the French state-controlled utility, said Monday that it was shutting down three nuclear reactors and that a reactor with a fault that has been shut down since June would remain so. The facilities, which are being investigated as a precaution, generate nearly a quarter of nuclear capacity in Britain.
The British Office for Nuclear Regulation said there had been no release of radioactive material and no injuries. Industry experts did not anticipate much effect on electricity supplies or prices in the short term.
EDF said that over the next few days it would idle a second reactor at the facility where the fault was found last year, Heysham 1, in northwest England. The company said it would also shut down two other reactors of similar design at Hartlepool in northeast England to investigate whether they had the same flaws.
The plants will be closed for an estimated eight weeks while the inspections are performed, EDF said. The company added that it was “not possible” to know exactly when they would return to operation.
The company indicated that it was still working to identify the nature of the defect at the reactor and said the reactor was likely to operate at reduced load “until a suitable repair strategy can be implemented.”
In a statement, the Office for Nuclear Regulation said it was “satisfied that EDF Energy is taking appropriate and conservative action in the interests of continued nuclear safety.”
EDF operates nearly all of Britain’s nuclear fleet, having bought most of the country’s existing plants through its acquisition of British Energy in 2008. The British utility Centrica, a 20 percent minority partner on the nuclear plants, said the shutdown would cut its earnings by an estimated 0.3 pence a share in 2014. Last year, the plants earned 26.6 pence a share.
The reactor problems highlight that most of Britain’s nuclear installations, which generate about 20 percent of the country’s electricity, are approaching the end of their lives. The four EDF reactors under investigation were commissioned in 1983 and are officially scheduled to be removed from service in 2019.
EDF Energy had been expected to seek extensions to the lives of the plants, but if the problems turn out to be too expensive to be worth fixing, then they might end up being permanently closed sooner than expected.
“If this fault is as a result of the aging of the unit, this has potential implications for the operational life of these four units and, potentially, others as well,” said Antony Froggatt, a nuclear analyst at Chatham House, a London research organization.
A prolonged shutdown would be a blow for EDF, which has invested heavily in Britain with the hopes of building new nuclear plants in the country.
The British government has said it was concerned about whether there will be enough power to keep the lights on and industry humming in the future. Not only is the nuclear fleet aging, but Britain is also shutting down coal-fired plants to meet reduction targets for greenhouse-gas emissions.
The government has been trying to attract investment into the nuclear industry not only from Britain but also from countries like France and China. There have been no nuclear plants brought online in Britain since the mid-1990s. The government is also offering subsidies to investors in renewable energy, including wind and tidal power.
The government and EDF have reached an agreement for the French utility to build a new nuclear power station at Hinkley Point in southwest England at a cost of at least 16 billion pounds ($27 billion). The European Union is considering whether various elements of the proposed deal, including guaranteeing EDF roughly twice the current cost of electric power for the plant’s output, violate rules against state aid.
A spokesman for EDF, Gordon Bell, said all four of the affected reactors were so-called advanced gas-cooled reactors, a design unique to Britain. He said inspections of the Heysham reactor had detected a defect in the “boiler spine,” an important piece of equipment in this type of reactor. He said the two factors that tend to limit the lives of this type of reactor were problems with their graphite cores and with their boilers.
Bell said, when functioning properly, the four reactors generated enough electricity to supply about 3 million homes.
Analysts said the shutdowns were not expected to have much impact on electricity prices as long as they were occurring in the low-demand summer season, but that they could test Britain’s capacity if they lasted into winter, when electricity use for heating picks up.
“It is not a worrying situation at the moment given the relatively low demand,” said John Musk, a utilities analyst at RBC Capital Markets in London. “Were the nukes to be out for an extended period into the depths of winter, it could have more significant impact.”
First Published August 10, 2014 8:00 PM