Nuclear reactors may stay offline until end of year, EDF says

Temporary closure of the four nuclear power reactors prompt concerns over winter electricity supply

Four nuclear power reactors that were shut down after a defect was discovered in one of them may not be back online until the end of the year, EDF Energy has said.

The reactors at the Heysham 1 and Hartlepool power stations were shut down in August after a routine inspection. All four reactors were closed after inspections found a crack in the boiler spine, a metal tube that supports the weight of boiler tubes around the reactor, was discovered at Heysham 1. The other three reactors were closed as a precautionary measure because they were of the same design.

EDF said the design was particular to these sites and not affecting its other nuclear power stations elsewhere in the country.

The firm now plans for a "phased return to service" for all four reactors which is expected to take place between the end of October and the end of December.

However, concerns over the country's winter power supply have been prompted by the temporary closures of Heysham 1 and Hartlepool, which account for roughly 10% of the country's nuclear capacity, enough to supply electricity to three million homes.

After EDF's announcement, as well as news of the closure of Barking power station, and fires at Ironbridge and Ferrybridge power stations earlier this week, National Grid declared it was seeking additional electricity suppliers for winter.

National Grid said it would take the “sensible precaution" of paying mothballed generators to be online over the period.

Engineers at EDF must now complete inspections to ensure there are no further defects which could develop into cracks, as well as understanding the cause of the crack found at Heysham 1. They must also present a safety case for reopening the boilers to satisfy the independent Office for Nuclear Regulation.

EDF said: "Dates for returning the stations to service depend on the findings and completion of the inspections. EDF Energy will give further updates on the progress of the programme when it is able."

EDF Energy's other nuclear plants are at Torness in Dunbar and Hunterston B in West Kilbride, Scotland; Sizewell B in Suffolk; Hinkley Point B in Somerset, and Dungeness in Kent.

The French-owned firm is leading a consortium which plans to build the new £16 billion Hinkley Point C nuclear plant in Somerset, due to be completed in 2024.