EDF Energy’s nuclear power generation subsidiary British Energy has announced that all four reactors at the Heysham-1 and Hartlepool nuclear power stations, which provide around 2,350MW of electricity generation in the UK, have been returned to service following a 17-month outage. Reactor-2 at Heysham-1, the last of the four reactors to return to service, has begun supplying power to the grid.

British Energy has said that this brings 4% of UK electricity generation back on line. The four reactors were taken out of service in October 2007 after a planned inspection revealed some corrosion on wires which are part of the boiler closure units.

Following a 17-month program encompassing, the four reactors have been returned to service. The first three units are operating at full load and the fourth reactor is being increased to full load in a planned power increase.

While the reactors were out of service, British Energy took the opportunity to bring forward maintenance work, including the replacement of a generator stator and main generator transformer at Hartlepool and the replacement of some 3km of cast iron cooling water pipe work at both stations.