UK-based EDF Energy has shut down two reactors at the 450MW Heysham Power Station in Lancashire, UK, due to an unforeseen outage.
The plant is operated by British Energy and is divided into two separately-managed stations, Heysham 1 and Heysham 2, both of the advanced gas-cooled reactor type.
The company has also closed the No 2 reactor at the 620MW Hartlepool Power Station in Durham, north-east UK, for a planned upgrade work.
France President Nicolas Sarkozy recently announced that he wanted the French state to remain a key shareholder in EDF.
Last year, EDF Group announced a five-year extension of its nuclear reactors at its Heysham 1 and Hartlepool until 2019.