EDF Energy’s Heysham 2 nuclear plant in Lancashire has ended a record run of non-stop operation at 940 days, after one of its reactors was taken offline for planned maintenance on Friday.

The record for continuous operation of a nuclear reactor had been held for 22 years by the Pickering 7 reactor in Ontario in Canada.

Heysham 2 began its run on 18 February 2014 and passed the benchmark of 894 days set by Pickering 7 in August this year. The plant features two advanced gas-cooled reactors with a combined generating capacity of 1.23GW.

The maintenance programme will see replacement of two large gas circulators used to cool the reactor which has been shut down. The other reactor is scheduled to continue running as normal during the period.

The Torness nuclear power station in East Lothian, which is also operated by EDF Energy, is expected to break the record again in February 2017. Provided there are no unplanned shutdowns, it will reach 996 days of continuous operation when it is taken out of service for maintenance in April 2017.

In February the firm announced it was extending the life of four of its nuclear plants, including Heysham 2 and Torness. Heysham 1 and Hartlepool had their closure dates pushed back by five years until 2024. Heysham 2 and Torness are set to close in 2030 – seven years earlier than previously planned.

Station director John Munro said: “This excellent performance only happens with lots of planning, investment and total commitment from a very professional team of people here at Heysham 2.

“The investment in the plant during the planned maintenance shutdown will support the plant’s lifetime extension – supported by 1,000 skilled people.”