Unit 2 of the UK’s Heysham II NPP, operated by EDF Energy, broke the world record for the continuous operation of a commercial nuclear power reactor on 1 August. The Advanced Gas-cooled Reactor (AGR) achieved 895 days of continuous operation, having operated non-stop since 18 February 2014. The reactor - also referred to as Heysham 2 unit 8 - is scheduled to continue operating until 16 September, when it will be taken offline for a planned maintenance and inspection outage. Assuming it operates until that time, it would have run continuously for 941 days. The reactor has generated 13.495TWh of electricity so far during this continuous operation, taking its lifetime generation to 115.46TWh. AGRs are refuelled without being shut down. During the current run, 123 fuel channels have been refuelled.
The previous record was held by unit 7 of the Pickering plant in Ontario, Canada, which had an 894-day continuous run between 26 April 1992 and 7 October 1994. This is a Candu pressurized heavy water reactor (PHWR), also designed to be refuelled during operation. Unit 2 at the Torness NPP in Scotland, another AGR, operated for 825 days between 4 August 1997 and 7 November 1999, making it the third longest running reactor. The current operating run of Torness 1 (AGR) currently exceeds 740 days, but the unit is not scheduled to be taken offline for maintenance until next April.