Reactor 1 at the Heysham A nuclear power station in the UK has resumed operations after five months offline. It was taken out of service along with three similar units (Heysham A2, and Hartlepool1&2) in August, following the discovery of a crack in a boiler spine in the reactor.

The UK Office for Nuclear Regulation granted permission for the Heysham A1 to restart after reviewing a safety justification for the return to service, submitted by EDF Nuclear Generation.

The regulator said it was satisfied that EDF has demonstrated the continued safe operation for the reactor, with the affected boiler isolated from service. It is due to publish a project assessment report outlining the decision.

Heysham A1 returned to service on Saturday 10 January 2015 and EDF Energy has confirmed that the reactor is ‘producing low carbon electricity.’ Heysham A2 and the Hartlepool reactors, which share boiler designs, all returned to service in November.

Heysham A1 is a 625 MWe advanced gas cooled reactor (AGR) that was first connected to the grid in 1983. It will operate at reduced load to limit boiler temperatures until its next statutory outage, scheduled for February 2017.

Photo: Heysham 1 (Copyright EDF Energy)