THERE was an outcry last night after it was revealed that a nuclear reactor at Hunterston B power station will temporarily return to service.

The station was shut down last year when cracks were found in its core.

Reactor 4 at the facility in North Ayrshire was one of two remaining reactors there taken out of service last year. Now, the Office for Nuclear Regulation (ONR) has given operator EDF Energy the go-ahead to return it to service for up to four months.

The ONR said it had focused on whether cracks seen in the reactor graphite core would compromise safety and concluded “an adequate safety case has been provided to allow a further period of operation”.

In a statement, it said: “ONR is satisfied that Reactor 4 is safe to operate for the next period and can be safely shut down in all foreseeable circumstances, including that of a significant seismic event.”

READ MORE: Hunterston reactors under ‘enhanced’ regulation to assess danger from cracks

Its deputy chief inspector, Donald Urquhart, said: “We have made the decision to allow Reactor 4 at Hunterston B to return to service following a long and detailed assessment of the safety case submitted by EDF Energy.

“Nuclear safety remains our utmost priority and we would only allow a reactor to restart with clear evidence that it remains safe for workers and the public.”

The regulator said the longer-term condition of the reactor “remains uncertain” and EDF “will need to justify safe operation” beyond the four-month period.

EDF Energy said: “We are pleased to confirm that the independent nuclear safety regulator, ONR, has given permission for EDF Energy to re-start Reactor 4 at Hunterston B power station.”

The company said tests had “demonstrated that even in the most extreme conditions our reactors operate within large safety margins”, adding the control rods will “safely shut down the reactor in all circumstances”.

However, Dr Richard Dixon, director of Friends of the Earth Scotland (FoES), said: “Restarting the Hunterston reactors is definitely not worth the risk. Most people in Scotland will not even have noticed these reactors at Hunterston have been offline for so long, as dependable renewable energy has more than made up for the difference.

The nuclear industry is doing a great job of showing how terrible a bet nuclear is. The industry is almost unique in that every new reactor costs more than the last, while everything else gets cheaper, including offshore wind power which is now coming in at just over half the price of nuclear for a unit of energy.”

West of Scotland Green MSP Ross Greer added: “The ONR themselves have detailed four previous notable safety incidents. These include lost cooling for a reactor, the failure of a shutdown pump and smoke from a control room panel.

“EDF have said these individual incidents are minor, but together with the 350 cracks in the reactors, they paint the picture of an ageing relic being pushed beyond its already repeatedly extended lifespan.”