The nuclear industry is bidding behind closed doors to relax safety standards by doubling the number of cracks allowed in the radioactive cores of Scotland’s ageing reactors.

EDF Energy is asking for the safety rules to be rewritten so that it can keep running its nuclear power stations at Hunterston in North Ayrshire and Torness in East Lothian until they are at least 47 and 42 years old. They were originally designed to last 30 years.

Prolonged radiation bombardment causes the thousands of graphite bricks that make up reactor cores to crack, threatening a safe shutdown. But EDF is asking the UK government’s watchdog, the Office for Nuclear Regulation (ONR), to permit an increase in the proportion of cracked bricks from 10 to 20 per cent.

The revelation has sparked alarm from politicians and campaigners, who say that the industry is “gambling with public safety” and the public must be consulted. One leading expert argues that Hunterston should be immediately shut down.

Hunterston nuclear power station started generating electricity in 1976. EDF currently plans to keep it operating until 2023, and the ONR is due to conclude a safety review of its future operation before the end of January.

On 13 January EDF closed down one of Hunterston’s two reactors for planned maintenance, including inspections of cracking in the graphite core. The reactor is due to be restarted on 10 February.

Torness was started up in 1988, and is currently planned to operate until 2030. EDF, however, has said that it is hoping that the lives of both nuclear stations can be extended by a few more years.

EDF’s bid to relax safety standards at Hunterston and Torness is highlighted in a new report today for the Scottish Greens. It concludes that the risks from graphite cracking are serious, and argues that an international convention demands that environmental risks must be assessed, alternative energy sources considered and the public consulted.

According to the report’s author, Edinburgh-based anti-nuclear campaigner and consultant, Peter Roche, Scotland’s doesn’t need nuclear electricity. “Despite the fact cracks are beginning in the graphite core of these reactors, increasing the risk for us all, the public has still not been asked for its opinion once,” he said.

“The Scottish Government should ask itself if it really wants ageing reactors to continue operating and producing nuclear waste for up to another thirteen years – gambling with public safety – when we know that there are plenty of ways to provide alternative sources of energy.”

Scottish Green MSP for West of Scotland, Ross Greer, warned that communities would be concerned about proposals to allow more cracking. “The lack of public consultation is just unacceptable,” he said.

“If we did this properly, the public would reject an ageing, cracking, safety hazard. The Scottish Government’s relaxed position on nuclear needs challenged. We simply don’t need to sweat these plants and add to our toxic legacy.”

John Large, a consulting nuclear engineer, pointed out that the integrity of the graphite bricks was vital to nuclear safety. If they failed, they could block channels that enable control rods to be inserted to close down reactors and prevent them from overheating.

“Ageing problems like this serious cracking of the graphite bricks at the heart of each reactor are deeply worrying, so much so that these nuclear plants should now be permanently shut down,” he said.

Large accused EDF and the ONR of “false confidence” in believing they fully understood graphite cracking, which was difficult to predict. “The Hunterston B nuclear reactors now in their 41st year of operation, should be immediately shut down,” he stated.

But EDF, which is a state-owned French company, insisted that its nuclear stations would continue to operate safely. “The graphite in our reactors is behaving exactly as experts predicted it would, and this is confirmed by our regular inspection programme,” said a company spokeswoman.

“We therefore remain confident in our plant lifetime forecasts. Nuclear safety drives everything we do and our reactors are operated with very large safety margins.”

EDF’s director of nuclear operations Brian Cowell told the BBC Costing the Earth programme that cracks in 1,000 of the 6,000 graphite bricks in a reactor would still give “massive margins of safety where the reactors will still operate safely and shut down safely.”

The company also argued that environmental impact assessments – and, by implication – public consultations were not required for life extensions at Hunterston and Torness.

ONR’s deputy chief inspector Mark Foy told the BBC that EDF had asked for the proportion of graphite bricks allowed to be cracked to rise from 10 to 20 per cent. “That is provided to us in the form of a comprehensive justification, which we will assess to see whether we’re satisfied it’s safe to operate,” he said.

The ONR confirmed that its periodic safety review for Hunterston was due at the end of January. “While the decision is still being made, it would not be appropriate to comment on it,” said an ONR spokesman.

The Scottish Government did not back demands for public consultation. “We support life extensions for existing nuclear power stations – but only where the strictest environmental and safety requirements are met,” said a spokesman.

“The ONR must ensure the nuclear industry controls its hazards effectively and maintains the highest nuclear safety and security standards. Extending the operating life of Scotland’s existing nuclear stations, subject to the agreement of the regulator that it is safe to do so, could help to maintain security of supply while the transition to renewables and cleaner thermal generation takes place.”

Ministers were opposed to building any new nuclear stations in Scotland, the spokesman stressed. “We continue to work towards an over-arching Scottish energy strategy and will shortly set out our priorities.”

Photo thanks to Richard Webb licensed for reuse under this Creative Commons Licence.

A version of this story was published in the Sunday Herald on 22 January 2017.