A senior official at the Nuclear Decommissioning Authority (NDA) told the BBC this week that the costs of dismantling 19 sites over the coming years will rise by billions of pounds.

Figures from the National Audit Office earlier this year said the estimated cost of decommissioning power sites had risen to £73bn.

Jim Morse, a senior director at the NDA, told the BBC: “I think it’s a high probability that in the short term it will undoubtedly go up.

“We’ve still a lot to discover. We haven’t started waste retrieval in those parts of the estate where the degradation and radioactive decay has been at its greatest.”

He estimated that the extra cost would run into billions but admitted that he could not be sure how much the total would be.

“No-one’s done this before,” he added.

A spokesman for the Department for Business, Enterprise and Regulatory Reform told edie it was vital to invest in nuclear clean up.

“This is precisely why the Government set up the NDA which is establishing a competitive market in nuclear clean up that will drive down the eventual costs and encourage innovative solutions,” he added.

“As the NDA continues its work to establish – for the first time – the scale of the challenge, the assessment of the costs involved will naturally need adjusting.”

This was not the only time nuclear power hit the headlines this week for the wrong reasons.

On Tuesday, the French nuclear safety authority (ASN) ordered EDF Energy to partly suspend the construction of its new-generation nuclear reactor in Flamanville after concerns about the quality of the construction work.

Two of British Energy’s ageing nuclear reactors – the Hunterston B7 reactor at Largs, Ayrshire, and the Sizewell B reactor in Leiston, Suffolk -also shut down unexpectedly triggering blackouts.

Robin Oakley, head of Greenpeace’s climate and energy campaign, said: “The nuclear industry has had a woeful 24 hours that must be shaking confidence in this outdated technology.

“Sizewell B shut down unexpectedly, clean-up costs are soaring and the reactor that France want to sell us has had construction halted for safety reasons.”

Kate Martin

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