The credibility of the nuclear industry was shaken last night after the estimated cost of cleaning up Britain's atomic waste was raised by a further £10bn.
The latest clean-up estimate from the Nuclear Decommissioning Authority (NDA) suggests the commonly accepted figure of £73bn should rise to £83bn. But the agency insisted that £10bn of income from generating and fuel reprocessing plants should also be taken into account.
It said the most accurate estimate of the clean-up bill over the next 130 years was £73bn, which included £10bn for the future construction of a high level waste depositary. The NDA's estimates for that project have not been revealed before.
The government agency blamed the latest rise in costs on the decision to tackle more complicated hazard problems at Sellafield along with rising inflation in the engineering sector, and a lack of income from the Thorp and Mox fuel reprocessing plants, which have been hit by a succession of problems.
The latest clean-up estimates came as a newly restarted fuel reprocessing plant was taken out of action until the end of the year and British Energy said four broken-down reactors would not be repaired on time or within budget.
But an NDA spokesman said there was good news in its annual report and accounts because the lifetime cost of running the Drigg low-level waste depositary - now under private management - had fallen by 18% and the cost of cleaning up the Dounreay site was down by 10%.
Further savings would come from placing Sellafield under private management, he said, but admitted there could be no guarantee that the clean-up bill would not rise again: "Obviously, with a civil engineering project over 130 years there will always be risks."
Last week a report from the Commons public accounts committee criticised ministers over last year's clean-up estimate and complained about the lack of certainty over the projected cost of decommissioning Britain's nuclear sites.
Greenpeace said the NDA figures were alarming. It questioned the agency's reliance on gaining £10bn of income from plants such as Thorp, which has a history of breakdowns, and pointed out that the plant had effectively been taken out of action for the rest of the year while a new evaporator was fitted.
"In just three years the estimated cost for dealing with our nuclear legacy has risen by over £20bn," said Greenpeace's senior nuclear campaigner, Ben Ayliffe. "It now stands at over £73bn and is spiralling out of control. The NDA admits that they have no idea what the final bill will be.
"They're stuck in a radioactive quagmire and as usual it's the public who will have to carry the can. It beggars belief that Gordon Brown and his nuclear stooges want to build more atomic plants when the plans for cleaning up after our existing reactors are such a drain on this country's coffers."
The latest clean-up figures came as British Energy, the UK's main nuclear power generator, admitted that the cost of bringing back on stream two key plants that had encountered problems nine months ago would be "significantly higher" than expected and would take considerably longer to fix than anticipated.
The company originally estimated that it would cost £50m to repair reactors at the Hartlepool and Heysham 1 facilities. But yesterday BE chairman Adrian Montague said a much more complex engineering solution was required and "the final costs will be significantly higher than this initial estimate".
The four broken reactors have already soaked up a million man-hours of work and while good progress has been made, British Energy said it could not be sure of bringing the units back into service until the last quarter of this calendar year. More specific details of the cost overrun would be given next month alongside first quarter earnings.
The latest difficulties to have beset British Energy were revealed by the chairman at the company's annual shareholders' meeting in Edinburgh. Montague admitted the performance of the nuclear power stations was "disappointing", with Hartlepool and Heysham's difficulties coming on top of boiler problems at Hinkley Point B and Hunterston B.
"However, these large events mask the continued improvement in what we have seen in many of our underlying operating metrics, notably the record low level of small generation losses and the strong and sustained safety and environmental performance achieved across the fleet," he said.
Turning to expectations that a new generation of atomic power plants would be constructed in the UK, British Energy said it was making prudent investments "to secure a pivotal role" in any such developments, most obviously from preparing some of its existing sites for new plant.
"We have recently held a series of public meetings with the communities around Sizewell about our proposals for a twin nuclear unit there, and we are scheduling similar meetings for our other lead sites at Hinkley Point, Dungeness and Bradwell," Montague said.
The company, whose nuclear plants generate 14% of the UK's electricity, last month rejected takeover overtures from EDF, the French nuclear power operator which is interested in British Energy primarily for the sites which could be used for its own new atomic stations. "Our dialogue is therefore continuing and a further announcement will be made in due course," the chairman said.
- £73bn: The NDA's figure for clean-up costs: it says £10bn will be offset by income
- 130: The number of years the nuclear clean-up is expected to take
- 14%: Percentage of the UK's electricity generated by British Energy plants