The NDA says ongoing "operational difficulties" mean it will take longer than expected to make safe old-style Magnox facilities at the Sellafield site. Much of the cash the NDA is depending on was put on hold by the work stoppage at Thorp, Britain’s main reprocessing at Sellafield.

A nine month long leak of nitric acid filed with radioactive substances was discovered and the facility was shut down until this summer, when the NDA allowed it to begin processing back orders. It will be reopened, despite the criticism of several environmental groups including Bellona, in 2008.

But The NDA’s decommissioning budget has been hobbled.

The NDA said it had been given an £8.5 billon ($16.8 billion) budget by the Treasury for the next three years – an increase of £671m compared with the last three years – but made clear that this was not enough to deal with a total clean-up bill that it now estimates at £73bilion, 16 percent higher than 12 months ago.

Most of the cash will go on work at Sellafield and Dounreay in Scotland.

NDA three-year plan targets decommissioning at Sellafield
These figures are made public in the NDA’s draft three-year plan, parts of which were shown to Bellona Web.

"So the key strategic challenges now facing us are how do we address hazard reduction in a pressurised funding environment?" the NDA asked in its business plan, before saying it would need to prioritise funds to Sellafield and Dounreay.

The NDA admitted its task was complicated by "logistical issues" at Sellafield which means it will not be possible to defuel the 11 Magnox stations within the original timetable.

"It is likely that the reprocessing of Magnox spent fuel at Sellafield, which was due to be completed by around 2012, will not be completed until 2016 or later," the report.

NDA Chief executive Dr Ian Roxburgh confirmed this in remarks to the BBC.

NDA chief confirms the strategy
"In line with our strategy, our priority is hazard reduction and we will be focused on the sites that require the most work,” he said, indicating that these are the Dounray and Sellafield sites.

"It is increasingly clear that due to operational difficulties at Sellafield, the timescales for defuelling the Magnox stations will need to be re-assessed and we will need to work through the implications of this with our stakeholders," said Roxburgh.

Barry Snelson, managing director at Sellafield, said: "We have received a higher level of funding than in previous years, and this will allow us to maintain our focus on reducing the high-level hazards on our sites.”

"While this will mean a reduction in the rate of growth at Sellafield, it clearly affirms our strategy of putting cleanup of the highest hazards as our first priority, he said. "We will need to increase the timescales associated with our clean-up plan but, on the plus side this should help deliver a longer, more stable work schedule rather than peaks and troughs."

Funding difficulties become clear
The difficulties have been apparent just a few weeks after the NDA suspended the planned competition process to put work on several reactors under the Magnox classification out of bid in a private tender, though NDA officials deny that had anything to do with funding problems.

Nick Baldwin, the NDA’s interim chairman, denied that it was a "gloom and doom" scenario facing the agency just two-and-a-half years after it was established with a mission to increase efficiency and speed up the national clean-up process.

"Its always possible to look at things with the glass half empty but we have a success here, Baldwin said in remarks to the London Guardian.“We have had been given more money in a very tough spending round and while we had aspirations to accelerate the pace of decommissioning we are dealing safely and efficiently with one of the nation’s most challenging issues."

But the unions expressed anger at a situation, which they fear will lead to hundreds of redundancies and destroy the UK’s nuclear skills base.

Unions warn of soaring costs resulting from delays
Mike Graham, general secretary of the biggest nuclear industry union, Prospect, said: "The NDA’s strategy is in tatters. This revised business plan reflects heavily on the problems but does not provide any solutions. It strongly promotes the idea of diverting monies from Magnox decommissioning sites to Sellafield high-hazard reduction, but does not deal with the consequences of such actions.

He said waiting to decommission Magnox sites just drives up the cost of doing do in years to come.

"The revised plan leaves Magnox hanging in the balance and risks losing the confidence of local stakeholders, for which industry has fought hard,” Graham said. “

There is no detailed examination of the cost of meeting the severance terms for employees on the sites where clean-up will be suspended, or recognition of how overall costs will soar for every year decommissioning is put on hold."