The total lifetime cost of decommissioning the Sellafield nuclear site has now reached £67.5 billion, and there's no indication of when that cost will stop rising, a new report from the UK Committee of Public Accounts has concluded.

The report says that over several decades, successive governments have been "guilty of failing to tackle issues on the Sellafield site, allowing an enormous nuclear legacy to build up." It calls for the Nuclear Decommissioning Authority to bring "a real sense of urgency" to its oversight of Sellafield so that the timetable for reducing risks does not slip further and costs do not continue to escalate year on year.

The Committee said that while the NDA expects Sellafield Limited to start retrieving hazardous waste currently held in legacy facilities in 2015, "given the track record on the site [it is] not yet convinced that this date will be met or that sufficient progress is being made."

Only two of the 14 major projects were delivered on or ahead of schedule in 2011-2012, the report said. It blamed "basic project management failings" for continuing to cause delays and increase costs.

The report questioned the cost reimbursement contract model in which the taxpayers, rather than Sellafield Limited or its subcontractors, bear the financial risks of the delays and cost increases.

"This contracting approach may be the best option while the plan and individual projects contain significant uncertainties, but the Authority has yet to work out how and when it will start to transfer more risk to the private sector," the report said.

The Committee also said that it is "not yet convinced" that taxpayers are getting a good deal from the NDA’s arrangement with Nuclear Management Partners (the parent body organization of Sellafield Limited). It said that all payments to NMP "need to be strictly controlled and determined by robust, verified assessments of the value gained."

The report, published 4 February 2013, is available on: http://tinyurl.com/brp2pd4