The Public Accounts Committee (PAC) has warned the UK Government needs to better manage the challenges posed by decommissioning the Sellafield nuclear waste site.

In a new report, the PAC criticises the Nuclear Decommissioning Authority (NDA) for not having systematically reviewed why major projects keep running into difficulties and stresses it must not become complacent because of recent progress in some areas.

It also highlights how cost overruns are now expected to stand at £913 million and calls for the Department for Business, Energy and Industrial Strategy (BEIS) to make a decision on the future of the site’s plutonium stockpile.

The PAC said it “remains sceptical” about the long-term strategy to decommission what is the largest nuclear waste facility in the country and said the NDA’s recently failed contract to decommission its Magnox sites did not offer any sign of hope.

PAC Deputy Chair, Sir Geoffrey Clifton-Brown MP, said: “The government’s oversight of the NDA’s performance could and should be much better, particularly on projects at Sellafield that cost a considerable amount of public money.

“In short, BEIS needs to seriously get a grip on its oversight of nuclear decommissioning in this country.”

A spokesperson from the NDA said: “The Report recognises that since 2015, when the NDA announced its intention to make Sellafield Ltd a subsidiary of the NDA, significant milestones in reducing risk at our largest and most hazardous site have been met. It also recognises the improvement that has been made in reducing delays and expected cost overruns.

“We will respond in full to the Committee’s recommendations.”

A BEIS spokesperson said: “Decommissioning is an important part of the nuclear cycle and as the PAC recognises, considerable progress has been made at Sellafield.

“This includes strengthening the governance structure and greater use of cutting-edge technologies to ensure the highest possible safety standards are maintained, whilst reducing the costs of decommissioning by 20% by 2030.”