Nuclear site under investigation by spending watchdog

The UK’s biggest nuclear waste dump faces an inquiry by the National Audit Office (NAO) over its soaring costs and safety record.

The public spending watchdog has said it wants to examine whether Sellafield in Cumbria is “managing and prioritising the risks and hazards of the site effectively in the short and long term”.

It follows growing concern over the costs of managing the site’s nuclear legacy.

An NAO statement said: “Cleaning up the site is a long-term endeavour, likely to last well into the next century. It is expected to cost £84bn (in discounted prices), though this cost estimate is highly uncertain.”

Sellafield stores and treats nuclear waste from weapons programmes and power generation. The site comprises more than 1,000 buildings and has about 81,000 tonnes of radioactive waste in storage. This is expected to rise to 3.3m tonnes over the coming years.

About 2,000 tonnes comprise high level waste – the most toxic – including around 140 tonnes of plutonium in what is the world’s largest stockpile.

The site employs about 11,000 people and cost the taxpayer around £2.5bn last year.

Scrutiny of its budget and safety record come after a series of critical reports in the Guardian, with allegations ranging from lax cyber security to a poor work culture. The Government, which ultimately controls Sellafield, has defended the site’s operations, insisting there is “no elevated risk to public safety as result of the issues reported”.

An NAO spokesman said it had reported regularly on Sellafield, most recently in 2018 and the findings of the latest investigation would be published in the autumn.

The spokesman said: “We concluded then that ‘work to reduce risk and high hazard at Sellafield has taken an encouraging turn for the better. However, more work was required to measure, evaluate and communicate progress more effectively.”

Sellafield is the largest of 17 nuclear sites across the country that need cleaning up, including former power stations, research centres and fuel-related facilities, as well as defence facilities.

Official estimates published last November estimated total clean-up costs at £263bn. UK Government Investments warned in its annual report that the cost of “nuclear decommissioning represents a risk to the Government due to its inherent uncertainty.”

The Office for Budget Responsibility has issued similar warnings.

A key problem for the UK is that, despite decades of trying, it still has no way of permanently storing nuclear waste. Plans for an underground “geological repository” have repeatedly stalled over objections from local communities.

Safe storage is essential because much nuclear waste remains dangerously radioactive for thousands or even millions of years.

Plutonium-240, one of the commoner forms of the element, takes 6,500 years for its radioactivity to halve, for example. Another, Plutonium-239, takes 24,000 years.

Sellafield is managed by a web of government bodies. The Department for Energy Security & Net Zero (DESNZ) is responsible for setting policy on nuclear decommissioning in England. 

It sponsors the Nuclear Decommissioning Authority (NDA), a semi-independent public body. Sellafield Ltd, a wholly-owned subsidiary of the NDA, actually manages the site.