The European Union executive said its patience had run out after repeatedly asking British Nuclear Fuels (BNFL) to open up access to a facility on the site in northeast England that stores spent nuclear fuel.

EU energy commissioner Loyola de Palacio gave British authorities until June to submit a plan proposing ways of ending the alleged breach of an EU atomic treaty.

"This problem has been known for a long time, but no concrete initiative has been taken by the operator to rectify it," she said. "The situation had therefore become untenable for the commission."

She added: "It calls into question the credibility of our safeguards, which our team of inspectors has been carrying out for 50 years in accordance with very high standards."

Under the terms of the 1957 Euratom Treaty, EU inspectors have the right to enter nuclear facilities in member states to ensure that material is being stored safely and cannot end up in the wrong hands.

But for several years, inspectors have been unable to gain access to a pond at Sellafield called B30 that stores irradiated fuel because of high radiation levels and poor visibility, Brussels complained.

"Should the UK authorities fail to meet these obligations within the deadlines set, the commission could impose penalties directly on BNFL," it warned.

The 34-year-old Sellafield plant has had a troubled history, long being the focus of environmental and anti-nuclear energy campaigners.

In 2000, BNFL suffered more bad publicity when an investigation found that safety records had been systematically falsified.

Jean McSorley of London-based campaign group Greenpeace backed the commission warning, but said Brussels was missing the point about nuclear energy.

"Sadly this dispute smacks of a demarcation row between the UK and the EU over whose officials will have responsibility for enforcing safety at nuclear sites rather than being about protecting the health and safety of workers at Sellafield and the people who live around the site," she said.

WAR.WIRE