The power station at Sellafield has been fined GBP 75,000 and could face injury compensation claims after two contractors were exposed to radioactive contamination.
It follows an incident in July 2007 in which a patch of concrete floor, which is believed to have been contaminated with radiation, was being drilled before it could be removed.
The two contractors inhaled dust produced by the drilling which contained so much plutonium that their suits triggered two radiation air monitors outside the enclosed area.
"Although the radiation doses in this case were below the statutory dose limits, they could potentially have been higher," commented Mark Bassett, superintending nuclear inspector for the Health and Safety Executive.
"They should have been zero. The incident highlights the importance of Sellafield Ltd following its own arrangements for protecting workers."
It follows reports in the Guardian that several residents near the site of the Buncefield oil depot explosion are still seeking injury compensation from Total UK.