CUMBRIA’S Sellafield nuclear plant has been given a formal caution for a radioactive leak.

Environment Agency officials said contaminated liquid ‘in the form of a steady drip’ leaked from a pipe designed to drain condensation from a ventilation duct.

It was discovered during the day Prime Minister Gordon Brown visited the site in January 2009.

Th EA said it had also issued a notice forcing Sellafield management to address the shortcomings that led to the leak, which is understood to have remained undetected for 14 months.

Although it led to a small patch of ground being contaminated, the leak had no impact to the environment or local people.

Stuart Page, the EA’s nuclear regulator, said: “The Environment Agency expect operators of nuclear facilities to employ the highest standards in controlling their wastes.

"Our investigation has revealed that Sellafield Ltd fell well short of these standards in this situation.

“While the environmental impact of the incident was minimal, a formal caution is warranted to reflect the seriousness with which we view such failings.

“Following the enforcement notice that we issued to the company in July 2009, Sellafield Ltd has made a number of improvements to its management arrangements, and we have confirmed by inspection that these improvements have gone a long way to addressing the failings that we identified.

"More work has still to be completed, and we are keeping the company’s progress in these areas under close and frequent review.”

Sellafield Ltd carries out a variety of activities at the west coast site, including spent nuclear fuel reprocessing and nuclear waste processing and storage.

Much of the site is being decommissioned.