A lead oxide release at the Sellafield site has prompted the nuclear watchdog to issue an improvement notice to its operators.
An unintentional release of lead oxide from flexible shielding at West Cumbrian complex’s First Generation Magnox Storage Pond was found in April by workers.
The lead shielding is used to protect workers from potential exposure to radiation.
The coating on the sheets used on the pond’s skip handling machine had degraded over time, resulting in lead oxide being released.
This posed a potential risk to workers, although there was no evidence that anyone had been harmed as a result of the shortfalls, the Office for Nuclear Regulation said.
It added further enquiries identified a number of other locations across the site where degraded flexible lead shielding sheets caused a risk of lead exposure.
Lead oxide is not a radioactive substance, but can be harmful if ingested, inhaled or absorbed.
The watchdog has issued an enforcement notice, requiring Sellafield Ltd to put in place measures to ensure the lead shielding sheets used in the pond facility are maintained and in working order.
It added: “Sellafield Ltd should also establish procedures for conducting routine visual inspections of these sheets and ensure timely repairs to maintain operational standards.
“This notice applies specifically to the pond facility, however ONR expects Sellafield Ltd to review its arrangements across the whole site.
“The company will be required to comply with this improvement notice by December 12.”
A Sellafield Ltd spokesman said: “During routine operations in the First Generation Magnox Storage Pond, members of our workforce spotted and reported that flexible lead sheets used for radiological shielding were in a degraded condition.
“Access to the affected area was immediately stopped, an investigation was initiated, and our regulator was informed.
“The affected sheeting is in the oldest part of the Sellafield site. This is a highly controlled environment, with low numbers of people in close proximity. Additional controls were already in place to prevent individuals coming into contact with the sheets.
“As our regulator has confirmed, no-one was harmed as a result.”
