Nuclear plant radioactive leak 'slowing down'

The Magnox Swarf Storage Silo is considered Sellafield's most hazardous building

A longstanding radioactive leak at a nuclear plant's storage silo appears to have slowed down, a report has said.

The leak in the Magnox Swarf Storage Silo (MSSS) - built more than 50 years ago at Sellafield in Cumbria - started in 2019 after first happening in the 1970s.

According to council documents, there has now been a "slight reduction in the rate of the leak", raising hopes that waste products could be removed and an affected pond drained earlier than expected.

Sellafield said it would continue to look for ways to "to stop or reduce the leak sooner".

The MSSS is considered to be Sellafield's most hazardous building.

The silo contains Magnox fuel cladding, mostly made up of magnesium, which was removed from nuclear fuel rods.

It was was built in the 1960s, with three further extensions built in the 1970s and 1980s.

Demolition plan

There is no way of stopping the leak without removing the waste first, according to Sellafield.

About 95% of the waste in the silo is expected to be moved by 2049 or 2050.

A Sellafield spokesman said: "In 2019 we reported that water from the silo was leaking to the ground in a recurrence of a historic leak from the 1970s.

"This was a known risk and something we planned and prepared for as part of our ongoing work to empty the silo."

The spokesman said new technologies continued to be explored, adding: "But our plan, approved and overseen by our regulators, remains the same: empty the silo contents, demolish the building as this will ultimately remove the source of the leak and we will continue to seek solutions to stop or reduce the leak sooner."

The Cumberland Council report said a silo emptying machine was in operation, with plans to install a second and a third one in 2026 and 2030 respectively.

"Monitoring confirms a slight reduction in the rate of the leak," the documents said.

The local authority has been contacted for a comment.