Divers enter highly-contaminated Sellafield nuclear pond, a first in 65 years

Over the past decade, significant progress has been made in retrieving and safely storing fuel, bulk sludge, and redundant equipment from the pond. However, it remains one of the world's most complex decommissioning challenges and a priority project for Sellafield Ltd. and the Nuclear Decommissioning Authority (NDA). Divers enter the pond via a specially installed access platform and position themselves on a metal dive stand with a shielded floor. From here, they work up to 3.5-hour shifts to retrieve sludge and debris from the pond floor, corners, and other hard-to-reach areas.

Even though robots and other tools are usually used to clean up and shut down nuclear plants today, the divers working in the pond have a lot of experience diving in radioactive environments around the world, including at Dungeness A and Sizewell A in the UK. Lessons learned from these sites have informed the team's work at the Pile Fuel Storage Pond, which presents unique challenges due to its age and complexity.

Carl Carruthers, Sellafield Ltd.'s head of program delivery for legacy ponds, said that the project, which took five years to plan, prioritized safety and contributed to real progress in cleaning up the pond. The divers' experience will help researchers determine how divers could help clean up and drain other nuclear ponds.

Once all waste materials have been removed from the pond, the water will be drained, and the building will be demolished. The decommissioning work is estimated to cost around £212 million (about $261 million) and is expected to be completed by 2039. David Redpath, NDA's director of performance improvement - Sellafield, praised the project as an essential decommissioning milestone and a testament to the skill and expertise of Sellafield and the diving team.

Alan Wylie, the Office for Nuclear Regulation's supervising inspector, also expressed satisfaction with Sellafield Ltd.'s safety submission, noting that the use of divers had allowed for progress in retrieving material that existing techniques could no longer manage.