The Ministry of Defence has confirmed that defuelling of the UK’s decommissioned nuclear-powered submarines is set to restart in 2026, as preparations continue at specialist dock facilities in Devonport.
In a written parliamentary answer, defence minister Luke Pollard said the twelve remaining first-generation submarines powered by pressurised water reactors would be handled through a tightly regulated process overseen by the Office for Nuclear Regulation.
He said the submarines would dock in “a specialised, licensed dock in Devonport”, where “the used fuel will be removed, loaded into a qualified transport container and transported to Sellafield prior to long-term storage in the Geological Disposal Facility.”
Pollard confirmed that dismantling of each vessel would only take place once defuelling is complete, adding that “work is underway to prepare the dock facilities and associated resources in line with plans to recommence defueling in 2026.”
The update also set out progress on the UK’s first full submarine dismantling programme. HMS Swiftsure, the demonstrator vessel for the Submarine Dismantling Project, began dismantling at Rosyth in 2023.
According to Pollard, the project “will refine the disposal process and is on track to be dismantled by the end of 2026, achieving the commitment given to the Public Accounts Committee in 2019.”
He said lessons from Swiftsure and the Devonport defuelling programme would be used to firm up timelines for the remaining fleet, stating that “lessons learned from these defuel and dismantling projects will provide more certainty around the schedule for defueling and dismantling the remaining 22 decommissioned submarines.”
The UK currently has 27 decommissioned nuclear submarines awaiting defuelling or dismantling, a long-running issue highlighted repeatedly by the National Audit Office and parliamentary committees concerned about safety, cost and delay.