August 14, 2025
Royal Navy submarine base records significant nuclear safety incident
The MoD has admitted that a ‘Category A’ nuclear safety incident occurred earlier this year at Faslane, home to the RN’s all-nuclear powered submarine flotilla.
Category A incidents are defined as having an actual or high potential for the release of radioactive material into the environment. The incident took place between January and April 2025, but the MoD has not said whether any contamination occurred. Further negative headlines are the last thing the struggling Submarine Service needs, and this kind of incompetence provides more ammunition for the usual suspects who are campaigning against the UK’s critical nuclear deterrent at a time when it is more relevant than ever.
Defence Procurement Minister, Maria Eagle, provided a parliamentary written answer that shows in the first four months of 2025, Faslane recorded one category A event, two category B, seven category C, four category D and five ‘below scale’ incidents. RNAD Culport, where the UK’s nuclear warheads are stored and loaded onto submarines, saw four category C and nine category D incidents in the same period. (Category B events have a high potential for contained release within a submarine or building. Category C incidents have moderate potential for a future release, while Category D events are unlikely to result in release but may indicate an adverse trend.)
The disclosure comes days after it emerged that radioactive water entered Loch Long following burst pipework at HMNB Clyde. The Scottish Environment Protection Agency found the network of around 1,500 pipes had not been adequately maintained, with up to half of the components still in use beyond their design life.
None of the events harmed personnel or the public, nor caused any radiological impact on the environment. Although most of these incidents are of minimal risk and significance, they are partly a reflection of the nuclear regulatory frameworks in the UK that have become some of the
. However, collectively repeated accidents, however minor, are not a good look and underline the complexity of nuclear ownership and the hollowing out of infrastructure budgets in the past.
The MoD claims that Nuclear Site Event Reports (NSERs) reflect a
“robust safety culture” designed to learn from equipment failures, human error, procedural shortcomings or near-misses.
