The UK Ministry of Defence (MoD) has confirmed a serious nuclear incident occurred earlier this year at HMNB Clyde, also known as the Faslane naval base in Scotland, according to The Times UK.
Classified as a “category A” incident—the highest risk level—the event carried a “high potential for radioactive release to the environment.” The MoD stressed that the incident posed no danger to the public and did not cause any measurable environmental impact.
The incident took place between January and April but details remain limited due to national security concerns. A Ministry of Defence source said the designation reflects the potential severity, explaining that “there was a high potential for a release, but there wasn’t a release.”
HMNB Clyde is home to the UK’s nuclear submarine fleet, including Vanguard-class submarines armed with Trident missiles. During this period, HMS Vengeance was undergoing sea trials in nearby Gare Loch.
The MoD also reported 27 other incidents at Faslane in the same timeframe, though these were deemed less serious. This is the second category A incident at the base in two years, following a similar event in 2023. Prior to that, the last incident of this severity occurred in 2008.
At Coulport, where the UK stores its nuclear warheads, there were no category A incidents, but 13 category C and 34 category D incidents occurred over the past two years.
A Ministry of Defence spokesperson said: “We place the utmost importance on handling radioactive substances safely and securely. Nuclear site event reports demonstrate our robust safety culture and commitment to learn from experience. Our government backs our nuclear deterrent as the ultimate guarantor of our national security.”
