UK MoD: Nuclear Safety Incidents at Sub Base Posed No Risk to Public

 

Following a report of a minor leak of radioactive tritium at the Royal Navy's Faslane / Coulport nuclear ballistic missile submarine complex, UK politicians have begun asking questions about the frequency of reportable HSE incidents at the facilities. This week, the UK's defense minister confirmed that a serious "category A" safety incident occurred as recently as this spring - though the UK MoD maintains that the public and environment were never in danger. 

The series of revelations began five days ago, when the Guardian and The Ferret published a long-awaited story on radioactive pollution from the Coulport nuclear warhead storage depot on Loch Long, part of HMNB Clyde. Since 2019, the outlets had been trying to publish regulatory documents about leaks at the depot, and this month they finally obtained clearance from the relevant classification authorities. The documents from Scotland's environmental regulator show that aging water pipes burst three times at Coulport in the 2010s, and one event resulted in a "significant" flooding incident in a nuclear weapons processing area at the depot in 2019. The water was contaminated with low levels of tritium, and it spilled out a drain and into the sea. 

The Scottish Environment Protection Agency (SEPA) reviewed the incident and wrote up an (initially classified) report on it, finding that the pollution level was very low and unlikely to endanger the public. However, it determined that the incident demonstrated asset management shortcomings at the base, resulting in the unexpected piping failure. 

The MoD pledged improvements after the report, but there were two more pipe bursts in 2021, including a second flooding incident in an area with radioactive materials. In 2022, SEPA concluded that MoD had moved too slowly in making safety management improvements.

Since 2023, there have been 12 additional "category A" nuclear safety incidents at the Faslane sub base, according to The Ferret. One occurred between January 1 and April 22, 2025, confirmed defense minister Maria Eagle this week. 

"None of the events caused harm to the health of any member of staff or to any member of the public and none have resulted in any radiological impact to the environment," Minister Eagle assured in a written response.

The MoD has pushed back on perceptions of risk, and it suggested this week that it is "factually incorrect to suggest" that there was any danger to the public or any radiological impact. It has presented the existence of safety incident reports as a positive, a demonstration of "robust safety culture and commitment to learn from experience."  

The news of Faslane's reportable safety incidents prompted protests from Scottish politicians. "With repeated reports of serious incidents at Faslane and now confirmed radioactive contamination in Loch Long, it's clear these weapons are not only poorly maintained but are a direct threat to our environment, our communities, and our safety," said MSP Keith Brown in a statement.