THERE have been 12 nuclear incidents that could have leaked radioactivity at the Faslane naval base since 2023, The Ferret can reveal.
According to the Ministry of Defence (MoD), the incidents at the Clyde nuclear submarine base had “actual or high potential for radioactive release to the environment”.
But the MoD has refused to say what actually happened in any of the incidents, or exactly when they occurred. There were five in 2023, four in 2024 and three in the first four months of 2025 – the highest for 17 years.
Campaigners warned that a “catastrophic” accident at Faslane could put lives at risk. The Trident submarines based there were a “chronic national security threat to Scotland” because they were “decrepit” and over-worked, they claimed.
New figures also revealed that the total number of nuclear incidents categorised by the MoD at Faslane and the neighbouring nuclear bomb store at Coulport more than doubled from 57 in 2019 to 136 in 2024. That includes incidents deemed less serious by the MoD.
The SNP described the rising number of incidents as “deeply concerning”. They branded the secrecy surrounding the incidents as “unacceptable”.
The MoD, however, insisted that it took safety incidents “very seriously”. The incidents could include “equipment failures, human error, procedural failings, documentation shortcomings or near-misses”, it said.
The latest figures on “nuclear site event reports” at Faslane and Coulport were disclosed in a parliamentary answer to the SNP’s defence spokesperson, Dave Doogan MP. They show that a rising trend of more serious events – first reported by The Ferret in April 2024 – is continuing.
There was one incident at Faslane between January 1 and April 22, 2025 given the MoD’s worst risk rating of “category A”. There was another category A incident at Faslane in 2023.
The MoD has defined category A incidents as having an “actual or high potential for radioactive release to the environment” in breach of safety limits.
The last category A incident reported by the MoD was in 2008, when radioactive waste leaked from a barge at Faslane into the Clyde. There were spillages from nuclear submarines at the base in 2007 and 2006.
There were also four “category B” incidents at Faslane in 2023, another four in 2024 and two in the first four months of 2025. The last time that many category B incidents were reported in a year was 2006, when there were five.
According to the MoD, category B meant “actual or high potential for a contained release within building or submarine”, or “actual or high potential for radioactive release to the environment” below safety limits.
The MoD also categorised nuclear site events as “C” and “D”. C meant there was “moderate potential for future release to the environment”, or an “actual radioactive release to the environment” too low to detect. D meant there was “low potential for release but may contribute towards an adverse trend”.
The number of reported C incidents at Faslane and Coulport increased from six in 2019 to 38 in 2024, while the number of D incidents rose from 50 to 94.
At the same time the number of incidents described by the MoD as “below scale” and “of safety interest or concern” dropped from 101 to 39.
SNP MP Doogan criticised the MoD in the House of Commons for the “veil of secrecy” which covered nuclear incidents. Previous governments had outlined what happened where there were “severe safety breaches”, he told The Ferret.
“The increased number of safety incidents at Coulport and Faslane is deeply concerning, especially so in an era of increased secrecy around nuclear weapons and skyrocketing costs,” Doogan added.
“As a bare minimum, the Labour Government should be transparent about the nature of safety incidents at nuclear weapons facilities in Scotland, and the status of their nuclear weapons projects. That the Scottish Government, and the Scottish people, are kept in the dark about these events is unacceptable.”
Doogan highlighted that the UK Government’s Infrastructure and Projects Authority had judged many of the MoD’s nuclear projects to have “significant issues”, as reported in February by The Ferret. The MoD nuclear programmes would cost an “eye-watering” £117.8 billion over the next 10 years, he claimed.
He said: “If the UK cannot afford to store nuclear weapons safely, then it cannot afford nuclear weapons.”
Anti-nuclear campaigners argued that the four Trident-armed Vanguard submarines based at Faslane were ageing and increasingly unreliable.
They required more maintenance and their patrols were getting longer to ensure that there was always one at sea.
“The Vanguard-class submarines are already years past their shelf-life and undergoing record-length assignments in the Atlantic due to increased problems with the maintenance of replacement vessels,” said Samuel Rafanell-Williams, from the Scottish Campaign for Nuclear Disarmament.
“There is a crisis-level urgency to decommission the nuclear-capable submarines lurking in the Clyde. They constitute a chronic national security threat to Scotland, especially now given their worsening state of disrepair.”
He added: “The UK Government is placing the people of Scotland at risk by continuing to operate these decrepit nuclear vessels until their replacements are built, which will likely take a decade or more.
“The Vanguards must be scrapped and the Trident replacement programme abandoned in favour of a proper industrial policy that could genuinely revitalise the Scottish economy and underpin our future security and prosperity.”
Dr David Lowry, a veteran nuclear consultant and adviser, said: “Ministers tell us the purpose of Britain’s nuclear weapons is to keep us safe.
“But with this series of accidents involving nuclear weapons-carrying submarines, we are in danger of actually killing our own, if one of these accidents proves to be catastrophic.”
According to Janet Fenton from the campaign group Secure Scotland, successive governments had hidden information about behaviour that “puts us in harm’s way” while preventing spending on health and welfare.
She said: “Doubling the number of incidents while not telling us the nature of them is making us all hostages to warmongers and the arms trade, while we pay for it.”
The Secretary of State for Defence, John Healey, told the House of Commons that he rejected “any accusation of a veil of secrecy”. He promised Doogan that he would look into the allegations and write to him.
When pressed by The Ferret, the MoD declined to outline what had happened in the three category A and B incidents at Faslane in 2025. It has also refused to give details of earlier incidents in response to a Freedom of Information request.
An MoD spokesperson said: “We have robust safety measures in place at all MoD nuclear sites and we take safety incidents very seriously. Our nuclear programmes are subject to regular independent scrutiny and reviews.
“In line with industry good practice and in common with other defence and civil nuclear sites, His Majesty’s Naval Base Clyde has a well-established system for raising nuclear site event reports.
“They are raised to foster a robust safety culture that learns from experience, whether that is of equipment failures, human error, procedural failings, documentation shortcomings or near-misses.”
In 2024, The Ferret revealed earlier MoD figures showing that the number of safety incidents that could have leaked radiation at Faslane had risen to the highest in 15 years. We have also reported on the risks of Trident-armed submarines being on patrol at sea for increasingly long periods.
