Freedom of Information Requests
The radioactive material was released into Loch Long, a sea loch near Glasgow in western Scotland, because the Royal Navy failed to properly maintain a network of 1,500 water pipes on the base, a regulator found.
The armaments depot at Coulport on Loch Long is one of the most secure and secretive military sites in the UK. It holds the Royal Navy’s supply of nuclear warheads for its fleet of four Trident submarines, which are based nearby.
Files compiled by the Scottish Environment Protection Agency (Sepa), a government pollution watchdog, suggest that up to half the components at the base were beyond their design life when the leaks occurred.
Sepa said the flooding at Coulport was caused by “shortfalls in maintenance”, resulting in the release of “unnecessary radioactive waste” in the form of low levels of tritium, which is used in nuclear warheads.
The leaks (multiple) are revealed in a cache of confidential inspection reports and emails given to the investigative website the Ferret and shared with the Guardian, which Sepa and the Ministry of Defence fought to keep secret.
They were released on the orders of David Hamilton, the Scottish information commissioner, who polices Scotland’s freedom of information laws, after a six-year long battle by reporters for access to the files.
The UK government insisted the files had to be kept secret for national security reasons, but in June Hamilton ruled that most had to be released. He said their disclosure threatened “reputations” not national security.
They were released in August following a further delay after the MoD asked for more time to review them, citing “additional national security considerations”.
Nuclear warheads are fitted on to the UK’s supply of Trident missiles at Coulport where the missiles are loaded on to Vanguard class submarines before they head to sea for secret patrols as part of the UK’s nuclear deterrent.
The Sepa files show there had been a pipe burst at Coulport in 2010 and a further two in 2019. One leak in August 2019 released “significant amounts of water” that flooded a nuclear weapons processing area, where it became contaminated with low levels of tritium and passed through an open drain that fed into Loch Long.
After an internal investigation and a Sepa inspection, the MoD promised 23 actions to prevent more bursts and floods in March 2020. It accepted that its lack of preparedness had caused “confusion”, “a breakdown in access control” and a “lack of communication of the hazards”.
However, there were two further pipe bursts in 2021, including one in another area that also held radioactive substances, prompting another inspection by Sepa in 2022. Progress on completing the 23 remedial actions “had been slow and delayed in many cases”, Sepa said. “The events have highlighted shortcomings in asset management across the naval base.”
David Cullen, a nuclear weapons expert with the defence thinktank Basic in London, said the repeated pollution incidents were shocking and the attempts to keep them secret were “outrageous”.