Radioactive air pollution from the nuclear weapons plant at Coulport, on the Clyde, has more than doubled over the last six years, prompting cancer warnings from campaigners.
Emissions of the radioactive gas, tritium, from the Royal Naval Armaments Depot on Loch Long, have risen steadily between 2018 and 2023 from 1.7 billion to 4.2 billion units of radioactivity, according to the latest official figures.
Campaigners say that tritium is “very hazardous” when it is breathed in, and can increase the risk of cancers. But according to the Scottish Environment Protection Agency (Sepa), the emissions are well within safety limits.
The Ministry of Defence (MoD) has declined to say what has caused the increased pollution. Tritium is known to leak from ageing nuclear submarine reactors, and is also an essential component of nuclear bombs.
Coulport, eight miles from the nuclear submarine base at Faslane on the Gareloch, is where Trident missiles and nuclear warheads are stored. They are loaded on and off Vanguard nuclear-powered submarines at an explosives handling jetty.
The rising tritium emissions from Coulport have been revealed in Sepa’s Scottish Pollution Release Inventory. The inventory was updated in October 2024 to include figures for 2023.
Rising tritium pollution from Coulport
| Year | Tritium emitted to air (MBq) |
|---|---|
| 2018 | 1,770 |
| 2019 | 2,046 |
| 2020 | 2,298 |
| 2021 | 3,038 |
| 2022 | 3,472 |
| 2023 | 4,224 |
| Total | 16,848 |
The inventory also disclosed that Faslane has discharged liquids contaminated with tritium into the Gareloch, amounting to a total of over 50 billion units of radioactivity from 2018 to 2023. The discharges peaked at 16.6 billion units in 2020.
A report released by Sepa under freedom of information law revealed that in 2019 it changed the rules to allow certain tritium-contaminated effluents from nuclear submarines at Faslane to be discharged into the Gareloch.
“Low levels” of tritium had been discovered in waste, sewage and ballast water from submarines. Sepa agreed a “minor variation” to radioactive waste regulations to allow the continued treatment and disposal of the effluents.
Tritium discharges into the Clyde from Faslane
| Year | Tritium discharged to water (MBq) |
|---|---|
| 2018 | 5,817 |
| 2019 | 6,510 |
| 2020 | 16,609 |
| 2021 | 13,416 |
| 2022 | 1,582 |
| 2023 | 6,946 |
| Total | 50,880 |
The Ferret reported in December 2022 that nuclear-armed Vanguard submarines were overstretched, having to spend increasingly long periods on patrol at sea. According to The Sun, one was recently on patrol for more than six months and ran so low on food that sailors were ordered to share their rations.
The four Vanguard submarines that carry Trident missiles armed with nuclear warheads are around 30 years old. They were launched from 1992-98 and are due to be replaced by new Dreadnought submarines “in the early 2030s”, according to the MoD.
Increasing tritium air pollution from Coulport was described as “worrying” by Dr Ian Fairlie, an expert on radioactivity in the environment and a former UK government advisor. He is now vice-president of the UK Campaign for Nuclear Disarmament.
“First, they are large, more than four billion becquerels per year; second, they are steadily increasing; and third, they are of tritium – which is very hazardous when it’s inhaled or ingested,” he told The Ferret.
The discharges from Faslane into the Gareloch were also of concern, he said. “Any dose of radiation is hazardous to some degree, so that these discharges – especially of tritium – are disquieting.”
The Scottish Campaign for Nuclear Disarmament agreed that any increase in radioactive pollution was dangerous. “Governments use the idea of ‘safe levels’ and ‘acceptable risk’ but scientists agree that any exposure to ionising radiation poses some health risk,” said the campaign’s chair, Lynn Jamieson.
She added: “Children and pregnant women are particularly vulnerable and the risk of cancers increases as exposure increases. No human-made increase in ionising radioactivity in our environment is good for human health and all increases should be challenged.”
Radioactive emissions ‘must be kept low’
The Scottish Greens described the doubling of radioactive pollution from Coulport as a “cause for concern” that required “serious scrutiny”. They urged action to “reduce harm and protect lives” by heeding calls for cleaner air and waters.
“It is preposterous that Sepa and MoD claim that the emissions are within safe, permitted limits when they themselves are changing the goalposts to further contribute to the toxic, moral failing that has plagued Scotland’s shores since the 1980s,” said the party’s co-leader and former minister, Patrick Harvie MSP.
The 26-strong nuclear-free-group of local authorities is planning on writing to the MoD urging it to tackle the pollution. “Given that Trident submarines are getting older, this is a problem which is likely to get worse,” said the group’s policy advisor, Pete Roche.
The Nuclear Information Service, which researches and criticises nuclear weapons, highlighted the official aim of keeping radioactive emissions to the environment “as low as reasonably practicable”.
This did not appear to be what had happened with tritium-contaminated effluents at Faslane, argued the group’s director, David Cullen.
“When tritium was found to be leaking into waste effluent, that should have set alarm bells ringing, and Sepa should have been demanding that the MoD track down the source and prevent it,” he said.
“Instead, they appear to have shrugged their shoulders and given the green light for it to be dumped in the Clyde.”
According to Sepa, “letters of agreement” with the MoD governed pollution from Coulport and Faslane, and included annual discharge limits. “All discharges have been within the limits set,” said a Sepa spokesperson.
“Variation in annual discharges is to be expected and relates to operational programmes.” Operational matters were “for the MoD”, Sepa added.
It pointed out that the environment around Coulport and Faslane was regularly monitored for radioactivity, with marine and land sample results openly reported. In 2022 the estimated radiation dose was less than one per cent of the annual safety limit for members of the public, it said.
An MoD spokesperson said: “All waste discharges, including gaseous elements from His Majesty’s Naval Base Clyde and Coulport, are in compliance with the conditions agreed between the MoD and Sepa.”
The Ferret reported on 22 October 2024 that the MoD had blocked Sepa from releasing unspecified information about “environmental issues with radioactivity” from Coulport and Faslane since 2016. We have appealed to the Scottish Information Commissioner, David Hamilton.
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Cover image of the Royal Naval Armaments Depot at Coulport thanks to Ofog direktaktion för fred, CC BY 2.0, via Wikimedia Commons.
What about the emissions from the mothballed submarines, rotting in former Royal Naval Dockyard Rosyth?
This article would benefit from some scientific context of MBq units – perhaps comparing Coulport figures as being less than 0.5% of power stations in Scotland like Torness or Chapelcross.
Also for those worried about the old submarines at Rosyth, they have all have their fuel removed so they are just hunks of metal waiting to be cut up. You can see the Dockyard figures in the SEPA SPRI report as 0.003% of even the Clyde scary story.
Precisely this is a rather onesided and lazy story. Perhaps also compare this with randon emissions from Scotlands large granite monoliths for context.