Submarine in Worst Nuclear Leak Since 80's
November 11, 2008
By Thomas Harding, Defence Correspondent and Stephen Adams
The most serious leak of radioactive liquid for 23 years at a Royal Navy base is under investigation after gallons of contaminated water spilled into a river from a nuclear submarine.
The nuclear submarine HMS Trafalgar. More than 61 gallons of toxic coolant poured from the submarine into the River Tamar in Devon. The Royal Navy is facing serious questions about why it kept quiet for four days about one of the worst radioactive spillages in recent years.
More than 61 gallons (280 litres) of toxic coolant poured into a river from a burst hose as it was being pumped from the nuclear submarine HMS Trafalgar on November 7.
But the Navy has only now admitted to the spill of the liquid, which contained tritium, a substance which can cause burns, cancer and DNA mutations as it breaks down.
Environmentalists said the incident "beggared belief" and made a mockery of tightly-regulated procedures for servicing the submarines.
The incident happened as the coolant was being pumped from the hunter-killer submarine into a large tank on a jetty at the Devonport Naval Base in Plymouth, Devon.
When the pipe split, the liquid, which had been used to cool the sub's nuclear reactor, poured into the River Tamar causing the worst spillage at the base for 23 years.
A Royal Navy spokesman said no-one had been hurt in the incident and vessel's nuclear power plant was unaffected.
He said the area was quarantined, monitoring and sampling carried out and a clean-up operation completed.
"Initial sampling has not detected any radioactive contamination in the local environment," said the spokesman.
"The environmental risk is assessed to be negligible and analysis of river water has not shown any detectable contamination."
Ian Avent, of the Campaign Against Nuclear Storage and Radiation, said: "This is the worst accident I have heard of. It beggars belief.
"The Royal Navy has been lucky that the consequences haven't been far, far worse. This doesn't inspire any confidence in them at all."
John Large, an independent nuclear engineer who has worked on the same class submarine as HMS Trafalgar, said dock workers could have been put at risk by the leak.
It demonstrated a "failure" of safety procedures, he added.
Tritium is an unstable radioactive form of hydrogen which glows in the dark and is used to create the luminous glow on watch dials. Concentrated tritium is also used as the fuel to kick-start the uncontrolled reaction in a nuclear bomb, but in nuclear reactors it is a by-product of the reaction process.
It is classed as a 'soft beta emitter', giving off low-energy beta radiation as it decays into a form of helium. Beta radiation can cause burns, cancer and DNA mutations, and tritiated water can enter the body through the skin's pores.
In normal circumstances that water would have been stored and treated until the radioactivity of the tritium had been sufficiently reduced. Then the Royal Navy would have legally released it into the estuary.
Trafalgar, which will be decommissioned next year after 25 years service, was involved in another safety incident in 2002 when it ran aground off the Isle of Skye. Two years later 11 crewmen refused to sail over safety fears in the boat's nuclear reactor and safety equipment. The Navy is also experiencing a worrying shortfall of submariners able to run a nuclear reactor.
There were 10 nuclear leaks at the base between 1980 and 1998, during which 570 litres of radioactive liquid was lost. The worst incident was in 1985 when around 350 litres was spilled.
Devonport is licensed to discharge low-level radioactive water in the Tamar and the limits were increased by 500 per cent in 2002.
Investigations are now being carried out by the Ministry of Defence and the Environment Agency with the Nuclear Installations Inspectorate.
A spokesman for the Environment Agency said: "We will investigate the circumstances of this unauthorised discharge and make sure that all necessary measures are taken to stop it happening again."