November 19 2000 BRITAIN
Nuclear sub 'came close to meltdown'
http://www.sunday-times.co.uk/news/pages/sti/2000/11/19/stinwenws02014.html
Adam Nathan

ONE of Britain's nuclear submarines came within "a few minutes" of a reactor meltdown, naval experts have revealed. HMS Tireless, a hunter-killer submarine now awaiting repair in Gibraltar, came far closer to catastrophe than previously thought.

 A Royal Navy source said the incident, originally described by the Ministry of Defence (MoD) as "minor", involved a failure of the cooling system that would have led to a meltdown in the reactor.

The resulting explosion would have released a cloud of radioactive dust contaminating thousands of square miles of the Mediterranean. Disaster was averted by the vigilance of the crew and the smooth functioning of the submarine's emergency systems.

The incident took place on May 18, when the submarine was on exercise in the Mediterranean. It limped into Gibraltar for repairs the next day and has been there since.

It emerged yesterday that the vessel's crew did not realise for several months how serious the failure could have been. Protests by local residents prevented detailed work on the submarine until last month, when the true extent of the fault was discovered.

 "The on-board safety systems worked exactly as they were intended to, thank God," said a source closely associated with the repair programme. "People were extremely alarmed to realise what could have happened had they not."

The problem arose from a leak in Tireless's cooling system, manufactured by Rolls-Royce and designed to keep the reactor at a safe temperature. MoD and Rolls-Royce engineers have discovered what one described as a crack of "critical length", which would have led to a "wholesale loss of coolant". Had the nuclear plant remained active, it would have heated up uncontrollably.

The effects of an explosion would have been similar to those in the area surrounding the nuclear power station at Chernobyl, in what is now Ukraine, which blew up in 1986, forcing the evacuation of several thousand inhabitants.

"We were fortunate that the fail-safe systems worked so the crew was able to detect a coolant leak and close down," said one naval source. "The problem was that the place where the leak happened could not be isolated. Once the fault had ripped through, it could not be isolated from the rest of the system."

 When the seriousness of the fault was realised, ministers and naval chiefs acted quickly. Geoff Hoon, the defence secretary, authorised the unprecedented removal from service of Britain's 11 other nuclear attack submarines for checks. One, HMS Triumph, returned to sea earlier this month. Seven of the submarines, however, are showing signs of the same problem as Tireless.

The disclosures last night sparked new fears in Gibraltar, where protests against Tireless's presence have been going on since it arrived. "We never wanted this here and we want it out now," said Janet Howatt of the Concerned Parents' Action Group, which is campagining to return Tireless to Britain.

Demonstrations have now extended over the border into southern Spain. Spanish concern at the submarine's continued presence near its territory overshadowed Tony Blair's visit to Madrid last month and the issue threatens to damage diplomatic relations between Spain and Britain.

MoD sources say that the submarine's reactor is now operating at low heat and insist it poses no radioactive threat.

But nuclear experts have yet to give a final judgment and Tireless is likely to stay in Gibraltar until at least next March, undergoing further repairs.