from Caledonian Mercury, 18 April 2011
The reactors that power all the nuclear submarines on the Clyde are twice as likely to suffer catastrophic accidents as US submarine reactors and civil nuclear power stations, according to a secret Ministry of Defence (MoD) report.
The pressurised water reactors, known as PWR2, are vulnerable to Fukushima-style loss of coolant accidents if they develop cracks larger than 15 millimetres. They also rely on manual cooling in an emergency, rather than a system that automatically injects coolant into the reactor.
These are the revelations that the MoD meant to censor from a report by its senior nuclear safety regulator, Commodore Andrew McFarlane. The report was released online in a form that enabled text that had been blacked out to be seen, simply by cutting and pasting it into another document.
The censored text also reveals that British submariners are more likely to drown than their American counterparts if the reactor fails while they are under water. British submarines "accept a much lower reliability from the main propulsion system" and the back-up system "will not provide sufficient dynamic lift", it says.
When the MoD's mistake was reported yesterday, an MoD spokesman said it "took steps to ensure the document was removed from the public domain". However, it was not removed from Google's online cache for about 24 hours, and so has been widely accessed.
The report, with the censored text revealed, has been posted on several websites, including banthebomb.org, cnduk.org, robedwards.com, largeassociates.com, nuclearinfo.org and cryptome.org. Britain’s 11 nuclear-powered submarines are all driven by reactors that are “unacceptable”, it says.
The PWR2 currently powers the Royal Navy’s six old Trafalgar class submarines and four Vanguard class submarines, which carry Trident nuclear missiles. It also drives HMS Astute, the first of a £10 billion programme of seven Astute class submarines, all of which will be based at Faslane on Gareloch.
HMS Astute returned to Faslane at the end of last week, after one of its sailors was charged with murdering a senior officer and seriously injuring another in an on-board shooting in Southampton. The submarine also hit the headlines last October when it accidently ran aground near the Isle of Skye during trials.
The MoD report, which was written in November 2009, was requested by John Ainslie, the co-ordinator of the Scottish Campaign for Nuclear Disarmament, and others. Heavily censored versions were released by the MoD under freedom of information law, but all the text in some of them could be easily read by anyone with a computer.
“The MoD is making a bungled attempt to keep this report under wraps not because it gives away any national security secrets but because it spells out fundamental design problems with the reactors on all Royal Navy submarines,” said Ainslie.
“The report shows that US nuclear submarines are substantially safer than their British counterparts. This makes a mockery of the claim that parts of the report should be classified because they might embarrass America. It is the poor state of British submarines that is laid bare.”
According to the nuclear consultant, John Large, the full report exposed the fact that Britain’s submarines were using out-dated and sub-standard technology. A small crack in the reactor could too easily trigger a major release of radioactivity, putting the lives of submariners and the pubic at risk, he said.
The MoD report argues that new submarines being considered to replace the Vanguard class boats must use a new, safer design, known as PWR3. The “necessary safety performance in response to a loss of coolant accident is likely to be delivered only through a PWR3 submarine,” it concludes.
Although no final decision on the type of reactor has been announced, indications are that PWR3 will be adopted. The UK defence secretary, Liam Fox, has told the House of Commons there was a “very clear-cut” case to use PWR3 in future submarines because it has “improved nuclear safety” and would give “a better safety outlook”.
http://www.robedwards.com/2011/04/the-submarine-reactor-risks-they-didnt-want-you-to-know.html
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