Brit SSNs Have Nuclear Valve Issues

This report in The Guardian details how two British SSNs, HMS Turbulent (S 87) and HMS Tireless (S 88) operated for up to two years with their Steam Generator Safety Valves isolated. Excerpts:

Safety valves designed to release pressure from steam generators in an emergency were completely sealed off when the nuclear hunter killers Turbulent and Tireless left port, a leaked memo discloses.
The problem went undetected on HMS Turbulent for more than two years, during which time the vessel was on operations around the Atlantic, and visited Bergen in Norway, the Portuguese capital, Lisbon, and Faslane naval base near Glasgow.
It was not noticed on HMS Tireless for more than a year, and was finally detected last month, two months after Tireless started sea trials from its home port at Devonport naval base in Plymouth...
... The blocked valves, on the hull of the submarines, meant that steam from nuclear-powered boilers could not have been released in an emergency, leading to a potentially disastrous build-up of pressure.
John Large, a consultant on nuclear safety who advises governments on submarine safety, said: "It was a very significant failure. These two submarines were unfit for service. It was a perilous situation."
He said sealing these valves was like blocking the valve on a domestic pressure cooker. If pressure had built up to dangerous levels, the submarine's steam circuit could have burst, leaking radioactivity into the submarine and shutting down the reactor. "There would be a risk of fatalities," Large said. "This was such a glaring and fundamental omission. It's jaw-dropping."

[Emphasis mine] Obviously, the nuclear "consultant" who thinks a steam rupture results in an immediate leak of radioactivity into the submarine, before the reactor shuts down, doesn't have a clue (unless all Brit subs have massive primary-to-secondary leaks), but the report is correct that this was a massive blunder by the shipyard and a big nuclear no-no. Admiral Rickover, who did so much to impose nuclear safety standards on the British submarine fleet in exchange for the S5W reactor design, must be on the governor right now.

(In discussing this, please remember not to disclose NNPI. For those wondering if I violated my own admonition in posting about this article, please note that I included links for both of the esoteric nuclear terms I used to show that the concepts are in the public domain.)