MercoPress. South Atlantic News Agency

Two Royal Navy Nuclear Subs Allowed to Sea with “Serious” Potential Risk

HMS Tireless the 1984 Trafalgar Class hunter killer submarine

Two Royal Navy nuclear submarines were allowed to sea with a safety defect putting the vessels at “serious” potential risk, it was revealed.

“Test blanks” were fitted to each vessel’s hull valves when the submarine hull was air pressurised during on-land maintenance to test for leaks. These were meant to be removed from the submarines following the work, but were left blocked off. This left both nuclear hunter killers without over-pressure protection on the steam generators, a leaked Royal Navy (RN) memo on the incident, written last month, revealed.

HMS Turbulent was operating for more than two years before the fault was discovered, while HMS Tireless, based in Devonport, Plymouth, operated for more than a year.

John Large, an independent consultant and nuclear engineer, said that if each vessel’s nuclear reactor had experienced excess pressure, it would not have been able to vent, leading to the risk of radioactive water bursting into the manned parts of the submarine, possibly exposing the crew to radiation.

An Ministry of Defence (MOD) spokesman said: “We can confirm that, as part of routine maintenance checks, an issue was identified on HMS Turbulent and HMS Tireless which have now been resolved. “We take safety extremely seriously and as soon as we were aware of this potential issue we took action to address the problem. Detailed investigations to assess the cause and any possible safety implications are ongoing and it is too early to speculate on the outcome of those investigations.”

HMS Turbulent is the second of seven Trafalgar Class submarines and was launched in 1982. HMS Tireless is third and was launched in March 1984. In 2007, two British sailors were killed after an explosion in air-purification equipment on board HMS Tireless during an exercise. The submarine was forced to dock at Gibraltar for a year in 2000 to undergo repairs when a fracture was found in a pipe close to its nuclear reactor.