Say freeze: Navy team fixes submarine nuclear reactor with liquid nitrogen

A Royal Navy team claimed a “world first” after freezing pipes and repairing a submarine nuclear reactor using liquid nitrogen.

Several institutions and societies, including IMechE, honoured the Submarine Mechanical Specialists team by awarding them the Churchill Medal. The accolade, named in honour of former prime minister Winston Churchill, is awarded for “outstanding achievements and contribution” in engineering and technical advancements supporting military operations.

The Institution of Engineering and Technology (IET) praised the engineers for their “innovative” adaptation of freeze seal isolation, a technique which uses ultra-cold liquid nitrogen to freeze and isolate pipes, for the restricted and technically challenging space of a nuclear submarine. The successful triple freeze seal was reportedly the first ever deployment to repair a nuclear reactor, offering flexibility for submarine operations and applications across the global nuclear industry.

“We are really stunned and honoured to win this prestigious industry medal, particularly when we were up against teams who are dealing with very complex areas of engineering, such as cyber,” said commander Philip Parvin. “It is testament to the hard work and efforts of the whole team.”

The work demonstrated “technical excellence, determination and self-sacrifice,” said IET chief executive Nigel Fine.

MP Nicholas Soames, Churchill’s grandson, presented the winners with their medal. The IET, IMechE, Institute of Marine Engineering, Science and Technology, Royal Aeronautical Society, Institution of Royal Engineers, Institution of Civil Engineers, Society of Operations Engineers and the British Computer Society jointly awarded the medal.