[Mr Quatro]

https://www.npr.org/2019/07/11/74069...viet-submarine

Norwegian researchers have completed a survey of a sunken Soviet-era nuclear submarine that went down 30 years ago. The research team found that the sub is leaking a small amount of radiation from its reactors, but that it poses no threat to the surrounding environment.

The vessel, known as Komsomolets, was a one-of-a-kind attack submarine. Its hull was made of titanium, allowing it to operate at depths of more than 3,000 feet — far below what U.S. submarines could achieve at the time. It was powered by two reactors and carried both nuclear and conventional weapons.

On April 7, 1989, a high-pressure air line connected to the sub's main ballast tanks burst. The failure sparked a fire aft that slowly worked its way forward through the submarine. Of the 69 crew, only 27 survived the incident, and the submarine sank to the ocean floor in the Norwegian Sea.