Naval Submarine Base New London by the Submarine Escape Immersion Equipment in the 2000s. On January 21, 1954 the first nuclear-powered submarine, , was launched from Groton. "Nautilus" became the first vessel to transit the North Pole during a historic trip across the Arctic in 1958. "Nautilus" spent most of her career assigned to Submarine Squadron 10 located at State Pier in New London. It was retired from service in 1980. In 1982 "Nautilus" was designated a National Historic Landmark in Groton. It is permanently moored south of the main gate, attached to the U.S. Submarine Force Museum. Self-guided tours are available to the public
Nuclear weapons and the United Kingdom remain classified. Much of the HEU supplied by the US was used not for weapons, but as fuel for the growing fleet of UK nuclear submarines. Under the MDA, the US supplied the UK with not just nuclear submarine propulsion technology, but a complete S5W pressurised water reactor of the kind used to power the US submarines. This was used in the Royal Navy's first nuclear-powered submarine, , which was launched in 1960 and commissioned in 1963. The S5W had a Nuclear reactor core that used uranium enriched to between 93 and 97 per cent uranium-235. Reactor technology was transferred