USS Seawolf (SSN-575)

USS Seawolf (SSN-575) was the second nuclear-powered submarine of the United States Navy and the only American submarine built with a liquid metal cooled reactor, the sodium-cooled, beryllium-moderated S2G. Her design was a variant of USS Nautilus with changes such as a conning tower and a stepped sail. The Electric Boat division of General Dynamics laid her down on 7 September 1953 at Groton, Connecticut; she was launched on 21 July 1955 and commissioned on 30 March 1957. Sodium leaks and the difficulty of maintaining the plant led to the reactor being replaced with a pressurized water reactor between December 1958 and September 1960. She later served on covert operations, was decommissioned on 30 March 1987, and was recycled by 30 September 1997.