S2W reactor

The S2W (Submarine platform Second generation core Westinghouse) reactor was a naval reactor built by Westinghouse used by the United States Navy to provide electricity generation and propulsion on warships.

It was a pressurized water reactor (PWR) initially installed aboard the USS Seawolf (SSN-575), the second nuclear-powered submarine launched by the U.S. Navy in 1955.

This design provided substantial improvements in submerged endurance and speed over conventional diesel-electric submarines, marking a pivotal advancement in naval propulsion.

Bettis Atomic Power Laboratory, operated by Westinghouse, developed the basic reactor plant design used in Nautilus after being given the assignment on 31 December 1947 to design a nuclear power plant for a submarine.

After the predictable problems arose with the S2G's use of 347 stainless steel caused by the sodium in the liquid sodium reactor in its superheater[3] the USS Seawolf (SSN-575) had her S2G liquid metal cooled reactor replaced using the spare S2W built for USS Nautilus.