S2W reactor

The S2W reactor is a naval reactor used by the United States Navy to provide electricity generation and propulsion on warships. The S2W designation stands for:

• S = Submarine platform
• 2 = Second generation core designed by the contractor
• W = Westinghouse was the contracted designer

This nuclear reactor is the shipboard equivalent of the prototype S1W reactor, with minor design changes, that was installed on the USS Nautilus (SSN-571). As installed in Nautilus it generated 13,400 horsepower (10.0 MW). It was originally designated STR.

After Nautilus was decommissioned, the reactor equipment was removed. The submarine is now moored and displayed as a museum ship at the Naval Submarine Base New London in Groton, Connecticut.