Crew members of the U.S.S. Enterprise, the first nuclear-powered aircraft carrier, spell out NR-50! To commemorate the 50th anniversary of the Nuclear Navy. Admiral Hyman G. Rickover formed the Nuclear Power Branch within the Navy’s Bureau of Ships in August 1948. The Office of Naval Reactors is an integrated organization of DOE and the Department of Navy. The Enterprise’s eight A2W nuclear reactors were developed by Bettis Laboratory, with the prototype A1W reactor constructed at Idaho’s National Reactor Testing Station.