b'1953 T\x07he\x07nation\x07that\x07first\x07develops\x07nuclear\x07engines\x07will\x07rule\x07the oceans of the world; our enemies are working on such\x07engines;\x07we\x07must\x07be\x07first.\x07\x07Adm.\x07Hyman\x07RickoverSubmarine Thermal Reactor Also known as S1W, the Submarine Thermal Reactor marked the birth of Americasnuclear navy. The prototype reactor, which was cooled and moderated by pressurized water, and the propulsion equipment were built at Idahos Naval Reactors Facility. The reactorand support systems were located inside a hull section duplicating the size and specifications of the USS Nautilus, the Navys first nuclear-powered submarine, which was under construction in Connecticut at the time. To facilitate shielding research, a tank of water surrounded a portion of the hull. Before the Nautilus was launched, S1W and its crew simulated a 96-hour voyage from Newfoundland to Ireland. For decades, the reactor aidedin the testing of advanced designs and provided training for sailors.11'