Riva

  Asus Proart

USS Seawolf Under the direction of Captain (later Admiral) Hyman Rickover, the US Navy developed both pressurized water and liquid metal prototypes. The company completed its first two nuclear submarines, the Nautilus and Seawolf, and tested the two types, but the Seawolf reactor ran into problems (including leaks), so the liquid metal concept was abandoned. The Navy then also developed natural circulation reactors. US attack submarines (except the natural circulation prototype USS Narwhal) are built with pressurized water reactors, while Ohio-class strategic submarines are powered by natural circulation reactors. The latter are inherently quieter than pressurized water units, since they do not require pumps, at least at low and medium power. Other nuclear navies used pressurized water or natural circulation reactors, with one exception: the Soviet Union's Alpha-class superfast attack submarines, built with liquid metal reactors in the 1970s and 1980s. Nuclear Navy The intr...