A nuclear submarine is driven by turbine engines which use steam heated by a nuclear reactor. The submarine seldom has to return to part to refuel. The world's first nuclear powered submarine was the US Navy's Nautilus(1955). A lamp of uranium fuel the size of an electric light bulb provided enough energy to drive the submarine 100,000 kilometers. In 1960 the US nuclear submarine Triton sailed around the world under water in which a distance of 67,000 kilometers in three months without needing to refuel.
