The propulsion plants of the earlier SKIPJACK, PERMIT, STURGEON, LOS ANGELES, SEAWOLF and VIRGINIA class nuclear-powered attack submarines, as well as GEORGE WASHINGTON, ETHAN ALLEN, LAFAYETTE, BENJAMIN FRANKLIN and OHIO class fleet ballistic missile submarines, and the nuclear-powered ships of the surface fleet are based upon the use of a nuclear reactor to provide heat. The heat comes from the fissioning of a nuclear fuel contained within the reator. Since the fissioning process also produces radiation, shields are placed around the reactor so that the crew is protected.
