and was decommissioned in 1995 instead of receiving its third nuclear refueling and proposed upgrade. It was sold for scrap in 2012 at Puget Sound Naval Shipyard. Currently the United States does not have any nuclear cruisers. Russia has four s, though only one is active, the other three being laid up. The command ship SSV-33 Ural, based on the Kirov class, is also laid up. Seven civilian nuclear icebreakers remain in service: four of six s, the two Taymyr-class icebreakers Taymyr and Vaygach, and the LASH carrier and container ship . United States Navy By 2003 the U.S. Navy had accumulated over 5,400 "reactor years" of accident-free experience, and operated more than 80 nuclear-powered ships. Admiral Hyman G. Rickover Admiral Hyman G. Rickover, (1900–1986), of the United States Navy, known as "father of the nuclear navy" was an electrical engineer by training, and was the primary architect who implemented this daring concept, and believed that it was the natural next phase for the way military vessels could be propelled and powered. The challenge was to reduce the size of a nuclear reactor to fit on board a ship or submarine, as well as to encase it sufficiently so that radiation hazards would not be a safety concern. Soon after World War II, Rickover was assigned to the Bureau of Ships in September 1947 and received training in nuclear power at Oak Ridge, Tennessee. In February 1949 he received an assignment to the Division of Reactor Development, U.S. Atomic Energy Commission and then assumed control of the United States Navy's effort as Director of the Naval Reactors Branch in the Bureau of Ships. This dual role allowed him to lead the efforts to develop the world's first nuclear-powered submarine, , which was launched in 1954. As Vice Admiral, from 1958, for three decades Rickover exercised tight control over the ships, technology, and personnel of the nuclear navy, even interviewing every prospective officer for new nuclear-powered navy vessels. Philip Abelson Leading nuclear physicist Philip Abelson (1913–2004) turned his attention under the guidance of Ross Gunn to applying nuclear power to naval propulsion. Their early efforts at Naval Research Laboratory (NRL) provided an early glimpse at what was to become the nuclear Navy. United States Naval reactors At the present time, many important vessels in the United States Navy are powered by nuclear reactors. All submarines and aircraft carriers are nuclear-powered. Several