A nuclear reactor is a device used to initiate and control a fission nuclear chain reaction or nuclear fusion reactions. Nuclear reactors are used at nuclear power plants for electricity generation and in nuclear marine propulsion. Heat from nuclear fission is passed to a working fluid, which in turn runs through steam turbines. These either drive a ship's propellers or turn electrical generators' shafts. Nuclear generated steam in principle can be used for industrial process heat or for district heating. Some reactors are used to produce isotopes for medical and industrial use, or for production of weapons-grade plutonium. As of early 2019, the IAEA reports there are 454 nuclear power reactors and 226 nuclear research reactors in operation around the world.
Nuclear power is the use of nuclear reactions to produce electricity. Nuclear power can be obtained from nuclear fission, nuclear decay and nuclear fusion reactions. Presently, the vast majority of electricity from nuclear power is produced by nuclear fission of uranium and plutonium in nuclear power plants. Nuclear decay processes are used in niche applications such as radioisotope thermoelectric generators in some space probes such as Voyager 2. Generating electricity from fusion power remains the focus of international research.
United States naval reactors are nuclear reactors used by the United States Navy aboard certain ships to generate the steam used to produce power for propulsion, electric power, catapulting airplanes in aircraft carriers, and a few more minor uses. Such naval nuclear reactors have a complete power plant associated with them. All U.S. Navy submarines and supercarriers built since 1975 are nuclear-powered by such reactors. There are no commissioned conventional (non-nuclear) submarines or aircraft carriers left in the U.S. Navy, since the last conventional carrier, USS Kitty Hawk, was decommissioned in May 2009. The U.S. Navy had nine nuclear-powered cruisers with such reactors also, but they have since been decommissioned. Reactors are designed by a variety of contractors, then developed and tested at one of several government owned and prime contractor-operated facilities: Bettis Atomic Power Laboratory in West Mifflin, Pennsylvania and its associated Naval Reactors Facility in Idaho, and Knolls Atomic Power Laboratory in Niskayuna, New York and its associated Kesselring site in West Milton, New York, all under the management of the office of Naval Reactors. Sometimes there were full-scale nuclear-powered prototype plants built at the Naval Reactors Facility, Kesselring, and Windsor to test the nuclear plants, which were operated for years to train nuclear-qualified sailors.
A nuclear power plant is a thermal power station in which the heat source is a nuclear reactor. As is typical of thermal power stations, heat is used to generate steam that drives a steam turbine connected to a generator that produces electricity. As of 2022, the International Atomic Energy Agency reported there were 439 nuclear power reactors in operation in 32 countries around the world.
The A3W reactor is a naval reactor used by the United States Navy to provide electricity generation and propulsion on warships. Like all operational U.S. naval reactors it was a pressurized water reactor (PWR) design. The A3W designation stands for:
A nuclear-powered icebreaker is a nuclear-powered ship, purpose-built for use in waters covered with ice. While nuclear-powered icebreakers have been considered or planned by other countries, the only country that has built and operated them as of 2022 is Russia. Nuclear-powered icebreakers were constructed by the Soviet Union and later Russia primarily to aid shipping along the Northern Sea Route in the frozen Arctic waterways north of Siberia. Nuclear-powered icebreakers are much more powerful than their diesel-powered counterparts. Although nuclear propulsion is expensive to install and maintain, very heavy fuel demands, limitations on range, and difficulty refueling in the Arctic region can make diesel vessels less practical and less economical overall for these ice-breaking duties.
A nuclear submarine is a submarine powered by a nuclear reactor, but not necessarily nuclear-armed. Nuclear submarines have considerable performance advantages over "conventional" submarines. Nuclear propulsion, being completely independent of air, frees the submarine from the need to surface frequently, as is necessary for conventional submarines. The large amount of power generated by a nuclear reactor allows nuclear submarines to operate at high speed for long periods, and the long interval between refuelings grants a range virtually unlimited, making the only limits on voyage times being imposed by such factors as the need to restock food or other consumables.
Nuclear marine propulsion is propulsion of a ship or submarine with heat provided by a nuclear reactor. The power plant heats water to produce steam for a turbine used to turn the ship's propeller through a gearbox or through an electric generator and motor. Nuclear propulsion is used primarily within naval warships such as nuclear submarines and supercarriers. A small number of experimental civil nuclear ships have been built.
A nuclear navy, or nuclear-powered navy, refers to the portion of a navy consisting of naval ships powered by nuclear marine propulsion. The concept was revolutionary for naval warfare when first proposed. Prior to nuclear power, submarines were powered by diesel engines and could only submerge through the use of batteries. In order for these submarines to run their diesel engines and charge their batteries they would have to surface or snorkel. The use of nuclear power allowed these submarines to become true submersibles and unlike their conventional counterparts, they became limited only by crew endurance and supplies.
A molten salt reactor (MSR) is a class of nuclear fission reactor in which the primary nuclear reactor coolant and/or the fuel is a molten salt mixture. Only two MSRs have ever operated, both research reactors in the United States. The 1950's Aircraft Reactor Experiment was primarily motivated by the compact size that the technique offers, while the 1960's Molten-Salt Reactor Experiment aimed to prove the concept of a nuclear power plant which implements a thorium fuel cycle in a breeder reactor. Increased research into Generation IV reactor designs began to renew interest in the technology, with multiple nations having projects, and as of September 2021, China is on the verge of starting its TMSR-LF1 thorium MSR.
The A1B reactor is an aircraft carrier nuclear reactor developed by the United States Navy. It is used in Gerald R. Ford–class aircraft carriers to provide electrical and propulsion energy. The A1B is the first naval reactor produced by Bechtel Corporation, which has "performed engineering and/or construction services on more than 80 percent of [land-based] nuclear plants in the United States".
The Bhabha Atomic Research Centre (BARC) is India's premier nuclear research facility, headquartered in Trombay, Mumbai, Maharashtra. Founded by Homi Jehangir Bhabha Atomic Energy Establishment, Trombay (AEET) in January 1954 as a multidisciplinary research program essential for India's nuclear program. It operates under the Department of Atomic Energy (DAE), which is directly overseen by the Prime Minister of India. In 1966 after the death of Mr. Bhabha, AEET was renamed as Bhabha Atomic Research Centre (BARC).
Research reactors are nuclear reactors that serve primarily as a neutron source. They are also called non-power reactors, in contrast to power reactors that are used for electricity production, heat generation, or maritime propulsion.
The C1W reactor is a nuclear reactor used by the United States Navy to provide electricity generation and propulsion on warships. C1W reactors, like all United States Naval reactors, are pressurized water reactors. The C1W designation stands for:
The Arktika class is a Russian class of nuclear-powered icebreakers. Formerly known as Project 10520 nuclear-powered icebreaker, they were the world's largest and most powerful icebreakers until the 2016 launch of the first Project 22220 icebreaker, also named Arktika. Ships of the Arktika class are owned by the federal government, but were operated by the Murmansk Shipping Company (MSCO) until 2008, when they were transferred to the fully government-owned operator Atomflot. Of the ten civilian nuclear-powered vessels built by Russia, six have been of this type. They are used for escorting merchant ships in the Arctic Ocean north of Siberia as well as for scientific and recreational expeditions to the Arctic.
The Fast Breeder Test Reactor (FBTR) is a breeder reactor located at Kalpakkam, Tamil Nadu, India. The Indira Gandhi Center for Atomic Research (IGCAR) and Bhabha Atomic Research Centre (BARC) jointly designed, constructed, and operate the reactor.
A liquid metal cooled nuclear reactor, liquid metal fast reactor or LMFR is an advanced type of nuclear reactor where the primary coolant is a liquid metal. Liquid metal cooled reactors were first adapted for nuclear submarine use and have been studied for power generation applications.
The VT-1 reactor was the nuclear fission reactor used in a pair to power Soviet submarine K-27 as part of the Soviet Navy's Project 645 Кит-ЖМТ. It is a liquid metal cooled reactor (LMR), using highly enriched uranium-235 fuel to produce 73 MW of power.
The S1B reactor is a naval reactor used by the United States Navy to provide electricity generation and propulsion on Columbia-class submarines. The S1B designation stands for:
The Indian Pressurized Water Reactor-900 (IPWR-900) is a class of pressurized water reactors being designed by Bhabha Atomic Research Centre (BARC) in partnership with Nuclear Power Corporation of India Limited to supplement the Indian three-stage nuclear power programme
