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 2022, the International Atomic Energy Agency reports there are 422 nuclear power reactors and 223 nuclear research reactors in operation around the world.
Enriched uranium is a type of uranium in which the percent composition of uranium-235 has been increased through the process of isotope separation. Naturally occurring uranium is composed of three major isotopes: uranium-238, uranium-235, and uranium-234. 235U is the only nuclide existing in nature that is fissile with thermal neutrons.
The nuclear fuel cycle, also called nuclear fuel chain, is the progression of nuclear fuel through a series of differing stages. It consists of steps in the front end, which are the preparation of the fuel, steps in the service period in which the fuel is used during reactor operation, and steps in the back end, which are necessary to safely manage, contain, and either reprocess or dispose of spent nuclear fuel. If spent fuel is not reprocessed, the fuel cycle is referred to as an open fuel cycle ; if the spent fuel is reprocessed, it is referred to as a closed fuel cycle.
The Baghdad Nuclear Research Facility adjacent to the Tuwaitha "Yellow Cake Factory" or Tuwaitha Nuclear Research Center contains the remains of nuclear reactors bombed by Iran in 1980, Israel in 1981, and the United States in 1991. It was used as a storage facility for spent reactor fuel and industrial and medical wastes. The radioactive material would not be useful for a fission bomb, but could be used in a dirty bomb. Following the 2003 invasion of Iraq, the facility was heavily looted by hundreds of Iraqis, though it is unclear what was taken.
Uranium-235 is an isotope of uranium making up about 0.72% of natural uranium. Unlike the predominant isotope uranium-238, it is fissile, i.e., it can sustain a nuclear chain reaction. It is the only fissile isotope that exists in nature as a primordial nuclide.
The Petten High Flux Reactor (HFR) is a nuclear research reactor located in Petten, Netherlands. The HFR is on the premises of the Petten research centre and it is a high flux reactor. It is owned by the Joint Research Centre (JRC) and managed by the Nuclear Research and Consultancy Group (NRG). The HFR’s original purpose was to provide experience and irradiation capabilities for the nascent Dutch nuclear power program. Construction began in 1958, and the reactor reached criticality on the 9th of November, 1961.
Research reactors are nuclear fission-based 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 SLOWPOKE is a family of low-energy, tank-in-pool type nuclear research reactors designed by Atomic Energy of Canada Limited (AECL) beginning in the late 1960s. John W. Hilborn is the scientist most closely associated with their design. They are beryllium-reflected with a very low critical mass, but provide neutron fluxes higher than available from a small particle accelerator or other radioactive sources.
The Megatons to Megawatts Program, also called the United States-Russia Highly Enriched Uranium Purchase Agreement, was an agreement between Russia and the United States whereby Russia converted 500 metric tons of "excess" weapons-grade uranium into 15,000 metric tons of low enriched uranium, which was purchased by the US for use in its commercial nuclear power plants. The official name of the program is the "Agreement between the Government of the Russian Federation and the Government of the United States of America Concerning the Disposition of Highly-Enriched Uranium Extracted from Nuclear Weapons", dated February 18, 1993. Under this Agreement, Russia agreed to supply the United States with low-enriched uranium (LEU) obtained from high-enriched uranium (HEU) found to be in excess of Russian defense purposes. The United States agreed to purchase the low-enriched uranium fuel.
The Chinese built Miniature Neutron Source reactor (MNSR) is a small and compact research reactor modeled on the Canadian HEU SLOWPOKE-2 design.
A nuclear fuel bank is reserve of low enriched uranium (LEU) for countries that need a backup source of LEU to fuel their nuclear reactors. Countries that do have enrichment technology would donate enriched fuel to a "bank", from which countries not possessing enrichment technology would obtain fuel for their power reactors.
The KLT-40 family are nuclear fission reactors originating from OK-150 and OK-900 ship reactors. KLT-40 were developed to power the Taymyr-class icebreakers and the LASH carrier Sevmorput. They are pressurized water reactors (PWR) fueled by either 30–40% or 90% enriched uranium-235 fuel to produce 135 to 171 MW of thermal power.
The Radiation Laboratory at the University of Massachusetts Lowell serves the Department of Applied Physics among others. The laboratory contains the University of Massachusetts Lowell Research Reactor (UMLRR), a 1 MW pool-type research reactor that has been operating since 1974, along with a 300 kCi Co-60 gamma ray source and a 5.5 MeV Van de Graaff accelerator.
The Maria reactor is Poland's second nuclear research reactor and is the only one still in use. It is located at Narodowe Centrum Badań Jądrowych (NCBJ) at Świerk-Otwock, near Warsaw and named in honor of Maria Skłodowska-Curie. It is the only reactor of Polish design.
Iran's nuclear program is made up of a number of nuclear facilities, including nuclear reactors and various nuclear fuel cycle facilities.
President Adly Mansour announced on 7 November 2013 that Egypt was restarting its nuclear power program in El Dabaa; a deal was reached with the residents in which it was agreed that a residential area will also be built. The Egyptian minister of electricity, Ahmed Emam, has called the project "necessary" because of a small amount of renewable energy sources and not enough fuel.
The Pakistan Atomic Research Reactor or (PARR) are two nuclear research reactors and two other experimental neutron sources located in the PINSTECH Laboratory, Nilore, Islamabad, Pakistan.
ETRR-1 or ET-RR-1, is the first nuclear reactor in Egypt supplied by the USSR in 1958. The reactor is owned and operated by Egyptian Atomic Energy Authority (AEA) at the Nuclear Research Center in Inshas, 40–60 kilometres (25–37 mi) northeast of Cairo.
The Ghana Research Reactor-1 (GHARR-1) is a nuclear research reactor located in Accra, Ghana and is the only nuclear reactor in the country. It is operated by the National Nuclear Research Institute, a sub-division of the Ghana Atomic Energy Commission. The reactor is a commercial version of the Chinese Miniature Neutron Source Reactor (MNSR) design. The reactor had its first criticality on December 17, 1994.
Depleted uranium hexafluoride (DUHF; also referred to as depleted uranium tails, depleted uranium tailings or DUF6) is a byproduct of the processing of uranium hexafluoride into enriched uranium. It is one of the chemical forms of depleted uranium (up to 73-75%), along with depleted triuranium octoxide (up to 25%) and depleted uranium metal (up to 2%). DUHF is 1.7 times less radioactive than uranium hexafluoride and natural uranium.
