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.
Isotope separation is the process of concentrating specific isotopes of a chemical element by removing other isotopes. The use of the nuclides produced is varied. The largest variety is used in research. By tonnage, separating natural uranium into enriched uranium and depleted uranium is the largest application. In the following text, mainly the uranium enrichment is considered. This process is crucial in the manufacture of uranium fuel for nuclear power plants, and is also required for the creation of uranium-based nuclear weapons. Plutonium-based weapons use plutonium produced in a nuclear reactor, which must be operated in such a way as to produce plutonium already of suitable isotopic mix or grade. While different chemical elements can be purified through chemical processes, isotopes of the same element have nearly identical chemical properties, which makes this type of separation impractical, except for separation of deuterium.
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.
Piketon is a village in Pike County in the U.S. state of Ohio, along the Scioto River. The village is best known for the uranium enrichment plant located there, which is one of only three such plants in the United States. The population was 2,111 at the 2020 U.S. census. Originally called Jefferson, it was the county seat of Pike County from 1815 to 1845, when James Emmitt, a wealthy local entrepreneur, influenced the transfer of the county seat to Waverly, due to its closer proximity to the then-new Ohio & Erie Canal. Piketon is the location of the Pike County Fairgrounds and is served by the Scioto Valley School District.
Uranium hexafluoride (UF6), (sometimes called "hex") is an inorganic compound with the formula UF6. Uranium hexafluoride is a volatile white solid that reacts with water, releasing corrosive hydrofluoric acid. The compound reacts mildly with aluminium, forming a thin surface layer of AlF3 that resists any further reaction from the compound. UF6 is used in the process of enriching uranium, which produces fuel for nuclear reactors and nuclear weapons.
Gaseous diffusion is a technology that was used to produce enriched uranium by forcing gaseous uranium hexafluoride (UF6) through microporous membranes. This produces a slight separation (enrichment factor 1.0043) between the molecules containing uranium-235 (235U) and uranium-238 (238U). By use of a large cascade of many stages, high separations can be achieved. It was the first process to be developed that was capable of producing enriched uranium in industrially useful quantities, but is nowadays considered obsolete, having been superseded by the more-efficient gas centrifuge process.
Erich Rudolf Bagge was a German scientist. Bagge, a student of Werner Heisenberg for his doctorate and Habilitation, was engaged in German Atomic Energy research and the German nuclear energy project during the Second World War. He worked as an Assistant at the Kaiser-Wilhelm-Institut für Physik in Berlin. Bagge, who became associated professor at the University of Hamburg in 1948, was in particular involved in the usage of nuclear power for trading vessels, and he was one of the founders of the Society for the Usage of Nuclear Energy in Ship-Building and Seafare. The first German nuclear vessel, the "NS Otto Hahn", was launched in 1962. A research reactor was installed in Geesthacht near Hamburg at about the same time which has over the years formed into a center for materials research with neutrons.
Atomic vapor laser isotope separation, or AVLIS, is a method by which specially tuned lasers are used to separate isotopes of uranium using selective ionization of hyperfine transitions. A similar technology, using molecules instead of atoms, is molecular laser isotope separation (MLIS).
K-25 was the codename given by the Manhattan Project to the program to produce enriched uranium for atomic bombs using the gaseous diffusion method. Originally the codename for the product, over time it came to refer to the project, the production facility located at the Clinton Engineer Works in Oak Ridge, Tennessee, the main gaseous diffusion building, and ultimately the site. When it was built in 1944, the four-story K-25 gaseous diffusion plant was the world's largest building, comprising over 5,264,000 square feet (489,000 m2) of floor space and a volume of 97,500,000 cubic feet (2,760,000 m3).
The Watts Bar Nuclear Plant is a Tennessee Valley Authority (TVA) nuclear reactor pair used for electric power generation. It is located on a 1,770-acre (7.2 km²) site in Rhea County, Tennessee, near Spring City, between the cities of Chattanooga and Knoxville. Watts Bar supplies enough electricity for about 1,200,000 households in the Tennessee Valley.
Eurodif, which means European Gaseous Diffusion Uranium Enrichment Consortium, is a subsidiary of the French company Orano, which operates a uranium enrichment plant established at the Tricastin Nuclear Power Center in Pierrelatte in Drôme. The nuclear site of Pierrelatte includes many nuclear installations, of which the largest are the Eurodif fuel factory and the Tricastin nuclear power station.
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.
In the United States, nuclear power is provided by 92 commercial reactors with a net capacity of 94.7 gigawatts (GW), with 61 pressurized water reactors and 31 boiling water reactors. In 2019, they produced a total of 809.41 terawatt-hours of electricity, which accounted for 20% of the nation's total electric energy generation. In 2018, nuclear comprised nearly 50 percent of US emission-free energy generation.
Separation of isotopes by laser excitation (SILEX) is a process for isotope separation that is being investigated to produce enriched uranium on an industrial scale using lasers. It was developed in the 1990s and is a variant of molecular laser isotope separation (MLIS). For uranium, it uses a cold molecular beam with UF6 in a carrier gas, in which the 235UF6 is selectively excited by an infrared laser near 16 µm. The nonexcited molecules tend to form clusters with the carrier gas and stay closer to the axis of the molecular beam, so that they pass a skimmer and are thus separated from the excited lighter isotopes. In contrast to earlier MLIS techniques developed since the 1970s, this method does not dissociate the molecule.
Kyger Creek Power Plant is a 1.08-gigawatt, 1,086 (MW) coal-fired power station located south of Cheshire, Ohio in Gallia County, Ohio. It is operated by the Ohio Valley Electric Corporation (OVEC).
The Portsmouth Gaseous Diffusion Plant is a facility located in Scioto Township, Pike County, Ohio, just south of Piketon, Ohio, that previously produced enriched uranium, including highly enriched weapons-grade uranium, for the United States Atomic Energy Commission (AEC), the U.S. nuclear weapons program and Navy nuclear propulsion; in later years, it produced low-enriched uranium for fuel for commercial nuclear power reactors. The site never hosted an operating nuclear reactor.
The Zippe-type centrifuge is a gas centrifuge designed to enrich the rare fissile isotope uranium-235 (235U) from the mixture of isotopes found in naturally occurring uranium compounds. The isotopic separation is based on the slight difference in mass of the isotopes. The Zippe design was originally developed in the Soviet Union by a team led by 60 Austrian and German scientists and engineers captured after World War II, working in detention. In the West the type is known by the name of the man who recreated the technology after his return to the West in 1956, based on his recollection of his work in the Soviet program, Gernot Zippe. To the extent that it might be referred to in Soviet/Russian usage by any one person's name, it was known as a Kamenev centrifuge.
The Paducah Gaseous Diffusion Plant (PGDP) is a facility located in McCracken County, Kentucky, near Paducah, Kentucky that produced enriched uranium from 1952 to 2013. It is owned by the U.S. Department of Energy (DOE). The PGDP was the only operating uranium enrichment facility in the United States in the period 2001 to 2010. The Paducah plant produced low-enriched uranium, originally as feedstock for military reactors and weapons, and later for commercial nuclear power fuel.
The Aurora powerhouse is an advanced fission plant concept design that received a site use permit for testing in 2020 from the United States Department of Energy (DOE). The site use permit, issued in December 2019 is not a Nuclear Regulatory Commission permit. It is the "first and only permit ever issued in the U.S. to a nuclear plant using something other than a light water ("water-cooled") reactor". It will use "recycled" high-assay, low-enriched uranium (HALEU) fuel originally fabricated for the Experimental Breeder Reactor II (EBR-II), and if fully operational, would become "the first fuel-recycling commercial reactor in the United States". The DOE's Idaho National Laboratory (INL) said it would provide 10 tons of HALEU for the test reactor which corresponds to most of the available supply. Reprocessing would occur at INL's Materials and Fuels Complex (MFC) and possibly also the Idaho Nuclear Technology and Engineering Center (INTEC), neither of which are operational facilities as of early 2020.
A nuclear microreactor is a plug-and-play type of nuclear reactor which can be easily assembled and transported by road, rail or air. Microreactors are 100 to 1,000 times smaller than conventional nuclear reactors, and when compared with small modular reactors (SMRs), their capacity is between 1 and 20 megawatts whereas SMRs comes in the range from 20 to 300 megawatts. Due to their size, they can be deployed to locations such as isolated military bases or communities affected by natural disasters. It can operate as part of the grid, independent of the grid, or as part of a small grid for electricity generation and heat treatment. They are designed to provide resilient, non-carbon emitting, and independent power in challenging environments. The nuclear fuel source for the majority of the designs is "High-Assay Low-Enriched Uranium", or HALEU.
