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GT-MHR
The Gas Turbine Modular Helium Reactor (GT-MHR) is a class of nuclear fission power Nuclear reactor technology, reactor designed that was under development by a group of Russian enterprises (OKBM Afrikantov, Kurchatov Institute, VNIINM and others), an American group headed by General Atomics, French Framatome and Japanese Fuji Electric. It is a helium cooled, graphite Neutron moderator, moderated reactor and uses TRISO fuel compacts in a Prism (geometry), prismatic Nuclear reactor core, core design. The power is generated via a gas turbine rather than via the more common steam turbine. A conceptual design was produced by 1997, and it was hoped to have a final design by 2005, and a prototype plant commissioning by 2010. Construction The core consists of a graphite cylinder with a radius of and a height of which includes axial reflectors at top and bottom. The cylinder allocates three or four concentric rings, each of 36 hexagonal blocks with an interstitial gap of . Each hexagona ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
General Atomics
General Atomics is an American energy and defense corporation headquartered in San Diego, California, specializing in research and technology development. This includes physics research in support of nuclear fission and nuclear fusion energy. The company also provides research and manufacturing services for remotely operated surveillance aircraft, including the General Atomics MQ-1 Predator, Predator drones, airborne sensors, and advanced electric, electronic, wireless, and laser technologies. History General Atomics (GA) was founded on July 18, 1955, in San Diego San Diego ( , ; ) is a city on the Pacific Ocean coast of Southern California located immediately adjacent to the Mexico–United States border. With a 2020 population of 1,386,932, it is the List of United States cities by population, eigh ..., California, by Frederic de Hoffmann with assistance from notable physicists Edward Teller and Freeman Dyson. Originally the company was part of the General Atomic divi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gas-cooled Fast Reactor
The gas-cooled fast reactor (GFR) system is a nuclear reactor design which is currently in development. Classed as a Generation IV reactor, it features a fast-neutron spectrum and closed fuel cycle for efficient conversion of fertile uranium and management of actinides. The reference reactor design is a helium- cooled system operating with an outlet temperature of 850 °C using a direct Brayton closed-cycle gas turbine for high thermal efficiency. Several fuel forms are being considered for their potential to operate at very high temperatures and to ensure an excellent retention of fission products: composite ceramic fuel, advanced fuel particles, or ceramic clad elements of actinide compounds. Core configurations are being considered based on pin- or plate-based fuel assemblies or prismatic blocks, which allows for better coolant circulation than traditional fuel assemblies. The reactors are intended for use in nuclear power plants to produce electricity, while at the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TRISO
Nuclear fuel is material used in nuclear power stations to produce heat to power turbines. Heat is created when nuclear fuel undergoes nuclear fission. Most nuclear fuels contain heavy fissile actinide elements that are capable of undergoing and sustaining nuclear fission. The three most relevant fissile isotopes are uranium-233, uranium-235 and plutonium-239. When the unstable nuclei of these atoms are hit by a slow-moving neutron, they frequently split, creating two daughter nuclei and two or three more neutrons. In that case, the neutrons released go on to split more nuclei. This creates a self-sustaining chain reaction that is controlled in a nuclear reactor, or uncontrolled in a nuclear weapon. Alternatively, if the nucleus absorbs the neutron without splitting, it creates a heavier nucleus with one additional neutron. The processes involved in mining, refining, purifying, using, and disposing of nuclear fuel are collectively known as the nuclear fuel cycle. Not all typ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gas-cooled Fast Reactor
The gas-cooled fast reactor (GFR) system is a nuclear reactor design which is currently in development. Classed as a Generation IV reactor, it features a fast-neutron spectrum and closed fuel cycle for efficient conversion of fertile uranium and management of actinides. The reference reactor design is a helium- cooled system operating with an outlet temperature of 850 °C using a direct Brayton closed-cycle gas turbine for high thermal efficiency. Several fuel forms are being considered for their potential to operate at very high temperatures and to ensure an excellent retention of fission products: composite ceramic fuel, advanced fuel particles, or ceramic clad elements of actinide compounds. Core configurations are being considered based on pin- or plate-based fuel assemblies or prismatic blocks, which allows for better coolant circulation than traditional fuel assemblies. The reactors are intended for use in nuclear power plants to produce electricity, while at the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
OKBM Afrikantov
OKBM Afrikantov (full name: OAO I. I. Afrikantov OKB Mechanical Engineering, russian: Опытное конструкторское бюро машиностроения им. И. И. Африкантова) is a nuclear engineering company located in Nizhny Novgorod, Russia. It is a subsidiary of Rosatom. The company is named after Igor Afrikantov. The company is best known as the main designer for the Soviet Union's and Russia's flagship nuclear propulsion projects, including reactors for nuclear submarines, nuclear-powered icebreakers, and the floating nuclear power plant project. It also designs fast breeder reactors. History The company was founded in 1945. In 1998, it was named after its former chief designer and director I. I. Afrikantov. Products The company is a developer of the nuclear reactors. It has designed and assembled KLT-40S reactors for the first Russian floating nuclear power station ''Akademik Lomonosov''. It also developed the RITM-200 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kurchatov Institute
The Kurchatov Institute (russian: Национальный исследовательский центр «Курчатовский Институт», 'National Research Centre "Kurchatov Institute) is Russia's leading research and development institution in the field of nuclear energy. It is named after Igor Kurchatov and is located at 1 Kurchatov Square, Moscow. In the Soviet Union it was known as I. V. Kurchatov Institute of Atomic Energy (russian: Институт Атомной Энергии им. И.В. Курчатова), abbreviated KIAE (russian: КИАЭ). Between 1991 and 2010, it was known as the Russian Scientific Centre "Kurchatov Institute" () before its name was changed to National Research Centre. History Until 1955 known under a secret name "Laboratory No. 2 of the USSR Academy of Sciences", the Kurchatov Institute was founded in 1943 with the initial purpose of developing nuclear weapons. The majority of Soviet nuclear reactors were designed in the insti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Fission
Nuclear fission is a reaction in which the nucleus of an atom splits into two or more smaller nuclei. The fission process often produces gamma photons, and releases a very large amount of energy even by the energetic standards of radioactive decay. Nuclear fission of heavy elements was discovered on Monday 19 December 1938, by German chemist Otto Hahn and his assistant Fritz Strassmann in cooperation with Austrian-Swedish physicist Lise Meitner. Hahn understood that a "burst" of the atomic nuclei had occurred. Meitner explained it theoretically in January 1939 along with her nephew Otto Robert Frisch. Frisch named the process by analogy with biological fission of living cells. For heavy nuclides, it is an exothermic reaction which can release large amounts of energy both as electromagnetic radiation and as kinetic energy of the fragments (heating the bulk material where fission takes place). Like nuclear fusion, for fission to produce energy, the total binding energy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Light Water Reactors
The light-water reactor (LWR) is a type of thermal-neutron reactor that uses normal water, as opposed to heavy water, as both its coolant and neutron moderator; furthermore a solid form of fissile elements is used as fuel. Thermal-neutron reactors are the most common type of nuclear reactor, and light-water reactors are the most common type of thermal-neutron reactor. There are three varieties of light-water reactors: the pressurized water reactor (PWR), the boiling water reactor (BWR), and (most designs of) the supercritical water reactor (SCWR). History Early concepts and experiments After the discoveries of fission, moderation and of the theoretical possibility of a nuclear chain reaction, early experimental results rapidly showed that natural uranium could only undergo a sustained chain reaction using graphite or heavy water as a moderator. While the world's first reactors ( CP-1, X10 etc.) were successfully reaching criticality, uranium enrichment began to develop from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Very High Temperature Reactor
A high-temperature gas-cooled reactor (HTGR), is a nuclear reactor that uses a graphite-moderated reactor, graphite moderator with a once-through uranium fuel cycle. The HTGR is a type of high-temperature reactor (HTR) that can conceptually have an outlet temperature of . The nuclear reactor core, reactor core can be either a "prismatic block" (reminiscent of a conventional reactor core) or a "Pebble-bed reactor, pebble-bed" core. The high temperatures enable applications such as process heat or hydrogen production via the thermochemical sulfur–iodine cycle. The HTR is the predecessor of the Very-high-temperature reactor (VHTR), one of the future Generation IV reactor-models, which initially would work with temperatures of 750 to 950 °C. Overview The HTGR is a type of high-temperature reactor that conceptually can reach high outlet temperatures (up to 750 °C). There are two main types of HTGRs: pebble bed reactors (PBR) and prismatic block reactors (PMR).The pri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pebble Bed Reactor
The pebble-bed reactor (PBR) is a design for a graphite-moderated, gas-cooled nuclear reactor. It is a type of very-high-temperature reactor (VHTR), one of the six classes of nuclear reactors in the Generation IV initiative. The basic design of pebble-bed reactors features spherical fuel elements called pebbles. These tennis ball-sized pebbles (approx. in diameter) are made of pyrolytic graphite (which acts as the moderator), and they contain thousands of micro-fuel particles called TRISO particles. These TRISO fuel particles consist of a fissile material (such as 235U) surrounded by a ceramic layer coating of silicon carbide for structural integrity and fission product containment. In the PBR, thousands of pebbles are amassed to create a reactor core, and are cooled by a gas, such as helium, nitrogen or carbon dioxide, that does not react chemically with the fuel elements. Other coolants such as FLiBe (molten fluoride, lithium, beryllium salt)) have also been suggested for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Transmutation
Nuclear transmutation is the conversion of one chemical element or an isotope into another chemical element. Nuclear transmutation occurs in any process where the number of protons or neutrons in the nucleus of an atom is changed. A transmutation can be achieved either by nuclear reactions (in which an outside particle reacts with a nucleus) or by radioactive decay, where no outside cause is needed. Natural transmutation by stellar nucleosynthesis in the past created most of the heavier chemical elements in the known existing universe, and continues to take place to this day, creating the vast majority of the most common elements in the universe, including helium, oxygen and carbon. Most stars carry out transmutation through fusion reactions involving hydrogen and helium, while much larger stars are also capable of fusing heavier elements up to iron late in their evolution. Elements heavier than iron, such as gold or lead, are created through elemental transmutations that can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Waste
Radioactive waste is a type of hazardous waste that contains radioactive material. Radioactive waste is a result of many activities, including nuclear medicine, nuclear research, nuclear power generation, rare-earth mining, and nuclear weapons reprocessing. The storage and disposal of radioactive waste is regulated by government agencies in order to protect human health and the environment. Radioactive waste is broadly classified into low-level waste (LLW), such as paper, rags, tools, clothing, which contain small amounts of mostly short-lived radioactivity, intermediate-level waste (ILW), which contains higher amounts of radioactivity and requires some shielding, and high-level waste (HLW), which is highly radioactive and hot due to decay heat, so requires cooling and shielding. In nuclear reprocessing plants about 96% of spent nuclear fuel is recycled back into uranium-based and mixed-oxide (MOX) fuels. The residual 4% is minor actinides and fission products the latter of wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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