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Uranium Zirconium Hydride
Uranium zirconium hydride (UZrH), a combination of uranium hydride and zirconium(II) hydride, is used as the fuel in TRIGA reactors. UZrH fuel is used in most research reactors at universities and has a large, prompt negative fuel temperature coefficient of reactivity, meaning that as the temperature of the core increases, the reactivity rapidly decreases. Franco-Belge de Fabrication du Combustible, in Romans-sur-Isère, France, is the only manufacturer of this fuel. References External links Technical Foundations of TRIGA: Thermalization In Zirconium Hydride TRIGA TRIGA (Training, Research, Isotopes, General Atomics) is a class of nuclear research reactor designed and manufactured by General Atomics. The design team for TRIGA, which included Edward Teller, was led by the physicist Freeman Dyson. Design ... {{DEFAULTSORT:Uranium zirconium hydride Isotope separation Nuclear fuels Nuclear materials Uranium ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uranium Hydride
Uranium hydride, also called uranium trihydride (UH3), is an inorganic compound and a hydride of uranium. Properties Uranium hydride is a highly toxic, brownish grey to brownish black pyrophoric powder or brittle solid. Its density at 20 °C is 10.95 g cm−3, much lower than that of uranium (19.1 g cm−3). It has a metallic conductivity, is slightly soluble in hydrochloric acid and decomposes in nitric acid. Two crystal modifications of uranium hydride exist, both cubic: an α form that is obtained at low temperatures and a β form that is grown when the formation temperature is above 250 °C. After growth, both forms are metastable at room temperature and below, but the α form slowly converts to the β form upon heating to 100 °C. Both α- and β-UH3 are ferromagnetic at temperatures below ~180 K. Above 180 K, they are paramagnetic. Formation in uranium metal Hydrogen gas reaction Exposure of uranium metal to hydrogen leads to hydrogen embrittlement. Hydrog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zirconium(II) Hydride
Zirconium(II) hydride, ZrH2 is a molecular chemical compound which has been prepared by laser ablation and isolated at low temperature. Zirconium(II) hydride has repeatedly been the subject of dirac equation, Dirac–hartree-Fock method, Hartree–Fock relativistic quantum chemistry, relativistic calculation studies, which investigate the stabilities, geometries, and relative energies of hydrides of the formula MH4, MH3, MH2, or MH. Zirconium(II) hydride has a dihedral (C2v) structure. In zirconium(II) hydride, the formal oxidation states of hydrogen and zirconium are −1 and +2, respectively, because the electronegativity of zirconium is lower than that of hydrogen. The stability of metal hydrides with the formula MH2 (M = Ti-Hf) decreases as the atomic number increases. References See also * Zirconium hydride Metal hydrides Zirconium(II) compounds {{inorganic-compound-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TRIGA
TRIGA (Training, Research, Isotopes, General Atomics) is a class of nuclear research reactor designed and manufactured by General Atomics. The design team for TRIGA, which included Edward Teller, was led by the physicist Freeman Dyson. Design TRIGA is a swimming pool reactor that can be installed without a containment building, and is designed for research and testing use by scientific institutions and universities for purposes such as undergraduate and graduate education, private commercial research, non-destructive testing and isotope production. The TRIGA reactor uses uranium zirconium hydride (UZrH) fuel, which has a large, prompt negative fuel temperature coefficient of reactivity, meaning that as the temperature of the core increases, the reactivity rapidly decreases. Because of this unique feature, it has been safely pulsed at a power of up to 22,000 megawatts. The hydrogen in the fuel is bound in the uranium zirconium hydride crystal structure with a vibrational energ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fuel Temperature Coefficient Of Reactivity
Fuel temperature coefficient of reactivity is the change in reactivity of the nuclear fuel per degree change in the fuel temperature. The coefficient quantifies the amount of neutrons that the nuclear fuel (such as uranium-238) absorbs from the fission process as the fuel temperature increases. It is a measure of the stability of the reactor operations. This coefficient is also known as the Doppler coefficient due to the contribution of Doppler broadening, which is the dominant effect in thermal systems. Contributing effects Doppler broadening Thermal Doppler motion of atoms within the fuel results in a broader neutron spectrum and, consequently, in a decreased neutron capture rate. Thermal expansion Thermal expansion of the fuel at higher temperatures results in a lower density which reduces the likelihood of a neutron interacting with the fuel. See also *Nuclear fission *Nuclear reactor physics *Void coefficient In nuclear engineering, the void coefficient (more properl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Franco-Belge De Fabrication Du Combustible
FBFC (''Franco-Belge de Fabrication du Combustible'', French-Belgian fabrication of fuel) is a nuclear fuel producing company. From 1977 onwards its headquarters are located in Romans-sur-Isère. It operates a further two facilities, one at the Tricastin Nuclear Power Center in France and one Dessel in Belgium. In 2001 FBFC became a wholly owned subsidiary of Areva. Since 2018, FBFC is a subsidiary of Framatome Framatome () is a French nuclear reactor business. It is owned by Électricité de France (EDF) (75.5%), Mitsubishi Heavy Industries (19.5%), and Assystem (5%). The company first formed in 1958 to license Westinghouse's pressurized water reacto .... In Dessel FBFC employs around 150 people. Areva Nuclear fuel companies Nuclear technology in Belgium Nuclear technology companies of France 2001 mergers and acquisitions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Romans-sur-Isère
Romans-sur-Isère (; Occitan: ''Rumans d'Isèra''; Old Occitan: ''Romans'') is a commune in the Drôme department in southeastern France. Geography Romans-sur-Isère is located on the Isère, northeast of Valence. There are more than 50,000 inhabitants in the urban area (if the neighboring town of Bourg-de-Péage is included). Romans is close to the Vercors. Population Economy * Nuclear fuel manufacture (FBFC, Franco-Belge de Fabrication du Combustible), Framatome subsidiary. * Shoe manufacture (including Robert Clergerie) History *Historian Emmanuel Le Roy Ladurie wrote ''Carnaval de Romans'' (1980) a microhistorical study, based on the only two surviving eyewitness accounts, of the 1580 massacre of about twenty artisans at the annual carnival in the town. He treats the massacre as a microcosm of the political, social and religious conflicts of rural society in the latter half of the 16th century in France. *On 18 July 2017, the town was the end point for Stage Sixteen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isotope Separation
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 (e.g. in chemistry where atoms of "marker" nuclide are used to figure out reaction mechanisms). 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 reaction, chemical processes, isotopes of the same element have nearly identical chemical properties, which makes this ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Fuels
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 Fissile material#Fissile vs fissionable, 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Materials
Nuclear material refers to the metals uranium, plutonium, and thorium, in any form, according to the IAEA. This is differentiated further into "source material", consisting of natural and depleted uranium, and "special fissionable material", consisting of enriched uranium (U-235), uranium-233, and plutonium-239. Uranium ore concentrates are considered to be a "source material", although these are not subject to safeguards under the Nuclear Non-Proliferation Treaty. According to the Nuclear Regulatory Commission(NRC), there are four different types of regulated nuclear materials: special nuclear material, source material, byproduct material and radium. Special nuclear materials have plutonium, uranium-233 or uranium with U233 or U235 that has a content found more than in nature. Source material is thorium or uranium that has a U235 content equal to or less than what is in nature. Byproduct material is radioactive material that is not source or special nuclear material. It can be a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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