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Romashka Reactor
The Romashka reactor (russian: Ромашка, translation=chamomile) was a Soviet experimental nuclear reactor. It began operation in 1964, and was developed by the Kurchatov Institute of Atomic Energy. The reactor used direct thermoelectric conversion to create electricity, rather than heating water to drive a turbine. It is thus similar to a radioisotope thermoelectric generator, but higher power. The Romashka reactor was developed with the intention of using nuclear power in space satellites, but was superseded by the more powerful BES-5 reactor. The project was canceled after the death of Sergei Korolev, who was heavily involved in the project. Reactor design The fuel was of highly enriched uranium (90% ) in the form of UC2 (uranium carbide). A beryllium reflector was used on the ends of the reactor, and electricity was generated using silicon-germanium semiconductors. The Romashka reactor didn't use liquid coolant; it was designed to be simple, compact, and light. Tempe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radioisotope Thermoelectric Generator
A radioisotope thermoelectric generator (RTG, RITEG), sometimes referred to as a radioisotope power system (RPS), is a type of nuclear battery that uses an array of thermocouples to convert the heat released by the decay of a suitable radioactive material into electricity by the Seebeck effect. This type of generator has no moving parts. RTGs have been used as power sources in satellites, space probes, and uncrewed remote facilities such as a series of lighthouses built by the Soviet Union inside the Arctic Circle. RTGs are usually the most desirable power source for unmaintained situations that need a few hundred watts (or less) of power for durations too long for fuel cells, batteries, or generators to provide economically, and in places where solar cells are not practical. Safe use of RTGs requires containment of the radioisotopes long after the productive life of the unit. The expense of RTGs tends to limit their use to niche applications in rare or special situations. Beca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World Nuclear Association
World Nuclear Association is the international organization that promotes nuclear power and supports the companies that comprise the global nuclear industry. Its members come from all parts of the nuclear fuel cycle, including uranium mining, uranium conversion, uranium enrichment, nuclear fuel fabrication, plant manufacture, transport, and the disposition of spent nuclear fuel, used nuclear fuel as well as electricity generation itself. Together, World Nuclear Association members are responsible for 70% of the world's nuclear power as well as the vast majority of world uranium, conversion and Enriched uranium, enrichment production. The Association says it aims to fulfill a dual role for its members: Facilitating their interaction on technical, commercial and policy matters and promoting wider public understanding of nuclear technology. It has a secretariat of around 30 staff. The Association was founded in 2001 on the basis of the Uranium Institute, itself founded in 1975. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TOPAZ Nuclear Reactor
The TOPAZ nuclear reactor is a lightweight nuclear reactor developed for long term space use by the Soviet Union. Cooled by liquid metal, it uses a high-temperature moderator containing hydrogen and highly enriched fuel and produces electricity using a thermionic converter. Nomenclature In initial discussions, it was unclear that TOPAZ and the somewhat similar YENISEI reactors were different systems, and when the existence of the two Russian thermionic reactors became generally known, US personnel began referring to TOPAZ as TOPAZ-I and YENISEI as TOPAZ-II. TOPAZ-I The first thermionic converter reactors were discussed by scientists at the Los Alamos Scientific Laboratory (LASL) in 1957. Following the visit of Soviet scientists to LASL in 1958, they carried out tests on TI systems in 1961, initially developing the single cell ENISY reactor (also known as TOPAZ-II). Work was carried out by the Kurchatov Institute of Atomic Energy and the Central Bureau for Machine Building to dev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SNAP-10A
SNAP-10A (Systems for Nuclear Auxiliary Power, aka Snapshot for Space Nuclear Auxiliary Power Shot, also known as OPS 4682) was a US experimental nuclear powered satellite launched into space in 1965 as part of the SNAPSHOT program.SNAPSHOT NASA Glenn Research Center, March 20, 2007. Retrieved 3 April 2019. Gunther's Space Page. Retrieved 3 April 2019. The test marked both the world's first operation of a nuclear reactor in orbit, [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Nuclear Power Systems In Space
This list of nuclear power systems in space includes nuclear power systems that were flown to space, or at least launched in an attempt to reach space. Such used nuclear power systems include: * radioisotope heater units (RHU) (usually produce heat by spontaneous decay of ) * radioisotope thermoelectric generators (RTG) (usually produce heat by spontaneous decay of and convert it to electricity using a thermoelectric generator) * miniaturized fission reactors (usually produce heat by controlled fission of highly enriched and convert it to electricity using a thermionic converter) Systems never launched are not included here, see Nuclear power in space. Initial total power is provided as either electrical power (We) or thermal power (Wt), depending on the intended application. See also *Outer Space Treaty * List of high-altitude nuclear explosions *Nuclear power in space * List of artificial radiation belts * :Nuclear-powered robots References {{DEFAULTSORT:Nuclear p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Critical Mass
In nuclear engineering, a critical mass is the smallest amount of fissile material needed for a sustained nuclear chain reaction. The critical mass of a fissionable material depends upon its nuclear properties (specifically, its nuclear fission cross-section), density, shape, enrichment, purity, temperature, and surroundings. The concept is important in nuclear weapon design. Explanation of criticality When a nuclear chain reaction in a mass of fissile material is self-sustaining, the mass is said to be in a ''critical'' state in which there is no increase or decrease in power, temperature, or neutron population. A numerical measure of a critical mass is dependent on the effective neutron multiplication factor , the average number of neutrons released per fission event that go on to cause another fission event rather than being absorbed or leaving the material. When ''k'' = 1, the mass is critical, and the chain reaction is self-sustaining. A ''subcritical'' mass is a ... [...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] |
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] |
Uranium Carbide
Uranium carbide, a carbide of uranium, is a hard refractory ceramic material. It comes in several stoichiometries (''x'' differs in ), such as uranium methanide (UC, CAS number 12070-09-6), uranium sesquicarbide (U2C3, CAS number 12076-62-9), and uranium acetylide (UC2, CAS number 12071-33-9). Like uranium dioxide and some other uranium compounds, uranium carbide can be used as a nuclear fuel for nuclear reactors, usually in the form of pellets or tablets. Uranium carbide fuel was used in late designs of nuclear thermal rockets. Uranium carbide pellets are used as fuel kernels for the US version of pebble bed reactors; the German version uses uranium dioxide instead. As nuclear fuel, uranium carbide can be used either on its own, or mixed with plutonium carbide (PuC and Pu2C3). The mixture is also labeled as uranium-plutonium carbide ( (U,Pu)C ). Uranium carbide is also a popular target material for particle accelerators. Ammonia synthesis from nitrogen and hydrogen is sometim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beryllium
Beryllium is a chemical element with the symbol Be and atomic number 4. It is a steel-gray, strong, lightweight and brittle alkaline earth metal. It is a divalent element that occurs naturally only in combination with other elements to form minerals. Notable gemstones high in beryllium include beryl ( aquamarine, emerald) and chrysoberyl. It is a relatively rare element in the universe, usually occurring as a product of the spallation of larger atomic nuclei that have collided with cosmic rays. Within the cores of stars, beryllium is depleted as it is fused into heavier elements. Beryllium constitutes about 0.0004 percent by mass of Earth's crust. The world's annual beryllium production of 220 tons is usually manufactured by extraction from the mineral beryl, a difficult process because beryllium bonds strongly to oxygen. In structural applications, the combination of high flexural rigidity, thermal stability, thermal conductivity and low density (1.85 times that of water) ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Highly Enriched Uranium
Enriched uranium is a type of uranium in which the percent composition of uranium-235 (written 235U) has been increased through the process of isotope separation. Naturally occurring uranium is composed of three major isotopes: uranium-238 (238U with 99.2739–99.2752% natural abundance), uranium-235 (235U, 0.7198–0.7202%), and uranium-234 (234U, 0.0050–0.0059%). 235U is the only nuclide existing in nature (in any appreciable amount) that is fissile with thermal neutrons. Enriched uranium is a critical component for both civil nuclear power generation and military nuclear weapons. The International Atomic Energy Agency attempts to monitor and control enriched uranium supplies and processes in its efforts to ensure nuclear power generation safety and curb nuclear weapons proliferation. There are about 2,000 tonnes of highly enriched uranium in the world, produced mostly for nuclear power, nuclear weapons, naval propulsion, and smaller quantities for research reactors. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
