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Kowari
The Open-pool Australian lightwater reactor (OPAL) is a 20 megawatt (MW) swimming pool nuclear research reactor. Officially opened in April 2007, it replaced the High Flux Australian Reactor as Australia's only nuclear reactor, and is located at the Australian Nuclear Science and Technology Organisation (ANSTO) Research Establishment in Lucas Heights, New South Wales, a suburb of Sydney. Both OPAL and its predecessor have been commonly known simply as the Lucas Heights reactor. Functions The main reactor uses are: * Irradiation of target materials to produce radioisotopes for medical and industrial applications * Research in the fields of materials science and structural biology using neutron beams and its sophisticated suite of experimental equipment * Analysis of minerals and samples using the neutron activation technique and the delay neutron activation technique * Irradiation of silicon ingots in order to dope them with phosphorus and produce the basic material used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megawatt
The watt (symbol: W) is the unit of Power (physics), power or radiant flux in the International System of Units, International System of Units (SI), equal to 1 joule per second or 1 kg⋅m2⋅s−3. It is used to quantification (science), quantify the rate of Energy transformation, energy transfer. The watt is named after James Watt (1736–1819), an 18th-century Scottish people, Scottish invention, inventor, mechanical engineer, and chemist who improved the Newcomen steam engine, Newcomen engine with his own Watt steam engine, steam engine in 1776. Watt's invention was fundamental for the Industrial Revolution. Overview When an object's velocity is held constant at one metre per second against a constant opposing force of one Newton (unit), newton, the rate at which Work (physics), work is done is one watt. : \mathrm In terms of electromagnetism, one watt is the rate at which electrical work is performed when a current of one ampere (A) flows across an electrical potentia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supermirror
A neutron supermirror is a highly polished, layered material used to reflect neutron beams. Supermirrors are a special case of multi-layer neutron reflectors with varying layer thicknesses. The first neutron supermirror concept was proposed by , inspired by earlier work with x-rays. Supermirrors are produced by depositing alternating layers of strongly contrasting substances, such as nickel and titanium, on a smooth substrate. A single layer of high refractive index material (e.g. nickel Nickel is a chemical element with symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive but large pieces are slow to ...) exhibits total external reflection at small grazing angles up to a critical angle \theta_c. For nickel with natural isotopic abundances, \theta_c in degrees is approximately 0.1 \cdot \lambda where \lambda is the neutron wavelength in Angstrom u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neutron
The neutron is a subatomic particle, symbol or , which has a neutral (not positive or negative) charge, and a mass slightly greater than that of a proton. Protons and neutrons constitute the nuclei of atoms. Since protons and neutrons behave similarly within the nucleus, and each has a mass of approximately one atomic mass unit, they are both referred to as nucleons. Their properties and interactions are described by nuclear physics. Protons and neutrons are not elementary particles; each is composed of three quarks. The chemical properties of an atom are mostly determined by the configuration of electrons that orbit the atom's heavy nucleus. The electron configuration is determined by the charge of the nucleus, which is determined by the number of protons, or atomic number. The number of neutrons is the neutron number. Neutrons do not affect the electron configuration, but the sum of atomic and neutron numbers is the mass of the nucleus. Atoms of a chemical element t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neutron Moderator
In nuclear engineering, a neutron moderator is a medium that reduces the speed of fast neutrons, ideally without capturing any, leaving them as thermal neutrons with only minimal (thermal) kinetic energy. These thermal neutrons are immensely more susceptible than fast neutrons to propagate a nuclear chain reaction of uranium-235 or other fissile isotope by colliding with their atomic nucleus. Water (sometimes called "light water" in this context) is the most commonly used moderator (roughly 75% of the world's reactors). Solid graphite (20% of reactors) and heavy water (5% of reactors) are the main alternatives. Beryllium has also been used in some experimental types, and hydrocarbons have been suggested as another possibility. Moderation Neutrons are normally bound into an atomic nucleus, and do not exist free for long in nature. The unbound neutron has a half-life of 10 minutes and 11 seconds. The release of neutrons from the nucleus requires exceeding the binding energy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Fuel
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] |
Nuclear Reactor Core
A nuclear reactor core is the portion of a nuclear reactor containing the nuclear fuel components where the nuclear reactions take place and the heat is generated. Typically, the fuel will be low-enriched uranium contained in thousands of individual fuel pins. The core also contains structural components, the means to both moderate the neutrons and control the reaction, and the means to transfer the heat from the fuel to where it is required, outside the core. Water-moderated reactors Inside the core of a typical pressurized water reactor or boiling water reactor are fuel rods with a diameter of a large gel-type ink pen, each about 4 m long, which are grouped by the hundreds in bundles called "fuel assemblies". Inside each fuel rod, pellets of uranium, or more commonly uranium oxide, are stacked end to end. Also inside the core are control rods, filled with pellets of substances like boron or hafnium or cadmium that readily capture neutrons. When the control rods are lowe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
OPAL Reactorpools
Opal is a hydrated amorphous form of silica (SiO2·''n''H2O); its water content may range from 3 to 21% by weight, but is usually between 6 and 10%. Due to its amorphous property, it is classified as a mineraloid, unlike crystalline forms of silica, which are considered minerals. It is deposited at a relatively low temperature and may occur in the fissures of almost any kind of rock, being most commonly found with limonite, sandstone, rhyolite, marl, and basalt. The name ''opal'' is believed to be derived from the Sanskrit word (), which means 'jewel', and later the Greek derivative (), which means 'to see a change in color'. There are two broad classes of opal: precious and common. Precious opal displays play-of-color (iridescence); common opal does not. Play-of-color is defined as "a pseudo chromatic optical effect resulting in flashes of colored light from certain minerals, as they are turned in white light." The internal structure of precious opal causes it to diffract ... [...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] |
Australian Radiation Protection And Nuclear Safety Agency
The Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) is a regulatory agency under the national Commonwealth government of Australia that aims to protect Australian citizens from both ionising and non-ionising radiation. ARPANSA works under the guidance of the Australian Radiation Protection and Nuclear Safety Act of 1998 as the national regulatory body of radiation in Australia, with independent departments within each state and territory that regulate radiation within each of their jurisdictions. Responsibilities ARPANSA's responsibilities include: * Regulating the use of ionising radiation * Setting national standards for radiation use * Protecting citizens from radiation exposure * Promoting the safe use of radiation in medicine * Enforcing national radiation standards * Providing advice to the Australian government and community about radiation or nuclear issues ARPANSA evaluates research conducted by the International Commission on Non-Ionizing Radi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HIFAR
The High Flux Australian Reactor (HIFAR) was Australia's first nuclear reactor. It was built at the Australian Atomic Energy Commission (later ANSTO) Research Establishment at , Sydney. The reactor was in operation between 1958 and 2007, when it was superseded by the Open-pool Australian lightwater reactor, also in Lucas Heights. Background and operation Based on the DIDO reactor at Harwell in the UK, HIFAR was cooled and moderated by heavy water ( D2O), and the fuel was enriched uranium. There was also a graphite neutron reflector surrounding the core. Like DIDO, its original purpose was nuclear materials testing, using its high neutron flux to give materials intended for use in nuclear power reactors their entire expected lifetime neutron exposure in a relatively short period. HIFAR was used for research, particularly neutron diffraction experiments, production of neutron transmutation doped (NTD) silicon, and for production of medical and industrial radioisotopes. HIF ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ANSTO
The Australian Nuclear Science and Technology Organisation (ANSTO) is a statutory body of the Australian government, formed in 1987 to replace the Australian Atomic Energy Commission. Its head office and main facilities are in southern outskirts of Sydney at Lucas Heights, in the Sutherland Shire. Purpose The Australian Nuclear Science & Technology Organisation (ANSTO) is Australia's national nuclear organisation and the centre of Australian nuclear expertise. The Australian Nuclear Science and Technology Organisation Act 1987 (Cth) prescribes its general purpose. The purpose is translated into action through corporate drivers of vision, mission and strategic goals. Mission statement * To support the development and implementation of government policies and initiatives in nuclear and related areas, domestically and internationally * To operate nuclear science and technology based facilities, for the benefit of industry and the Australian and international research communit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
