CANDU

A Nuclear Reactor is only a small part of the life-cycle for nuclear power. The process starts with mining. Generally, uranium mines are either open-pit strip mines, or in-situ leach mines. In either case, the uranium ore is extracted, usually converted into a stable and compact form such as yellowcake, and then transported to a processing facility. At the reprocessing facility, the yellowcake is converted to uranium hexafluoride, which is then enriched using various techniques. At this point, the enriched uranium, containing more than the n ...

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Nuclear power, Nuclear power - History, Nuclear power - Origins, Nuclear power - Early years, Nuclear power - Development, Nuclear power - Current and planned use, Nuclear power - Reactor Types, Nuclear power - Current Technology, Nuclear power - Experimental Technologies, Nuclear power - Life cycle, Nuclear power - Fuel resources, Nuclear power - Reprocessing, Nuclear power - Solid waste, Nuclear power - Economy, Nuclear power - Capital costs, Nuclear power - Operating costs, Nuclear power - Subsidies, Nuclear power - Other economic issues, Nuclear power - Risks, Nuclear power - Accident or attack, Nuclear power - Air pollution, Nuclear power - Waste heat in water systems, Nuclear power - Health effect on population near nuclear plants, Nuclear power - Nuclear proliferation, Nuclear power - List of atomic energy groups

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Opponents of nuclear power claim that any of the environmental benefits are outweighed by safety compromises and by the costs related to construction and operation of nuclear power plants, including costs for spent-fuel disposition and plant retirement. Proponents of nuclear power state that nuclear energy is the only power source which explicitly factors the estimated costs for waste containment and plant decommissioning into its overall cost, and that the quoted cost of fossil fuel plants is deceptively low for this reason. The cost of many renewables would be increased too if they included necessary ...

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Nuclear power, Nuclear power - History, Nuclear power - Origins, Nuclear power - Early years, Nuclear power - Development, Nuclear power - Current and planned use, Nuclear power - Reactor Types, Nuclear power - Current Technology, Nuclear power - Experimental Technologies, Nuclear power - Life cycle, Nuclear power - Fuel resources, Nuclear power - Reprocessing, Nuclear power - Solid waste, Nuclear power - Economy, Nuclear power - Capital costs, Nuclear power - Operating costs, Nuclear power - Subsidies, Nuclear power - Other economic issues, Nuclear power - Risks, Nuclear power - Accident or attack, Nuclear power - Air pollution, Nuclear power - Waste heat in water systems, Nuclear power - Health effect on population near nuclear plants, Nuclear power - Nuclear proliferation, Nuclear power - List of atomic energy groups

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FBRs usually use a mixed oxide fuel core of up to 20% plutonium dioxide (PuO2) and at least 80% uranium dioxide (UO2). The plutonium used can be from reprocessed civil or dismantled nuclear weapons sources. Surrounding the reactor core is a blanket of tubes containing non-fissile uranium-238 which, by capturing fast neutrons from the reaction in the core, is partially converted to fissile plutonium 239 (as is some of the uranium in the core), which can then be reprocessed for use as nuclear fuel. There is no moderator as this would slow the neutrons leaving the core. Early FBRs used metallic fuel, ei ...

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Fast breeder, Fast breeder - Technical, Fast breeder - FBR generating plants, Fast breeder - Future plants, Fast breeder - Economics, Fast breeder - Proliferation, Fast breeder - Associated reactor types

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The opposite of enriching is downblending; Surplus HEU can be downblended to LEU to make it suitable for use in commercial nuclear fuel. The HEU feedstock, can contain unwanted uranium isotopes: 234U is a minor isotope contained in natural uranium; during the enrichment process, its concentration increases even more than that of 235U. High concentrations of 234U may cause excessive worker radiation exposures during fuel fabrication; 236U is a byproduct from irradiation in a reactor an ...

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Enriched uranium, Enriched uranium - Grades, Enriched uranium - Highly enriched uranium HEU, Enriched uranium - Low-enriched uranium LEU, Enriched uranium - Slightly enriched uranium SEU, Enriched uranium - Methods, Enriched uranium - Thermal Diffusion, Enriched uranium - Gaseous diffusion, Enriched uranium - The Gas centrifuge, Enriched uranium - The Zippe centrifuge, Enriched uranium - Aerodynamic Processes, Enriched uranium - Electromagnetic Isotope Separation, Enriched uranium - Laser processes, Enriched uranium - Chemical methods, Enriched uranium - Plasma separation, Enriched uranium - The SWU separative work unit, Enriched uranium - Downblending

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Separative Work Unit (SWU) is a complex unit which is a function of the amount of uranium processed and the degree to which it is enriched, ie the extent of increase in the concentration of the 235U isotope relative to the remainder. Separative work is expressed in SWUs, kg SW, or kg UTA (from the German Urantrennarbeit ) 1 SWU = 1 kg SW = 1 kg UTA 1 ...

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Enriched uranium, Enriched uranium - Grades, Enriched uranium - Highly enriched uranium HEU, Enriched uranium - Low-enriched uranium LEU, Enriched uranium - Slightly enriched uranium SEU, Enriched uranium - Methods, Enriched uranium - Thermal Diffusion, Enriched uranium - Gaseous diffusion, Enriched uranium - The Gas centrifuge, Enriched uranium - The Zippe centrifuge, Enriched uranium - Aerodynamic Processes, Enriched uranium - Electromagnetic Isotope Separation, Enriched uranium - Laser processes, Enriched uranium - Chemical methods, Enriched uranium - Plasma separation, Enriched uranium - The SWU separative work unit, Enriched uranium - Downblending

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Enriched uranium - Highly enriched uranium HEU. Highly enriched uranium (HEU) has a greater than 20% concentration of 235U. The fissile uranium in nuclear weapons usually contains 85% or more of 235U known as weapon(s)-grade, though for a crude inefficient weapon 20% is sufficient (called weapon(s)-usable); some argue that even less is sufficient, but then the critical mass required rapidly increases. The presence of too much of the 238U isotope inhibits the runaway nuclear chain reaction ...

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Enriched uranium, Enriched uranium - Grades, Enriched uranium - Highly enriched uranium HEU, Enriched uranium - Low-enriched uranium LEU, Enriched uranium - Slightly enriched uranium SEU, Enriched uranium - Methods, Enriched uranium - Thermal Diffusion, Enriched uranium - Gaseous diffusion, Enriched uranium - The Gas centrifuge, Enriched uranium - The Zippe centrifuge, Enriched uranium - Aerodynamic Processes, Enriched uranium - Electromagnetic Isotope Separation, Enriched uranium - Laser processes, Enriched uranium - Chemical methods, Enriched uranium - Plasma separation, Enriched uranium - The SWU separative work unit, Enriched uranium - Downblending

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During both the First World War and Second World War, Canada was an important producer and developer of chemical weapons for the Allied war effort. These were used in combat in World War I, but not in World War II. Human experimentation was carried out during World War II, with CFB Suffield becoming the leading research facility. Thousands of Canadian soldiers were exposed to mustard gas, blister gas, tear gas, and other agents, and some were permanently injured. Human testing of weapons such as sarin and VX gas continued well into the 60's, ...

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Canada and weapons of mass destruction, Canada and weapons of mass destruction - Nuclear weapons, Canada and weapons of mass destruction - Chemical weapons, Canada and weapons of mass destruction - Biological weapons, Canada and weapons of mass destruction - Disarmament, Canada and weapons of mass destruction - External References

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Canada, with its strong belief in multilateralism, has long been a strong advocate of arms limitation treaties. Canada is a member of every international disarmament organization and is committed to pushing for an end to nuclear weapons testing, reduction in nuclear arsenals, a ban on all chemical and biological weapons, bans on the weaponization of outer space, and blocks on nuclear proliferation. Canada maintains a division of its Foreign Affairs department devoted to pursuing these ends. It also dedicates significant resources in t ...

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Canada and weapons of mass destruction, Canada and weapons of mass destruction - Nuclear weapons, Canada and weapons of mass destruction - Chemical weapons, Canada and weapons of mass destruction - Biological weapons, Canada and weapons of mass destruction - Disarmament, Canada and weapons of mass destruction - External References

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The Blak Sea littoral is the preferred destination for the summer holidays in Romania. The resorts are: Năvodari. Mamaia. Eforie (North and South). Costineşti. Olimp-Neptun. Jupiter-Cap Aurora. Venus. Mangalia - Saturn. 2 Mai. Vama Veche. Also worth visiting are: The city of Constanţa. The mausoleum from ...

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Constanţa County, Constanţa County - Neighbours, Constanţa County - Demographics, Constanţa County - Geography, Constanţa County - Economy, Constanţa County - Tourism, Constanţa County - Administrative divisions, Constanţa County - Municipalities, Constanţa County - Towns, Constanţa County - Communes

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The predominant industries in the county are: Chemical and petrochemical industry. Food and beverages industry. Textile industry. Ship building industry. Construction materials. Mechanical components industry. Paper industry. Agriculture is an important part in the county's economy, Constanţa being the county with the largest irrigations systems in the country (more than 4,300 km2), cereals being the most important products. Also, the county is fa ...

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Constanţa County, Constanţa County - Neighbours, Constanţa County - Demographics, Constanţa County - Geography, Constanţa County - Economy, Constanţa County - Tourism, Constanţa County - Administrative divisions, Constanţa County - Municipalities, Constanţa County - Towns, Constanţa County - Communes

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This county has a total area of 7,071 km². Much of the territory of Constanţa county comprises of a low-lying plateau with a continental semi-arid climate. The Black Sea coast - streching about 120 km (75 miles) - has a maritime climate with less contrasts than the interior. The average January temperature in Constanţa county is -1°C (30°F), while the average July temperature reaches 23°C (75°F). In the North-East of the county there is the lagoon - lake Sinoe. O ...

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Constanţa County, Constanţa County - Neighbours, Constanţa County - Demographics, Constanţa County - Geography, Constanţa County - Economy, Constanţa County - Tourism, Constanţa County - Administrative divisions, Constanţa County - Municipalities, Constanţa County - Towns, Constanţa County - Communes

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Twenty-one plutonium radioisotopes have been characterized. The most stable are Pu-244, with a half-life of 80.8 million years, Pu-242, with a half-life of 373,300 years, and Pu-239, with a half-life of 24,110 years. All of the remaining radioactive isotopes have half-lives that are less than 7,000 years. This element also has eight meta states, though none are very stable (all have half-lives less than one second). The isotopes of plutonium range in atomic weight from 228.0387 u (Pu-228) to 247.074 u (Pu-247). The primary decay modes ...

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Plutonium, Plutonium - Notable characteristics, Plutonium - Applications, Plutonium - History, Plutonium - Occurrence, Plutonium - Manufacture, Plutonium - Compounds, Plutonium - Allotropes, Plutonium - Isotopes, Plutonium - Precautions

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Even at ambient pressure, plutonium occurs in a variety of allotropes. These allotropes differ widely in crystal structure and density; the α and δ allotropes differ in density by more than 25% at the same volume. The presence of these many allotropes makes machining plutonium very difficult, as it changes state very readily. The reasons for the complicated phase diagram are not entirely understood; recent research has focused on constructing accurate c ...

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Plutonium, Plutonium - Notable characteristics, Plutonium - Applications, Plutonium - History, Plutonium - Occurrence, Plutonium - Manufacture, Plutonium - Compounds, Plutonium - Allotropes, Plutonium - Isotopes, Plutonium - Precautions

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The Vienna Convention on Civil Liability for Nuclear Damage puts in place an international framework for nuclear liability [2]. However states with a majority of the world's nuclear power plants, including the U.S., Russia, China and Japan, are not party to any international nuclear liability conventions. In the U.S., insurance for nuclear or radiological incidents is covered (for facilities licensed throu ...

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Nuclear power plant, Nuclear power plant - History, Nuclear power plant - Types of nuclear power plants, Nuclear power plant - Fission reactors, Nuclear power plant - Fusion reactors, Nuclear power plant - Advantages and disadvantages, Nuclear power plant - Accident Indemnification

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Nuclear reactors require water to keep the reactor cool. The process of extracting energy from a heat source, called the Rankine cycle, requires the steam to be cooled down. Rivers are the most common source of cooling water, as well as the destination for waste heat. The temperature of exhaust water must be regulated to avoid killing fish; long-term impact of hotter-than-natural water on ecosystems is an environmental concern. The need to regulate exhaust temperature also limits generation capacity. On extremely hot days, which is wh ...

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Nuclear power, Nuclear power - History, Nuclear power - Origins, Nuclear power - Early years, Nuclear power - Development, Nuclear power - Current and planned use, Nuclear power - Reactor Types, Nuclear power - Current Technology, Nuclear power - Experimental Technologies, Nuclear power - Life cycle, Nuclear power - Fuel resources, Nuclear power - Reprocessing, Nuclear power - Solid waste, Nuclear power - Economy, Nuclear power - Capital costs, Nuclear power - Operating costs, Nuclear power - Subsidies, Nuclear power - Other economic issues, Nuclear power - Risks, Nuclear power - Accident or attack, Nuclear power - Air pollution, Nuclear power - Waste heat in water systems, Nuclear power - Health effect on population near nuclear plants, Nuclear power - Nuclear proliferation, Nuclear power - List of atomic energy groups

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Opponents of nuclear power such as Greenpeace, argue against its use due to issues like the long term problems of storing radioactive waste, the potential for severe radioactive contamination by an accident, and the possibility that its use will lead to the proliferation of nuclear weapons. They point to the nuclear accidents. According to a 1978 finding by the Supreme Court of the United States, comprehensive testing and study had not yet removed the risk of a major nuclear accident [45]. In the 1980s and 1990s each US nuclear plant ...

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Nuclear power, Nuclear power - History, Nuclear power - Origins, Nuclear power - Early years, Nuclear power - Development, Nuclear power - Current and planned use, Nuclear power - Reactor Types, Nuclear power - Current Technology, Nuclear power - Experimental Technologies, Nuclear power - Life cycle, Nuclear power - Fuel resources, Nuclear power - Reprocessing, Nuclear power - Solid waste, Nuclear power - Economy, Nuclear power - Capital costs, Nuclear power - Operating costs, Nuclear power - Subsidies, Nuclear power - Other economic issues, Nuclear power - Risks, Nuclear power - Accident or attack, Nuclear power - Air pollution, Nuclear power - Waste heat in water systems, Nuclear power - Health effect on population near nuclear plants, Nuclear power - Nuclear proliferation, Nuclear power - List of atomic energy groups

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The amount and nature of neutron moderation affects reactor controllability and hence safety. Because moderators both slow and absorb neutrons, there is an optimum amount of moderator to include in a given geometry of reactor core. Less moderation reduces the effectiveness by reducing the Pfission term in the evolution equation, and more moderation reduces the effectiveness by increasing the PSee also:

Nuclear reactor physics, Nuclear reactor physics - Starter sources, Nuclear reactor physics - Moderators and reactor design, Nuclear reactor physics - Long-lived poisons and fuel reprocessing, Nuclear reactor physics - Short-lived poisons and controllability

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In practice, buildup of reactor poisons in nuclear fuel is what determines the lifetime of nuclear fuel in a reactor: long before all possible fissions have taken place, buildup of long-lived neutron absorbing fission products damps out the chain reaction. This is the reason that nuclear reprocessing is a useful activity: spent nuclear fuel contains about 99% of the original fissionable material present in newly manufactured nuclear fuel. Chemical separa ...

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Nuclear reactor physics, Nuclear reactor physics - Starter sources, Nuclear reactor physics - Moderators and reactor design, Nuclear reactor physics - Long-lived poisons and fuel reprocessing, Nuclear reactor physics - Short-lived poisons and controllability

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Initially predicted by Walter Russell, the production of plutonium and neptunium by bombarding uranium-238 with neutrons was predicted in 1940 by two teams working independently: Edwin M. McMillan and Philip Abelson at Berkeley Radiation Laboratory at the University of California, Berkeley and by Norman Feather & Egon Bretscher at the Cavendish Laboratory at University of Cambridge. Coincidentally both teams proposed the same names to follow on from uranium, li ...

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Plutonium, Plutonium - Notable characteristics, Plutonium - Applications, Plutonium - History, Plutonium - Occurrence, Plutonium - Manufacture, Plutonium - Compounds, Plutonium - Allotropes, Plutonium - Isotopes, Plutonium - Precautions

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The isotope Plutonium-239 is a key fissile component in modern nuclear weapons, due to its ease of fissioning and availability. The critical mass for an unreflected sphere of plutonium is 16 kg, but through the use of a neutron reflecting tamper the pit of plutonium in a fission bomb is reduced to 10 kg, which is a sphere with a diameter of 10 cm. Complete detonation of plutonium will produce an explosion of 20 kilotons of TNT per kilogram. (See also Nuclear Weapon Design.) Plutonium could also be used to manufacture radiological weapons ...

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Plutonium, Plutonium - Notable characteristics, Plutonium - Applications, Plutonium - History, Plutonium - Occurrence, Plutonium - Manufacture, Plutonium - Compounds, Plutonium - Allotropes, Plutonium - Isotopes, Plutonium - Precautions

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Plutonium is silvery in pure form, but has a yellow tarnish when oxidized. Peculiarly, the metal goes through phases of contraction as its temperature is increased. The heat given off by alpha particle emission makes plutonium warm to the touch in reasonable quantities; larger amounts can boil water. It displays four ionic oxidation states in aqueous solution: Pu3+ (blue lavender) Pu4+ (yellow brown) PuO2+ (pink orange) PuO+ (thought to be pink; this i ...

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Plutonium, Plutonium - Notable characteristics, Plutonium - Applications, Plutonium - History, Plutonium - Occurrence, Plutonium - Manufacture, Plutonium - Compounds, Plutonium - Allotropes, Plutonium - Isotopes, Plutonium - Precautions

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It is generally agreed that the FBR poses a greater risk of proliferation of nuclear weapons than light water-moderated reactors. Water-moderated reactors must shutdown and refuel every four months or less to produce weapons grade plutonium, relatively pure Pu-239, because the level of Pu-240 in the fuel increases over time. Pu-240 undergoes spontaneous fission at a relatively high rate and is unsuitable for nuclear weapons production. An FBR can more easily produce weapons grade material, depending on its design. However, to date all known ...

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Fast breeder reactor, Fast breeder reactor - FBR generating plants, Fast breeder reactor - Future plants, Fast breeder reactor - Economics, Fast breeder reactor - Proliferation, Fast breeder reactor - Associated reactor types

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