The term of art for the amount of effort required to enrich uranium is a separative work unit, or SWU.
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" On June 4, in his first official response to Trump's pullout decision, Khamenei ordered the AEOI to lay the groundwork for achieving "190 000 SWUs [Separative Work Units]" involving uranium enrichment capacity "as soon as possible," but "within the framework of JCPOA for the time being.
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The simplest gas centrifuge is the concurrent centrifuge, where separative effect is produced by the centrifugal effects of the rotor's rotation. In these centrifuges, the heavy fraction is collected at the periphery of the rotor, and the light fraction from nearer the axis of rotation. Inducing a countercurrent flow uses countercurrent multiplication to enhance the separative effect. A vertical circulating current is set up, with the gas flowing axially along the rotor walls in one direction, and a return flow closer to the center of the rotor.
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USEC currently awaits approval of this $2 billion loan guarantee before it can remobilize the construction, which will create nearly 8,000 jobs in the United States. Once completed, the commercial plant will use approximately 11,500 centrifuge machines to generate 3.8 million separative work units (SWU) a year.
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In grammar, the locative case (abbreviated ) is a grammatical case which indicates a location. It corresponds vaguely to the English prepositions "in", "on", "at", and "by". The locative case belongs to the general local cases, together with the lative and separative case. The locative case exists in many language groups.
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The relationship between the separative force field and retention time can be illustrated from first principles. Consider two particle populations within the FFF channel. The cross field drives both particle clouds towards the bottom "accumulation" wall. Opposing this force field is the particles natural diffusion, or Brownian motion, which produces a counter acting motion.
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In grammar, lative (abbreviated ) is a grammatical case which indicates motion to a location. It corresponds to the English prepositions "to" and "into". The lative case belongs to the group of the general local cases together with the locative and separative case. The term derives from the Latin lat-, the participle stem of ferre, "to bring".
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Because of the improvements in gas centrifuge technology in the 2000s, replacing former gaseous diffusion plants, cheaper separative work units have enabled the economic production of more enriched uranium from a given amount of natural uranium, by re-enriching tails ultimately leaving a depleted uranium tail of lower enrichment. This has somewhat lowered the demand for natural uranium.
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In use, the plant consumed a peak electrical demand of 2,100 megawatts. A commercial centrifuge plant at the Portsmouth site began construction in May 2007 for the production of commercial nuclear fuel for power reactors. Once completed, the commercial plant will use approximately 11,500 centrifuge machines to generate 3.8 million separative work units (SWU) a year.
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The magnitude of F and ∆F depend on particle properties, field strength and the type of field. This allows for variations and specialisations for the technique. From this basic principle many forms of FFF have evolved varying by the nature of the separative force applied and the range in molecule size to which they are targeted.
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These devices are known as Gloveboxes. Gloveboxes do not offer the separative control provisions of an isolator or RABS. Gloveboxes were originally designed for non-sterile product applications, such as weighing or manipulating a toxic drug and have a long track record for such non-sterile applications. Such gloveboxes can be very effective in preventing exposure of an operator to a toxic drug.
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In addition to (low cost) thorium, a 1 GWe reactor initially requires 3,156 kg of 20% low enriched uranium along with 11 kg per day of operation. Every 8 years the fuel must be changed out. At a yellowcake cost of $66/kg, a $7.50 conversion cost and $90 per separative work unit, the levelized fuel cost is 0.53 cents per kilowatt-hour.
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The relationship between Iraqi Kurdistan and other states of the Iraq federation can be characterized as asymmetric federalism. The political and cultural distinctiveness of Iraqi Kurdistan is lawfully recognized in Article 5 of the Iraqi Constitution. Iraqi Kurdistan is the sole federative region in Iraq, which enjoyed its separative political entity as de facto state from 1991 to 2003, and voluntarily rejoined a federal democratic Iraq.
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The Paducah plant had a capacity of 11.3 million separative work units per year (SWU/year) in 1984. 1812 stages were located in five buildings: C-310 with 60 stages, C-331 with 400 stages, C-333 with 480 stages, C-335 with 400 stages and C-337 with 472 stages. Before cessation of uranium enrichment on May 31, 2013, the Paducah facility consumed about 2,000 megawatts of electricity. Power for the Paducah gaseous diffusion plant came from the Tennessee Valley Authority (TVA).
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A topological field of sets is called algebraic if and only if there is a base for its topology consisting of complexes. If a topological field of sets is both compact and algebraic then its topology is compact and its compact open sets are precisely the open complexes. Moreover, the open complexes form a base for the topology. Topological fields of sets that are separative, compact and algebraic are called Stone fields and provide a generalization of the Stone representation of Boolean algebras.
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The value of the process is in two components: the LEU Feed (feed component of natural uranium) and the work involved in the conversion process, measured as separative work units (SWU). Both have separate commercial values. Early disagreements on interpretations of the terms of the governmental and commercial agreements on this issue led to controversy and some delays. Although each shipment contains LEU, the commercial nature of the global uranium market defines the uranium and the enrichment components as separate commercial values and costs.
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Following the shutdown of many nuclear power plants after the Fukushima Daiichi nuclear disaster in 2011, demand had fallen to about per year in 2015 with future forecasts uncertain. Because of the improvements in gas centrifuge technology in the 2000s, replacing former gaseous diffusion plants, cheaper separative work units have enabled the economic production of more enriched uranium from a given amount of natural uranium, by re-enriching tails ultimately leaving a depleted uranium tail of lower enrichment. This has somewhat lowered the demand for natural uranium.
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As Wellmon observes, Goethe's concept of science is one in which "not only the object of observation changes and moves but also the subject of observation." Thus, a true science of vital nature would be based on an approach that was itself vital, dynamic, labile. The key for this is a living, direct, interactive experience (Erlebnis) involving the mind, but also higher faculties more participatory and Imaginative (Gemüt), not dissociative and separative (Sinn). Only since the 1970s have other mainstream scientists come to be interested in Goethe's more holistic-humanistic approach to experiments.
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Up to this time, sociology had approached children and childhood mainly from a socialization perspective, and the emergence of the new childhood sociological paradigm ran parallel to the feminist critique of sociological traditions. Childhood sociologists attacked the "adultocentric" approach and the "separative view" of sociology towards children. Not surprisingly, then, the key works in the sociology of childhood are quite interdisciplinary, linking history, cultural studies, ethnomethodology, and pedagogy. Key texts include James and Prout's Constructing and Reconstructing Childhood (1990/1997), James, Jenks and Prout Theorizing Childhood (1998)and Prout's The Future of Childhood (2005).
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Brazzaville Beach consists of three separative narratives. The first is Hope Clearwater's reflections on her current life whilst living in a beach house on Brazzaville Beach. The second narrative is a description of her former marriage to John Clearwater, a mathematician, who gradually goes mad resulting from failure to make progress in his academic research. The third narrative, and by far the most graphic, is the narrator's account of her work in a national park called Grosso Arvore (Big Tree), where she tracks the movements of a small band of chimpanzees that have split off from a larger group in the north.
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The word oakum derives from Middle English ', from Old English ', from ' (separative and perfective prefix) + ' (akin to Old English ', 'comb')—literally 'off-combings'. Oakum was at one time recycled from old tarry ropes and cordage, which were painstakingly unravelled and reduced to fibre, termed "picking". The task of picking and preparation was a common occupation in prisons and workhouses, where the young or the old and infirm were put to work picking oakum if they were unsuited for heavier labour. Sailors undergoing naval punishment were also frequently sentenced to pick oakum, with each man made to pick of oakum a day.
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Operations began in 1954 while construction was ongoing with the plant coming fully online in early 1956, several months ahead of schedule. The primary mode of enrichment was the gaseous diffusion of uranium hexafluoride to separate the lighter fissile isotope, U-235, from the heavier non-fissile isotope, U-238. The plant initially produced material for the U.S. nuclear weapons program. In the mid-1960s, the plant converted to fuel production for commercial nuclear power plants. Portsmouth took material from Paducah that was enriched to 2.75% U-235 and further enriched it to approximately 4% and 5%. The Portsmouth plant had a capacity of 8.3 million separative work units per year (SWU/year) in 1984 in 4,080 stages.
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For example, beginning with of natural uranium (NU), it takes about 62 SWU to produce of Low-enriched uranium (LEU) in 235U content to 4.5%, at a tails assay of 0.3%. The number of separative work units provided by an enrichment facility is directly related to the amount of energy that the facility consumes. Modern gaseous diffusion plants typically require 2,400 to 2,500 kilowatt-hours (kW·h), or 8.6–9 gigajoules, (GJ) of electricity per SWU while gas centrifuge plants require just 50 to 60 kW·h (180–220 MJ) of electricity per SWU. Example: A large nuclear power station with a net electrical capacity of 1300 MW requires about 25 tonnes per year (25 t/a) of LEU with a 235U concentration of 3.75%.
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Many of his theorists were unsure that military-grade uranium would be feasible on time without the centrifuges, since Alam had notified PAEC that the "blueprints were incomplete" and "lacked the scientific information needed even for the basic gas-centrifuges." Calculations by Tasneem Shah, and confirmed by Alam, showed that Khan's earlier estimation of the quantity of uranium needing enrichment for the production of weapon-grade uranium was possible, even with the small number of centrifuges deployed. Against a popular perception that the centrifuge technology was stolen by Khan from Urenco Group, the designs of the centrifuges were filled with serious technical errors, and components that he brought for analysis were broken pieces, making them useless for quick assembly of a centrifuge. Its separative work unit (SWU) rate was extremely low, so that it would have to be rotated for thousands of RPMs at the cost of millions of taxpayers money, Allam maintained.
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In addition to the separative work units provided by an enrichment facility, the other important parameter to be considered is the mass of natural uranium (NU) that is needed to yield a desired mass of enriched uranium. As with the number of SWUs, the amount of feed material required will also depend on the level of enrichment desired and upon the amount of 235U that ends up in the depleted uranium. However, unlike the number of SWUs required during enrichment, which increases with decreasing levels of 235U in the depleted stream, the amount of NU needed will decrease with decreasing levels of 235U that end up in the DU. For example, in the enrichment of LEU for use in a light water reactor it is typical for the enriched stream to contain 3.6% 235U (as compared to 0.7% in NU) while the depleted stream contains 0.2% to 0.3% 235U. In order to produce one kilogram of this LEU it would require approximately 8 kilograms of NU and 4.5 SWU if the DU stream was allowed to have 0.3% 235U.
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