{"id":27294,"date":"2020-06-10T04:44:35","date_gmt":"2020-06-10T04:44:35","guid":{"rendered":"http:\/\/sitepourvtc.com\/?page_id=27294"},"modified":"2023-08-01T10:20:18","modified_gmt":"2023-08-01T10:20:18","slug":"uranium-milling","status":"publish","type":"page","link":"https:\/\/sitepourvtc.com\/nuclear-power-plant\/nuclear-fuel\/nuclear-fuel-cycle\/uranium-milling\/","title":{"rendered":"Uranium Milling"},"content":{"rendered":"<div   id="8n9s8rpp6h"     class=\"lgc-column lgc-grid-parent lgc-grid-100 lgc-tablet-grid-100 lgc-mobile-grid-100 lgc-equal-heights \"><div   id="8n9s8rpp6h"     class=\"inside-grid-column\">\n<figure id=\"attachment_27214\" aria-describedby=\"caption-attachment-27214\" style=\"width: 290px\" class=\"wp-caption alignright\"><a href=\"http:\/\/sitepourvtc.com\/wp-content\/uploads\/2019\/05\/nuclear-fuel-cycle-processes-min.png\"><img loading=\"lazy\" class=\"size-medium wp-image-27214\" src=\"http:\/\/sitepourvtc.com\/wp-content\/uploads\/2019\/05\/nuclear-fuel-cycle-processes-min-300x264.png\" alt=\"nuclear fuel cycle\" width=\"300\" height=\"264\" srcset=\"https:\/\/sitepourvtc.com\/wp-content\/uploads\/2019\/05\/nuclear-fuel-cycle-processes-min-300x264.png 300w, https:\/\/sitepourvtc.com\/wp-content\/uploads\/2019\/05\/nuclear-fuel-cycle-processes-min-768x675.png 768w, https:\/\/sitepourvtc.com\/wp-content\/uploads\/2019\/05\/nuclear-fuel-cycle-processes-min-1024x899.png 1024w, https:\/\/sitepourvtc.com\/wp-content\/uploads\/2019\/05\/nuclear-fuel-cycle-processes-min.png 1151w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/a><figcaption id=\"caption-attachment-27214\" class=\"wp-caption-text\">Nuclear Fuel Cycle. Source: Nuclear Regulatory Commission from the US. License: CC BY 2.0<\/figcaption><\/figure>\n<p><strong>Uranium milling<\/strong> is a series of mechanical and chemical processes that process extracted uranium ore and produces dry powder-form material consisting of <a href=\"http:\/\/sitepourvtc.com\/nuclear-power-plant\/nuclear-fuel\/uranium\/natural-uranium\/\">natural uranium<\/a>\u00a0called \u201c<strong>yellowcake<\/strong>\u201d (chemically U<sub>3<\/sub>O<sub>8<\/sub>) \u00a0because of its yellowish color. Uranium ores are normally processed by <strong>grinding<\/strong> the ore materials to uniform particle size and then treating the ore to extract the uranium by <strong>chemical leaching<\/strong>.<\/p>\n<p>A conventional uranium mill is a chemical plant, usually built near the uranium mine. Uranium milling extracts uranium using the following process:<\/p>\n<ul>\n<li><strong>Milling<\/strong>. Trucks deliver uranium ore to the mill, which is crushed into smaller particles before extraction (or leaching). Due to the very low concentration of uranium in the rock, immense amounts of rock must be moved and processed to get a few kilograms of natural uranium. This results in enormous heaps. Due to high amounts of material, milling is generally carried out close to a uranium mine.<\/li>\n<li><strong>Leaching.<\/strong> After milling, a fine slurry is leached in sulfuric acid (or sometimes a strong alkaline solution) to allow the separation of uranium from the waste rock. It is then recovered from the solution and precipitated as <strong>uranium oxide (U<sub>3<\/sub>O<sub>8<\/sub>) concentrate<\/strong>. After drying and usually heating, a yellow-brownish powder, yellowcake, \u00a0is packed in 200-liter drums as a concentrate. In addition to extracting 90 to 95 percent of the uranium from the ore, the leaching agent also extracts several other \u201cheavy metal\u201d constituents, including molybdenum, vanadium, selenium, iron, lead, and arsenic.)<\/li>\n<li><strong>Further processing.<\/strong> Yellowcake is then refined to obtain almost pure uranium in the form of triuranium octoxide (U<sub>3<\/sub>O<sub>8<\/sub>). Pure U<sub>3<\/sub>O<sub>8<\/sub> is then used to prepare uranium fuel for nuclear reactors, for which triuranium octoxide powder may be sintered into fuel pellets (UO<sub>2<\/sub>) for use in fuel rods for pressurized heavy-water reactors. For other systems that use enriched uranium, uranium conversion and enrichment must follow this process.<\/li>\n<\/ul>\n<p>The remainder of the ore, containing most of the radioactivity and nearly all the rock material, becomes <strong>uranium tailings<\/strong>, which are emplaced in engineered facilities near the mine (often in a mined-out pit). It must be noted that uranium tailings contain almost all the descendants of radioactive cascades that have been in radioactive equilibrium for millions of years. For example, pure <a href=\"http:\/\/sitepourvtc.com\/nuclear-power-plant\/nuclear-fuel\/uranium\/uranium-238\/\">uranium-238<\/a>, from the <a href=\"http:\/\/sitepourvtc.com\/nuclear-power\/reactor-physics\/atomic-nuclear-physics\/radioactive-decay\/radioactive-decay-chain\/radioactive-series-radioactive-cascade\/uranium-series\/\">uranium series,<\/a> is weakly radioactive (proportional to its long half-life). Still, uranium ore is about 13 times more radioactive than the pure uranium-238 metal because of its daughter isotopes (e.g., radon, radium, etc.) it contains. Not only are unstable radium isotopes significant radioactivity emitters, but as the next stage in the decay chain, they also generate <a href=\"http:\/\/sitepourvtc.com\/nuclear-engineering\/radiation-protection\/sources-of-radiation\/radon-health-effects-health-risks\/properties-of-radon-characteristics-of-radon\/\">radon<\/a>, a heavy, inert, naturally occurring radioactive gas. At this place, we are discussing natural facts, and it must be noted that the decay heat of uranium and its decay products (e.g., radon, radium, etc.) contributes to the heating of Earth\u2019s core. Together with thorium and potassium-40 in the Earth\u2019s mantle, these elements are the main source of heat that keeps the Earth\u2019s core liquid. But <strong>uranium tailings<\/strong> need to be isolated from the environment because they are concentrated and contain these long-lived radioactive materials from the <a href=\"http:\/\/sitepourvtc.com\/nuclear-power\/reactor-physics\/atomic-nuclear-physics\/radioactive-decay\/radioactive-decay-chain\/\">radioactive decay chain<\/a>.<\/p>\n<p><strong>Consumption of a 3000MWth (~1000MWe) pressurized water reactor (12-month fuel cycle)<\/strong><\/p>\n<p><em>It is an illustrative example, and the following data <strong>do not<\/strong> correspond to any reactor design.<\/em><\/p>\n<ul>\n<li>A typical reactor may contain about <strong>100 tonnes of<\/strong><a href=\"http:\/\/sitepourvtc.com\/nuclear-power-plant\/nuclear-fuel\/uranium\/\"><strong> enriched uranium<\/strong><\/a> (i.e., about 113 tonnes of uranium dioxide).<\/li>\n<li>This fuel is loaded within, for example, <strong>157 fuel assemblies<\/strong> composed of over <strong>45,000 fuel rods.<\/strong><\/li>\n<li>A common fuel assembly contains energy for approximately <strong>4 years of operation at full power<\/strong>.<\/li>\n<li>Therefore about<strong> one-quarter of the core<\/strong> is yearly removed from the <strong>spent fuel pool <\/strong>(i.e., about 40 fuel assemblies). At the same time, the remainder is rearranged to a location in the core better suited to its remaining level of enrichment (see Power Distribution).<\/li>\n<\/ul>\n<p><strong>The annual natural uranium consumption<\/strong> of this reactor is about <strong>250 tonnes of <\/strong><a href=\"http:\/\/sitepourvtc.com\/nuclear-power-plant\/nuclear-fuel\/uranium\/natural-uranium\/\"><strong>natural uranium<\/strong><\/a> (to produce about 25 tonnes of enriched uranium).<\/p>\n<\/div><\/div><div   id="8n9s8rpp6h"     class=\"lgc-column lgc-grid-parent lgc-grid-100 lgc-tablet-grid-100 lgc-mobile-grid-100 lgc-equal-heights \"><div   id="8n9s8rpp6h"     class=\"inside-grid-column\">\n<div   id="8n9s8rpp6h"    class=\"su-spoiler su-spoiler-style-default su-spoiler-icon-plus su-spoiler-closed\" data-scroll-offset=\"0\"><div   id="8n9s8rpp6h"    class=\"su-spoiler-title\" tabindex=\"0\" role=\"button\"><span class=\"su-spoiler-icon\"><\/span>References:<\/div><div   id="8n9s8rpp6h"    class=\"su-spoiler-content su-u-clearfix su-u-trim\"><strong>Nuclear and Reactor Physics:<\/strong>\n<ul>\n<li style=\"list-style-type: none;\">\n<ul>\n<li style=\"list-style-type: none;\">\n<ol>\n<li>J. R. Lamarsh, Introduction to Nuclear Reactor Theory, 2nd ed., Addison-Wesley, Reading,\u00a0MA (1983).<\/li>\n<li>J. R. Lamarsh, A. J. Baratta, Introduction to Nuclear Engineering, 3d ed., Prentice-Hall, 2001, ISBN: 0-201-82498-1.<\/li>\n<li>W. M. Stacey, Nuclear Reactor Physics, John Wiley &amp; Sons, 2001, ISBN: 0- 471-39127-1.<\/li>\n<li>Glasstone, Sesonske. Nuclear Reactor Engineering: Reactor Systems Engineering,\u00a0Springer; 4th edition, 1994, ISBN:\u00a0978-0412985317<\/li>\n<li>W.S.C. Williams. Nuclear and Particle Physics.\u00a0Clarendon Press; 1 edition, 1991, ISBN:\u00a0978-0198520467<\/li>\n<li>G.R.Keepin. Physics of Nuclear Kinetics.\u00a0Addison-Wesley Pub. Co; 1st edition, 1965<\/li>\n<li>Robert Reed Burn, Introduction to Nuclear Reactor Operation, 1988.<\/li>\n<li>U.S. Department of Energy, Nuclear Physics and Reactor Theory.\u00a0DOE Fundamentals Handbook,\u00a0Volume 1 and 2.\u00a0January\u00a01993.<\/li>\n<\/ol>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p><strong>Advanced Reactor Physics:<\/strong><\/p>\n<ul>\n<li style=\"list-style-type: none;\">\n<ul>\n<li style=\"list-style-type: none;\">\n<ol>\n<li>K. O. Ott, W. A. Bezella, Introductory Nuclear Reactor Statics, American Nuclear Society, Revised edition (1989), 1989, ISBN: 0-894-48033-2.<\/li>\n<li>K. O. Ott, R. J. Neuhold, Introductory Nuclear Reactor Dynamics, American Nuclear Society, 1985, ISBN: 0-894-48029-4.<\/li>\n<li><span style=\"font-weight: 400;\">D. L. Hetrick, Dynamics of Nuclear Reactors, American Nuclear Society, 1993, ISBN: 0-894-48453-2.\u00a0<\/span><\/li>\n<li>E. E. Lewis, W. F. Miller, Computational Methods of Neutron Transport, American Nuclear Society, 1993, ISBN: 0-894-48452-4.<\/li>\n<\/ol>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/div><\/div>\n<div   id="8n9s8rpp6h"    class=\"su-divider su-divider-style-dotted\" style=\"margin:15px 0;border-width:2px;border-color:#999999\"><\/div><\/div><\/div><div   id="8n9s8rpp6h"     class=\"lgc-column lgc-grid-parent lgc-grid-33 lgc-tablet-grid-33 lgc-mobile-grid-100 lgc-equal-heights \"><div   id="8n9s8rpp6h"     class=\"inside-grid-column\"><\/div><\/div><div   id="8n9s8rpp6h"     class=\"lgc-column lgc-grid-parent lgc-grid-33 lgc-tablet-grid-33 lgc-mobile-grid-100 lgc-equal-heights \"><div   id="8n9s8rpp6h"     class=\"inside-grid-column\">\n<h2>See above:<\/h2>\n<p>Nuclear Fuel Cycle<a href=\"http:\/\/sitepourvtc.com\/nuclear-power-plant\/nuclear-fuel\/nuclear-fuel-cycle\/\" class=\"su-button su-button-style-flat\" style=\"color:#606060;background-color:#ffffff;border-color:#cccccc;border-radius:10px;-moz-border-radius:10px;-webkit-border-radius:10px\" target=\"_self\"><span style=\"color:#606060;padding:7px 20px;font-size:16px;line-height:24px;border-color:#ffffff;border-radius:10px;-moz-border-radius:10px;-webkit-border-radius:10px;text-shadow:0px 0px 0px #000000;-moz-text-shadow:0px 0px 0px #000000;-webkit-text-shadow:0px 0px 0px #000000\"><i class=\"sui sui-link\" style=\"font-size:16px;color:#5d5d5d\"><\/i> <\/span><\/a><\/p><\/div><\/div><div   id="8n9s8rpp6h"     class=\"lgc-column lgc-grid-parent lgc-grid-33 lgc-tablet-grid-33 lgc-mobile-grid-100 lgc-equal-heights \"><div   id="8n9s8rpp6h"     class=\"inside-grid-column\"><\/div><\/div>\n","protected":false},"excerpt":{"rendered":"","protected":false},"author":1,"featured_media":0,"parent":27209,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"generate_page_header":""},"_links":{"self":[{"href":"https:\/\/sitepourvtc.com\/wp-json\/wp\/v2\/pages\/27294"}],"collection":[{"href":"https:\/\/sitepourvtc.com\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/sitepourvtc.com\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/sitepourvtc.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/sitepourvtc.com\/wp-json\/wp\/v2\/comments?post=27294"}],"version-history":[{"count":1,"href":"https:\/\/sitepourvtc.com\/wp-json\/wp\/v2\/pages\/27294\/revisions"}],"predecessor-version":[{"id":38631,"href":"https:\/\/sitepourvtc.com\/wp-json\/wp\/v2\/pages\/27294\/revisions\/38631"}],"up":[{"embeddable":true,"href":"https:\/\/sitepourvtc.com\/wp-json\/wp\/v2\/pages\/27209"}],"wp:attachment":[{"href":"https:\/\/sitepourvtc.com\/wp-json\/wp\/v2\/media?parent=27294"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}