Proportions of uranium-238 (blue) and uranium-235 (red) at different levels of enrichment

Enriched uranium is a kind of uranium in which the percent composition of uranium-235 has been increased through the process of isotope separation. Uranium (jʊˈreɪniəm is a silvery-gray Metallic Chemical element in the Uranium-235 is an isotope of uranium that differs from the element's other common isotope Uranium-238, by its ability to cause a rapidly expanding fission Isotope separation is the process of concentrating specific Isotopes of a Chemical element by removing other isotopes for example separating Natural uranium Natural uranium (or NU) is 99. 284% ²³⁸U isotope, with ²³⁵U only constituting about 0. Uranium-238 (U-238 is the most common isotope of Uranium found in nature Isotopes (Greek isos = "equal" tópos = "site place" are any of the different types of atoms ( Nuclides 711% of its weight. However, ²³⁵U is the only isotope existing in nature (in any appreciable amount) that is fissionable by thermal neutrons. Nuclear fission is the splitting of the nucleus of an atom into parts (lighter nuclei) often producing Free neutrons and other smaller nuclei which may The neutron temperature, also called the neutron energy, indicates a free neutron's Kinetic energy, usually given in Electron volts The term

Enriched uranium is a critical component for both civil nuclear power generation and military nuclear weapons. Nuclear power is any Nuclear technology designed to extract usable Energy from atomic nuclei via controlled Nuclear reactions A nuclear weapon is an explosive device that derives its destructive force from Nuclear reactions either fission or a combination of fission and fusion. 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. The International Atomic Energy Agency ( IAEA) is an international organization that seeks to promote the peaceful use of nuclear energy and to inhibit its Nuclear proliferation is a term now used to describe the spread of Nuclear weapons, fissile material and weapons-applicable nuclear technology and information to nations

During the Manhattan Project enriched uranium was given the codename oralloy, a shortened version of Oak Ridge alloy, after the location of the plants where the uranium was enriched. The World War II Manhattan Project developed the first Nuclear weapon (atomic bomb Oak Ridge is an incorporated City in Anderson and Roane Counties in East Tennessee, USA, about 25 miles northwest of An alloy is a Solid solution or Homogeneous mixture of two or more elements, at least one of which is a Metal, which itself has The term oralloy is still occasionally used to refer to enriched uranium. There are about 2,000 tonnes (t, Mg) of highly enriched uranium in the world,^[1] produced mostly for nuclear weapons, naval propulsion, and smaller quantities for research reactors. This article is about the tonne or metric ton For other tons see Ton. A nuclear weapon is an explosive device that derives its destructive force from Nuclear reactions either fission or a combination of fission and fusion. A nuclear submarine is a Submarine powered by Atomic energy. Previously conventional submarines used diesel engines that required air for moving on the

The ²³⁸U remaining after enrichment is known as depleted uranium (DU), and is considerably less radioactive than even natural uranium, though still extremely dense. Depleted uranium (DU is Uranium primarily composed of the Isotope Uranium-238 (U-238 Radioactive decay is the process in which an unstable Atomic nucleus loses energy by emitting ionizing particles and Radiation. It is useful for armour- penetrating weapons, and other applications requiring very dense metals, though at the present time, only 5% of it is put to any use; the rest remains in storage at the enrichment facilities. For body armour see Armour, for armoured forces see Armoured warfare, for other uses see Armour (disambiguation. Staballoys are metal alloys of a high proportion of Depleted uranium with other metals usually Titanium or Molybdenum, designed for use in Kinetic

Grades

Slightly enriched uranium (SEU)

A drum of yellowcake (a mixture of uranium precipitates)

Slightly enriched uranium (SEU) has a ²³⁵U concentration of 0. For the falsified documents see Yellowcake forgery. Yellowcakes (also called urania) are Uranium concentrates obtained 9% to 2%.

This new grade is being used to replace natural uranium (NU) fuel in some heavy water reactors like the CANDU. Natural uranium (NU refers to refined Uranium with the same Isotopic ratio as found in nature Heavy water reactors use Heavy water as a Neutron moderator. Heavy water is Deuterium Oxide, D2O The CANDU reactor is a Canadian-invented Pressurized heavy water reactor developed initially in the late 1950s and 1960s by a partnership between Atomic Energy of Costs are lowered because less uranium and fewer bundles are needed to fuel the reactor. This in turn reduces the quantity of used fuel and its subsequent waste management costs.

Recovered uranium (RU) is a variation of SEU. Reprocessed uranium (RepU is the Uranium recovered from Nuclear reprocessing, as done commercially in France the UK and Japan and by nuclear weapons states' military It is based on a fuel cycle involving used fuel recovered from light water reactors (LWR). The nuclear fuel cycle, also called nuclear fuel chain, is the progression of Nuclear fuel through a series of differing stages See also Nuclear power "LWR" redirects here See also LWR (disambiguation A light water reactor or LWR is The spent fuel from a LWR typically contains slightly more U-235 than natural uranium, and therefore could be used to fuel reactors that customarily use natural uranium as fuel. However, it also contains the undesirable isotope uranium-236. Uranium-236 is an isotope of Uranium that is neither Fissile with Thermal neutrons nor very good Fertile material, but is generally considered

Low-enriched uranium (LEU)

Low-enriched uranium (LEU) has a lower than 20% concentration of ²³⁵U. For use in commercial light water reactors (LWR), the most prevalent power reactors in the world, uranium is enriched to 3 to 5% ²³⁵U. See also Nuclear power "LWR" redirects here See also LWR (disambiguation A light water reactor or LWR is Fresh LEU used in research reactors is usually enriched 12% to 19. Research reactors are Nuclear reactors that serve primarily as a Neutron source. 75% U-235, the latter concentration being used to replace HEU fuels when converting to LEU.

Highly enriched uranium (HEU)

A billet of highly enriched uranium metal

Highly enriched uranium (HEU) has a greater than 20% concentration of ²³⁵U or ²³³U.

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. A critical mass is the smallest amount of Fissile material needed for a sustained Nuclear chain reaction. However, judicious use of implosion and neutron reflectors can enable construction of a weapon from a quantity of uranium below the usual critical mass for its level of enrichment, though this would likely only be possible in a country which already had extensive experience in developing nuclear weapons. The presence of too much of the ²³⁸U isotope inhibits the runaway nuclear chain reaction that is responsible for the weapon's power. A nuclear chain reaction occurs when one Nuclear reaction causes an average of one or more nuclear reactions thus leading to a self-propagating number of these reactions The critical mass for 85% of highly enriched uranium is about 50 kilograms, which at normal density would be a sphere less than 30 centimetres (12 in) in diameter.

HEU is also used in fast neutron reactors as well as in naval reactors, where it contains at least 50% ²³⁵U, but typically does not exceed 90%. A fast neutron reactor or simply a fast reactor is a category of Nuclear reactor in which the fission Chain reaction is sustained by Fast neutrons Nuclear marine propulsion is propulsion of a ship powered by a Nuclear reactor. The Fermi-1 commercial fast reactor prototype used HEU with 26. 5% ²³⁵U. For criticality experiments, enrichment of uranium to over 97% has been accomplished. ^[2]

Enrichment methods

Isotope separation is a difficult and energy intensive activity. Enriching uranium is difficult because the two isotopes have very nearly identical chemical properties, and are very similar in weight: ²³⁵U is only 1. 26% lighter than ²³⁸U. Several production techniques applied to enrichment have been used, and several are under investigation. In general these methods exploit the slight differences in atomic weights of the various isotopes. The atomic mass (ma is the Mass of an atom most often expressed in unified atomic mass units The atomic mass may be considered to be the total mass Some work is being done that would use nuclear resonance; however there is no reliable evidence that any nuclear resonance processes have been scaled up to production.

A feature common to all large-scale enrichment schemes is that they employ a number of identical stages which produce successively higher concentrations of ²³⁵U. Each stage concentrates the product of the previous step further before being sent to the next stage. Similarly, the tailings from each stage are returned to the previous stage for further processing. This sequential enriching system is called a cascade. In Chemical engineering, a cascade is a plant consisting of several similar stages with each processing the output from the previous stage

There are currently two generic commercial methods employed internationally for enrichment: gaseous diffusion (referred to as first generation) and gas centrifuge (second generation). Later generation methods will become established because they are more efficient in terms of the energy input for the same degree of enrichment and the next method of enrichment to be commercialized will be referred to as third generation.

Diffusion techniques

Gaseous diffusion

Gaseous diffusion is a technology used to produce enriched uranium by forcing gaseous uranium hexafluoride (hex) through semi-permeable membranes. Gaseous diffusion is a technology used to produce Enriched uranium by forcing gaseous Uranium hexafluoride, UF6 through semi-permeable membranes Uranium hexafluoride (UF6 referred to as "hex" in the nuclear industry is a compound used in the Uranium enrichment process that produces A semipermeable membrane, also termed a selectively-permeable membrane, a partially-permeable membrane or a differentially-permeable membrane, is a membrane This produces a slight separation between the molecules containing ²³⁵U and ²³⁸U. Throughout the Cold War, gaseous diffusion played a major role as a uranium enrichment technique, and continues to account for about 33% of enriched production^[3] but is now an obsolete technology that is steadily being replaced by the later generations of technology as the diffusion plants reach their ends-of-life. Cold War is the state of conflict tension and competition that existed between the United States and the Soviet Union (USSR and their respective allies from the

Thermal diffusion

Thermal diffusion utilizes the transfer of heat across a thin liquid or gas to accomplish isotope separation. The process exploits the fact that the lighter ²³⁵U gas molecules will diffuse toward a hot surface, and the heavier ²³⁸U gas molecules will diffuse toward a cold surface. The S-50 plant at Oak Ridge, Tennessee was used during World War II to prepare feed material for the EMIS process. Oak Ridge is an incorporated City in Anderson and Roane Counties in East Tennessee, USA, about 25 miles northwest of World War II, or the Second World War, (often abbreviated WWII) was a global military conflict which involved a majority of the world's nations, including It was abandoned in favor of gaseous diffusion.

Centrifuge techniques

Gas centrifuge

A cascade of gas centrifuges at a U. S. enrichment plant

The gas centrifuge process uses a large number of rotating cylinders in series and parallel formations. A gas centrifuge is a separating machine specifically developed to separate Uranium-235 from Uranium-238. This rotation creates a strong centrifugal force so that the heavier gas molecules containing ²³⁸U move toward the outside of the cylinder and the lighter gas molecules rich in ²³⁵U collect closer to the center. It requires less energy to achieve the same separation than the older gaseous diffusion process, which it has largely replaced and so is the current method of choice and is termed second generation. Gas centrifuge techniques produce about 54% of enriched production with an efficiency relative to gaseous diffusion of 1. 3. ^[3]

Zippe centrifuge

Diagram of the principles of a Zippe-type gas centrifuge with U-238 represented in dark blue and U-235 represented in light blue

The Zippe centrifuge is an improvement on the standard gas centrifuge, the primary difference being the use of heat. The Zippe-type centrifuge is a device designed to collect Uranium-235. The bottom of the rotating cylinders is heated, producing convection currents that move the ²³⁵U up the cylinder, where it can be collected by scoops. This improved centrifuge design is used commercially by Urenco to produce nuclear fuel and was used by Pakistan in their nuclear weapons program. The Urenco Group operates Uranium enrichment plants in Germany The Netherlands and the United Kingdom and supplies nuclear power stations in about 15 countries in Europe Pakistan () officially the Islamic Republic of Pakistan, is a country located in South Asia, Southwest Asia, Middle East and

Laser techniques

Laser processes promise lower energy inputs, lower capital costs and lower tails assays, hence significant economic advantages. Several laser processes have been investigated or are under development.

None of the laser processes below is yet ready for commercial use, though SILEX is well advanced and expected to begin commercial production in 2012. (see here: 30 April 2008)

AVLIS—Atomic vapor laser isotope separation

Atomic vapor laser isotope separation employs specially tuned lasers to separate isotopes of uranium using selective ionization of hyperfine transitions. AVLIS Is an acronym which stands for Atomic Vapor Laser Isotope separation and is a method by which specially tuned lasers are used AVLIS Is an acronym which stands for Atomic Vapor Laser Isotope separation and is a method by which specially tuned lasers are used The technique uses lasers which are tuned to frequencies that ionize a ²³⁵U atom and no others. A laser is a device that emits Light ( Electromagnetic radiation) through a process called Stimulated emission. The positively-charged ²³⁵U ions are then attracted to a negatively-charged plate and collected.

MLIS—molecular laser isotope separation

molecular laser isotope separation uses an infrared laser directed at UF₆, exciting molecules that contain a ²³⁵U atom. Molecular laser isotope separation ( MLIS) is a method of Isotope separation, where specially tuned lasers are used to separate Isotopes of A second laser frees a fluorine atom, leaving uranium pentafluoride which then precipitates out of the gas. Fluorine, fluorum meaning "to flow" is the Chemical element with the symbol F and Atomic number 9 Uranium pentafluoride is a coordination polymer which consists of UF5 units linked by bridging fluorides forming Linear chains

SILEX—Separation of Isotopes by Laser EXcitation

Separation of Isotopes by Laser EXcitation is an Australian development that also uses UF₆. SILEX is an Acronym for Separation of Isotopes by Laser Excitation, a technology developed in the 1990s for Isotope separation to produce Enriched After a protracted development process involving U. S. enrichment company USEC acquiring and then relinquishing commercialization rights to the technology, GE Hitachi Nuclear Energy (GEH) signed a commercialization agreement with Silex Systems in 2006 (see here). The United States Enrichment Corporation, a subsidiary of USEC Inc GEH has since begun construction of a demonstration test loop and announced plans to build an initial commercial facility. (see here: 30 April 2008). Details of the process are restricted by inter-Governmental agreements between USA and Australia and the commercial entities. SILEX has been indicated to be an order of magnitude more efficient than existing production techniques but again, the exact figure is classified. ^[3]

Other techniques

Aerodynamic processes

Schematic diagram of an aerodynamic nozzle. Many thousands of these small foils would be combined in an enrichment unit.

Aerodynamic enrichment processes include the Becker jet nozzle techniques developed by E. W. Becker and associates and the vortex tube separation process. For the term 'vortex-tube' used in Fluid dynamics please see Vorticity The vortex tube, also known as the Ranque-Hilsch vortex These aerodynamic separation processes depend upon diffusion driven by pressure gradients, as does the gas centrifuge. In effect, aerodynamic processes can be considered as non-rotating centrifuges. Enhancement of the centrifugal forces is achieved by dilution of UF₆ with hydrogen or helium as a carrier gas achieving a much higher flow velocity for the gas than could be obtained using pure uranium hexafluoride. Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 Helium ( He) is a colorless odorless tasteless non-toxic Inert Monatomic Chemical The Uranium Enrichment Corporation of South Africa (UCOR) developed and deployed the Helikon vortex separation process based on the vortex tube and a demonstration plant was built in Brazil by NUCLEI, a consortium led by Industrias Nucleares do Brasil that used the separation nozzle process. The Helikon vortex separation process is an aerodynamic uranium enrichment process designed around a device called a Vortex tube. |utc_offset = -2 to -4 |time_zone_DST = BRST |utc_offset_DST = -2 to -5 |cctld However both methods have high energy consumption and substantial requirements for removal of waste heat; neither is currently in use.

Electromagnetic isotope separation

Schematic diagram of uranium isotope separation in a calutron shows how a strong magnetic field is used to redirect a stream of uranium ions to a target, resulting in a higher concentration of uranium-235 (represented here in dark blue) in the inner fringes of the stream. A Calutron was a Mass spectrometer used for separating the isotopes of Uranium developed by Ernest O

Main article: Calutron

In the electromagnetic isotope separation process (EMIS), metallic uranium is first vaporized, and then ionized to positively charged ions. A Calutron was a Mass spectrometer used for separating the isotopes of Uranium developed by Ernest O Isotope separation is the process of concentrating specific Isotopes of a Chemical element by removing other isotopes for example separating Natural uranium The cations are then accelerated and subsequently deflected by magnetic fields onto their respective collection targets. A production-scale mass spectrometer named the Calutron was developed during World War II that provided some of the ²³⁵U used for the Little Boy nuclear bomb, which was dropped over Hiroshima in 1945. Mass spectrometry is an analytical technique that identifies the chemical composition of a compound or sample based on the Mass-to-charge ratio of charged particles A Calutron was a Mass spectrometer used for separating the isotopes of Uranium developed by Ernest O Little Boy was the Codename of the Atomic bomb, developed via the "Manhattan Project" which was dropped on Hiroshima, on August 6 1945 by the The Japanese city of ( is the capital of Hiroshima Prefecture, and the largest city in the Chūgoku region of western Honshū, the largest of Japan 's Properly the term 'Calutron' applies to a multistage device arranged in a large oval around a powerful electromagnet. Electromagnetic isotope separation has been largely abandoned in favour of more effective methods.

Chemical methods

One chemical process has been demonstrated to pilot plant stage but not used. The French CHEMEX process exploited a very slight difference in the two isotopes' propensity to change valency in oxidation/reduction, utilising immiscible aqueous and organic phases. In Chemistry, valence, also known as valency or valency number, is a measure of the number of Chemical bonds formed by the Atoms Redox (shorthand for reduction-oxidation reaction describes all Chemical reactions in which atoms have their Oxidation number ( Oxidation state

An ion-exchange process was developed by the Asahi Chemical Company in Japan which applies similar chemistry but effects separation on a proprietary resin ion-exchange column. For a topic outline on this subject see List of basic Japan topics. Ion exchange is an exchange of Ions between two Electrolytes or between an electrolyte Solution and a complex.

Plasma separation

Plasma separation process (PSP) describes a technique that makes use of superconducting magnets and plasma physics. A superconducting magnet is an Electromagnet that is built using superconducting coils In Physics and Chemistry, plasma is an Ionized Gas, in which a certain proportion of Electrons are free rather than being bound In this process, the principle of ion cyclotron resonance is used to selectively energize the ²³⁵U isotope in a plasma containing a mix of ions. A cyclotron is a type of Particle accelerator. Cyclotrons accelerate Charged particles using a high- Frequency, alternating Voltage (potential In Physics and Chemistry, plasma is an Ionized Gas, in which a certain proportion of Electrons are free rather than being bound An ion is an Atom or Molecule which has lost or gained one or more Valence electrons giving it a positive or negative electrical charge The French developed their own version of PSP, which they called RCI. Funding for RCI was drastically reduced in 1986, and the program was suspended around 1990, although RCI is still used for stable isotope separation.

Separative work unit

The Separative work unit (SWU) is a function of the amount of uranium processed, the composition of the starting material, and the degree to which it is enriched; it is proportional to the total machine operation time required to achieve this, but is defined independent of the enrichment tecnhology.

Separative work is expressed in SWUs, kg SW, or kg UTA (from the German Urantrennarbeit)

• 1 SWU = 1 kg SW = 1 kg UTA
• 1 kSWU = 1 tSW = 1 t UTA
• 1 MSWU = 1 ktSW = 1 kt UTA

The unit is strictly kilogram separative work unit, and is indicative of the energy used in enrichment, when feed, tails and product quantities are expressed in kilograms. The work W_SWU necessary to separate a mass F of feed of assay x_f into a mass P of product assay x_p, and tails of mass T and assay x_t is expressed in terms of the number of separative work units needed, given by the expression

where is the value function, defined as

The feed to product ratio is given by the expression

whereas the tails to product ratio is given by the expression

For example, beginning with 100 kilograms (220 lb) of NU, it takes about 61 SWU to produce 10 kilograms (22 lb) of LEU in ²³⁵U content to 4. A Bellman equation (also known as a dynamic programming equation) named after its discoverer Richard Bellman, is a necessary condition for optimality associated 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. The joule (written in lower case ˈdʒuːl or /ˈdʒaʊl/ (symbol J) is the SI unit of Energy measuring heat, Electricity

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. This article is about the tonne or metric ton For other tons see Ton. In Astronomy, a Julian year (symbol a) is a unit of measurement of Time defined 75%. This quantity is produced from about 210 t of NU using about 120 kSWU. An enrichment plant with a capacity of 1000 kSWU/a is, therefore, able to enrich the uranium needed to fuel about eight large nuclear power stations.

Cost issues

In addition to the separative work units provided by an enrichment facility, the other important parameter to be considered is the mass of 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. On the other hand, if the depleted stream had only 0. 2% ²³⁵U, then it would require just 6. 7 kilograms of NU, but nearly 5. 7 SWU of enrichment. Because the amount of NU required and the number of SWUs required during enrichment change in opposite directions, if NU is cheap and enrichment services are relatively more expensive, then the operators will typically choose to allow more ²³⁵U to be left in the DU stream whereas if NU is relatively more expensive and enrichment is less so, then they would choose the opposite.

• Uranium enrichment calculator designed by the WISE Uranium Project

Downblending

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 but remains well below 1%. Uranium-234 is an isotope of Uranium. In Natural uranium and uranium ore 234U occurs as an indirect Decay product of 238U Natural uranium (NU refers to refined Uranium with the same Isotopic ratio as found in nature High concentrations of ²³⁶U is a byproduct from irradiation in a reactor and may be contained in the HEU, depending on its manufacturing history. HEU reprocessed from nuclear weapons material production reactors (with an ²³⁵U assay of approx. 50%) may contain ²³⁶U concentrations as high as 25%, resulting in concentrations of approximately 1. 5% in the blended LEU product. ²³⁶U is a neutron poison; therefore the actual ²³⁵U concentration in the LEU product must be raised accordingly to compensate for the presence of ²³⁶U. A nuclear poison, also called a neutron poison is a substance with a large neutron absorption cross-section in applications such as Nuclear reactors

The blendstock can be NU, or DU, however depending on feedstock quality, SEU at typically 1. 5 wt% ²³⁵U may used as a blendstock to dilute the unwanted byproducts that may contained in the HEU feed. Concentrations of these isotopes in the LEU product in some cases could exceed ASTM specifications for nuclear fuel, if NU, or DU were used. ASTM International ( ASTM) originally known as the American Society for Testing and Materials is an international Standards organization that develops and publishes So, the HEU downblending generally cannot contribute to the waste management problem posed by the existing large stockpiles of depleted uranium.

A major downblending undertaking called the Megatons to Megawatts Program converts ex-Soviet weapons-grade HEU to fuel for U. The Megatons to Megawatts Program is the name given to the program that implemented the 1993 United States - Russia nonproliferation agreement to convert S. commercial power reactors. From 1995 through mid-2005, 250 tonnes of high-enriched uranium (enough for 10,000 warheads) was recycled into low-enriched-uranium. The goal is to recycle 500 tonnes by 2013. The decomissioning programme of Russian nuclear warheads accounted for about 13% of total world requirement for enriched uranium leading up to 2008. ^[3]

The United States Enrichment Corporation has been involved in the disposition of a portion of the 174. The United States Enrichment Corporation, a subsidiary of USEC Inc 3 tonnes of highly enriched uranium (HEU) that the U. S. government declared as surplus military material in 1996. Through the U. S. HEU Downblending Program, this HEU material, taken primarily from dismantled U. S. nuclear warheads, was recycled into low-enriched uranium (LEU) fuel, used by nuclear power plants to generate electricity. Nuclear power is any Nuclear technology designed to extract usable Energy from atomic nuclei via controlled Nuclear reactions ^[4]

• A uranium downblending calculator designed by the WISE Uranium Project

Global enrichment facilities

The following countries are known to operate enrichment facilities: Argentina, Brazil, China, France, Germany, India, Japan, the Netherlands, Pakistan, Russia, the United Kingdom and the United States. Israel and North Korea are also suspected of having enrichment programs. Belgium, Iran, Italy and Spain hold an investment interest in the French Eurodif enrichment plant, with Iran's holding entitling it to 10% of the enriched uranium output. Eurodif, which means European Gaseous Diffusion Uranium Enrichment Consortium, is a subsidiary of the French company AREVA which operates a Dominique Lorentz is a French Investigative journalist who has written books on the stakes and reality of Nuclear proliferation, as well as a Film Countries that had enrichment programs in the past include Libya and South Africa, although Libya's facility was never operational. ^[5] Australia has announced its intention to pursue commercial enrichment, and is actively researching laser enrichment. ^[6]

References

1. ^ Thomas B. Cochran (Natural Resources Defense Council) (1997-06-12). The Natural Resource Defense Council ( NRDC) is a New York City -based Non-profit, Non-partisan international environmental Advocacy Year 1997 ( MCMXCVII) was a Common year starting on Wednesday (link will display full 1997 Gregorian calendar Events 1381 - Peasants' Revolt: in England, rebels arrive at Blackheath. Safeguarding Nuclear Weapon-Usable Materials in Russia. Proceedings of international forum on illegal nuclear traffic.
2. ^ Mosteller, R. D. (1994). "Detailed Reanalysis of a Benchmark Critical Experiment: Water-Reflected Enriched-Uranium Sphere". Los Alamos technical paper (LA-UR-93-4097): 2. “The enrichment of the pin and of one of the hemispheres was 97. 67 w/o, while the enrichment of the other hemisphere was 97. 68 w/o. ” 
3. ^ ^{a b c d} Lodge Partners Mid-Cap Conference 11 April 2008. Silex Ltd (2008-04-11). 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 491 - Flavius Anastasius becomes Byzantine Emperor, with the name of Anastasius I.
4. ^ http://www.usec.com/v2001_02/HTML/Megatons_DOEstatus.asp
5. ^ BBC (2006-09-01). Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 462 - Possible start of first Byzantine indiction cycle. Q&A: Uranium enrichment.
6. ^ Laser enrichment could cut cost of nuclear power. The Sydney Morning Herald (2006-05-26). Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 451 - The Battle of Avarayr between Armenian rebels and the Sassanid Empire takes place

See also

• Uranium mining
• Uranium market
• Nuclear reprocessing
• United States Enrichment Corporation
• Nuclear fuel cycle
• Nuclear power
• Eurodif—European Gaseous Diffusion Uranium Enrichment Consortium
• Urenco Group

External links

• Uranium Enrichment and Nuclear Weapon Proliferation, by Allan S. Krass, Peter Boskma, Boelie Elzen and Wim A. Smit, 296 pp., Published for SIPRI by Taylor and Francis Ltd, London, 1983
• Silex Systems Ltd
• Nuclear Issues Briefing Paper 33
• [1] Overview and history of U. Uranium mining is the process of extraction of Uranium Ore from the ground The uranium market, like all commodity markets has a history of volatility moving not only with the standard forces of Supply and demand, but also to whims of Geopolitics Nuclear reprocessing separates components of Spent nuclear fuel such as Reprocessed uranium Plutonium Minor The United States Enrichment Corporation, a subsidiary of USEC Inc The nuclear fuel cycle, also called nuclear fuel chain, is the progression of Nuclear fuel through a series of differing stages Nuclear power is any Nuclear technology designed to extract usable Energy from atomic nuclei via controlled Nuclear reactions Eurodif, which means European Gaseous Diffusion Uranium Enrichment Consortium, is a subsidiary of the French company AREVA which operates a The Urenco Group operates Uranium enrichment plants in Germany The Netherlands and the United Kingdom and supplies nuclear power stations in about 15 countries in Europe S. HEU production
• News Resource on Uranium Enrichment