uran

Radioaktivt giftigt grundstof, det 92. grundstof i det periodiske system, hvor den i naturen forekommende fordeling af isotober er 99,3 procent uranium 238 og 0,71 procent uranium 235. Det er sidstnævnte isotop der er interessant ved fremstilling af atomvåben og brændstof til atomreaktorer.
Transuraner er grundstoffer med atomnummer fra 92 indtil nr. 103.
Uran anvendes efter berigelse bl.a. i kernevåben og i panserbrydende granater.
Brændstof indeholdende både uran og plutonium kaldes Mixed Oxide (MOX) Fuel.
Uran kan være lavradioaktivt eller højradioaktivt affald.
Miljøforurening
/ Contamination, environmental pollution
Barium ; beryllium ; cerium ; cæsium ; jod ; krypton ; lanthanum ; molybdæn ; neptunium ; niobium ; plutonium ; polonium ; radioaktivitet ; ruthenium ; strontium-90 ; tellur ; tritium ; xenon ; zirkonium.
Se også: Euatom ; Fernald Feed Materials Production Center ; K25 ; neptunium ; Oak Ridge National Laboratory ; Oklo fossil reaktorerne ; plamgate ; US Radiation Exposure Compensation Act 1990 ; Paducah Gaseous Diffusion Plant ; Portsmouth Gaseous Diffusion Plant ; radium ; uran-gate ; World Nuclear Association.
Se tillige: Allanit ; Bastnäsit ; Brannerit ; Carburan ; Columbit ; Euxenit ; Monazit ; Pyrochlor ; Steenstrupin ; Uraninit ; Uranothorit ; Zirkon

Litteratur

CHEM Study, College of Chemistry, U.C. Berkeley: Transuranium Elements (1963).
- http://www.archive.org/details/transuranium_elements
'This film, produced in the Lawrence Radiation Laboratory of the University of California, Berkeley, features four scientists who were principals in the discovery and identification of several of the transuranium elements. Glenn Seaborg reviews the historical problem of the placement of the transuranium elements in the periodic table. Burris Cunningham performs experiments showing that neptunium, plutonium, and americium have chemical properties similar to those of uranium, but that under the same experimental conditions curium behaves like its rare-earth homolog, gadolinium. Stanley Thompson demonstrates how the ion-exchange separation technique is used in identification, using actual solutions of curium, berkelium, californium and einsteinium. Albert Ghiorso discusses the methods used in the synthesis of elements 102 and 103, and proposes a similar type of reaction which may lead to the discovery of element 104.'
Congo Uranium and the Tragedy of Hiroshima / Mads Fleckner and John Avery
Tournier, BB, S Frelon, E Tourlonias, L Agez, O Delissen, I Dublineau, F Paquet, and F Petitot. 2009. Role of the olfactory receptor neurons in the direct transport of inhaled uranium to the rat brain.
Toxicology Letters doi:10.1016/j.toxlet.2009.05.022.
GAO: The Department of Energy: Enhanced Transparency Could Clarify Costs, Market Impact,
Risk, and Legal Authority to Conduct Future Uranium Transactions
, 2014.
- http://www.gao.gov/assets/670/663087.pdf
'The Department of Energy (DOE) undertook four uranium transactions involving USEC Inc. (USEC) in 2012 and 2013. These transactions served to provide the company with operating cash. According to DOE, the department benefited from these transactions in two ways: (1) by ensuring availability of domestic low-enriched uranium (LEU) for the production of tritium, a key radioactive isotope used to enhance the power of nuclear weapons, and (2) by supporting USEC’s development of next generation enrichment technology. Three of the four transactions involved transferring ownership of depleted uranium tails (tails), a product of the enrichment process. Tails are generally considered to be an environmental liability, but can have value as an asset when uranium market conditions make tails re-enrichment economical in lieu of enriching natural uranium. In two transactions, DOE accepted ownership of tails, along with liability for disposal costs, in exchange for other benefits. In another transaction, DOE transferred ownership of tails to a third party to be re-enriched by USEC. The fourth transaction involved the transfer of uranium material other than tails.
GAO identified legal concerns with all four of DOE’s uranium transactions. For the largest transaction—DOE’s transfer of tails to a third party for re-enrichment—GAO believes that DOE likely did not have authority to transfer tails under restrictions imposed by the USEC Privatization Act. DOE disagreed, citing its authority to conduct this transaction under the Atomic Energy Act. Even if DOE had such authority, GAO found that it did not meet the Act’s requirement to charge a price for the tails because it transferred them without charging any price at all. In another transaction, DOE transferred ownership of uranium material that it previously obtained to meet national security needs, without obtaining a presidential determination that the uranium material was no longer necessary for national security needs, as GAO found is required by the USEC Privatization Act.'
Transuranic elements in the environment : a summary of environmental research on transuranium radionuclides funded by the U.S. Department of Energy through calendar year 1979. United States. Dept. of Energy. Office of Health and Environmental Research; Hanson, Wayne C. - [Oak Ridge, TN] : Technical Information Center/U.S. Dept. of Energy ; Springfield, Va. 1980. - 764 s.
Global Fissile Material Report 2015 : Nuclear Weapon and Fissile Material Stockpiles and Production. / : International Panel on Fissile Materials, 2015.
The global stockpile of HEU at the end of 2014 was about 1370 ± 125 tons, enough for more than 76,000 simple, first generation fission implosion weapons. About 99 percent of this material is held by the nuclear weapon states, mostly by Russia and the United States. The large uncertainty in the HEU estimate is due to a lack of official information about Russia’s historical production of HEU. The uncertainty in the size of the Russian HEU stockpile is larger than the total HEU stocks held by all other states except for the United States.
United States Department of the Interior, National Park Service, National Register of Historic Places: Guide to Assessing Historic Radium, Uranium, and Vanadium Mining Resources in Montrose and San Miguel Counties, Colorado and Name of Multiple Property Listing Guide to Assessing Historic Mining Resources. Part I+II, 2008. - 136+121 s.
- http://www.blm.gov/co/st/en/fo/ufo/cultural_resources.html
World Distribution of Uranium Deposits (UDEPO) with Uranium Deposit Classification 2009 Edition.
- Vienna : International Atomic Energy Agency, International Centre, 2009. - 126 pp.
- http://www-pub.iaea.org/MTCD/publications/PDF/TE_1629_web.pdf
World Nuclear Association: Uranium in Africa, 2010. - 5 s.
- http://www.vaec.gov.vn/userfiles/file/Uranium_in_Africa_12_09.pdf


Send kommentar, email eller søg i Fredsakademiet.dk
Locations of visitors to this page