Natural uranium (NU or Unat[1]) refers to uranium with the same isotopic ratio as found in nature. It contains 0.711% uranium-235, 99.284% uranium-238, and a trace of uranium-234 by weight (0.0055%). Approximately 2.2% of its radioactivity comes from uranium-235, 48.6% from uranium-238, and 49.2% from uranium-234.
The 0.72% uranium-235 is not sufficient to produce a self-sustaining critical chain reaction in light water reactors or nuclear weapons; these applications must use enriched uranium. Nuclear weapons take a concentration of 90% uranium-235, and light water reactors require a concentration of roughly 3% uranium-235.[3] Unenriched natural uranium is appropriate fuel for a heavy-water reactor, like a CANDU reactor.
On rare occasions, earlier in geologic history when uranium-235 was more abundant, uranium ore was found to have naturally engaged in fission, forming natural nuclear fission reactors. Uranium-235 decays at a faster rate (half-life of 700 million years) compared to uranium-238, which decays extremely slowly (half-life of 4.5 billion years). Therefore, a billion years ago, there was more than double the uranium-235 compared to now.
During the Manhattan Project, the name Tuballoy was used to refer to natural uranium in the refined condition; this term is still in occasional use. Uranium was also codenamed "X-Metal" during World War II. Similarly, enriched uranium was referred to as Oralloy (Oak Ridge alloy), and depleted uranium was referred to as Depletalloy (depleted alloy).
natural, uranium, this, article, needs, additional, citations, verification, please, help, improve, this, article, adding, citations, reliable, sources, unsourced, material, challenged, removed, find, sources, news, newspapers, books, scholar, jstor, march, 20. This article needs additional citations for verification Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed Find sources Natural uranium news newspapers books scholar JSTOR March 2013 Learn how and when to remove this template message Natural uranium NU or Unat 1 refers to uranium with the same isotopic ratio as found in nature It contains 0 711 uranium 235 99 284 uranium 238 and a trace of uranium 234 by weight 0 0055 Approximately 2 2 of its radioactivity comes from uranium 235 48 6 from uranium 238 and 49 2 from uranium 234 Natural uranium can be used to fuel both low and high power nuclear reactors Historically graphite moderated reactors and heavy water moderated reactors have been fueled with natural uranium in the pure metal U or uranium dioxide UO2 ceramic forms However experimental fuelings with uranium trioxide UO3 and triuranium octaoxide U3O8 have shown promise 2 The 0 72 uranium 235 is not sufficient to produce a self sustaining critical chain reaction in light water reactors or nuclear weapons these applications must use enriched uranium Nuclear weapons take a concentration of 90 uranium 235 and light water reactors require a concentration of roughly 3 uranium 235 3 Unenriched natural uranium is appropriate fuel for a heavy water reactor like a CANDU reactor On rare occasions earlier in geologic history when uranium 235 was more abundant uranium ore was found to have naturally engaged in fission forming natural nuclear fission reactors Uranium 235 decays at a faster rate half life of 700 million years compared to uranium 238 which decays extremely slowly half life of 4 5 billion years Therefore a billion years ago there was more than double the uranium 235 compared to now During the Manhattan Project the name Tuballoy was used to refer to natural uranium in the refined condition this term is still in occasional use Uranium was also codenamed X Metal during World War II Similarly enriched uranium was referred to as Oralloy Oak Ridge alloy and depleted uranium was referred to as Depletalloy depleted alloy See also EditList of uranium mines Nuclear engineering Nuclear fuel cycle Nuclear physics Nuclear chemistryReferences EditDesign Parameters for a Natural Uranium Fueled Nuclear Reactor C M Hopper et al ORNL TM 2002 240 November 2002 Nuclear Fuel Cycle Overview World Nuclear Association October 2014 Archived from the original on 2016 01 30 Retrieved 2014 10 15 Oak Ridge National Laboratory ed Design Parameters for a Natural Uranium UO3 or U3O8 Fueled Nuclear Reactor PDF Loveland W Morrissey D J Seaborg G T 2006 Chapter 16 Nuclear Reactor Chemistry Modern Nuclear Chemistry PDF External links EditThe evolution of CANDU fuel cycles Retrieved from https en wikipedia org w index php title Natural uranium amp oldid 1149263566, wikipedia, wiki, book, books, library,
