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The Y-12 National Security Complex is a United States Department of Energy National Nuclear Security Administration facility located in Oak Ridge, Tennessee, near the Oak Ridge National Laboratory. It was built as part of the Manhattan Project for the purpose of enriching uranium for the first atomic bombs. In the years after World War II, it has been operated as a manufacturing facility for nuclear weapons components and related defense purposes. Y-12 is managed and operated under contract by Consolidated Nuclear Security, LLC (CNS), which is composed of member companies Bechtel National, Inc., Lockheed Martin Services, Inc., ATK Launch Systems, Inc., and SOC LLC, with Booz Allen Hamilton, Inc. as a teaming subcontractor. CNS also operates Pantex Plant in Texas.〔http://cns-llc.us/the-cns-team/〕 ==History== Y-12 is the World War II code name for the electromagnetic isotope separation plant producing enriched uranium at the Clinton Engineer Works in Oak Ridge, Tennessee, as part of the Manhattan Project. Construction began in February 1943 under the management of Stone and Webster. Because of a wartime shortage of copper, the massive electromagnetic coils were made with 14,700 tons of coinage silver from U.S. government vaults at West Point.〔(【引用サイトリンク】 url = http://www.tnengineering.net/AICHE/eastman-oakridge-young.htm )〕 Colonel Kenneth D. Nichols met with the Under Secretary of the Treasury, Daniel W. Bell, and requested between five and ten thousand tons of silver. Bell's stunned reply was ''"Colonel, in the Treasury we do not speak of tons of silver; our unit is the troy ounce."'' Thus the Manhattan Engineer District requested and was loaned 395 million troy ounces of silver (13,540 short tons, 12,300 tonnes) from the West Point Depository for the duration of the Manhattan Project. Special guards and accountants were assigned to the silver, and their responsible caretaking meant that at the end of the war, less than 0.0036% out of more than $300 million worth of silver was lost to the process, with the remainder returned to the Treasury.〔(【引用サイトリンク】 url = https://www.y12.doe.gov/sites/default/files/history/pdf/articles/07-10-11.pdf )〕 The Y-12 facility began operating in November 1943, separating uranium-235 from natural uranium, which is 99.3% uranium-238, by using calutrons to perform electromagnetic isotope separation. Y-12 separated the uranium-235 for Little Boy, the nuclear weapon that was dropped on Hiroshima, Japan on August 6, 1945. K-25, another facility in Oak Ridge, produced enriched uranium using gaseous diffusion. However, K-25 did not begin operating until March 1945 and fed slightly enriched uranium to Y-12's Beta Calutrons as the push to obtain enough uranium 235 for Little Boy came in the early summer of 1945. The S-50 Thermal Diffusion Plant at the K-25 site also provided feed material for Y-12's Beta Calutrons. Tennessee Eastman was hired by the Army Corps of Engineers to manage Y-12 during the Manhattan Project. The company transferred scientists from Kingsport, Tennessee to Y-12 and operated the plant from 1943 to May 1947.〔Martha Avaleen Egan, (Tennessee Eastman Company/Eastman Chemical Company ), ''Tennessee Encyclopedia of History and Culture'', 2009. Retrieved: 14 February 2013.〕 The Y-12 electromagnetic plant units were initially operated by scientists from Berkeley to remove bugs and achieve a reasonable operating rate. They were then turned over to trained Tennessee Eastman operators who had only a high school education. Nichols compared unit production data, and pointed out to physicist Ernest Lawrence that the young "hillbilly" girl operators were outproducing his PhDs. They agreed to a production race and Lawrence lost, a morale boost for the Tennessee Eastman workers and supervisors. The girls were "trained like soldiers not to reason why", while "the scientists could not refrain from time-consuming investigation of the cause of even minor fluctuations of the dials".〔Nichols, Kenneth D. ''Ibid'', page 131〕 The Union Carbide corporation succeeded Tennessee Eastman as the operating contractor in 1947, remaining until 1984, when Union Carbide relinquished the contract for operating DOE's Oak Ridge facilities, and the Martin Marietta corporation (later Lockheed Martin) won the contract to take over the operation. BWXT Y-12 (name later changed to B&W Y-12) succeeded Lockheed Martin as the Y-12 operator in November 2000.〔"(Y-12 Receives 'Good' Award Fee Rating from DOE )," ''BWX Times'', Vol. 2, No. 6 (10 January 2002). Retrieved: 14 February 2013.〕 A chemical explosion injured several workers at the Y-12 facility on December 8, 1999, when NaK was cleaned up after an accidental spill, inappropriately treated with mineral oil, and inadvertently ignited when the surface coating of potassium superoxide was scratched by a metal tool.〔(【引用サイトリンク】title=Type A Accident Investigation of the December 8, 1999, Multiple Injury Accident Resulting from the Sodium-Potassium Explosion in Building 9201-5 at the Y-12 Plant )〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Y-12 National Security Complex」の詳細全文を読む スポンサード リンク
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