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The Washington State University Reactor (WSUR) is housed in the Washington State University Nuclear Radiation Center (WSUNRC), and was completed in 1961. The (then) Washington State College Reactor was the brainchild of Harold W. Dodgen, a former researcher on the Manhattan Project where he earned his PhD from 1943 to 1946. He secured funding for the ambitious 'Reactor Project' from the National Science Foundation, the Atomic Energy Commission, and the College administration totaling $479,000 (roughly $3.5 million in today's dollars). Dodgen's basis for constructing a reactor was that the College was primly located as a training facility for the Hanford site, as well as Idaho National Laboratory because there was no other research reactor in the West at that time. After completing the extensive application and design process with the help of contractors from General Electric they broke ground in August 1957 and the first criticality was achieved on March 7, 1961 at a power level of 1W. They gradually increased power over the next year to achieve their maximum licensed operating power of 100 kW. It was initially a General Electric Materials Test Reactor with plate-type fuel bundles, but was upgraded in 1967 to a 1MW General Atomics TRIGA (Teaching Research Isotopes General Atomics) reactor.〔 Standard TRIGA fuel rods are cylindrical rods, clad in stainless steel utilizing Uranium-235 dispersed in a ceramic zirconium-hydride matrix as fuel.〔http://www.triga.ga.com〕 The WSUR operated with this TRIGA fuel until the Fuel Life Improvement Program (FLIP) once again upgraded the reactor in 1976 with a partial new core of high-enriched 'TRIGA FLIP' fuel designed for an extended lifetime.〔http://nrc.wsu.edu/〕 Two years later, in 1978, due to global fears of nuclear proliferation it was federally mandated that all high-enriched reactor fuel (except for military use) be replaced with Low Enriched Uranium Fuel (LEU).〔http://www.nrc.gov/reactors/non-power.html〕 Due to the extensive work, cost, and the number of research reactors undergoing the procedure, the WSUR was not converted until October 2008. All FLIP fuel was replaced by another TRIGA fuel known as 30/20 LEU and when the new core went critical on October 7, 2008 it became the world's only mixed 8.5/20(Standard TRIGA) and 30/20 LEU core.〔WSUNRC〕 The facility license was renewed for an additional 20 years upon completion of a safety analysis and review. The effective date was September 30, 2011 ==Design== The WSUR core consists of a rectangular aluminum box suspended from a movable bridge structure. Surrounding the core is a 242,000 liter pool of high purity deionized light water, which is used as both a coolant, shield, and moderator. Inside the core box there is a bottom grid-plate into which 3 and 4-rod clusters of TRIGA fuel sit separated by boron-aluminum (Boral) control elements. These control elements are raised out of the core via servo-motors to control reactor power. Power is monitored via three different and independent detectors that sit inside the core structure; there is a compensated ion chamber, an uncompensated ion chamber, and a fission chamber in three of the four corners of the grid box.〔United States. Nuclear Regulatory Commission. Research and Test Reactors. Safety Analysis Report for the Washington State University Modified TRIGA Nuclear Reactor. Washington DC: Nuclear Regulatory Commission, 2002. Print.〕 Due to the highly energetic nature of the fission process, a substantial amount of heat is generated during operation (~350 °C).The fuel is cooled by the natural convection of light water which is circulated through a plate-type heat exchanger with a primary and secondary loop.〔 A cooling tower is utilized to discharge heat from the secondary loop to the environment, ensuring that the system remains well within temperature limits while preventing environmental exposure of water which has contacted the reactor.〔 The WSUR is purely a research reactor, lacking both a pressure vessel and steam turbine which are used to generate electricity in power reactors. The primary use for the WSUR is to generate neutrons which can be used for a multitude of experimental purposes. There are several specialized experimental facilities for NAA and isotope production (see below), and several generalized sample rotator tubes whereby samples are lowered into the core for a set time, then pulled back out and sent to the laboratory where the data analysis will take place.〔 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「Washington State University Reactor」の詳細全文を読む スポンサード リンク
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