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Isotopes & Radiation
Members are devoted to applying nuclear science and engineering technologies involving isotopes, radiation applications, and associated equipment in scientific research, development, and industrial processes. Their interests lie primarily in education, industrial uses, biology, medicine, and health physics. Division committees include Analytical Applications of Isotopes and Radiation, Biology and Medicine, Radiation Applications, Radiation Sources and Detection, and Thermal Power Sources.
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General Kenneth Nichols and the Manhattan Project
Nichols
The Oak Ridger has published the latest in a series of articles about General Kenneth D. Nichols, the Manhattan Project, and the 1954 Atomic Energy Act. The series has been produced by Nichols’ grandniece Barbara Rogers Scollin and Oak Ridge (Tenn.) city historian David Ray Smith. Gen. Nichols (1907–2000) was the district engineer for the Manhattan Engineer District during the Manhattan Project.
As Smith and Scollin explain, Nichols “had supervision of the research and development connected with, and the design, construction, and operation of, all plants required to produce plutonium-239 and uranium-235, including the construction of the towns of Oak Ridge, Tennessee, and Richland, Washington. The responsibility of his position was massive as he oversaw a workforce of both military and civilian personnel of approximately 125,000; his Oak Ridge office became the center of the wartime atomic energy’s activities.”
Viktoriya V. Kulik, John C. Lee
Nuclear Science and Engineering | Volume 153 | Number 1 | May 2006 | Pages 69-89
Technical Paper | doi.org/10.13182/NSE06-A2596
Articles are hosted by Taylor and Francis Online.
The presence of a localized spallation source in an accelerator-driven subcritical system leads to significant spatial variations in the power distribution and invalidates the simple point-kinetics approach. To eliminate higher-harmonics contamination in the detector response and to account properly for spatial and spectral effects in reactivity determination, a method directly combining measurements with numerical simulations of the experimental data is developed through a quasi-static formulation. The method provides space-time correction to a variety of traditional point-kinetics techniques and determines the reactivity essentially independent of the detector position, as long as sufficiently accurate information on the reactor configuration is provided. In the current work, the space-time corrections are derived for two well-known point-kinetics methods: area-ratio technique and -method. Numerical simulations performed with the FX2-TH diffusion theory code along with a space-time analysis of MUSE-4 pulsed source experimental data illustrate the applicability of the proposed methods for the determination of significant subcriticality levels in fast and thermal reactor systems.