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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.”
Z. Weiss
Nuclear Science and Engineering | Volume 22 | Number 1 | May 1965 | Pages 60-77
Technical Paper | doi.org/10.13182/NSE65-A19763
Articles are hosted by Taylor and Francis Online.
Making use of the isotropic incident flux approximation, the disadvantage factor ζ for a two-region unit cell can be written as a linear combination of two so-called X functions, each of them depending on the properties of one region only. A general variational approach, based on Ritz-Galerkin's method, is used to find a closed expression for X in terms of the ‘weighted’ collision probabilities, From this expression the properties of X will be deduced once more, but then in a general way. An analytical calculation of X in slab geometry and a numerical one in cylindrical geometry are given. The results of the first have been used for a comparison with Theys' generalization of the Amouyal-Benoist-Horowitz theory; the results of the second example were compared with Leslie's calculation of the same X function by means of successive collision probabilities. It is furthermore shown that the same procedure that serves to calculate X functions gives, as an important by-product, the constant production and the isotropic abledo solutions of Peierl's integral transport theory. From these solutions the flux distribution in the unit cell (of arbitrary geometry) can be constructed. Sauer's simple recipe for calculating the X function is discussed and is shown to be inaccurate for weakly absorbing media.