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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.”
Y. Harima, S. Tanaka
Nuclear Science and Engineering | Volume 90 | Number 2 | June 1985 | Pages 165-173
Technical Paper | doi.org/10.13182/NSE85-A17674
Articles are hosted by Taylor and Francis Online.
Exposure buildup factors for plane isotropic, point isotropic, and plane normal sources have been calculated using a discrete ordinates direct integration code, PALLAS-PL, SP-Br, in infinite and finite water shields in the 0.06- to 0.1-MeV range. The values of the attenuation kernel, Be-µr, are greater than unity at distances up to a few mean-free-paths in an infinite medium. The maximum value of Be-µr depends on the incident energy, and this effect reaches a maximum for a 0.08-MeV source. The implication that the dose rate with a shield is greater than without a shield should be noticed. Results of this study show, however, that the large degree of scattering in a low-z material, such as water, produces this effect. Buildup factors, energy spectra, and angular distributions were analyzed for three source geometries in the comparisons of scattered gamma-ray transport in infinite and finite water shields.
