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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.”
J. H. Marable, C. R. Weisbin, G. de Saussure
Nuclear Science and Engineering | Volume 75 | Number 1 | July 1980 | Pages 30-55
Technical Paper | doi.org/10.13182/NSE80-A20316
Articles are hosted by Taylor and Francis Online.
Using an extensive data base of sensitivities and evaluated covariances, this work incorporates 11 fast-reactor benchmark experiments and 2 neutron-field benchmark experiments into the adjustment of a 26-group cross-section library based primarily on Evaluated Nuclear Data File (ENDF)/B-IV. The covariance data include correlations between cross sections for different energies, reactions, and materials, and between integral experiments, and covariances of calculational bias factors due to specific modeling and calculational procedures. The adjustments of the group cross sections are examined in some detail and are smaller than the estimated standard deviations. The results of the adjustment are applied to the determination of the uncertainties in the multiplication factor and in the breeding ratio of a large liquid-metal fast breeder reactor design model fixed by the Large Core Code Evaluation Working Group. For this static model the adjustment procedure reduces the calculated uncertainty in keff from 3.1% to 0.5% and in breeding ratio for the critical reactor from 3.5% to 1.9%.