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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.”
Pinky Batheja, Feroz Ahmed, L. S. Kothari, Otohiko Aizawa
Nuclear Science and Engineering | Volume 89 | Number 4 | April 1985 | Pages 366-380
Technical Note | doi.org/10.13182/NSE85-A18629
Articles are hosted by Taylor and Francis Online.
Using diffusion theory and the eigenfunction expansion method, a detailed time-dependent study of fast neutrons has been made for three iron assemblies: infinite, 1 m3, and 0.5 m3. Various results have been obtained by taking two different source energies, namely, 14.47 and 1.0076 MeV. All the calculations have been carried out using the 50-group cross-section set of Ahmed et al. For the 1.0076-MeV source, (a) the time-dependent spectra exhibit two distinct peaks up to ∼50 ns, (b) energy variation of the mean slowing down time shows “anomalous” behavior similar to that observed by Bey non et al., and (c) the most probable time has two different values for some energy groups below ∼240 keV, in conformity with the results of White et al. The double values of (except for the 40th and 41st groups) and the “anomalous” behavior observed in cease when we take the source energy to be 14.47 MeV. Further, for all values of energy Ei, the values of both and decrease as the size of the assembly is reduced. It has been shown that in the two larger assemblies, pseudoasymptotic conditions are established in certain time intervals. It was determined that some energy groups tend to cluster and decay with the same decay constant after a certain time.