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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.”
Paul S. Feigenbaum, Martin Becker, Donald R. Harris Bimal K. Malaviya, Robert C. Block, S. A. Hayashi, S. Yamamoto
Nuclear Science and Engineering | Volume 114 | Number 2 | June 1993 | Pages 112-117
Technical Paper | doi.org/10.13182/NSE93-A24022
Articles are hosted by Taylor and Francis Online.
Integral neutron spectrum measurements of thoria (ThO2) were performed and analyzed at the Rensselaer Polytechnic Institute Gaerttner Linac Laboratory to assess the relative accuracy of ENDF/B- V thorium cross sections. This project was performed by first measuring the neutron spectrum that emanated from an assembly of thoria and then simulating that spectrum using ENDF/B- V evaluated data and the neutron transport code DTF-IV The neutron spectrum emanating from a 0.6-m-diam assembly of powdered thoria was recorded from 3.62 keV to 14.0 MeV using a pulsed photoneutron source, intermediate- and fast-energy neutron detectors, and the time-of-flight technique. Overall, there appears to be relatively good agreement between the measured and calculated spectra. However, the calculated spectrum underpredicts the measured spectrum between 2.87 and 0.639 MeV and overpredicts the measured spectrum between 388.0 and 72.6 keV. One interpretation of the results is that in the 0.7- to 5.0-MeV energy region, the thorium evaluated cross sections for inelastic scattering are too large.
