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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.”
Mikio Sakai, Kazuya Shibata, Seiichi Koshizuka
Nuclear Science and Engineering | Volume 154 | Number 1 | September 2006 | Pages 63-73
Technical Paper | doi.org/10.13182/NSE06-A2618
Articles are hosted by Taylor and Francis Online.
Particle dynamics of nuclear fuel material has not been considered in conventional nuclear criticality evaluations. However, the particle motion influences nuclear criticality significantly. In the present study, the criticality calculation is combined with the discrete element method (DEM) to investigate the effects of the particle macroscopic behavior on nuclear criticality. Particle motion is analyzed in a rotating drum by the DEM, and then, the nuclear calculation is carried out. This paper focuses on particle size distribution, size segregation, and change of surface area of the particle bed. The particle size distribution has an important influence on the nuclear criticality evaluation because it affects not only the particle movement but also the atomic number densities in the bed. The surface area of the particle bed shows a close correlation with the multiplication factor. On the other hand, the size segregation does not have a significant effect on nuclear criticality.
