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The mission of the Decommissioning and Environmental Sciences (DES) Division is to promote the development and use of those skills and technologies associated with the use of nuclear energy and the optimal management and stewardship of the environment, sustainable development, decommissioning, remediation, reutilization, and long-term surveillance and maintenance of nuclear-related installations, and sites. The target audience for this effort is the membership of the Division, the Society, and the public at large.
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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.”
A. K. Ghatak and S. Pearlstein
Nuclear Science and Engineering | Volume 22 | Number 2 | June 1965 | Pages 182-190
Technical Paper | doi.org/10.13182/NSE65-A20237
Articles are hosted by Taylor and Francis Online.
A numerical experiment of the transient neutron behavior following a source burst has been performed. The time-dependent Boltzmann equation (in the diffusion approximation without delayed neutrons) was propagated in time until asymptotic conditions were reached. The explicit time, space and energy solution was programed for the IBM-7094. Space-independent calculations of defined effective multiplication factors, neutron lifetimes and decay constants were performed for hydrogenous and graphite-moderated U235 or Pu239 systems. Seventy-three velocity groups were employed to detail spectral changes that occur in the approach to equilibrium. About 20 µsec and 150 µsec, respectively, were required for the energy modes to decay in the hydrogenous and graphite systems considered. The initial response of a cadmium detector is shown to be similar in multiplying and nonmultiplying assemblies and indicates the neutron slowing-down time to the cadmium resonance. No further structure in the cadmium-detector response due to the regenerative process was noted. The space-dependent properties of bare and reflected one-dimensional slabs were also briefly studied.
