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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.”
G. E. Hansen and H. A. Sandmeier
Nuclear Science and Engineering | Volume 22 | Number 3 | July 1965 | Pages 315-320
Technical Paper | doi.org/10.13182/NSE65-A20935
Articles are hosted by Taylor and Francis Online.
Adjoint transport theory is most widely used in perturbation theory. A most common problem here is the determination of the reactivity change in a self-multiplying system due to the insertion of an absorber in a small region. There is, however, a class of problems of the source-detector type where adjoint transport theory proves to be a very effective and fast way of obtaining the desired results. In many practical source problems we want to evaluate the reaction rate, say fissions or absorptions, in a material surrounded by a moderator due to a neutron flux incident on the assembly. Here the main advantage of using the adjoint method as opposed to the conventional real-flux shell-source calculations is a significant reduction in computer time. The reactions induced by each group of source neutrons is obtained from one run of an adjoint problem. To obtain the same information from real-flux calculations we need an individual run for every energy group g. Computer time savings ranging by a factor of 5 to 30 are representative. The theory previously reported by one of us (H.A.S.) in the classified literature is derived and subsequently applied to the following problems. a. the fissions induced in a spherical plutonium-detector foil separated by a moderating layer from an incident collimated neutron beam; b. a neutron-dose-rate detector device consisting of a lithium iodide crystal to register absorptions surrounded by a sphere of polyethylene; c. the theoretical evaluation of the neutronic coupling coefficient between two reactors, as one might visualize in a clustered-Rover nuclear-reactor rocket-engine system.