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Division members promote the advancement of mathematical and computational methods for solving problems arising in all disciplines encompassed by the Society. They place particular emphasis on numerical techniques for efficient computer applications to aid in the dissemination, integration, and proper use of computer codes, including preparation of computational benchmark and development of standards for computing practices, and to encourage the development on new computer codes and broaden their use.
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ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
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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.”
Donald Bogart
Nuclear Technology | Volume 112 | Number 1 | October 1995 | Pages 9-20
Technical Paper | Fission Reactor | doi.org/10.13182/NT95-A15848
Articles are hosted by Taylor and Francis Online.
Precise calculation of radial distributions of resonance region capture in 238U metal rods and for partially enriched uranium-oxide fuels is important for current and proposed water-moderated power reactors. Advanced core designs for pressurized and boiling water reactors have considered resonance region in-core generation of 239Pu as a means of extending core operating cycles between refuelings. The calculations of detailed spatial resonance captures are beyond the scope of multigroup codes used for practical reactor core design because of the broad resonance energy groups required. Group average resonance capture cross-section parameters employed may conserve total neutron captures, but the spatial detail is washed out. A simplified method is presented that enables direct calculation of resonance region spatial captures in fuel moderator lattices. The validity of the method is confirmed by comparison with published experimental measurements for epicadmium capture with radial distance from the moderator-fuel interface for metal uranium rods from 0.8 to 5.0 cm in diameter. A method is illustrated for spatial resonance capture in partially enriched uranium-oxide fuel rods, and the spatial complexity of 239Pu production during conversion of 238U in the resonance region is discussed. Although the products of the conversion chain can be precisely defined geometrically with operating time, their spatial concentrations cannot be calculated with the accuracy required to determine net production of 239Pu.
