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Reactor Physics
The division's objectives are to promote the advancement of knowledge and understanding of the fundamental physical phenomena characterizing nuclear reactors and other nuclear systems. The division encourages research and disseminates information through meetings and publications. Areas of technical interest include nuclear data, particle interactions and transport, reactor and nuclear systems analysis, methods, design, validation and operating experience and standards. The Wigner Award heads the awards program.
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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.”
Nathan E. White, Robert V. Tompson, Sudarshan K. Loyalka
Nuclear Science and Engineering | Volume 195 | Number 2 | February 2021 | Pages 137-147
Technical Paper | doi.org/10.1080/00295639.2020.1793559
Articles are hosted by Taylor and Francis Online.
Although aerosols in some postaccident nuclear environments can be nonspherical, chainlike, or agglomerates, there have been limited investigations of the rate processes (such as coagulation, evaporation, condensation, and deposition) involving such particles. In a previous investigation, the understandings of condensation and evaporation on such particles were expanded through use of a one-speed approximation for modeling vapor (or fission product) molecular transport, and the present paper extends that work to energy- and mass-dependent transport of vapor molecules within the context of the linear Boltzmann equation via the Monte Carlo particle transport method for rigid sphere molecules. The results are benchmarked against available numerical results and experimental data for a single sphere, and it is found again that the normalized condensation rate has only a weak dependence on the molecular mass ratio (vapor to background) and that the one-speed approximation is quite good. Results are reported for a range of chainlike and agglomerate aerosols.