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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.”
Hiroki Takezawa, Toru Obara
Nuclear Science and Engineering | Volume 164 | Number 1 | January 2010 | Pages 80-86
Technical Note | doi.org/10.13182/NSE08-91
Articles are hosted by Taylor and Francis Online.
The integral kinetic model is applicable to space-dependent kinetic analysis for any weakly coupled system because of its applicability to any geometry. Transient parameters that describe the time distribution of neutron transport between regions in a system are essential for this model. This paper presents a formula for calculating the parameters based on the nonanalog Monte Carlo neutron transport simulation technique. A continuous-energy Monte Carlo code MVP2.0 was modified to calculate the parameters, and the modification was verified using the static coupled reactor theory. The parameters were calculated in a simple fast-thermal coupled reactor. The results showed a difference in fission starting times between a fast region and a thermal region, which can cause a time lag in the transient behavior between the two regions. The results also revealed the time distribution of neutron energy groups that trigger fissions in each region. A space-dependent kinetic analysis code based on the integral kinetic model is under development, and these parameters can be used in the integral kinetic model to perform space-dependent kinetic analysis for weakly coupled systems.
