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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
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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.”
T. C. Chawla, B. M. Hoglund
Nuclear Science and Engineering | Volume 44 | Number 3 | June 1971 | Pages 320-344
Technical Paper | doi.org/10.13182/NSE71-A20165
Articles are hosted by Taylor and Francis Online.
The flow transients as initiated by rapid gas release are studied both experimentally and analytically. The mathematical model developed considers a multiple pin failure in a fast-reactor subassembly. In formulating the model, it is assumed that the released gas fills the subassembly cross section uniformly and that the coolant flow is incompressible. The model considers the inertial contribution of the liquid columns beyond the pin assembly, as well as the three-dimensional flow effects in the inlet and outlet plenums. In the application of the model to out-of-pile simulation loops, or in-pile test loops, points of departure in hydraulic simulation of the actual reactor conditions can be taken into account. A quantitative criterion for valid application of the model is obtained in terms of breach size, number of pins ruptured, initial gas plenum pressure and temperature, and subassembly operating conditions. The predictions of the flow transients obtained by means of the model agree well with the experimental data. An example of the application of the model to a reactor configuration is given using an FFTF fuel subassembly.