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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.”
Thuy Dung Vu, Dookie Kim, Sung Gook Cho
Nuclear Technology | Volume 182 | Number 1 | April 2013 | Pages 75-83
Technical Paper | Nuclear Plant Operations and Control/Miscellaneous | doi.org/10.13182/NT13-A15828
Articles are hosted by Taylor and Francis Online.
The application of base isolation to nuclear systems has been limited to date for some important reasons, including the deprivation of sufficient data for the long-term operation of such isolation devices and the lack of specific standards. Moreover, it is difficult to provide seismic protection in the vertical direction and to qualify the large-scale isolators up to experimentally large deformations in real dynamic conditions. The effect of aging on isolators is therefore one of the issues to be considered for the safety and reliability of base-isolated nuclear power plants (NPPs). Accounting for the variations of the post-aging parameters of the isolators on the structural performance of the plant, this study proposes a simplified and efficient method to update the analytical model of base-isolated structures based on mean-iterative neural networks (MINNs). A bilinear model with a zero length element was built to represent the characteristics of lead-rubber bearings for their numerical analysis. Analytical model updating by MINNs has been successfully performed, and the observed results are found to be in good agreement with those obtained from experiments. Additionally, it is observed that the stiffening or hardening with time in the shear properties of isolation devices affects the seismic performance of the base-isolated structure. Seismic design over the service life span of NPP structures should take these aging effects of the isolators into account.