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Thermal Hydraulics
The division provides a forum for focused technical dialogue on thermal hydraulic technology in the nuclear industry. Specifically, this will include heat transfer and fluid mechanics involved in the utilization of nuclear energy. It is intended to attract the highest quality of theoretical and experimental work to ANS, including research on basic phenomena and application to nuclear system design.
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ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
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The Standards Committee is responsible for the development and maintenance of voluntary consensus standards that address the design, analysis, and operation of components, systems, and facilities related to the application of nuclear science and technology. Find out What’s New, check out the Standards Store, or Get Involved today!
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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.”
Russell D. Mosteller, Peter J. Jensen, Michael J. Anderson,+ Laurance D. Eisenhart, Rana Abdollahian, Jason Chao, Walter J. Eich
Nuclear Technology | Volume 86 | Number 1 | July 1989 | Pages 40-48
Technical Paper | Nuclear Safety | doi.org/10.13182/NT89-A34280
Articles are hosted by Taylor and Francis Online.
A pressurized water reactor (PWR) with a positive moderator temperature coefficient of reactivity is potentially susceptible to a severe overheating transient. This study identifies a scenario in which such a transient could occur and is similar in some respects to the accident at Chernobyl Unit 4. The scenario so identified is a natural circulation test at beginning of life under the assumption that all scrams are disabled. The results obtained demonstrate that a runaway power excursion does not occur and that the domestically designed PWR that was analyzed displays inherently safe behavior for the chosen scenario. The analysis is performed using two codes in tandem over three sequential stages of the analysis. Since the transient is assumed to be quasi-steady-state, steadystate calculations first are performed with the advanced three-dimensional core simulation code ARROTTA to generate a moderator reactivity table for input to the point kinetics model in the RETRAN-02 systems transient code. The entries in this table are taken directly from ARROTTA results, so they implicitly contain three-dimensional reactivity effects. Next, a RETRAN-02 transient analysis is performed for the system as a whole. This analysis serves two purposes: It predicts the overall behavior of the plant during the transient, and it also produces time-dependent forcing functions for ARROTTA. Finally, ARROTTA is run in a transient mode, providing a detailed description of the behavior of the core during the transient. The high level of consistency produced by the two transient calculations validates the initial assumption of quasisteady-state behavior. A methodology that may be applied to the analysis of this and similar transients is developed and tested as part of this study.