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Division Spotlight
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
Standards Program
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.”
T. Höhne, E. Krepper, D. Lucas, G. Montoya
Nuclear Technology | Volume 205 | Number 1 | January-February 2019 | Pages 48-56
Technical Paper | doi.org/10.1080/00295450.2018.1495025
Articles are hosted by Taylor and Francis Online.
The paper presents the extension of the GENeralized TwO Phase flow (GENTOP) model for phase transfer and discusses the submodels used. Boiling flow inside a wall heated vertical pipe is simulated by a multifield computational fluid dynamics (CFD) approach. Subcooled water enters the pipe from the lower end and heats up first in the near-wall region leading to the generation of small bubbles. Farther along the pipe, larger and larger bubbles are generated by coalescence and evaporation. This leads to transitions of the two-phase-flow patterns from bubbly to churn-turbulent and annular flow. The CFD simulation is based on the recently developed GENTOP concept. It is a multifield model using the Euler-Euler approach. It allows the consideration of different local flow morphologies including transitions between them. Small steam bubbles are handled as dispersed phases while the interface of large gas structures is statistically resolved. The GENTOP submodels and the wall boiling model need a constant improvement and separate, intensive validation effort using CFD-grade experiments.