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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.”
Joseph L. Bottini, Sabrina Hammouti, David Ruzic, Caleb S. Brooks (Univ of Illinois)
Proceedings | Advances in Thermal Hydraulics 2018 | Orlando, FL, November 11-15, 2018 | Pages 440-448
Boiling heat transfer is an effective method for transferring heat from system components, enabling high heat transfer rates from minimal surface superheats. While it is effective, two-phase heat transfer offers added complexities to single-phase heat transfer caused by the addition of deformable interfaces, dissimilar fluid properties, and phase transition. The critical heat flux (CHF) marks the upper limit of safe operation for many boiling heat transfer systems, and its prediction is essential to ensure safe operation. While much effort has been devoted to studying boiling heat transfer and CHF, the characteristics of the surface, such as wettability and roughness, influence the boiling heat transfer, but are not well understood. Heat transfer surfaces of varying wettability and roughness have been prepared, characterized, and subjected to flow experiments up to CHF to study the role the surface properties have in flow boiling heat transfer. The surfaces were prepared using a high-power laser to texture the surface altering the wettability and roughness. Increasing the roughness and decreasing the wettability are found to have competing effects on both the boiling curves and the CHF points. The onset of nucleate boiling (ONB) points are delayed for the lesswetting surfaces, and the CHF value is lower. An increase in roughness for the textured surface causes earlier ONB and increases CHF, but the CHF values are lower than for the original, polished surface. The roughness and wettability are demonstrated to be influential properties on both the boiling heat transfer and the CHF point, and are not well captured by the existing CHF models.