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Division Spotlight
Operations & Power
Members focus on the dissemination of knowledge and information in the area of power reactors with particular application to the production of electric power and process heat. The division sponsors meetings on the coverage of applied nuclear science and engineering as related to power plants, non-power reactors, and other nuclear facilities. It encourages and assists with the dissemination of knowledge pertinent to the safe and efficient operation of nuclear facilities through professional staff development, information exchange, and supporting the generation of viable solutions to current issues.
Meeting Spotlight
2025 ANS Annual Conference
June 15–18, 2025
Chicago, IL|Chicago Marriott Downtown
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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Nuclear Science and Engineering
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Latest News
High-temperature plumbing and advanced reactors
The use of nuclear fission power and its role in impacting climate change is hotly debated. Fission advocates argue that short-term solutions would involve the rapid deployment of Gen III+ nuclear reactors, like Vogtle-3 and -4, while long-term climate change impact would rely on the creation and implementation of Gen IV reactors, “inherently safe” reactors that use passive laws of physics and chemistry rather than active controls such as valves and pumps to operate safely. While Gen IV reactors vary in many ways, one thing unites nearly all of them: the use of exotic, high-temperature coolants. These fluids, like molten salts and liquid metals, can enable reactor engineers to design much safer nuclear reactors—ultimately because the boiling point of each fluid is extremely high. Fluids that remain liquid over large temperature ranges can provide good heat transfer through many demanding conditions, all with minimal pressurization. Although the most apparent use for these fluids is advanced fission power, they have the potential to be applied to other power generation sources such as fusion, thermal storage, solar, or high-temperature process heat.1–3
Michio Murase, Yoichi Utanohara
Nuclear Technology | Volume 209 | Number 7 | July 2023 | Pages 1086-1100
Technical Paper | doi.org/10.1080/00295450.2023.2175598
Articles are hosted by Taylor and Francis Online.
The objective of this study was to evaluate the effects of superheat on wall condensation from a steam and air mixture. We previously measured the radial and axial temperature profiles of a superheated steam-air mixture in a vertical pipe with a diameter of 49.5 mm and a cooling height of 610 mm. In this study, we carried out a numerical simulation for the previous measurements by using the computational fluid dynamics (CFD) code FLUENT, and evaluated the profiles of the mixture temperature Tg and steam mass fraction Xs. The profiles of Tg and the saturated temperature Ts obtained from Xs agreed well with those measured with superheated and saturated conditions, respectively. The validity of the correlation to evaluate a condensation heat flux qc (which was based on the gradient of Xs) was confirmed. Profiles of the dimensionless velocity u+, temperature T+, and steam mass fraction Ys+ were obtained, and they were compared with wall functions (i.e., the linear function for a viscous sublayer and the logarithmic law for a turbulent layer). The computed profile agreed with the wall function for u+, agreed relatively well with the wall function for T+, and agreed well with the correlation for Ys+ obtained from data measured with saturated steam-air conditions in the region of the turbulent layer.
