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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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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
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.
