ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
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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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Fusion Science and Technology
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
M. Nematollahi, M. Rezaiean
Fusion Science and Technology | Volume 61 | Number 1 | January 2012 | Pages 174-177
Fission | Proceedings of the Fifteenth International Conference on Emerging Nuclear Energy Systems | doi.org/10.13182/FST12-A13416
Articles are hosted by Taylor and Francis Online.
Using natural circulation as the primary core cooling mechanism in next generation nuclear reactors provides advantages such as improved safety, less operation and maintenance costs (because of elimination of pumps), and simplicity of system. Large scale deployment of natural circulation based reactors and safety systems depend on the successful resolution of the challenges specific to natural circulation such as driving force, system pressure drops, instability effects, and critical heat flux.In this work, natural circulation two-phase flow pressure drops in a single channel are studied experimentally. For this purpose, natural circulation hydrodynamic loop was designed. The overall pressure drop was measured by use of pressure transducer sensors and the void fraction in visible boxes which located at the end of heated tube is measured by use of high speed camera. The frictional and acceleration pressure drop are evaluated in different conditions from experimental data and corresponding theoretical formulas. The results could be useful in natural circulation based reactor design and computer codes validation.
