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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.
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
Junghyun Bae, Robert S. Bean
Nuclear Science and Engineering | Volume 196 | Number 10 | October 2022 | Pages 1224-1235
Technical Paper | doi.org/10.1080/00295639.2022.2055700
Articles are hosted by Taylor and Francis Online.
In pool-type research reactors, the fuel core is placed in a large open pool of water, and it is consistently cooled by natural circulation. To meet the increasing demands of reactor-based research, i.e., neutron irradiation and isotope production, many institutes have been considering upgrading the designed power levels of their research reactors to maximize their utility. However, increasing operating power levels without replacing the major components of the reactor system is challenging because two important analyses must be extensively performed: (1) neutron transport analysis for nuclear fission and decay heat generation and (2) thermohydraulic analysis for heat removal in the core. In this paper, we investigate thermohydraulic limits on the maximum power of the Purdue University research reactor (PUR-1) using computational fluid dynamics (CFD) simulations which are coupled with the results from Monte Carlo neutron transport simulations. We design a PUR-1 fuel assembly, which is designated as the hottest one for CFD simulations, that includes a narrow, rectangular, and upward coolant channel. Here we demonstrate that the thermohydraulic limit for PUR-1 core power is 350 kW without changing the coolant system. Given a conservative safety margin, however, the estimated maximum power level is decreased to 170 kW. In the end, the results of two additional cooling systems—guide pipe and lowered coolant temperature—are presented to demonstrate the potential of advanced cooling capacity. They would enable reactors to operate at higher core power levels.