ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
Explore the many uses for nuclear science and its impact on energy, the environment, healthcare, food, and more.
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!
Latest Magazine Issues
May 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
July 2025
Nuclear Technology
June 2025
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
Yeongshin Jeong, Koroush Shirvan, Michael Buric
Nuclear Science and Engineering | Volume 197 | Number 5 | May 2023 | Pages 868-885
Technical Paper | doi.org/10.1080/00295639.2022.2102388
Articles are hosted by Taylor and Francis Online.
This work establishes a generic multiphysics tool for liquid-fueled molten salt reactors (LFMSRs) to select key installation locations and specify the expected operating temperature range for the development of advanced instrumentation and control systems, particularly distributed temperature sensors using fiber optics. A commercial computation fluid dynamics package (STAR-CCM+) is used to formulate a neutronics and thermal-hydraulic coupled solver, showing good agreement with a recent benchmark problem developed for evaluating the coupling methodology of neutronics and thermal hydraulics. The multiphysics model is then applied to the reference molten chloride salt fast reactor (MCFR) design under development by TerraPower based on publicly available information. The available two-dimensional axisymmetric model for the reactor core is used for coupling calculations, and system component details are leveraged using the lumped method to complete the energy balance. The dynamic responses of the MCFR model are investigated during operational transients, such as unprotected loss-of-flow and uniform perturbation scenarios. Maximum temperature and local temperature distributions are characterized during unprotected loss of flow and unprotected loss of heat sink events. The thermal responses of the fuel salt and core components are analyzed from induced perturbation of the system parameters, such as the flow rate and the heat sink capacity. The results motivate the use of continuous monitoring of the temperature variation in real time along the reflector region with the use of fiber optics to validate the multiphysics code to support a reactor’s licensing basis, as well as to support the structural longevity and improve safety in LFMSRs.