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Division Spotlight
Nuclear Installations Safety
Devoted specifically to the safety of nuclear installations and the health and safety of the public, this division seeks a better understanding of the role of safety in the design, construction and operation of nuclear installation facilities. The division also promotes engineering and scientific technology advancement associated with the safety of such facilities.
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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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
S. Wang, T. Beuthe, X. Huang, A. Nava Dominguez, A. V. Colton, B. P. Bromley
Nuclear Technology | Volume 207 | Number 4 | April 2021 | Pages 469-493
Technical Paper | doi.org/10.1080/00295450.2020.1788302
Articles are hosted by Taylor and Francis Online.
The use of advanced uranium-based and thorium-based fuel bundles in pressure tube heavy water reactors (PT-HWRs) has the potential to improve the utilization of uranium resources while also providing improvements in performance and safety characteristics of PT-HWRs. Previous lattice physics and core physics studies have demonstrated the feasibility of using such advanced fuels; however, thermal-hydraulic (T-H) studies are required to confirm that these advanced fuels will have adequate T-H safety margins. Preliminary system T-H transient simulations have been performed for a 700-MW(electric)–class PT-HWR in a postulated loss-of-coolant accident (LOCA) using the CATHENA code. One purpose of this work was to demonstrate that such simulations of a PT-HWR with advanced fuels could be set up and executed successfully in a CATHENA transient simulation model. The other purpose was to evaluate the peak fuel sheath and fuel centerline temperatures in two designated fuel channels containing advanced uranium-based or thorium-based fuel during a LOCA transient event. In the CATHENA simulation models, a PT-HWR core is fueled with conventional 37-element natural uranium fuel bundles in 378 out of 380 fuel channels while two designated fuel channels, the channel with the highest total power and the channel containing the bundle with the highest power level, are filled with various types of advanced fuels. Results indicate that setting up these models is feasible and that the predicted peak fuel centerline temperatures and peak sheath temperatures for the advanced fuel channels are well below the fuel melting points and the rapid oxidation temperature for the Zircaloy-4 sheath/clad (~1200°C), respectively. These preliminary results provide confidence that the advanced fuels will likely have adequate T-H safety margins in a transient LOCA event in a PT-HWR. These results set the stage for more detailed and comprehensive system T-H models of PT-HWRs fueled entirely with advanced uranium-based or thorium-based fuels.
