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Reactor Physics
The division's objectives are to promote the advancement of knowledge and understanding of the fundamental physical phenomena characterizing nuclear reactors and other nuclear systems. The division encourages research and disseminates information through meetings and publications. Areas of technical interest include nuclear data, particle interactions and transport, reactor and nuclear systems analysis, methods, design, validation and operating experience and standards. The Wigner Award heads the awards program.
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2025 ANS Annual Conference
June 15–18, 2025
Chicago, IL|Chicago Marriott Downtown
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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
Chad L. Pope, Colby B. Jensen, Douglas M. Gerstner, James R. Parry
Nuclear Technology | Volume 205 | Number 10 | October 2019 | Pages 1378-1386
Technical Note | doi.org/10.1080/00295450.2019.1599615
Articles are hosted by Taylor and Francis Online.
The Transient Reactor Test (TREAT) facility was designed and built in the late 1950s. The air-cooled reactor design incorporates fuel composed of highly enriched uranium dispersed in graphite with a 10 000:1 carbon-to-uranium atom ratio to provide a very fast-acting highly negative temperature coefficient of reactivity. The reactor utilizes a forced-air-cooling system for decay heat removal, with a primary function of reducing the time at temperature (oxidation) of the reactor fuel cladding. The simple design with lack of a cooling system pressure boundary provides relatively easy access for instrumentation and experiments. The large thermal mass of the reactor and the simple design allow for high-power transients approaching 18 000 MW in an inherently safe manner. The simple design has allowed TREAT to operate successfully for 35 years before being placed in standby in 1994 and subsequently restarted in 2017 after more than 20 years of standby to continue the transient fuel testing mission in the United States. This technical note addresses the reactor design and experiment capabilities.
