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
Fuel Cycle & Waste Management
Devoted to all aspects of the nuclear fuel cycle including waste management, worldwide. Division specific areas of interest and involvement include uranium conversion and enrichment; fuel fabrication, management (in-core and ex-core) and recycle; transportation; safeguards; high-level, low-level and mixed waste management and disposal; public policy and program management; decontamination and decommissioning environmental restoration; and excess weapons materials disposition.
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
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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
Daniel L. P. Watson, Ronald Daryll E. Gatchalian, Hui-Yu Hsieh, Pramatha Bhat, Pavel V. Tsvetkov
Nuclear Technology | Volume 211 | Number 1 | April 2025 | Pages S49-S61
Research Article | doi.org/10.1080/00295450.2024.2423144
Articles are hosted by Taylor and Francis Online.
A fast spectrum surface fission power microreactor for lunar deployment is conceptualized and modeled utilizing the primary design drivers of the SpaceX Falcon Heavy mass constraints, a 10-year operation lifetime, high-assay low-enrichment uranium fuel enrichment, a 100-kW(electric) system power rating, and a Stirling conversion cycle. The reactor is demonstrated to remain subcritical during launch accidents resulting in oceanic submersion and throughout control system failures in the highest reactivity positions. Neutron shielding requirements for the high-leakage core were satisfied with 40 cm of natural enrichment LiH at 100% solid density, while photon shielding for the reactor at full power exceeded the in the National Aeronautics and Space Administration scope of work design requirement 18960 DR-3 of 5 rem·y−1 at rates of 30 rem·y−1 for a 1-km standoff. A conversion cycle was approximated using an experimental carbon-carbon thermal radiator coupled with published analytical and experimental results for free-piston Stirling systems.
