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
Materials Science & Technology
The objectives of MSTD are: promote the advancement of materials science in Nuclear Science Technology; support the multidisciplines which constitute it; encourage research by providing a forum for the presentation, exchange, and documentation of relevant information; promote the interaction and communication among its members; and recognize and reward its members for significant contributions to the field of materials science in nuclear technology.
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
Y. S. Na, W. Lee, S. Song
Nuclear Technology | Volume 206 | Number 4 | April 2020 | Pages 544-553
Technical Paper | doi.org/10.1080/00295450.2019.1657328
Articles are hosted by Taylor and Francis Online.
This study observed the breakup of helium stratification, which was 30 vol % helium in air and formed in the upper part of a cylindrical test vessel with a height of 9.5 m and a diameter of 3.4 m. An air jet collided with the density interface on which the restoring buoyancy of the helium and the disturbing inertial force of the impinging jet were balanced. The Reynolds number of the jet was about 20 000 at the exit of a vertical pipe located 3.0 m below the initial stratification. The helium concentration was measured by sampling the gas mixture with thermal conductivity analyzers. Particle image velocimetry (PIV) visualized the flow field of the jet impinging on the density interface. The density interface was clearly shown by the binary images generated from the number of tracer particles for the PIV. From the continuous impinging jet, the density interface gradually moved upward. The interaction Froude number, which was defined by the ratio of the inertial force of the impinging jet to the buoyancy of a light gas on the density interface, was about unity calculated by the helium concentration and the flow visualization. The density interface went up to 0.0002 m/s.
