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
Radiation Protection & Shielding
The Radiation Protection and Shielding Division is developing and promoting radiation protection and shielding aspects of nuclear science and technology — including interaction of nuclear radiation with materials and biological systems, instruments and techniques for the measurement of nuclear radiation fields, and radiation shield design and evaluation.
Meeting Spotlight
International Conference on Mathematics and Computational Methods Applied to Nuclear Science and Engineering (M&C 2025)
April 27–30, 2025
Denver, CO|The Westin Denver 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
Apr 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
June 2025
Nuclear Technology
May 2025
Fusion Science and Technology
Latest News
Sam Altman steps down as Oklo board chair
Advanced nuclear company Oklo Inc. has new leadership for its board of directors as billionaire Sam Altman is stepping down from the position he has held since 2015. The move is meant to open new partnership opportunities with OpenAI, where Altman is CEO, and other artificial intelligence companies.
Lambert H. Fick, Elia Merzari, Yassin A. Hassan
Nuclear Technology | Volume 208 | Number 3 | March 2022 | Pages 539-561
Technical Paper | doi.org/10.1080/00295450.2021.1930456
Articles are hosted by Taylor and Francis Online.
We present results for a direct numerical simulation study of isothermal incompressible flow in a regularly packed pebble-bed domain with a bounding wall. We focus specifically on the near-wall behavior of the flow. Our simulation is carried out at a Reynolds number of 9308 to facilitate cross verification with available high-fidelity data. To reduce the required time to achieve statistically stationary results, we implemented an ensemble-averaging scheme that allowed for multiple simulation runs to be carried out concurrently. The close packing of the spheres in the domain causes significant acceleration effects in the domain, which result in boundary layer detachment and reattachment. Presented results include selected first- and second-order turbulence statistics, as well as selected terms of the turbulent kinetic energy transport equation. The acceleration effects in the near-wall region of the domain cause negative production of turbulent kinetic energy. The presented data may be useful for benchmarking Reynolds-averaged Navier-Stokes–based simulations of pebble beds.