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
Isotopes & Radiation
Members are devoted to applying nuclear science and engineering technologies involving isotopes, radiation applications, and associated equipment in scientific research, development, and industrial processes. Their interests lie primarily in education, industrial uses, biology, medicine, and health physics. Division committees include Analytical Applications of Isotopes and Radiation, Biology and Medicine, Radiation Applications, Radiation Sources and Detection, and Thermal Power Sources.
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!
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Apr 2025
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Nuclear Science and Engineering
June 2025
Nuclear Technology
Fusion Science and Technology
May 2025
Latest News
Argonne’s METL gears up to test more sodium fast reactor components
Argonne National Laboratory has successfully swapped out an aging cold trap in the sodium test loop called METL (Mechanisms Engineering Test Loop), the Department of Energy announced April 23. The upgrade is the first of its kind in the United States in more than 30 years, according to the DOE, and will help test components and operations for the sodium-cooled fast reactors being developed now.
Samuel E. Bays, Joseph Nielsen, Joshua Cogliati, Charles Wemple
Nuclear Technology | Volume 208 | Number 5 | May 2022 | Pages 811-821
Technical Paper | doi.org/10.1080/00295450.2021.1980320
Articles are hosted by Taylor and Francis Online.
The neutronics software, HELIOS, was validated in 2015 for performing core reload design and safety analysis of the Advanced Test Reactor. However, when HELIOS was benchmarked against historic fission-wire measurements (i.e., zero-power full-core measurements), a statistically resolved calculation-to-measurement bias was discovered. The azimuthal power along each fuel plate computed by HELIOS has consistently shown to underpredict measurements made by fission wires in historic zero-power tests near the fuel element side plates.
It was hypothesized during the HELIOS software validation work that this bias is attributable to local moderation in coolant vents in the side plates axially just above and below the fission wires on the fuel plate edges. This work used detailed MCNP and MC21 models of the side plate vents to test this hypothesis. By comparing the average azimuthal biases between HELIOS and two-dimensional and three-dimensional (3-D) MCNP models and a 3-D MC21 model, it was found that the HELIOS azimuthal bias is not due to the measurement.
