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
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.
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
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.
M. Andersson, D. Blanchet, H. Nylén, R. Jacqmin
Nuclear Science and Engineering | Volume 185 | Number 2 | February 2017 | Pages 277-293
Technical Paper | doi.org/10.1080/00295639.2016.1272359
Articles are hosted by Taylor and Francis Online.
Advanced sodium-cooled fast reactors with improved safety features such as the French Advanced Sodium Technological Reactor for Industrial Demonstration (ASTRID) CFV (French acronym of Coeur à Faible effet de Vide sodium, meaning low sodium void effect core) core concept are characterized by an axial heterogeneous core that will present a challenge for the homogenization procedures used today, taking into account all the different axial material transitions. Reliable modeling of the control rod and accurate prediction of the control rod worth are essential to determining the shutdown margins and to ensuring safe operation.
In this work (part II of two companion papers), two different homogenization schemes are compared. One is based on the traditional reactivity-equivalence procedure in two dimensions, and the other is a newly implemented three-dimensional (3-D) version of the reactivity-equivalence procedure, with approximations based on the results in the companion paper. The deterministic results are compared with a Monte Carlo reference.
Both cross-section sets from the two homogenization schemes yielded results within the requested ±5% error margin in reactivity. The largest discrepancy was found for the classical procedure for the case with a slightly inserted control rod (normal operating conditions). Both cross-section sets yielded similar power profiles in the fuel subassembly neighboring the control rod within the 2σ Monte Carlo standard deviation. Neither of the cross-section sets was able to predict the large gradients in capture rates close to the internal control rod interfaces.
The study showed that the traditional two-dimensional (2-D) reactivity-equivalence procedure produces homogenized cross sections that yield reliable results in a CFV-type core. One exception from this was found for slightly inserted control rods, where the effect of the follower-absorber interface could not be fully captured by the 2-D scheme, and for such cases, 3-D modeling is recommended.