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Division Spotlight
Operations & Power
Members focus on the dissemination of knowledge and information in the area of power reactors with particular application to the production of electric power and process heat. The division sponsors meetings on the coverage of applied nuclear science and engineering as related to power plants, non-power reactors, and other nuclear facilities. It encourages and assists with the dissemination of knowledge pertinent to the safe and efficient operation of nuclear facilities through professional staff development, information exchange, and supporting the generation of viable solutions to current issues.
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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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.
Zoltán István Böröczki, Boglárka Babcsány, János Endre Maróti, Máté Szieberth
Nuclear Science and Engineering | Volume 197 | Number 8 | August 2023 | Pages 1545-1563
Technical papers from: PHYSOR 2022 | doi.org/10.1080/00295639.2023.2167469
Articles are hosted by Taylor and Francis Online.
Most of the codes available for homogenized group constant generation for deterministic transport calculations apply the approximation of scalar flux weighting during energy group condensation of higher-order anisotropic scattering matrices. In this paper, we point out the bias caused by scalar flux weighting of linearly anisotropic scattering matrices in the result of SP3 and S12 calculations. An infinite pin cell was homogenized with Serpent 2 and ERANOS ECCO to compare group constants with different energy group condensation options. Serpent 2 applies scalar flux while ERANOS ECCO performs current weighting of the linearly anisotropic scattering matrices. Three simple reactor models were built assuming different core sizes using standard rectangular assemblies with 15 ×15 fuel pins to analyze the effect of the various weighting options. Diffusion, SP3, and S12 calculations were performed for the three models using group constants generated with Serpent 2 and ERANOS ECCO. The effect of scalar flux weighting of linearly anisotropic scattering matrices in higher-order transport calculations is shown by comparing the decrease in reactivity due to the decreased reactor size and the assembly power distribution to reference results obtained with Serpent 2 Monte Carlo calculations. Analogous results were observed during the extension of our investigations to a VVER-440 benchmark and the Budapest University of Technology and Economics (BME) Training Reactor. We also studied the effect of increasing the number of groups in these examples. Neglecting higher than linearly anisotropic scattering and indirect application of diffusion coefficients in higher-order transport calculations is advised with few-group structures if angular flux-moment spectra-weighted higher-order scattering matrices cannot be generated. Although in few-group calculations, it can lead to more accurate higher-order transport solutions than applying scalar flux–weighted linearly anisotropic scattering matrices, by increasing the number of energy groups, the distorting effect of scalar flux weighting can also be decreased.
