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Division Spotlight
Nuclear Criticality Safety
NCSD provides communication among nuclear criticality safety professionals through the development of standards, the evolution of training methods and materials, the presentation of technical data and procedures, and the creation of specialty publications. In these ways, the division furthers the exchange of technical information on nuclear criticality safety with the ultimate goal of promoting the safe handling of fissionable materials outside reactors.
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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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.
Masao Yamanaka, Cheol Ho Pyeon
Nuclear Science and Engineering | Volume 193 | Number 4 | April 2019 | Pages 404-416
Technical Paper | doi.org/10.1080/00295639.2018.1525978
Articles are hosted by Taylor and Francis Online.
To elucidate the accuracy of benchmarks of criticality at the Kyoto University Critical Assembly (KUCA), uncertainty analysis is conducted for manufacturing tolerances in highly enriched uranium (HEU) plates and modeling of core configurations in addition to nuclear data. For evaluation of eigenvalue bias, eigenvalue calculations are conducted using MCNP6.1 and SCALE6.2/KENO-VI together with ENDF/B-VII.1. The modeling of reference core configurations and material properties with average values is validated through a comparison between calculated and measured results. The uncertainty induced by nuclear data is evaluated with SCALE6.2/TSUNAMI-3D together with ENDF/B-VII.1 for sensitivity calculations and 56groupcov.7.1 for the covariance matrix. In the breakdown of the uncertainty induced by nuclear data, the impact of 235U shows significant dominance, about 900 pcm in hard and soft spectrum cores. Furthermore, uncertainty evaluation by manufacturing tolerances in HEU plates and reproducibility of control rod positions demonstrates that the impact of variation on measured reactivity is minor. Through experimental analyses, the index of accuracy in benchmark experiments of criticality is conducive to the reliability of benchmarks at KUCA.