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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!
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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.
R. E. Chrien, H. I. Liou, M. J. Kenny, M. L. Stelts
Nuclear Science and Engineering | Volume 72 | Number 2 | November 1979 | Pages 202-215
Technical Paper | doi.org/10.13182/NSE79-A19464
Articles are hosted by Taylor and Francis Online.
The cross sections for neutron interactions with thorium targets were measured at several energies. Capture cross sections at 0.0253 eV and at 2 and 24.3 keV were measured by activation techniques. Transmission measurements were made from 10 to 100 eV, and capture cross sections were determined from 0.03 to 15 eV by recording discrete lines for the (n,γ) spectrum. The measured thermal cross section is 7.41 ± 0.08 b, at 2 keV the cross section is 1.96 ± 0.10 b, and at 24.3 keV it is 0.540 ± 0.014 b. These values are reported relative to an assumed 231Pa branching ratio of 38.5% for the 311-keV gamma ray, and they do not include the branching ratio error. The results are fitted to R-matrix parameters. The transmission and (n,γ) measurements lead to parameters that give a somewhat higher epithermal capture than previously expected in thorium. This result brings the differential data into better agreement with experiments on subcritical assemblies.