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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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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.
Luisa F. Hansen, Calvin Wong, Ted T. Komoto, Bertram A. Pohl, Eugene Goldberg, Robert J. Howerton, Walter M. Webster
Nuclear Science and Engineering | Volume 72 | Number 1 | October 1979 | Pages 35-51
Technical Paper | doi.org/10.13182/NSE79-A19307
Articles are hosted by Taylor and Francis Online.
The neutron and gamma-ray leakage spectra from pulsed spheres having a radius equal to 1.0 mean-free-path (mfp) for 14-MeV neutrons in 232Th, 235U (with radii of 0.7 and 1.5 mfp), 228U (with radii of 0.8 and 2.8 mfp), and 239Pu (with radii of 0.7 and 1.25 mfp) were measured by using time-of-flight techniques. The neutron spectra were measured between 0.9 and 15 MeV using stilbene and NE-213 scintillators. For the gamma rays, the electron recoil spectra were measured between 0.35 and 8 MeV with the NE-213 detector only. Pulse-shape discrimination and flight paths of ∼10 m were used in these measurements. The measured spectra are compared with calculations carried out with TARTNP, a coupled neutron-photon Monte Carlo transport code. The Lawrence Livermore Laboratory ENDL (neutron and photon cross sections) and ENDF/B-IV libraries were used in these calculations. In the region between 10 and 15 MeV, the calculated neutron spectra are in good agreement with the measurements (±5%). The maximum discrepancy observed for the neutrons between 0.9 and 10 MeV is 30%. The notable exception is 232Th, where calculations carried out with the ENDF/B-IV underestimate by a factor of 2 the neutron emission between 5 and 10 MeV. The gamma-ray emission calculations were carried out only with ENDL because of its overall better representation of the neutron measurements; ENDL overestimates the gamma-ray production, with discrepancies ranging between 5 and 20%. However, use of the measured detector efficiency would reduce the maximum discrepancy to <13%. To facilitate the use of the neutron data for calculational purposes by other laboratories, an “experimental” one-dimensional neutron energy spectrum is given for each measurement.