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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.
H. L. McMurry, L. J. Gannon, W. A. Hestir
Nuclear Science and Engineering | Volume 15 | Number 4 | April 1963 | Pages 438-450
Technical Paper | doi.org/10.13182/NSE63-A26461
Articles are hosted by Taylor and Francis Online.
The methods presented in the accompanying paper for computing partial differential scattering cross sections are evaluated by comparing calculated results with experimental results for methane and propane, and by comparing results on a hypothetical OH molecule of the more approximate methods with the most rigorous ones. The method which treats rotations quantum mechanically gives good agreement with experiments on methane and can be considered as rigorous. The method which treats rotations classically, vibrations by quantum mechanics, and averages over orientation exactly also agrees well with methane experiments, except for scattering at forward angles and low neutron energies where the energy exchanges are comparable to the rotational level spacings. It is used as a standard of comparison for calculations on the OH molecule. The Krieger-Nelkin method, which also treats rotations classically but averages over orientation by inserting average values of functions of the Eulerian angles wherever they appear, works very well at low neutron energies. Calculations on OH show that when the characteristic vibrational energy is high, but much lower than the incident neutron energy, the K.N. averaging breaks down. The short collision time method of treating low energy vibrations is impractical because too many terms in the required series expansion are needed to give good results. The method which treats low energy vibrations classically is very promising. It gives very good results when the characteristic vibrational energies are low, and is better than the K.N. when the characteristic energy is high, but much lower than the neutron energy. It is indicated how the third and fifth methods can be used to treat liquids and solids when the atomic motions can be described by simple dynamical models.