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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.
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ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
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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
First astatine-labeled compound shipped in the U.S.
The Department of Energy’s National Isotope Development Center (NIDC) on March 31 announced the successful long-distance shipment in the United States of a biologically active compound labeled with the medical radioisotope astatine-211 (At-211). Because previous shipments have included only the “bare” isotope, the NIDC has described the development as “unleashing medical innovation.”
M. R. Mendelson
Nuclear Science and Engineering | Volume 28 | Number 1 | April 1967 | Pages 127-132
Technical Paper | doi.org/10.13182/NSE67-A18675
Articles are hosted by Taylor and Francis Online.
The sensitivity of three thermal-energy model problems to anisotropic scattering was investigated by comparing double P5 solutions with P3 and P1 scattering expansions. Results indicate that P3 scattering effects can be significant in the calculation of absorption rates in certain sensitive plane-geometry configurations. Monte Carlo calculations were also performed for one of these problems, using two different anisotropic scattering representations: the transport approximation; and a “histogram” kernel, which match the first two and four Legendre moments of the scattering kernel, respectively. The transport approximation was found to give discrepancies of eight to nine percent in thermal absorption rates, and it is concluded that this scattering representation can lead to serious errors in Monte Carlo calculations.
