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Division Spotlight
Operations & Power
Members focus on the dissemination of knowledge and information in the area of power reactors with particular application to the production of electric power and process heat. The division sponsors meetings on the coverage of applied nuclear science and engineering as related to power plants, non-power reactors, and other nuclear facilities. It encourages and assists with the dissemination of knowledge pertinent to the safe and efficient operation of nuclear facilities through professional staff development, information exchange, and supporting the generation of viable solutions to current issues.
Meeting Spotlight
ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
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
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.”
P. Köhler, J. Ligou
Nuclear Science and Engineering | Volume 54 | Number 3 | July 1974 | Pages 357-360
Technical Note | doi.org/10.13182/NSE74-A23426
Articles are hosted by Taylor and Francis Online.
Calculations of neutron streaming in gas-cooled fast reactors (GCFR) designed with fuel pins have not been made properly up to now. The usual approach for computing the diffusion coefficients fails for two reasons: (a) the voided region is located at the cell boundary, and (b) the pitch is such that two-dimensional infinite gaps extend through the reactor. For an infinite lattice, the diffusion coefficient will diverge, which means that, in principle, the diffusion theory is no longer valid. This fact has been more or less forgotten because most theories assume cylindrical cells and therefore remove this difficulty artificially. Introducing the real size of the reactor at the beginning, a new theory of the streaming, which generalizes the usual approach is developed; it appears as a buckling dependent term in the diffusion coefficient which diverges slowly for an infinite lattice. Fortunately, this term is small for usual reactor sizes, and one may, therefore, continue to use diffusion theory for practical calculations. The numerical applications to GCFR lattices show that the streaming was underestimated in the past.