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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.”
Mohamed Belhadj, Tunc Aldemir, Richard N. Christensen
Nuclear Technology | Volume 95 | Number 1 | July 1991 | Pages 95-102
Technical Paper | Heat Transfer and Fluid Flow | doi.org/10.13182/NT91-A34571
Articles are hosted by Taylor and Francis Online.
Plate-type research reactor cores have involute or rectangular coolant channels with channel gap size in the range 2 ≤ d ≤ 5 mm. Heat transfer under fully developed nucleate boiling (FDNB) and low-velocity (<0.15 m/s) upward flow conditions is important in accident situations where core cooling may be by natural convection. Using data from previous experimental work with 2 ≤ d ≤ 4 mm rectangular channels, it is shown that (a) wall superheat (ΔTsat) in thin channels under FDNB decreases with increasing probability of bubble contact, (b) ΔTsat is a function of the bubble departure diameter Db as well as d, and (c) ΔTsat can be significantly overestimated by the FDNB correlations that are conventionally used in plate-type research reactor analysis but that are based on higher pressure and larger d flow data and that predict ΔTsat as a function of local channel heat flux and pressure only (e.g., as in the Jens-Lottes and Thom correlations). A new FDNB correlation is proposed that represents the bubble contact mechanism through the dimensionless number (d — cDb)/d, where c is a fitting parameter that accounts for the statistical aspects of bubble formation and contact. The ΔTsat predictions of the new correlation agree with the experimental data to within 16% and approach those obtained from the Jens-Lottes correlation with decreasing Db/d.
