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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.
2021 Student Conference
April 8–10, 2021
North Carolina State University|Raleigh Marriott City Center
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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ANS Board of Directors votes to retire outdated position statements
The American Nuclear Society’s Board of Directors on November 19 voted to retire several outdated position statements, as requested by the Public Policy Committee. Among them are Position Statements #37 and #63, dating from 2010, which have been retired for lacking policy recommendations and for being redundant, as other position statements exist with language that better articulates the Society’s stance on those topics.
Wadim Jaeger, Wolfgang Hering
Nuclear Science and Engineering | Volume 193 | Number 1 | January-February 2019 | Pages 160-170
Technical Paper – Selected papers from NURETH 2017 | dx.doi.org/10.1080/00295639.2018.1493855
Articles are hosted by Taylor and Francis Online.
The heat transfer in liquid metal–cooled rod bundles is modeled with a knowledge-based best-estimate system code. Thereby, the focus is on the heat transfer enhancement due to flow perturbations. These perturbations are caused by local geometrical variations, such as sudden expansions and contractions, in the flow channel. The accurate calculation of the heat transfer is important for the safety demonstration of, e.g., subassemblies. Safety-related parameters, such as fluid and wall temperature, have to satisfy certain limits during normal and off-normal operation as well as during accidents. Up to now, fully developed flow is assumed for heat transfer in liquid metal–cooled rod bundles. The effects of local heat transfer enhancements were ignored in best-estimate system codes. The currently used empirical heat transfer models are functions of the Péclet number only. Several experimental and numerical investigations show that flow perturbations induce higher heat transfer due to increased turbulences, accelerated flows, and secondary motions. In this paper, the effects of the entrance region and the presence of spacer grids on the heat transfer are investigated. Empirical models for that are selected and applied. These empirical models are functions of the Péclet number, the geometrical perturbation, and the distance from the perturbation in the flowing direction. The calculated heat transfer coefficients at the bundle entrance and in the vicinity of spacer grids are twice as high compared to bare rod bundles under a fully developed flow condition without any flow perturbation. Because of the higher heat transfer, lower wall temperatures are to be expected. This provides additional safety margins during normal and off-normal operation as well as during accidents. Furthermore, the considerable increase of heat transfer shows that existing perturbations have to be considered to obtain accurate and reliable results.