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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
2024 ANS Winter Conference and Expo
November 17–21, 2024
Orlando, FL|Renaissance Orlando at SeaWorld
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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August 2024
Latest News
New laws offer nuclear industry incentives for existing power plant uprates
This year, the U.S. nuclear industry received a much-needed economic boost that could help preserve operating nuclear power plants and incentivize upgrades that extend their lifespan and power output.
Signed into law in 2022, the Inflation Reduction Act offers production tax credits (PTCs) for existing nuclear power plants and either PTCs or investment tax credits (ITCs) for new carbon-free generation. These credits could make power uprates—increasing the maximum power level at which a commercial plant may operate—a much more appealing option for utilities.
Martin A. Lopez de Bertodano, Jian-Feng Shi,Stephen G. Beus
Nuclear Science and Engineering | Volume 126 | Number 1 | May 1997 | Pages 108-114
Technical Paper | doi.org/10.13182/NSE97-A24462
Articles are hosted by Taylor and Francis Online.
New experimental data are obtained for pressure drop and entrainment for annular upflow in a vertical pipe. The 9.5-mm pipe has a hydraulic diameter similar to the subchannels in the fuel assemblies of water-cooled reactors. The test section has a length-to-diameter ratio of 440 to ensure fully developed annular flow. The pressure covers the range from 140 to 660 kPa. Therefore, the density ratio is varied by a factor of ∼4. This allows the investigation of the effect of pressure on the interfacial shear models. Gas superficial velocities between 25 and 126 m/s are tested, extending the range of previous data to higher gas velocities. The data are compared with well-known models for interfacial shear that represent the state of the art. Good results are obtained with the models by Wallis, and Henstock and Hanratty. When the model by Asali, Hanratty, and Andreussi is modified for the effect of pressure, the agreement is also good, and the data collapse with very little scatter. There is a close relationship between these models and mixing length theory such that the models may be viewed as correlations for the surface roughness. This points toward a more fundamental approach in terms of the interfacial structure.