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Division Spotlight
Thermal Hydraulics
The division provides a forum for focused technical dialogue on thermal hydraulic technology in the nuclear industry. Specifically, this will include heat transfer and fluid mechanics involved in the utilization of nuclear energy. It is intended to attract the highest quality of theoretical and experimental work to ANS, including research on basic phenomena and application to nuclear system design.
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2025 ANS Annual Conference
June 15–18, 2025
Chicago, IL|Chicago Marriott Downtown
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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ANS announces 2025 Presidential Citations
One of the privileges of being president of the American Nuclear Society is awarding Presidential Citations to individuals who have demonstrated outstanding effort in some manner for the benefit of ANS or the nuclear community at large. Citations are conferred twice each year, at the Annual and Winter Meetings.
ANS President Lisa Marshall has named this season’s recipients, who will receive recognition at the upcoming Annual Conference in Chicago during the Special Session on Tuesday, June 17.
Xingang Zhao, Koroush Shirvan, Yingwei Wu, Mujid S. Kazimi
Nuclear Technology | Volume 196 | Number 3 | December 2016 | Pages 553-567
Technical Paper | doi.org/10.13182/NT16-45
Articles are hosted by Taylor and Francis Online.
With the objective of providing long-term energy supply via actinide breeding and burning, the next-generation boiling water reactor (BWR) design, the Hitachi’s resource-renewable BWR (RBWR), has been proposed. Unlike a traditional square lattice BWR fuel bundle, the RBWR bundles are shorter with hexagonal tight lattice arrangement and heterogeneous axial fuel zoning. The RBWR’s different core geometry combined with the higher power-to-flow ratio and void fraction necessitates the reexamination of the standard BWR thermal-hydraulic models.
For the prediction of dryout, the previously derived best-estimate empirical correlation showed significant scatter when compared to experimental data within its calibration database. In this work, the correlation is further calibrated and improved by supplementing tight bundle data with relevant critical power data for tubes and annuli to better quantify the effects of various parameters and by incorporating subchannel-level results to account for intra-assembly flow mixing. Another approach using the mechanistic three-field model is also investigated, and the minimum critical power ratio of the RBWR design is evaluated.
For the prediction of void fraction, measurements and the three-field model in annular flow regime reveal that the common drift flux approaches tend to overestimate the void fraction at small hydraulic diameters. The void fraction dependence on hydraulic diameter below 10 mm requires further experimentation and high-fidelity mechanistic simulations.