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Conference Spotlight
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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Hash Hashemian: Visionary leadership
As Dr. Hashem M. “Hash” Hashemian prepares to step into his term as President of the American Nuclear Society, he is clear that he wants to make the most of this unique moment.
A groundswell in public approval of nuclear is finding a home in growing governmental support that is backed by a tailwind of technological innovation. “Now is a good time to be in nuclear,” Hashemian said, as he explained the criticality of this moment and what he hoped to accomplish as president.
Ikuo Kinoshita, Michio Murase, Yoichi Utanohara, Dirk Lucas, Christophe Vallée, and Akio Tomiyama
Nuclear Technology | Volume 187 | Number 1 | July 2014 | Pages 44-56
Technical Paper | Fission Reactors | doi.org/10.13182/NT13-32
Articles are hosted by Taylor and Francis Online.
A numerical study is presented to examine the effects on countercurrent flow limitation (CCFL) of the shape and size of hot leg models with a rectangular cross section. The CCFL was described in terms of Wallis parameters using the channel height H as the characteristic length. Numerical simulations, using the computational fluid dynamics software code FLUENT 6.3.26, were done for the air-water CCFL experiments carried out previously at Helmholtz-Zentrum Dresden-Rossendorf in a 1/3-scale hot leg model with a rectangular channel (H×W = 0.25×0.05 m2), and the results were compared with the air-water CCFL data obtained at Kobe University in a 1/5-scale hot leg model with rectangular cross section (H×W = 0.15×0.01 m2) and the results of simulations. It was found that both the height-to-width ratio and the size of the cross section affected the CCFL characteristics in the Wallis diagram. Comparison of CCFL characteristics in rectangular channels with those in circular channels showed that the hydraulic diameter Dh was a major cross-section geometry term influencing the CCFL characteristics. CCFL constants of the Wallis correlation were ∼0.61 on average for the range 0.05 m ≤ Dh ≤ 0.75 m but became small for Dh ≤ 0.0254 m, and these tendencies were well reproduced by the numerical simulations.