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Meeting Spotlight
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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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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The U.S. Million Person Study of Low-Dose-Rate Health Effects
There is a critical knowledge gap regarding the health consequences of exposure to radiation received gradually over time. While there is a plethora of studies on the risks of adverse outcomes from both acute and high-dose exposures, including the landmark study of atomic bomb survivors, these are not characteristic of the chronic exposure to low-dose radiation encountered in occupational and public settings. In addition, smaller cohorts have limited numbers leading to reduced statistical power.
Dong Hun Lee, Dong-Ha Lee, Jae Jun Jeong, Kyung Doo Kim
Nuclear Technology | Volume 198 | Number 1 | April 2017 | Pages 79-84
Technical Note | doi.org/10.1080/00295450.2017.1287503
Articles are hosted by Taylor and Francis Online.
Frictional pressure drop (also called wall drag) for a two-phase flow has been investigated for several decades. However, the two-phase frictional pressure drop models in the state-of-the-art thermal-hydraulic system codes are significantly different from each other, especially in the way to partition the wall friction force of liquid and vapor phases in the two-fluid momentum equations. This may lead to unphysical results in some flow conditions.
In this technical note, the two-phase wall frictional pressure drop models in the RELAP5/MOD3, TRACE V5, and SPACE codes are discussed in terms of the wall friction partition into the liquid and vapor momentum equations. To show the effect of different partition methods in the three codes, we simulated air-water bubbly flows in a horizontal pipe. The results of the calculations show that the partition method has a direct effect on the relative velocity of the two phases, and it may lead to unphysical behaviors of dispersed bubbles and droplets. It is strongly recommended to revisit the two-fluid formulation and the partition method of two-phase wall drag in the state-of-the-art system codes.