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Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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The RAIN scale: A good intention that falls short
Radiation protection specialists agree that clear communication of radiation risks remains a vexing challenge that cannot be solved solely by finding new ways to convey technical information.
Earlier this year, an article in Nuclear News described a new radiation risk communication tool, known as the Radiation Index, or, RAIN (“Let it RAIN: A new approach to radiation communication,” NN, Jan. 2025, p. 36). The authors of the article created the RAIN scale to improve radiation risk communication to the general public who are not well-versed in important aspects of radiation exposures, including radiation dose quantities, units, and values; associated health consequences; and the benefits derived from radiation exposures.
Xia Wang, Xiaodong Sun
Nuclear Technology | Volume 167 | Number 1 | July 2009 | Pages 71-82
Technical Paper | NURETH-12 / Thermal Hydraulics | doi.org/10.13182/NT09-A8852
Articles are hosted by Taylor and Francis Online.
In the study of gas-liquid two-phase flows, one challenge is to describe the dynamic changes in flow structure, which can be considerably affected by bubble coalescence and/or disintegration in addition to bubble nucleation and condensation processes. The interfacial structure, to a first-order approximation, may be characterized by the void fraction and a geometric parameter named "interfacial area concentration," the evolution of which can be modeled by an interfacial area transport equation (IATE). A one-group IATE has been developed for bubbly flows in the literature, accounting for three dominant mechanisms: coalescence of bubbles due to random bubble collisions driven by turbulence, coalescence of bubbles due to wake entrainment, and disintegration of bubbles caused by turbulent-eddy impact. The current study is aimed at examining the capability of a computational fluid dynamics code, namely, FLUENT, with the one-group IATE implemented, in predicting two-phase-flow phase distributions. Simulations using the Eulerian multiphase model in FLUENT 6.2.16 have been performed for adiabatic upward bubbly flows in a pipe of 50.8-mm inner diameter with a range of void fractions from 4.9 to 23.1%. The predicted phase distributions yield satisfactory agreement with available experimental data, demonstrating that FLUENT with the IATE can provide a valuable simulation tool for two-phase bubbly flows.
