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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.
Wen-Shan Lin, Bau-Shei Pei, Chien-Hsiung Lee, I. A. Mudawwar
Nuclear Technology | Volume 85 | Number 2 | May 1989 | Pages 213-226
Technical Paper | Heat Transfer and Fluid Flow | doi.org/10.13182/NT89-A34242
Articles are hosted by Taylor and Francis Online.
A theoretical critical heat flux (CHF) model based on microlayer dryout and Helmholtz instability for subcooled tube flow under pressurized water reactor operation conditions is first extended to the conditions of saturated low-quality flow. Then the applicability of this extended theoretical CHF model to rod bundles is evaluated. The effects of grid spacers, cold wall, and axial heat flux nonuniformity on bundle CHFs are investigated. The extended CHF model is very accurate when compared with three other well-known CHF correlations on a data base of round tube CHF. In the simple case with uniform axial heat flux distribution, simple grid spacers, and no guide tubes in bundles, the theoretical CHF model gives good results. In other more complex cases, the cold-wall effects due to the existence of guide tubes, the effects of mixing vane grids, and the effects of nonuniform axial heat flux distributions on CHF are significant. The present model generally gives satisfactory results when compared with ∼1400 bundle CHF experimental data points although corrections for grid spacers, cold wall, and axial heat flux have not yet been considered.