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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.
Constantine P. Tzanos
Nuclear Technology | Volume 147 | Number 2 | August 2004 | Pages 181-190
Technical Paper | Thermal Hydraulics | doi.org/10.13182/NT04-A3524
Articles are hosted by Taylor and Francis Online.
Benchmark experiments simulating flows in a pressurized water reactor rod bundle were analyzed to evaluate the performance of a state-of-the-art computational fluid dynamics (CFD) code. For the simulation of turbulence a number of standard k-[curly epsilon] models were used. Away from components that cause significant flow deflections, the difference between mean velocity predictions and measurements is within the experimental error. Near such components there is significant discrepancy between velocity predictions and measurements. Even in rod bundles without flow deflectors, the turbulence predictions of standard k-[curly epsilon] models show significant discrepancy with measurements. These discrepancies are greater near components that cause flow deflections. Turbulence generated by vanes on spacer grids significantly enhances thermal mixing. To improve the fidelity of CFD simulations of flows in reactor rod bundles, the development of Reynolds averaging of the Navier-Stokes equations turbulence models based on such flows is needed.