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Conference Spotlight
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.
Jiyun Zhao, Pradip Saha, Mujid S. Kazimi
Nuclear Technology | Volume 158 | Number 2 | May 2007 | Pages 174-190
Technical Paper | Nuclear Reactor Thermal Hydraulics | doi.org/10.13182/NT07-A3834
Articles are hosted by Taylor and Francis Online.
The single hot-channel thermal-hydraulic stability model is expanded to investigate the effects of heat transport from fuel rods and to water rods on supercritical water-cooled reactor (SCWR) stability. Furthermore, the stability margin of the SCWR is compared with that of a typical boiling water reactor (BWR) by conducting a sensitivity study on operating conditions.The fuel thermal-dynamic effect is studied by coupling a lumped-parameter fuel model with the three-region coolant thermal-hydraulics model. It is found that the fuel heat capacity would dampen the oscillations in the coolant channel and therefore increase the stability of the system. Also, heating of the water rods, which could be allowed in the core, would improve single-channel stability.The stability sensitivity to power and flow rate conditions is analyzed for the U.S. reference SCWR design and compared with a typical BWR. The SCWR is found to be more sensitive to power and flow rate changes than the typical BWR. The water rod heating cannot significantly improve this sensitivity feature of the SCWR stability. The traditional stability measure of oscillation amplitude decay ratio does not capture the extent to which a stability margin exists in a particular design of the SCWR. The robustness of stability should be ascertained by examining accommodation of the potential variation and/or uncertainty about the nominal conditions.