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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.
Constantine P. Tzanos, Dean R. Pedersen
Nuclear Technology | Volume 95 | Number 3 | September 1991 | Pages 253-265
Technical Paper | Fission Reactor | doi.org/10.13182/NT91-A34575
Articles are hosted by Taylor and Francis Online.
Two large-scale decay heat removal experiments are analyzed to support the validation of the thermal-hydraulic code COMMIX and the design of advanced liquid metal reactors (ALMRs). The experiments were performed in the reactor vessel auxiliary cooling system (RVACS) test facility, which provides a scaled simulation of the passive decay heat removal paths of a pool ALMR with the core simulated by electrically heated rods. The first experiment simulates a transient where decay heat is removed by the direct reactor auxiliary cooling system (DRACS) only. In the second experiment, heat is removed by both the DRACS and RVACS. These experiments are characterized by (a) three-dimensional in-pool sodium flows of very low velocity, driven by sodium density differences, (b) a significant pool thermal stratification, and (c) a complex heat sink. In the DRACS test, the thermal stratification occurs in the hot pool while the cold pool is nearly isothermal. When both systems are in operation the thermal stratification of the hot pool is drastically reduced while the upper third of the cold pool is significantly stratified. The COMMIX predictions for the sodium pool temperatures and the air outlet temperature of the RVACS are in good agreement with measurements.