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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.
Chae Y. Yang, Nam Z. Cho
Nuclear Science and Engineering | Volume 101 | Number 3 | March 1989 | Pages 243-258
Technical Paper | doi.org/10.13182/NSE89-A23612
Articles are hosted by Taylor and Francis Online.
A nonlinear reactor model is developed taking into account several feedback effects, such as moderator and fuel temperatures, xenon absorption, and soluble boron concentration, through energy balance relations in the core. The resulting equation belongs to a class of nonlinear boundary value problems, and it is shown through bifurcation theory that there may exist multiple steady-state solutions for a range of parameters that correspond to various design and operating conditions. Solutions are obtained numerically for ranges of the parameters by the arc-length continuation method in combination with Newton’s method. Stability analysis is also applied to each solution to investigate whether the solution is stable or not. When the stable and unstable regions of the steady-state solutions are plotted for a wide range of the parameters, we can choose a range of the reactor design and operating conditions such that the reactor does not encounter unstable situations.