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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.
M. L. Williams
Nuclear Science and Engineering | Volume 108 | Number 2 | June 1991 | Pages 150-171
Technical Paper | doi.org/10.13182/NSE91-A23814
Articles are hosted by Taylor and Francis Online.
Perturbation theory has been used to obtain expressions for the reactivity associated with deformation of a thin plate in a critical reactor. The methodology uses reactivity worth coefficients computed for a homogeneous system to assess the effect of changes in the shape and composition of heterogeneous components such as structural and fuel elements. The resulting expressions are applied to two heuristic sample problems consisting of a uniform plate displacement and a sinusoidal plate bowing deformation. In the former case, the perturbation results agree well with exact analytical calculations. The second case provides useful analytical approximations that illustrate how the deformation reactivity is expected to vary with the fractional plate elongation, the location of the plate in the core, and other parameters.