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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.
R. K. Lane, L. W. Nordheim, J. B. Sampson
Nuclear Science and Engineering | Volume 14 | Number 4 | December 1962 | Pages 390-396
Technical Paper | doi.org/10.13182/NSE62-A26247
Articles are hosted by Taylor and Francis Online.
The problem of resonance absorption is investigated for materials in which the absorber is lumped in small grains imbedded in a matrix of moderator. The point of departure is to take the grains themselves as the fundamental elements in heterogeneous geometry. It is important to treat correctly the mutual shielding between the grains, that is, the Dancoff correction. Introduction of this correction solves immediately the case of macroscopically homogeneous assemblies. The result can be expressed in terms of “shielded” cross sections for the lumped absorber. Utilization of this concept permits also the treatment of additional macroscopic heterogeneities. Existing calculational methods can be employed if the macroscopic heterogeneities are treated with the help of the equivalence relations, and this procedure permits an adequate comparison between the grain structured and homogeneous compounds. Numerical examples are given in Section IV. The average shielding is nearly linear in the grain size. For grains of ThO2 in a graphite matrix, the reduction is about 15% for grains of 0.06 cm diam. On the other hand, the temperature derivative of the resonance integral is increased slightly, particularly at higher temperatures. One can, therefore, either maintain the Doppler coefficient of reactivity with a reduced resonance absorption or increase the Doppler coefficient for the same resonance absorption.