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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.
Masaoki Komata
Nuclear Science and Engineering | Volume 47 | Number 4 | April 1972 | Pages 489-493
Technical Note | doi.org/10.13182/NSE72-A22442
Articles are hosted by Taylor and Francis Online.
The perturbation formula of Usachev-Gandini for a ratio of reaction rates is newly explained by (a) a formal functional treatment of perturbation theory and (b) the variational principle. At the outset a time-dependent problem is considered, and a perturbation formula of a reaction number ratio is obtained. In a static problem this formula directly turns to a formula of a reaction rate ratio which reduces to the Usachev-Gandini formula when an adiabatic approximation is introduced. It is shown that there is no need to solve iterative equations of successive neutron generations.
