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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 Standards Committee is responsible for the development and maintenance of voluntary consensus standards that address the design, analysis, and operation of components, systems, and facilities related to the application of nuclear science and technology. Find out What’s New, check out the Standards Store, or Get Involved today!
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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.
E. E. Gross, J. H. Marable
Nuclear Science and Engineering | Volume 7 | Number 4 | April 1960 | Pages 281-291
Technical Paper | doi.org/10.13182/NSE60-A25718
Articles are hosted by Taylor and Francis Online.
The theory of the stable period of a fixed-fuel reactor is developed by considering the gross conservation of neutrons in the reactor. The resulting inhour equation directly relates the dynamic multiplication factor to the actual delayed-neutron fractions. It is shown that the inhour equation may also be written in terms of the conventional multiplication factor if so-called “effective” delayed neutron fractions are introduced. The results are shown to be in agreement with those of the perturbation method.