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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.
W. M. Lopez, J. R. Beyster
Nuclear Science and Engineering | Volume 12 | Number 2 | February 1962 | Pages 190-202
Technical Paper | doi.org/10.13182/NSE62-A26058
Articles are hosted by Taylor and Francis Online.
Neutron diffusion parameters in water have been measured at 26.7°C with the pulsed neutron technique. The results are 210 ± 1 µsec for the neutron mean lifetime, 37,503 ± 366 cm2 sec−1 for the average diffusion coefficient, and 5116 ± 776 cm4 sec−1 for the diffusion cooling constant. From these values the thermal absorption cross section of hydrogen and the thermal diffusion length in water can be inferred to be 325 ± 2 mb and 2.83 ± 0.02 cm, respectively. With a pulsed high-intensity neutron source provided by an electron linear accelerator, neutron lifetime measurements were performed on small and large water samples with values of the geometrical buckling from 0.014 cm−2 to 0.59 cm−2. Effects of harmonic modes in the large water geometries, which were determined by measurements of the time-dependent spatial flux distributions resulting from an external pulsed source of fast neutrons, were found to be adequately predictable with simple diffusion theory.