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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.
Evgeny Ivanov, Tatiana Ivanova, Sophie Pignet
Nuclear Science and Engineering | Volume 178 | Number 3 | November 2014 | Pages 363-376
Technical Paper | doi.org/10.13182/NSE14-25
Articles are hosted by Taylor and Francis Online.
The effective delayed neutron fraction βeff is of primary importance for reactivity control of fissile systems and therefore for reactor design and safety analyses. Validation of βeff calculations is complicated by the limited availability of benchmark-quality data. This paper focuses on evaluation and analysis of βeff measurements with 252Cf-source pseudo-worth and noise methods performed at SNEAK 7A and SNEAK 7B assemblies in Germany in the 1970s. The experiments are thoroughly documented in the International Handbook of Evaluated Reactor Physics Benchmark Experiments and briefly presented in this paper. The measurements performed with the two different methods on SNEAK 7A and SNEAK 7B and other facilities systematically produce different values. Given that the noise approach presumes evolution of neutron field fluctuations in a one-point kinetic model, it was assumed that the discrepancies originate from spatial effects. A two-point kinetic model was tested to check this assumption. The paper demonstrates that the βeff measured with the noise method on the SNEAK 7A and SNEAK 7B facilities should be corrected while the 252Cf-source pseudo-worth measurement produces an accurate value.