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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.
K. S. Smith, T. Bahadir, R. Ferrer, D. B. Lancaster, A. J. Machiels
Nuclear Technology | Volume 185 | Number 1 | January 2014 | Pages 39-56
Technical Paper | Fuel Cycle and Management | doi.org/10.13182/NT13-31
Articles are hosted by Taylor and Francis Online.
Pressurized water reactor (PWR) assembly reactivity distributions are inferred from ∼600 in-core flux maps taken during 44 cycles of operation of the Catawba and McGuire nuclear power plants. The reactivity distribution for each flux map is determined by systematically searching for fuel subbatch reactivities that minimize differences between measured and computed 235U fission rates. More than eight million core calculations are used to reduce one million measured signals to a set of ∼2500 experimental fuel reactivities for fuel with up to 55 GWd/T burnup. These measured reactivity changes with depletion can be used to validate computer code systems used for burnup credit. To reduce the effort required to quantify computer code system biases and uncertainties, the measured changes in fuel depletion reactivity have been reduced to a set of experimental PWR lattice benchmarks for the change in reactivity as a function of fuel burnup. Results demonstrate that the uncertainty of hot-full-power (HFP) depletion reactivity of the benchmarks is < 250 pcm up to 55 GWd/T burnup. Oak Ridge National Laboratory's TSUNAMI tools are used to extend HFP results to cold conditions, and reactivity decrement uncertainties increase to ∼600 pcm. These experimental benchmarks provide a basis for quantification of combined nuclide inventory and cross-section uncertainties in computed reactivity decrements. It is demonstrated that flux map data reduction is not sensitive to the analytical tools (CASMO/SIMULATE) employed here, and experimental fuel depletion reactivity decrements and uncertainties are anticipated to be independent of fuel management code system use for the data reduction. For CASMO-based analysis, the HFP reactivity burnup decrement biases are shown to be <250 pcm up to 55 GWd/T burnup, and results show that the historical “Kopp memo” 5% reactivity decrement uncertainty assumption is conservative.