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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.
Leonard W. Gray
Nuclear Technology | Volume 52 | Number 1 | January 1981 | Pages 66-72
Technical Paper | Chemical Processing | doi.org/10.13182/NT81-A32690
Articles are hosted by Taylor and Francis Online.
Plutonium metal dissolves readily in sulfamic acid; the dissolution rate is a function of surface area, sulfamic acid concentration, and temperature. Below a temperature of ∼ 50°C, the dissolution mechanism appears to proceed through a PuH2 intermediate that yields a pyrophoric sludge. Above a temperature of ∼60°C, neither the intermediate nor the sludge forms unless the sulfamic acid concentration drops below 0.4 M. Overall dissolution rates of 400 to 500 g Pu/h are obtainable with typical plutonium buttons. Downstream processing requires conversion of the sulfamate to a nitrate medium. Approximately 90% of the residual sulfamate ion can be precipitated as sulfamic acid by the addition of two volumes of 72% HNO3 to one volume of the plutonium sulfamate-sulfamic acid solution if the solution is chilled to -10°C. The small amount of sulfamate remaining can be oxidized either by diluting the nitric acid to ∼3 M and irradiating the solution with ultraviolet light or by diluting the solution with pre-irradiated 3 M HNO3.