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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.
Thomas J. Marciniak
Nuclear Technology | Volume 8 | Number 5 | May 1970 | Pages 401-416
Paper | Reactor | doi.org/10.13182/NT70-A28685
Articles are hosted by Taylor and Francis Online.
A simple, stable, time-optimal digital control program has been developed with general application to zero- or low-power nuclear reactors for power-level changes, especially power increases. The program is required to increase the power level while maintaining a minimum allowed period, and to reach the demand power with little or no overshoot. A switching criterion was derived using a discrete version of the Pontryagin Maximum Principle. The switch point was found to be dependent upon the minimum allowed period and the maximum reactivity removal rate of the controlled regulating rod. The control program developed was applied to digital simulation of three reactor models and was adapted for use on the Argonne Thermal Source Reactor (ATSR) for power-level changes. The maximum overshoot experienced was ∼1% for various minimum allowed reactor periods and reactivity removal rates.