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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.
Peter S. Martini, Ronald J. Onega
Nuclear Technology | Volume 36 | Number 3 | December 1977 | Pages 285-293
Technical Paper | Reactor | doi.org/10.13182/NT77-A31942
Articles are hosted by Taylor and Francis Online.
The accumulation of impurities in a controlled thermonuclear reactor makes steady-state operation unlikely. The energy output during the burn phase will depend on the ion temperatures and densities. A dynamic model of the burn cycle of a tokamak is used to investigate the ion densities and temperatures as a function of time. The total energy output per cycle is investigated as a function of the ion feed rates, plasma current, and the divertor efficiency. The point-kinetics model of the plasma incorporates ion and energy balance equations and explicitly accounts for the impurity ion buildup. The D-D, D-T, and D-3He reactions are all considered in this model. The energy carried off by the neutrons in the D-D and D-T reactions is lost from the plasma. Impurities enter the plasma as a result of wall interactions with escaping ions and neutrons. The trapped-ion mode is used for calculating the confinement times. An equilibrium state vector was obtained using currently projected operating parameters. The total energy density for a burn cycle was found to be a monotonically increasing function of the source rates and the plasma current. The energy density was not substantially increased until the divertor efficiency was greater than ∼60% when the other parameters were held constant.