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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.
G. C. Pomraning
Nuclear Science and Engineering | Volume 29 | Number 2 | August 1967 | Pages 220-236
Technical Paper | doi.org/10.13182/NSE67-A18531
Articles are hosted by Taylor and Francis Online.
It is shown that variational principles need not be postulated and then correctness proved; they can, in fact, be derived, making their use more a matter of routine than ingenuity. A Lagrange multiplier technique is used to derive a second-order variational principle for estimating an arbitrary functional of the solution to an inhomogeneous equation. The relationship of this principle to a functional Taylor series expansion and to elementary perturbation theory is established. A normalization independent second-order variational principle for an arbitrary functional is derived which reduces to the Schwinger principle if the functional is linear. Two higher order variational principles are derived and shown to be generalizations of the principles of Kostin and Brooks. The Lagrange multiplier technique is applied to the inhomogeneous Sturm-Liouville equation, which leads to a second-order variational principle for estimating an arbitrary functional which allows trial functions that are not continuous and do not satisfy the boundary conditions. This functional is of the type suggested by Buslik plus boundary terms. The differences between a variational principle which can only be used to estimate a functional of interest and one which also acts as a Lagrangian are discussed.