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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.
Takanori Kameyama, Tetsuo Matsumura, Motoyasu Kinoshita
Nuclear Technology | Volume 106 | Number 3 | June 1994 | Pages 334-341
Technical Paper | Nuclear Fuel Cycle | doi.org/10.13182/NT94-A34963
Articles are hosted by Taylor and Francis Online.
The peripheral region of a high burnup light water reactor (LWR) fuel pellet shows a microstructure that is different from the as-fabricated microstructure. The region where the microstructure change occurs (the rim region) is highly porous, and the original grains in the rim region are divided into much smaller subgrains. The electron probe microanalysis data of high burnup fuels indicate fission gas depletion in the rim region as well as in the central region. The burnup in the rim region is enhanced by built-up plutonium derived from a 238U self-shielding effect, which is called a rim effect. The rim effect accelerates microstructure change in the peripheral region. We developed a detailed burnup analysis code ANRB computing the rim effect in LWR fuels. We have verified the ANRB code performance with the data of the High Burnup Effects Program. The analysis shows that the microstructure change occurs where local burnup gets to the threshold burnup of 70 to 80 MWd/kg U in both pressurized water reactor and boiling water reactor types of fuels. The threshold burnup never changes with the plutonium/uranium burnup ratio or fission rate during the irradiation. The storage of radiation damage is expected to cause the microstructure change.
