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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.
Richard Simms, Robert K. LO, William F. Murphy, Alan B. Rothman, George S. Stanford
Nuclear Technology | Volume 50 | Number 3 | October 1980 | Pages 225-241
Technical Paper | Reactor Siting | doi.org/10.13182/NT80-A32526
Articles are hosted by Taylor and Francis Online.
In a transient overpower (TOP) accident, the fuel element failure threshold is a function of the rate of reactivity increase and the fuel microstructure. Test E8 simulated a hypothetical $3/s TOP accident in a liquid-metal fast breeder reactor using seven (Pu,U)O2 fuel elements of the fast test reactor (FTR) type. The test elements were pre-irradiated at 30 kW/m in the Experimental Breeder Reactor II to 5 at.% burnup, leading to a low-to-moderate power micro structure typical of FTR fuel Data from test vehicle sensors, hodoscope, and post-test examinations were used to deduce the sequence of events occurring within the test zone. The initial fuel failure event occurred abruptly at ∼29 times the nominal power level at an estimated average enthalpy of ∼925 kJ/kg relative to 20°C, with 50% of the fuel cross-sectional area above the solidus at the suspected failure site. After the initial failure, ∼2% of the fuel was ejected above the top of the active fuel region. Sodium voiding occurred rapidly. An upper blockage was formed that apparently prevented further fuel dispersal. Inherent test vehicle limitations, loss of flow tube geometry, and nontypical power generation after fuel element failure may have caused a departure from the fuel motion predicted for the FTR conditions. No violent fuel-coolant interactions were observed in the test.