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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 Standards Committee is responsible for the development and maintenance of voluntary consensus standards that address the design, analysis, and operation of components, systems, and facilities related to the application of nuclear science and technology. Find out What’s New, check out the Standards Store, or Get Involved today!
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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.
Jack Galloway, Joshua Richard, Cetin Unal
Nuclear Science and Engineering | Volume 196 | Number 1 | October 2022 | Pages S50-S62
Technical Paper | doi.org/10.1080/00295639.2022.2053488
Articles are hosted by Taylor and Francis Online.
The Versatile Test Reactor (VTR) is a sodium-cooled fast reactor designed to accelerate the design and approval of new nuclear material and reactor concepts by providing a high neutron fast flux environment on U.S. soil. To ensure that the reactor simultaneously achieves the target irradiation environment while maintaining sufficient margin to safety limits, supporting design analysis of the VTR has been performed using MCNP and TRACE. High-fidelity MCNP calculations have been performed that confirm design parameters, such as control rod worth and neutron and photon flux distributions, and provide needed reactivity coefficients for TRACE analyses. The MCNP simulations additionally provide fuel rod power profiles of interest to fuel performance designers and provide an excellent model for experimental cartridge design within the VTR core. TRACE simulations of several postulated transients, such as station blackout, loss of heat sink, and transient overpower, have been performed (results included here are limited to the transient overpower), and the obtained results confirm the robust safety behavior of the VTR. The TRACE simulations provide a valuable confirmatory transient analysis capability using a U.S. Nuclear Regulatory Commission–developed safety analysis tool incorporating inputs from the high-fidelity neutronic simulations performed with MCNP. Taken together, the confirmatory analysis capability provided by MCNP and TRACE serves to further strengthen the understanding of and confidence in the VTR’s performance.