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Conference Spotlight
2025 ANS Winter Conference & Expo
November 9–12, 2025
Washington, DC|Washington Hilton
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Latest News
Senate EPW Committee to hold Nieh nomination hearing
Nieh
The Senate Environment and Public Works Committee will hold a nomination hearing Wednesday for Ho Nieh, President Donald Trump’s nominee to serve as commission at the Nuclear Regulatory Commission.
Trump nominated Nieh on July 30 to serve as NRC commissioner the remainder of a term that will expire June 30, 2029, as Nuclear NewsWire previously reported.
Nieh has been vice president of regulatory affairs at Southern Nuclear since 2021, though since June 2024 he has been at the Institute of Nuclear Power Operations as a loaned executive.
A return to the NRC: If confirmed by the Senate, Nieh would be returning to the NRC after three previous stints totaling nearly 20 years.
Dean Price, Leia Barrowes, James Wells, Brendan Kochunas
Nuclear Technology | Volume 211 | Number 5 | May 2025 | Pages 1014-1043
Research Article | doi.org/10.1080/00295450.2024.2369476
Articles are hosted by Taylor and Francis Online.
The emission of antineutrinos from nuclear reactors offers a potential avenue for the international enforcement of reactor safeguards. A variety of frameworks have been proposed for detecting these particles, with the objective of verifying an agreed-upon composition of fuel in the operating reactor. More specifically, these frameworks should identify the diversion of a “significant quantity” of fissile material from an agreed upon core loading. For any quantitative analysis of these frameworks, isotope-specific fission rates of a nuclear reactor are required to calculate the reactor neutrino source. Unfortunately, the calculation of isotope-specific fission rates for a realistic core is nontrivial and can require significant simulation efforts.
Therefore, this work uses industry-standard simulation tools (CASMO-4/SIMULATE-3) to provide isotope-specific fission rates for a set of 15 plutonium diversion scenarios for a mixed-oxide-loaded pressure water reactor. These diversion scenarios span a wide range of diverted fuel amounts, from 2.17 to 655.19 kg of fissile plutonium. The isotope-specific fission rates reported in this paper can be combined with a neutrino emission model for the direct calculation of the reactor neutrino source. This work can be considered a dedicated effort toward the calculation of realistic isotope-specific reaction rates for use in the development and analysis of safeguarding frameworks. As such, these isotope-specific fission rates are provided over three cycles with realistic fuel loading and shuffling patterns. In this way, this work can act as a standard neutrino source reference for the development and comparison of safeguarding frameworks.