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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.
Andrew Denig, Michael Eades
Nuclear Technology | Volume 206 | Number 8 | August 2020 | Pages 1171-1181
Technical Paper | doi.org/10.1080/00295450.2020.1719798
Articles are hosted by Taylor and Francis Online.
Two methodologies for performing decay heat analysis with Monte Carlo simulations were developed and implemented on a representative nuclear thermal propulsion (NTP) system. This paper presents the underlying theory, discusses the methodology, and states the key results. This work investigated the importance of utilizing a time-dependent Q-value for fission in NTP systems due to their short burn time. Two approaches for deriving the Q-value were taken: one based on deconvolving the fission rate from the reactor power to yield the rate of fission energy deposition, and the other based on the convergence of the fission product decay power during a long burn. The fission product decay power method is hypothesized to be the more accurate representation of an NTP system as it captures more of the underlying physics occurring during burnup, such as fission product transmutation. The calculated Q-values were employed to derive decay power profiles that were compared to the current state-of-the-art NTP decay power model. According to these new models, it is shown that the cooling requirements for decay heat removal calculated with the state-of-the-art model differ from the developed methods by as much as 23.3%. There exists a need to experimentally validate, and by extension improve, the proposed methods to better understand the nature of decay heat production in NTP systems.