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2025 ANS Winter Conference & Expo
November 9–12, 2025
Washington, DC|Washington Hilton
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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.
Rei Kimura, Kazuhito Asano
Nuclear Technology | Volume 210 | Number 8 | August 2024 | Pages 1496-1502
Note | doi.org/10.1080/00295450.2023.2299899
Articles are hosted by Taylor and Francis Online.
A novel microreactor, called MoveluXTM, was previously proposed that utilizes heat pipes as the primary heat transfer device and calcium hydride as the moderator. In this core design, the moderator temperature is the critical core operation limit because at high temperatures above 800°C, the hydrogen dissociates from the calcium hydride. The core temperature distribution, therefore, was previously evaluated. However, this evaluation did not consider gamma heating in the core and assumed that power was produced only in the fuel region. By contrast, the moderator region has a power density under realistic conditions due to gamma heating. Thus, the present work considers gamma heating in the core power distribution calculation and evaluates the impact on the moderator temperature. The power density of gamma heating was 1/10th that of the fuel region and around 1/100th that of the core thermal power. This increased the temperature of the moderator by 10 K from the case without considering gamma heating. In addition, this temperature distribution difference did not have an impact on the core criticality. In conclusion, considering the gamma heating, concerns regarding the core design are not suggested.