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Conference Spotlight
2025 ANS Winter Conference & Expo
November 9–12, 2025
Washington, DC|Washington Hilton
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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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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.
Marina Sessim, Michael R. Tonks
Nuclear Technology | Volume 207 | Number 7 | July 2021 | Pages 1004-1014
Technical Paper | doi.org/10.1080/00295450.2021.1910005
Articles are hosted by Taylor and Francis Online.
Nuclear thermal propulsion (NTP) provides a consistent source of thrust for long space missions. However, fuel development for NTP reactors is a major technological hurdle. Existing modeling and simulation tools developed by the U.S. Nuclear Engineering Advanced Modeling and Simulation (NEAMS) program for power reactors can be leveraged to help accelerate the fuel development. This work is a preliminary demonstration of the application of NEAMS tools to model NTP fuel. Specifically, the fuel performance tool BISON and the mesoscale reactor materials tool MARMOT are used to develop a multiscale model of thermal transport in a W-UO2 CERMET fuel element for NTP reactors. Three-dimensional simulations in MARMOT are used to estimate the effective thermal conductivity (ETC) of fresh CERMET fuel at temperatures ranging from 1500 K to 3000 K. The ETC values from MARMOT are then used in BISON simulations that predict the steady-state temperature profile throughout a 61-subchannel hexagonal fuel element. The temperature varies by 83 K throughout the fuel element, with the highest temperature occurring near the outer edges of the element. BISON is also used to show that the temperature profile in prototype fuel elements with fewer subchannels does not vary significantly from that in the 61-subchannel element.
