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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.
R. Ponciroli, Y. Wang, Z. Zhou, A. Botterud, J. Jenkins, R. B. Vilim, F. Ganda
Nuclear Technology | Volume 200 | Number 3 | December 2017 | Pages 189-207
Technical Paper | doi.org/10.1080/00295450.2017.1388668
Articles are hosted by Taylor and Francis Online.
This work explores the technical challenges associated with flexible operation for nuclear power plants (NPPs) and evaluates whether a flexible operational mode could improve the profitability of nuclear units by allowing nuclear plant owners/operators to reduce output when prices are low and instead shift capacity to the ancillary services markets. As compared to conventional power plants, NPP flexible operation capabilities are affected by additional physics-induced constraints. Among the most limiting constraints is the negative reactivity insertion following every reactor power drop due to the increased concentration of xenon, a strong neutron poison. In this work, a previously available power system operation model based on mixed-integer linear programming optimization was improved by implementing a dedicated representation of these physics-induced constraints for pressurized water reactors (PWRs). Because the xenon-related constraint involves nonlinear governing dynamics, a dedicated parametric approach was implemented. To evaluate the economic implications of flexible PWR operation, a case study using realistic power system data representative of the southwestern United States was analyzed. The results indicate that flexible operation can increase the revenue of nuclear units while at the same time reducing total electric system operating costs.