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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.
M. T. Farmer, R. Bunt, M. Corradini, P. Ellison, M. Francis, J. Gabor, R. Gauntt, C. Henry, R. Linthicum, W. Luangdilok, R. Lutz, C. Paik, M. Plys, C. Rabiti, J. Rempe, K. Robb, R. Wachowiak
Nuclear Science and Engineering | Volume 184 | Number 3 | November 2016 | Pages 293-304
Technical Paper | doi.org/10.13182/NSE16-13
Articles are hosted by Taylor and Francis Online.
The reactor accidents at Fukushima Daiichi have rekindled interest in light water reactor (LWR) severe accident phenomenology. Postevent analyses have identified several areas that may warrant additional research and development (R&D) to reduce modeling uncertainties and assist industry in the development of mitigation strategies and in the refinement of severe accident management guidelines to both prevent significant core damage given a beyond-design-basis event and mitigate source term release if core damage does occur. On these bases, a technology gap evaluation on accident-tolerant components and severe accident analysis methodologies was completed with the goal of identifying any data and/or knowledge gaps that may exist given the current state of LWR severe accident research and augmented by insights gained from recent analyses of the Fukushima Daiichi accident. The ultimate benefit of this activity is that the results can be used as a basis for refining research plans to address key knowledge gaps in severe accident phenomenology that affect reactor safety and that are not being directly addressed by the nuclear industry or the U.S. Nuclear Regulatory Commission. As a result of this study, 13 gaps were identified in the areas of severe accident–tolerant components and accident modeling. The results clustered in three main areas: (1) modeling and analysis of in-vessel melt progression phenomena, (2) emergency core cooling system equipment performance under beyond-design-basis accident conditions, and (3) ex-vessel debris coolability and core-concrete interaction behavior relevant to accident management actions. This paper provides a high-level summary of the methodology used for the evaluation, the identified gaps, and, finally, the appropriate R&D that may be completed to address the gaps.