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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.
Josep M. Soler, Pekka Kekäläinen, Veli-Matti Pulkkanen, Luis Moreno, Aitor Iraola, Paolo Trinchero, Milan Hokr, Jakub Říha, Václava Havlová, Dagmar Trpkošová, Aleš Vetešník, Dušan Vopálka, Libor Gvoždík, Martin Milický, Michal Polák, Yuta Fukatsu, Tsuyoshi Ito, Yukio Tachi, Urban Svensson, Dong Kyu Park, Sung-Hoon Ji, Björn Gylling, G. William Lanyon
Nuclear Technology | Volume 209 | Number 11 | November 2023 | Pages 1765-1784
Regular Research Article | doi.org/10.1080/00295450.2023.2209234
Articles are hosted by Taylor and Francis Online.
The REPRO-TDE test was performed at a depth of about 400 m in the ONKALO underground research facility in Finland. Synthetic groundwater containing radionuclide tracers [tritiated water tracer (HTO), 36Cl, 22Na, 133Ba, and 134Cs] was circulated for about 4 years in a packed-off interval of the injection borehole. Tracer activities were additionally monitored in two observation boreholes. The test was the subject of a modeling exercise by the SKB GroundWater Flow and Transport of Solutes Task Force. Eleven teams participated in the exercise, using different model concepts and approaches. Predictive model calculations were based on laboratory-based information concerning porosities, diffusion coefficients, and sorption partition coefficients. After the experimental results were made available, the teams were able to revise their models to reproduce the observations.
General conclusions from these back-analysis calculations include the need for reduced effective diffusion coefficients for 36Cl compared to those applicable to HTO (anion exclusion), the need to implement weaker sorption for 22Na compared to results from laboratory batch sorption experiments, and the observation of large differences between the theoretical initial concentrations for the strongly sorbing 133Ba and 134Cs, and the first measured values a few hours after tracer injection.
Different teams applied different concepts, concerning mainly the implementation of isotropic versus anisotropic diffusion, or the possible existence of borehole disturbed zones around the different boreholes. The role of microstructure was also addressed in two of the models.