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Conference Spotlight
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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Ho Nieh nominated to the NRC
Nieh
President Trump recently nominated Ho Nieh for the role of commissioner in the Nuclear Regulatory Commission through the remainder of a term that will expire June 30, 2029.
Nieh has been the vice president of regulatory affairs at Southern Nuclear since 2021, though he is currently working as a loaned executive at the Institute of Nuclear Power Operations, where he has been for more than a year.
Nieh’s experience: Nieh started his career at the Knolls Atomic Power Laboratory, where he worked primarily as a nuclear plant engineer and contributed as a civilian instructor in the U.S. Navy’s Nuclear Power Program.
From there, he joined the NRC in 1997 as a project engineer. In more than 19 years of service at the organization, he served in a variety of key leadership roles, including division director of Reactor Projects, division director of Inspection and Regional Support, and director of the Office of Nuclear Reactor Regulation.
François Martin, André Bergeron, Guillaume Campioni, Yannick Gorsse, Nathan Greiner, Elsa Merle
Nuclear Science and Engineering | Volume 199 | Number 1 | April 2025 | Pages S994-S1005
Research Article | doi.org/10.1080/00295639.2024.2328964
Articles are hosted by Taylor and Francis Online.
The CEA multiphysics tool combining the deterministic neutronics code APOLLO3® and the computational fluid dynamics (CFD) platform TRUST/TrioCFD is used to model the first-ever-built molten salt nuclear reactor, the Aircraft Reactor Experiment (ARE). A neutronics model and a thermal-hydraulic model of the reactor were created and coupled. Steady-state and transient simulations were performed in order to reproduce experiments realized on the ARE. The simulation results and experimental data are compared as a way of validating the multiphysics tool. The nominal state of the ARE is reproduced first; significant discrepancies were observed regarding the liquid sodium flow. Variations of βeff with the fuel flow rate were then studied. While the simulation was in very good agreement with the experimental data for high flow rates, some discrepancies were observed at low and null flow rates. Finally, a transient simulation of a rod withdrawal was reproduced. While the beginning of the transient simulation was in good agreement with the experimental data, oscillations appeared in the second half of the simulation.