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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.
Hugues W. Bonin, Alexander Sesonske
Nuclear Technology | Volume 68 | Number 3 | March 1985 | Pages 319-335
Technical Paper | Fuel Cycle | doi.org/10.13182/NT85-A33578
Articles are hosted by Taylor and Francis Online.
The optimization of in-core fuel management for a thorium-fueled Canada deuterium uranium (CANDU) nuclear reactor was investigated by minimizing the total refueling rate at equilibrium with respect to criticality and power-peaking constraints. The computer code ASTERIX was written to solve the optimization problem, using a steepest descent technique with a moderate number of diffusion calculations required. Because of the presence of 233Pa in the fuel, the diffusion calculations are nonlinear and are solved numerically by the specially written program CALYPSO. Simulation was performed on simple models of a CANDU 600-MW reactor, with the core divided into two or four refueling zones. Results indicated that the optimization method investigated did work out well and that potential savings of up to 14% in the feed rate are possible for the self-sufficient equilibrium thorium cycle fuel, with an optimum refueling rate of 1.372 × 10−4 MgHE (heavy elements)/MWd. Sensitivity of the optimal discharge burnups to the value of the power-peaking constraint was significant.
