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Conference Spotlight
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
Standards Program
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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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.
M. Zarei
Nuclear Science and Engineering | Volume 199 | Number 6 | June 2025 | Pages 977-987
Research Article | doi.org/10.1080/00295639.2024.2397622
Articles are hosted by Taylor and Francis Online.
Closed-loop control of the reactor-follow-turbine operation is attempted in this work. The reactor power is intended to follow the turbine load demand, whereas the coolant average temperature is to be maintained constant for reasons of design safety. To this effect, a standardized pressurized water reactor model is adopted wherein the reactor external reactivity and the feedwater mass flux are deemed the manipulated control signals. Offline system identification is carried out on the model input/output (I/O) terminals to extract first order plus time delay models thereof. A further relative gain array analysis is conducted to determine the most tightly coupled I/O channels. A proportional integral controller is thereafter designed for each channel, making use of an analytical gain/phase margin tuning mechanism. The results for different output tracking scenarios confirm a feasible and quite satisfactory closed-loop control practice.