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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.
William J. Garland, Simon H. Pang
Nuclear Technology | Volume 75 | Number 3 | December 1986 | Pages 239-260
Technical Paper | Fission Reactor | doi.org/10.13182/NT86-A33840
Articles are hosted by Taylor and Francis Online.
The thermohydraulic stability of the Canada deuterium uranium (CANDU)-600 heat transport system was investigated from a theoretical, numerical, and experimental point of view. Simple theoretical models, used to provide phenomenological insight as a guide to the numerical and experimental studies, showed that a major form of positive feedback existed through an interplay of circuit flow, outlet header void fraction, and outlet header pressure. The flow and pressure dynamics proved to be good indicators of system stability. System computer codes (SOPHT, FIREBIRD, and HYDNA) were used for the detailed modeling of system dynamics. These codes showed that neither Ledinegg nor parallel channel instabilities occur in CANDU-600 nuclear reactors. Loop stability was predicted under all conditions with the reactor outlet header interconnect line in service as designed. With the interconnect line disconnected, loop instability was predicted for a narrow outlet header quality range (1 to 8%). These predictions were fully confirmed by semiscale experimental loop tests and plant commissioning tests.
