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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.
Sadayuki Izutsu, Yoshiro Kudo, Junichi Onuma, Tomohiko Iwasaki, Sakae Muto, Akio Toba
Nuclear Technology | Volume 89 | Number 1 | January 1990 | Pages 92-102
Technical Paper | Nuclear Safety | doi.org/10.13182/NT90-A34361
Articles are hosted by Taylor and Francis Online.
Rod drop accidents (RDAs) were calculated for a typical 1100-MW(electric) boiling water reactor (BWR) using the three-dimensional core dynamics simulation code ARIES. Calculated cases are for cold start-up and hot standby cores. In both cold start-up and hot standby core RDAs, the moderator density reactivity feedback has an important effect on suppressing fuel enthalpy increase. Hot standby core RDAs, in particular, show remarkable effects of the moderator density reactivity feedback on reducing the power peak and succeeding fuel enthalpy rise. Sensitivity analyses of the effects of initial power level, core inlet subcooling, rod drop speed, dropping rod worth, etc., have been carried out under both cold start-up and hot standby core conditions for a typical 1100-MW(electric) BWR. In the hot standby core RDAs, the parameters affecting neutronic conditions (such as Doppler feedback) and moderator density proved to be very sensitive. In the cold start-up core RDAs, the parameters affecting moderator density are not so sensitive, but the parameters affecting Doppler feedback or neutronic conditions proved to be more sensitive than in the hot standby core RDAs.
