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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.
Reuben Rainisch, Victor R. Fricke
Nuclear Technology | Volume 87 | Number 2 | October 1989 | Pages 478-485
Technical Paper | TMI-2: Health Physics and Environmental Release / Nuclear Safety | doi.org/10.13182/NT89-A27740
Articles are hosted by Taylor and Francis Online.
During the accident at Three Mile Island Unit 2, a significant mass of core debris relocated to the bottom head of the reactor vessel. Subsequently, defueling activities in the core area redistributed the fuel and caused further core debris to relocate to the lower head region. An analytical approach is presented for determining the relative increase in lower plenum debris bed mass from observed changes in ex-core neutron detector readings. The neutron source magnitude of the fuel in the lower reactor vessel plenum and the degree of subcritical multiplication of neutrons in the lower head are investigated. Based on the mathematical relation formulated, it is estimated that during lower core area defueling (September 1986 to November 1987), between 12 and 23.5 additional tonnes of core materials relocated to the lower head.
