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Conference Spotlight
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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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.
Tunc Aldemir, Joseph W. Talnagi,*, Don W. Miller
Nuclear Technology | Volume 86 | Number 3 | September 1989 | Pages 248-263
Technical Paper | Fission Reactor | doi.org/10.13182/NT89-A34293
Articles are hosted by Taylor and Francis Online.
The 10-kW, highly enriched uranium (HEU) fueled Ohio State University Research Reactor (OSURR) is being upgraded to operate at 500 kW under natural convection core cooling with the recently licenced lowenriched uranium (LEU), high-density U3Si2fuel. The OSURR will be the first university reactor to use standardized U3Si2 plates for a full-core conversion from HEU to LEU fuel. The activities toward conversion/power upgrade objectives include (a) a neutronic performance assessment of 15 LEU cores with 16 plate standard and 10 plate control elements under expected operating conditions; (b) simulation of OSURR threedimensional pool dynamics under various pool configurations to limit the pool top 16N activity (PTNA) to operationally allowable levels; (c) determination of a new correlation to predict onset of nucleate boiling (ONB) in thin, rectangular channels under low-velocity, upward flow conditions; and (d) design of a pool heat removal system (PHRS). These activities have identified three possible LEU cores with a cold, clean shutdown margin in the range from 1.57 to 1.91% Δk/k that allow steady-state operation at 500 kW with a 50 to 60% margin to ONB. A system configuration that minimizes PTNA while maximizing the primary inlet temperature to PHRS to improve the heat exchanger efficiency has also been identified. The PHRS is designed to remove 500 kW through an ethylene-glycol heat exchanger and a dry cooler when the outside air temperature is <33°C. The PHRS also has an auxiliary heat exchanger to allow operation without power derating when the air temperature is >33°C.
