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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.
Yine-Ping Ting
Nuclear Technology | Volume 70 | Number 1 | July 1985 | Pages 94-103
Technical Paper | Third International Retran Meeting / Heat Transfer and Fluid Flow | doi.org/10.13182/NT85-A33667
Articles are hosted by Taylor and Francis Online.
The RETRAN analysis of San Onofre Nuclear Generating Station Unit 2 (SONGS 2) turbine trip from 100% power is a continuing effort of our in-house RETRAN model development to benchmark the calculations against the plant test data. The previous benchmarked calculations—RETRAN analyses of SONGS 2 flow measurements and low-power natural circulation test—showed very good agreement with the plant test data. The latter RETRAN model was then expanded for the current study to include steam generator secondary side, main steam line pipings, control valves, and plant control systems. The benchmarked turbine trip model has been used to analyze the station-requested plant operational transients. These are (a) assessment of strategies for performing turbine overspeed surveillance, (b) determining a manual position of one steam bypass valve following a reactor trip from 100% power, and (c) plant response to one main steam isolation valve closure at 90 and 50% power levels. In addition, the RETRAN calculations employing benchmarked models can be used to verify the simulator predictions and assess the existing plant operating procedures.
