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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.
John Sorensen
Nuclear Technology | Volume 83 | Number 3 | December 1988 | Pages 383-395
Technical Paper | Fifth International Retran Meeting / Heat Transfer and Fluid Flow | doi.org/10.13182/NT88-A34151
Articles are hosted by Taylor and Francis Online.
The possibility of instabilities under certain conditions of operation has been a special concern for boiling water reactors (BWRs). A stability analysis is performed to demonstrate that the total system and its primary components are inherently stable over the allowable operating envelope. The current methodology used by BWR fuel vendors for core reactivity and channel hydrodynamic stability is based on frequency domain analysis. RETRAN is the Electric Power Research Institute time domain system transient analysis code that is widely used by domestic and foreign utilities. RETRAN allows the reactor system to be modeled in a highly accurate manner including all important phenomena (linear and nonlinear) associated with anticipated and unforeseen conditions of operation. RETRAN is demonstrated to be adequate for the analysis of total plant stability, core reactivity stability, and channel hydrodynamic stability. All key phenomena are adequately modeled by RETRAN and core reactivity analyses have been shown to agree well with measured plant data.
