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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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Latest News
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.
Harald Zänker
Nuclear Technology | Volume 86 | Number 3 | September 1989 | Pages 239-247
Technical Paper | Fission Reactor | doi.org/10.13182/NT89-A34292
Articles are hosted by Taylor and Francis Online.
Periods of continuously decreasing levels of fuel rod integrity due to debris-induced cladding damage, vibration-induced fretting wear of the cladding, etc., cause difficulties in the assessment of fuel rod performance from coolant activity data. The calculational models currently in use for this purpose in nuclear power plants are not sufficiently capable of indicating cases in which they are invalid. This can mislead reactor operators by misinterpretation of the coolant activity data, especially in situations where fast reactions are necessary. A quick test of validity is suggested to check the applicability of the currently available calculational models for estimating the number and average size of fuel rod defects. The criteria of applicability are the fission product total activity, the slope tanα in the relationship Ig(Ri/Bi) = tanαlg λi for the volatile fission product isotopes, and the activity of nonvolatile nuclides such as 239Np and the isotopes of ruthenium and cerium. The objective is to recognize immediately periods of continuously decreasing levels of fuel rod integrity in order to prevent complications in routine power plant maintenance as well as accident situations caused by more severe fuel rod degradation.
