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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.
Martin Victor Polley
Nuclear Technology | Volume 71 | Number 3 | December 1985 | Pages 557-567
Technical Paper | Fission Reactor | doi.org/10.13182/NT85-A33678
Articles are hosted by Taylor and Francis Online.
It is widely experienced that operation with a low primary coolant pHT leads to heavy deposition on fuel-pin cladding in pressurized water reactors (PWRs). This is thought to be due principally to solubilities of corrosion products exhibiting negative temperature dependencies at low coolant pHT, leading to precipitation from the solution onto core surfaces. Solubilities also increase at low pHT values and this may be an additional reason for the increased deposition. Particulate deposition may also depend on coolant pHT. Operation at low coolant pHT may thus cause increased corrosion product activity transport, leading to higher dose rates around the primary circuit. The possible correlation between low pHT operation and steam generator channel head dose rates was investigated, using detailed data from nine Westinghouse PWRs. The coolant chemistry was quantified by calculating both the percentage of operating time at low pHT and a numerical “precipitation index” in order to establish the extent of operation below that coolant pHT above which little core crud deposition is expected. Time averaged pH’s were also calculated for each cycle. End-of-cycle dose rates were plotted against these coolant chemistry parameters on a plantby-plant basis and statistical tests were applied following linear regression analysis. Positive correlations were obtained and it was found that, for the limited number of plants in the survey, these correlations were between the categories “significant” and “probably significant” for cycle 1 and cycle 2 data.
