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Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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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.
Edmondo Zamorani
Nuclear Technology | Volume 77 | Number 3 | June 1987 | Pages 313-319
Technical Paper | Radioactive Waste Management | doi.org/10.13182/NT87-A33971
Articles are hosted by Taylor and Francis Online.
Previous works on cement leached in water and containing radioactive wastes like cesium and strontium agree to attribute the release in the liquid phase to a diffusion mechanism. The kinetic release can be represented by an empirical relationship in which the dependence of the leached fraction Fr = C/C0 versus time t assumes the form Fr = Btn and the factor n = 0.5 is typical of a diffusion process. On the other hand, the results of our studies on cement leached in static water demonstrate that the release of calcium, considered to be representative of matrix degradation, follows a time dependence of t0.25. A model is suggested for which the release of calcium depends on superposition of two processes: a diffusion through a reaction layer of calcium silicate hydrate around the cement particles during the hydration step and a diffusion of elements from the bulk of cement toward the external surface of the specimen. Based on this schematic diffusion mechanism, some suggestions are advanced to improve the physical characteristics and to increase the retention of the radioactive waste encapsulated in the cement matrix.
