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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.
Jaakko Leppänen
Nuclear Science and Engineering | Volume 174 | Number 3 | July 2013 | Pages 318-325
Technical Paper | doi.org/10.13182/NSE12-54
Articles are hosted by Taylor and Francis Online.
This paper presents a methodology for applying continuously varying density distributions in Monte Carlo particle transport simulation. The capability is implemented in the Serpent 2 code, as part of an effort for developing a universal multiphysics interface for the coupling of Monte Carlo neutronics to thermal hydraulics and fuel performance codes. The method is based on rejection sampling of particle path lengths, but despite its close resemblance to the Woodcock delta-tracking method, the routine can be used with conventional surface tracking as well. The modified tracking routine is put to the test in a simple boiling water reactor pin-cell calculation with continuously changing void distribution in the coolant channel.