ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
Explore the many uses for nuclear science and its impact on energy, the environment, healthcare, food, and more.
Explore membership for yourself or for your organization.
Conference Spotlight
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
Standards Program
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!
Latest Magazine Issues
Aug 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
September 2025
Nuclear Technology
August 2025
Fusion Science and Technology
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.
Adel Alapour, Robert A. Hommerson
Nuclear Technology | Volume 70 | Number 1 | July 1985 | Pages 64-73
Technical Paper | Third International Retran Meeting / Heat Transfer and Fluid Flow | doi.org/10.13182/NT85-A33664
Articles are hosted by Taylor and Francis Online.
A dual recirculation pump trip (2-RPT) test, conducted as a part of the Edwin I. Hatch Nuclear Plant Unit 2 (Hatch-2) startup testing, is analyzed using onedimensional reactor kinetics and point reactor kinetics options in RETRAN-02 MOD002. The nuclear data utilized in RETRAN are obtained by SIMTRAN using the three-dimensional core simulator solution by SIMULATE (RTS/7), taking into account exposure and the steady-state core conditions prior to the test. Scram does not occur during this test despite the actual sensed water level rise of ∼43 cm (water level had initially been lowered), while core power, flow, and pressure continue dropping until the natural circulation establishes a new equilibrium condition at a lower reactor power level. A combined interaction of system components is taken into account in the analysis by interfacing a detailed hydraulic model of the system, with control system models for feedwater flow and steam line pressure regulation using actual plant settings. Analysis of the actual data recorded during the 2-RPT test indicates good agreement between measured and calculated parameters. It is also demonstrated that in spite of rather large changes in the axial power distribution with time, as predicted by onedimensional reactor kinetics compared with that of the point kinetics model, a good overall agreement is reached.