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.
Shi-Ping Teng, Duaine G. Lindstrom
Nuclear Science and Engineering | Volume 69 | Number 3 | March 1979 | Pages 363-366
Technical Paper | doi.org/10.13182/NSE79-A19953
Articles are hosted by Taylor and Francis Online.
The criticality constants of fissile solutions containing borated Raschig rings are evaluated using the Monte Carlo code KENO IV with various geometry models. In addition to those used by other investigators, a new geometry model, the random geometry model, is presented to simulate the system of randomly oriented Raschig rings in solution. A technique to obtain the material thickness distribution functions of solution and rings for use in the random geometry model is also presented. Comparison between the experimental data and the calculated results using the Monte Carlo method with various geometry models indicates that the random geometry model is a reasonable alternative to models previously used in describing the system of Raschig-ring-filled solution. The random geometry model also provides a solution to the problem of describing an array containing Raschig-ring-filled tanks that is not available to techniques using other models.