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Nuclear Installations Safety
Devoted specifically to the safety of nuclear installations and the health and safety of the public, this division seeks a better understanding of the role of safety in the design, construction and operation of nuclear installation facilities. The division also promotes engineering and scientific technology advancement associated with the safety of such facilities.
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Utility Working Conference and Vendor Technology Expo (UWC 2024)
August 4–7, 2024
Marco Island, FL|JW Marriott Marco Island
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!
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Latest News
NRC engineers share their expertise at the University of Puerto Rico
Robert Roche-Rivera and Marcos Rolón-Acevedo are licensed professional engineers who work at the U.S. Nuclear Regulatory Commission. They are also alumni of the University of Puerto Rico–Mayagüez (UPRM) and have been sharing their knowledge and experience with students at their alma mater since last year, serving as adjunct professors in the university’s Department of Mechanical Engineering. During the 2023–2024 school year, they each taught two courses: Fundamentals of Nuclear Science and Engineering, and Nuclear Power Plant Engineering.
Mekiel Olguin, Christopher Perfetti, Forrest Brown
Nuclear Science and Engineering | Volume 196 | Number 11 | November 2022 | Pages 1323-1332
Technical Paper | doi.org/10.1080/00295639.2022.2087831
Articles are hosted by Taylor and Francis Online.
The dominance ratio is the ratio of the first higher-order mode eigenvalue of a system to the fundamental eigenvalue, k1/k0. It can be used to determine how well coupled the neutrons in a multiplying system are, as well as the computational difficulty of the power iteration method in a Monte Carlo simulation. The purpose of this study is to investigate the University of New Mexico’s (UNM’s) AGN-201M reactor’s unusually low dominance ratio of 0.632. The AGN-201M reactor is a small, thermal spectrum reactor located at the UNM. It is moderated by polyethylene, reflected by graphite, and uses fuel comprised of uranium microspheres embedded in polyethylene plates that are separated by an aluminum baffle. The investigation included a parametric study of the reactor’s fuel geometry, fuel density, and reflector thickness to examine their impact on the reactor’s dominance ratio. In addition, neutronically similar systems were examined to identify common causes for systems with low dominance ratios. The reason for the small dominance ratio of the AGN-201M reactor when compared to large thermal reactors was determined to be because of its size and fuel plate composition. The reflector’s effect on the dominance ratio is small in comparison to the other factors but was found to have a nonzero effect. Furthermore, the AGN-201M was found to have a significantly lower dominance ratio than systems with which it shares a very high ( > 95%) degree of neutronic similarity. However, the two most similar systems were close in size to the core of the AGN-201M reactor and were moderated with polyethylene as well.