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Division Spotlight
Young Members Group
The Young Members Group works to encourage and enable all young professional members to be actively involved in the efforts and endeavors of the Society at all levels (Professional Divisions, ANS Governance, Local Sections, etc.) as they transition from the role of a student to the role of a professional. It sponsors non-technical workshops and meetings that provide professional development and networking opportunities for young professionals, collaborates with other Divisions and Groups in developing technical and non-technical content for topical and national meetings, encourages its members to participate in the activities of the Groups and Divisions that are closely related to their professional interests as well as in their local sections, introduces young members to the rules and governance structure of the Society, and nominates young professionals for awards and leadership opportunities available to members.
Meeting Spotlight
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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Jun 2024
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Nuclear Science and Engineering
August 2024
Nuclear Technology
July 2024
Fusion Science and Technology
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.
Paul Hurley, Connor Pigg, Yang Liu, Tomasz Kozlowski, Juliana Pacheco Duarte
Nuclear Technology | Volume 210 | Number 6 | June 2024 | Pages 1083-1096
Note | doi.org/10.1080/00295450.2023.2277005
Articles are hosted by Taylor and Francis Online.
Density wave oscillation (DWO) is one of the most extensively studied dynamic two-phase flow instabilities. The accurate prediction of these phenomena is important to ensuring safety in two-phase flow systems, such as boiling water reactors (BWRs). Recent reactor power uprates have led to the need for more accurate simulations at the system scale. For reactor licensing, the thermal-hydraulic computational code TRACE, developed by the U.S. Nuclear Regulatory Commission, is used for best-estimate predictions of light water reactors. One BWR power uprate condition of recent interest is the Maximum Extended Load Line Limit Analysis Plus, or MELLLA+, which allows BWRs to operate at lower core flow rates while maintaining the same power levels. Experiments performed at the Karlstein thermal-hydraulic test facility (KATHY) have shown that an anticipated transient without scram while operating under these conditions can lead to the development of DWOs.
This technical note assesses the capability of TRACE V5P7 to simulate DWO onset and development by comparison to the KATHY experimental data under natural circulation, focusing only on the thermal-hydraulic mechanisms. This study shows the analysis of DWO development from this data set, which utilized electrically heated fuel rods with a nonuniform axial power profile in a full-scale BWR rod bundle. The developed TRACE model is shown to be capable of producing DWO-type instability under the experimental conditions, while also allowing for an expanded parametric study on factors impacting stability.