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Nuclear Nonproliferation Policy
The mission of the Nuclear Nonproliferation Policy Division (NNPD) is to promote the peaceful use of nuclear technology while simultaneously preventing the diversion and misuse of nuclear material and technology through appropriate safeguards and security, and promotion of nuclear nonproliferation policies. To achieve this mission, the objectives of the NNPD are to: Promote policy that discourages the proliferation of nuclear technology and material to inappropriate entities. Provide information to ANS members, the technical community at large, opinion leaders, and decision makers to improve their understanding of nuclear nonproliferation issues. Become a recognized technical resource on nuclear nonproliferation, safeguards, and security issues. Serve as the integration and coordination body for nuclear nonproliferation activities for the ANS. Work cooperatively with other ANS divisions to achieve these objective nonproliferation policies.
Meeting 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!
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Latest News
NextGen MURR Working Group established in Missouri
The University of Missouri’s Board of Curators has created the NextGen MURR Working Group to serve as a strategic advisory body for the development of the NextGen MURR (University of Missouri Research Reactor).
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.