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Division Spotlight
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
International Conference on Mathematics and Computational Methods Applied to Nuclear Science and Engineering (M&C 2025)
April 27–30, 2025
Denver, CO|The Westin Denver Downtown
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
TerraPower begins U.K. regulatory approval process
Seattle-based TerraPower signaled its interest this week in building its Natrium small modular reactor in the United Kingdom, the company announced.
TerraPower sent a letter to the U.K.’s Department for Energy Security and Net Zero, formally establishing its intention to enter the U.K. generic design assessment (GDA) process. This is TerraPower’s first step in deployment of its Natrium technology—a 345-MW sodium fast reactor coupled with a molten salt energy storage unit—on the international stage.
Matthieu A. André, Ross A. Burns, Paul M. Danehy, Seth R. Cadell, Brian G. Woods, Philippe M. Bardet
Nuclear Technology | Volume 205 | Number 1 | January-February 2019 | Pages 262-271
Technical Paper | doi.org/10.1080/00295450.2018.1516954
Articles are hosted by Taylor and Francis Online.
Molecular tagging velocimetry (MTV) is a nonintrusive velocimetry technique based on laser spectroscopy. It is particularly effective in challenging gas flow conditions encountered in thermal hydraulics where particle-based methods such as particle image (or tracking) velocimetry do not perform well. The main principles for designing and operating this diagnostic are presented as well as a set of gases that have been identified as potential seeds. Two gases [H2O and nitrous oxide (N2O)] have been characterized extensively for thermodynamic conditions ranging from standard temperature and pressure to environments encountered in integral effects test (IET) facilities for high-temperature gas reactors. A flexible, modular, and transportable laser system has been designed and demonstrated with H2O and N2O seed gases. The laser system enables determining the optimum excitation wavelength, tracer concentration, and timing parameters. Velocity precision and thermodynamic domain of applicability are discussed for both tracers. The spectroscopic nature of the diagnostics enables one to perform first-principle uncertainty analysis, which makes it attractive for validating numerical models.
Molecular tagging velocimetry is demonstrated for two flows. First, in blowdown tests with H2O seed, the unique laser system enables one of the largest dynamic ranges reported to date for velocimetry: 5000:1 (74 dB). N2O-MTV is then deployed in situ in an IET facility, i.e., the High-Temperature Test Facility at Oregon State University, during a depressurized conduction cooldown (DCC) event. Data enable researchers to gain insights into flow instabilities present during DCC. Thus, MTV shows a strong potential to gain a fundamental understanding of gas flows in nuclear thermal hydraulics and to provide validation data for numerical solvers.