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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
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
Argonne’s METL gears up to test more sodium fast reactor components
Argonne National Laboratory has successfully swapped out an aging cold trap in the sodium test loop called METL (Mechanisms Engineering Test Loop), the Department of Energy announced April 23. The upgrade is the first of its kind in the United States in more than 30 years, according to the DOE, and will help test components and operations for the sodium-cooled fast reactors being developed now.
Lucian Ivan (CNL), Scott Northrup (Univ of Toronto), Nusret Aydemir (CNL)
Proceedings | Advances in Thermal Hydraulics 2018 | Orlando, FL, November 11-15, 2018 | Pages 17-26
The governing equations of thermal-hydraulic flows exhibit numerical stiffness as a consequence of significant differences in the physical behavior of the phase constituents and the presence of stiff source terms. Computational methods to cope with these issues are evaluated in this work based on a two-fluid model. To circumvent the stringent time-step restrictions of explicit schemes imposed by stability limits, a parallel implicit Newton-Krylov-Schwarz (NKS) approach is investigated. However, the ability to take a much larger time step is not tantamount to low computational cost, as implicit methods applied to multiphase flows do require the solution of a sparse, linear system of equations, which increases the memory requirements and computational cost per iteration. Parallel implementations of implicit schemes are also more difficult to achieve than those of explicit methods. Consequently, an assessment of the implicit method is required to guide the choice of optimal parameters for convergence acceleration, which in many instances is problem dependent. Previous studies on the computational cost of implicit vs. explicit methods for the same solution accuracy have not been conclusive. This work aims to expand the body of research on this issue by studying the properties of the parallel implicit NKS algorithm for a range of relevant thermal-hydraulic benchmark problems.