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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.
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2024 ANS Winter Conference and Expo
November 17–21, 2024
Orlando, FL|Renaissance Orlando at SeaWorld
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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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General Atomics R&D team recognized for contributions to NIF’s fusion ignition
The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory has achieved fusion ignition at least five times, each time by directing its 192 high-powered lasers on a capsule containing a tiny, 2-millimeter target filled with hydrogen fuel. Not every shot achieves ignition, however. Tiny imperfections in the targets can mean fizzle, not fusion. But each of the targets used in successful experiments to date have something in common: they were characterized and selected by the 4Pi Integrated Metrology System, a new measurement system developed by General Atomics. Now, the team behind that system is being recognized.
GA announced last week that its Metrology Research and Development team had won the 2024 "Team of the Year" R&D 100 Professional Award from R&D World. The magazine that each year announces the R&D 100 awards that have been dubbed the “Oscars of Innovation” also selects just one “Team of the Year” and announces that award together with four other professional awards.
Daniel F. Gill, Yousry Y. Azmy
Nuclear Science and Engineering | Volume 167 | Number 2 | February 2011 | Pages 141-153
Technical Paper | doi.org/10.13182/NSE09-98
Articles are hosted by Taylor and Francis Online.
We present an approach to the k-eigenvalue problem in multigroup diffusion theory based on a nonlinear treatment of the generalized eigenvalue problem. A nonlinear function is posed whose roots are equal to solutions of the k-eigenvalue problem; a Newton-Krylov method is used to find these roots. The Jacobian-vector product is found exactly or by using the Jacobian-free Newton-Krylov (JFNK) approximation. Several preconditioners for the Krylov iteration are developed. These preconditioners are based on simple approximations to the Jacobian, with one special instance being the use of power iteration as a preconditioner. Using power iteration as a preconditioner allows for the Newton-Krylov approach to heavily leverage existing power method implementations in production codes. When applied as a left preconditioner, any existing power iteration can be used to form the kernel of a JFNK solution to the k-eigenvalue problem. Numerical results generated for a suite of two-dimensional reactor benchmarks show the feasibility and computational benefits of the Newton formulation as well as examine some of the numerical difficulties potentially encountered with Newton-Krylov methods. The performance of the method is also seen to be relatively insensitive to the dominance ratio for a one-dimensional slab problem.