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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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ANS Student Conference 2025
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Albuquerque, NM|The University of New Mexico
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The American Nuclear Society election is now open. Members can vote for the Society’s next vice president/president-elect and treasurer as well as six board members (four U.S. directors, one non-U.S. director, and one student director). Completed ballots must be submitted by 1:00 p.m. (EDT) on Tuesday, April 15, 2025.
Paul G. Lorenzini, Alan H. Robinson
Nuclear Science and Engineering | Volume 44 | Number 1 | April 1971 | Pages 27-36
Technical Paper | doi.org/10.13182/NSE71-A18902
Articles are hosted by Taylor and Francis Online.
The spectral-synthesis method is investigated to assess its applicability for solving the diffusion equation in fast reactor design. The equations are derived so they may be solved by a standard diffusion theory code that allows upscattering. A reference 1000-MW(e) fast reactor is studied and two-dimensional solutions are obtained. The problem of selecting trial functions is examined and four different sets are used in the calculations. The results are compared with few-group calculations to test both accuracy and running times. The few-group and synthesis approximations are, in turn, compared with a 26-group solution which is treated as an exact solution. Some numerical instabilities are experienced and examined. It is concluded that the instabilities are caused by a complete coupling between equations in the scattering matrix. The accuracy of the synthesis approximation is comparable with the few-group approximation for calculating eigenvalues and is slightly superior for determining the flux in the core.
