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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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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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NRC cuts fees by 50 percent for advanced reactor applicants
The Nuclear Regulatory Commission has announced it has amended regulations for the licensing, inspection, special projects, and annual fees it will charge applicants and licensees for fiscal year 2025.
Yasuyoshi Kato
Nuclear Science and Engineering | Volume 104 | Number 4 | April 1990 | Pages 402-411
Technical Note | doi.org/10.13182/NSE90-A23738
Articles are hosted by Taylor and Francis Online.
Spatial mesh effects are studied for three-dimensional x-y-z neutron diffusion calculations. By applying the perturbation theory, it is analytically predicted that the errors in eigenvalue and control rod worth due to the mesh effect vary with the square of the mesh spacing, or inversely with the square of the mesh number, along the x, y, and z axes. The relationships are confirmed numerically by three-dimensional diffusion calculations in ZPPR-10A. Exact solutions are obtained from extrapolation to infinitely fine mesh spacing using these relations and results of coarse-mesh calculations.
