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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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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
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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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Ariz. governor vetoes “fast track” bill for nuclear
Gov. Katie Hobbs put the brakes on legislation that would have eliminated some of Arizona’s regulations and oversight of small modular reactors, technology that is largely under consideration by data centers and heavy industrial power users.
H. Kschwendt
Nuclear Science and Engineering | Volume 44 | Number 3 | June 1971 | Pages 423-434
Technical Paper | doi.org/10.13182/NSE71-A20173
Articles are hosted by Taylor and Francis Online.
A synthesis and generalization of several recently developed methods for the numerical solution of the neutron transport equation in a homogeneous slab, assuming anisotropic scattering and energy dependence is presented. The generalization lies in the explicit inclusion of anisotropic scattering. After a Fourier transformation, a system of linear integral equations is obtained, the kernal of which is expanded in spherical Bessel functions. To process the final result in the direction of numerical evaluation, an approximation is proposed that results in the SPN - PL method where the flux is given by a double sum over spatial and angular Legendre polynomials. The expansion coefficients are determined from a system of linear integral equations. Treating the energy dependence by means of the multigroup concept, this system is reduced to a linear system of algebraic equations. Corresponding matrix elements depend on the optical thickness of the slab and can be computed from expansions available for arbitrary slab thicknesses. The SPN - PL method is of great practical importance since it is possible to obtain the solution of the transport equation with low computational effort. For example, assuming monoenergetic neutrons and isotropic scattering, the first and second eigenvalues of the transport equation can both be obtained with five exact digits from 3 × 3 or 4 × 4 matrices. The influence of the mean value of the linear anisotropy on the first and second eigenvalue and the decay constant is studied in detail. The validity of our approach is confirmed by comparing it with the SN and other methods. For certain mean values and optical thicknesses the second eigenvalue is found to be a complex number. Critical flux distribution is determined with great accuracy and shows perfect agreement with other published values. The flux due to a δ source, and a combination of a δ source with a flat one, is analyzed; it is confirmed that the SPN - PL method is not only applicable to small systems, but also (in most cases) to very large assemblies.
