ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
Explore the many uses for nuclear science and its impact on energy, the environment, healthcare, food, and more.
Division Spotlight
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
ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
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!
Latest Magazine Issues
Apr 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
May 2025
Nuclear Technology
April 2025
Fusion Science and Technology
Latest News
General Kenneth Nichols and the Manhattan Project
Nichols
The Oak Ridger has published the latest in a series of articles about General Kenneth D. Nichols, the Manhattan Project, and the 1954 Atomic Energy Act. The series has been produced by Nichols’ grandniece Barbara Rogers Scollin and Oak Ridge (Tenn.) city historian David Ray Smith. Gen. Nichols (1907–2000) was the district engineer for the Manhattan Engineer District during the Manhattan Project.
As Smith and Scollin explain, Nichols “had supervision of the research and development connected with, and the design, construction, and operation of, all plants required to produce plutonium-239 and uranium-235, including the construction of the towns of Oak Ridge, Tennessee, and Richland, Washington. The responsibility of his position was massive as he oversaw a workforce of both military and civilian personnel of approximately 125,000; his Oak Ridge office became the center of the wartime atomic energy’s activities.”
Jeremy A. Roberts, Matthew S. Everson, Benoit Forget
Nuclear Science and Engineering | Volume 181 | Number 3 | November 2015 | Pages 331-341
Technical Paper | doi.org/10.13182/NSE14-132
Articles are hosted by Taylor and Francis Online.
A study of the convergence behavior of the eigenvalue response matrix method (ERMM) for nuclear reactor eigenvalue problems is presented. The eigenvalue response matrix equations are traditionally solved by a two-level iterative scheme in which an inner eigenproblem yields particle balance across node boundaries and an outer fixed-point iteration updates the global k-eigenvalue. Past work has shown the method converges rapidly, but the properties of its convergence have not been studied in detail. To perform a formal assessment of these properties, the one-dimensional, one-group diffusion approximation is used to derive the asymptotic error constant of the fixed-point iteration. Several problems are solved numerically, and the observed convergence behavior is compared to the analytic model based on buckling and nodal dimensions (in mean free paths). The results confirm the method converges quickly, with no degradation in the convergence rate for small nodes, which is an observation that suggests ERMM can be used for large-scale, parallel computations with no penalty from the decomposition of a domain into smaller nodes. In addition, results from multigroup problems show that convergence depends strongly on the heterogeneity and the energy representation of a model. In particular, the convergence for two-group and heterogeneous, one-group models is substantially slower than for the homogeneous, one-group model.