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
Mar 2025
Jul 2024
Latest Journal Issues
Nuclear Science and Engineering
March 2025
Nuclear Technology
Fusion Science and Technology
April 2025
Latest News
Nuclear News 40 Under 40 discuss the future of nuclear
Seven members of the inaugural Nuclear News 40 Under 40 came together on March 4 to discuss the current state of nuclear energy and what the future might hold for science, industry, and the public in terms of nuclear development.
To hear more insights from this talented group of young professionals, watch the “40 Under 40 Roundtable: Perspectives from Nuclear’s Rising Stars” on the ANS website.
J. R. Beeler
Nuclear Science and Engineering | Volume 14 | Number 3 | November 1962 | Pages 254-265
doi.org/10.13182/NSE62-A26215
Articles are hosted by Taylor and Francis Online.
Monte Carlo computational experiments were used to study the diffusion anisotropy of fast and slow neutrons in singly- and doubly-periodic, two-region reactor lattices. In two-region systems, it is shown that the separation of the anisotropy factor into a part representing mean free path discontinuity and a part representing absorption probability discontinuity is physically meaningful. In the singly-periodic lattice, the anisotropy factor for fast neutrons was greater than unity, while that for slow neutrons was less than unity. It is possible, however, for the slow neutron anisotropy factor to exceed unity in doubly-periodic lattices. The anisotropy extreme, in the singly-periodic lattice, occurred when the albedo of the moderator slab was equal to that of the fuel slab.