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.
Explore membership for yourself or for your organization.
Conference Spotlight
2026 ANS Annual Conference
May 31–June 3, 2026
Denver, CO|Sheraton Denver
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
Dec 2025
Jul 2025
Latest Journal Issues
Nuclear Science and Engineering
January 2026
Nuclear Technology
December 2025
Fusion Science and Technology
November 2025
Latest News
AI at work: Southern Nuclear’s adoption of Copilot agents drives fleet forward
Southern Nuclear is leading the charge in artificial intelligence integration, with employee-developed applications driving efficiencies in maintenance, operations, safety, and performance.
The tools span all roles within the company, with thousands of documented uses throughout the fleet, including improved maintenance efficiency, risk awareness in maintenance activities, and better-informed decision-making. The data-intensive process of preparing for and executing maintenance operations is streamlined by leveraging AI to put the right information at the fingertips for maintenance leaders, planners, schedulers, engineers, and technicians.
M. opi
Nuclear Science and Engineering | Volume 49 | Number 3 | November 1972 | Pages 370-376
Technical Note | doi.org/10.13182/NSE72-A22549
Articles are hosted by Taylor and Francis Online.
A new approach to the determination of average neutron transport properties of regular lattices is presented in a form amenable to any desired order of approximation. It is based on the time dependent one group integro-differential transport equation in which the cross sections are expanded in Fourier series corresponding to the periodicity of the lattice. The integral transform method yields in this case the Fourier series also for the neutron density, the zero’th term of which is separated out as the average over the lattice. The remaining Fourier coefficients are solved by a method analogous to the collision probability method and expressed in terms of the angular moments of the average neutron density. An approximate integral transform of the transport equation for the average neutron angular density is obtained that contains through its effective scattering integral the effects of the anisotropy and of the heterogeneity of the lattice. The method is applied to the problem of anisotropic diffusion constants in lattices containing voids, in particular, the diffusion constant parallel to empty channels at large channel radia is resolved. As an example, the simultaneous determination of the disadvantage factor and the anisotropic diffusion constant is also presented.