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
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!
Latest Magazine Issues
Jul 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
August 2025
Nuclear Technology
Fusion Science and Technology
Latest News
ANS joins others in seeking to discuss SNF/HLW impasse
The American Nuclear Society joined seven other organizations to send a letter to Energy Secretary Christopher Wright on July 8, asking to meet with him to discuss “the restoration of a highly functioning program to meet DOE’s legal responsibility to manage and dispose of the nation’s commercial and legacy defense spent nuclear fuel (SNF) and high-level radioactive waste (HLW).”
Dean Wang, Tseelmaa Byambaakhuu
Nuclear Science and Engineering | Volume 195 | Number 12 | December 2021 | Pages 1347-1358
Technical Note | doi.org/10.1080/00295639.2021.1924048
Articles are hosted by Taylor and Francis Online.
It has been well known that the analytic neutron transport solution tends to the analytic solution of a diffusion problem for optically thick systems with small absorption and source. The standard technique for proving the asymptotic diffusion limit is constructing an asymptotic power series of the neutron angular flux in small positive parameter , which is the ratio of a typical mean free path of a particle to a typical dimension of the problem domain. In this paper, first, we provide an analysis of the asymptotic properties of the SN transport eigenvalues. Then, we show that the analytical SN transport solution satisfies the diffusion equation in the asymptotic diffusion limit based on a recently obtained closed-form analytical solution to the one-dimensional monoenergetic SN neutron transport equation. The boundary conditions for the diffusion equation are discussed.