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
Education, Training & Workforce Development
The Education, Training & Workforce Development Division provides communication among the academic, industrial, and governmental communities through the exchange of views and information on matters related to education, training and workforce development in nuclear and radiological science, engineering, and technology. Industry leaders, education and training professionals, and interested students work together through Society-sponsored meetings and publications, to enrich their professional development, to educate the general public, and to advance nuclear and radiological science and engineering.
Meeting Spotlight
Conference on Nuclear Training and Education: A Biennial International Forum (CONTE 2025)
February 3–6, 2025
Amelia Island, FL|Omni Amelia Island Resort
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
Jan 2025
Jul 2024
Latest Journal Issues
Nuclear Science and Engineering
February 2025
Nuclear Technology
Fusion Science and Technology
Latest News
IAEA’s nuclear security center offers hands-on training
In the past year and a half, the International Atomic Energy Agency has established the Nuclear Security Training and Demonstration Center (NSTDC) to help countries strengthen their nuclear security regimes. The center, located at the IAEA’s Seibersdorf laboratories outside Vienna, Austria, has been operational since October 2023.
Dean Wang
Nuclear Science and Engineering | Volume 193 | Number 12 | December 2019 | Pages 1339-1354
Technical Paper | doi.org/10.1080/00295639.2019.1638660
Articles are hosted by Taylor and Francis Online.
The SN transport equation asymptotically tends to an equivalent diffusion equation in the limit of optically thick systems with small absorption and sources. A spatial discretization of the SN equation is of practical interest if it possesses the optically thick diffusion limit. Such a numerical scheme will yield accurate solutions for diffusive problems if the spatial mesh size is thin with respect to a diffusion length, whereas the mesh cells are thick in terms of a mean free path. Many spatial discretization methods have been developed for the SN transport equation, but only a few of them can obtain the thick diffusion limit under certain conditions. This paper presents a theoretical result that simply states that the mesh size required for a finite difference scheme to attain the diffusion limit is , where is the order of accuracy of spatial discretization, is the “diffusion” mesh size that can be many mean free paths thick, and is a small positive scaling parameter that can be defined as the ratio of a particle mean free path to a characteristic scale length of the system. Numerical results for schemes such as the Diamond Difference method, Step Characteristic method, Step Difference method, Second-Order Upwind method, and Lax-Friedrichs Weighted Essentially Non-Oscillatory method of the third order (LF-WENO3) are presented that demonstrate the validity and accuracy of our analysis.
