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
Reactor Physics
The division's objectives are to promote the advancement of knowledge and understanding of the fundamental physical phenomena characterizing nuclear reactors and other nuclear systems. The division encourages research and disseminates information through meetings and publications. Areas of technical interest include nuclear data, particle interactions and transport, reactor and nuclear systems analysis, methods, design, validation and operating experience and standards. The Wigner Award heads the awards program.
Meeting Spotlight
2025 ANS Annual Conference
June 15–18, 2025
Chicago, IL|Chicago Marriott Downtown
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
May 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
July 2025
Nuclear Technology
June 2025
Fusion Science and Technology
Latest News
BREAKING NEWS: Trump issues executive orders to overhaul nuclear industry
The Trump administration issued four executive orders today aimed at boosting domestic nuclear deployment ahead of significant growth in projected energy demand in the coming decades.
During a live signing in the Oval Office, President Donald Trump called nuclear “a hot industry,” adding, “It’s a brilliant industry. [But] you’ve got to do it right. It’s become very safe and environmental.”
Nobuo Sasamoto, Kiyoshi Takeuchi
Nuclear Science and Engineering | Volume 80 | Number 4 | April 1982 | Pages 554-569
Technical Paper | doi.org/10.13182/NSE82-A18969
Articles are hosted by Taylor and Francis Online.
A numerical method is presented for calculating neutron transport problems in three-dimensional (x,y,z) geometry on the basis of a method of direct integration of the integral transport equation. Several new techniques are introduced to the method to make it well adapted to practical neutron transport calculations in three-dimensional geometry. A technique for evaluating the scattering source based on an estimated spectral shape in each material region allows use of coarse energy mesh intervals without reducing calculational accuracy as compared with the calculation with fine meshes. A quadratic function approximation for the source spatial distribution in each spatial mesh interval is found to improve the mathematical error in direct integration of the source term over the spatial variable as compared with the linear- or exponential-function approximation used in the original method. In addition, Lagrange's interpolation formula is applied instead of the linear interpolation used in the original method for more accurate estimation of both flux and source. Comparisons are made of the calculations with experiments for three neutron transport problems, the pool critical assembly experiment, the Winfrith iron benchmark experiment, and the annular duct neutron streaming experiment, and also with the three-dimensional Sn calculation to verify the validity of the present method for neutron transport calculations in (x,y,z) geometry.
