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 Criticality Safety
NCSD provides communication among nuclear criticality safety professionals through the development of standards, the evolution of training methods and materials, the presentation of technical data and procedures, and the creation of specialty publications. In these ways, the division furthers the exchange of technical information on nuclear criticality safety with the ultimate goal of promoting the safe handling of fissionable materials outside reactors.
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
Canada clears Darlington to produce Lu-177 and Y-90
The Canadian Nuclear Safety Commission has amended Ontario Power Generation’s power reactor operating license for Darlington nuclear power plant to authorize the production of the medical radioisotopes lutetium-177 and yttrium-90.
L. D. Noble and J. O. Mingle
Nuclear Science and Engineering | Volume 21 | Number 2 | February 1965 | Pages 240-249
Technical Paper | doi.org/10.13182/NSE65-A21048
Articles are hosted by Taylor and Francis Online.
In the spherical-harmonics component form of the Boltzmann equation for a cylindrical system with radial symmetry and z-dependence, application of the commonly applied boundary conditions gives rise to more equations than there are unknowns. This paper considers selected combinations of the equations resulting from the application of these radial boundary conditions for the P3 approximation. Numerical evaluation of the angular flux at a free surface and at an interface between two different media shows that a combination of equations which closely satisfies the desired conditions is that suggested by Davison.
