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
Latest Magazine Issues
Mar 2026
Jan 2026
Latest Journal Issues
Nuclear Science and Engineering
April 2026
Nuclear Technology
February 2026
Fusion Science and Technology
Latest News
NRC to add new items to categorical exclusions list
The Nuclear Regulatory Commission has identified five categories of action to add to its list of categorical exclusions to reduce its documentation work under National Environmental Policy Act (NEPA) procedures.
These revisions are included in the final rule, “Categorical exclusions from environmental review,” which was published in the Federal Register on March 30. The final rule will become effective on April 29.
S. N. Cramer
Nuclear Science and Engineering | Volume 139 | Number 2 | October 2001 | Pages 186-208
Technical Paper | doi.org/10.13182/NSE01-A2231
Articles are hosted by Taylor and Francis Online.
Several one-energy group, discrete-direction radiation transport systems having analytic flux solutions are presented as an aid in Monte Carlo benchmark analysis techniques independent of realistic geometry and cross-section data requirements. Exact comparison of analytic and Monte Carlo results to several significant digits is possible for up to 26 directions in one, two, and three dimensions. A continuous direction model has also been formulated from an infinite limit of the discrete-direction model. Complete analytic flux solutions are possible through the imposition of boundary sources dictated by assumed exponential solutions of the transport equation. Extensions to two energy groups, two cross-section media, secondary particle production, time dependence, and continuous slowing down are examined. A website is provided from which codes and sample output files for the analytic and Monte Carlo models can be downloaded.