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
May 2026
Jan 2026
2026
Latest Journal Issues
Nuclear Science and Engineering
June 2026
Nuclear Technology
Fusion Science and Technology
Latest News
NRC proposes changes to its rules on nuclear materials
In response to Executive Order 14300, “Ordering the Reform of the Nuclear Regulatory Commission,” the NRC is proposing sweeping changes to its rules governing the use of nuclear materials that are widely used in industry, medicine, and research. The changes would amend NRC regulations for the licensing of nuclear byproduct material, some source material, and some special nuclear material.
As published in the May 18 Federal Register, the NRC is seeking public comment on this proposed rule and draft interim guidance until July 2.
E. M. Pennington
Nuclear Science and Engineering | Volume 52 | Number 4 | December 1973 | Pages 486-492
Technical Note | doi.org/10.13182/NSE73-A23318
Articles are hosted by Taylor and Francis Online.
Reactor physics calculations were performed with ENDF/B Version-Ill cross-section data for several of the fast-reactor data-testing assemblies specified by the Cross Section Evaluation Working Group. In these calculations, multigroup cross sections were generated using both the Argonne MC2 and SDX codes for comparative purposes. The multigroup cross sections were then used in Sn transport-theory calculations to obtain keff and central activation ratios, and in perturbation-theory calculations to obtain central worths. Results with MC2 and SDX cross sections are in good agreement except when regions containing large amounts of a structure material are involved.