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.
B. Merk, F. P. Weiß
Nuclear Science and Engineering | Volume 163 | Number 2 | October 2009 | Pages 152-174
Technical Paper | doi.org/10.13182/NSE163-152
Articles are hosted by Taylor and Francis Online.
This work presents the development of an analytical approximation solution for a space-time-dependent neutron transport problem in a one-dimensional system consisting of a homogenized medium with a central external source with Green's functions. The delayed neutron production is implemented in two additional timescales with the multiple-scale expansion method. Qualitative results for a given system are analyzed, and a detailed comparison of the developed analytical approximation solution with results gained by the point-kinetics equation and the time-dependent diffusion equation without separation of space and time is given.
