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.
Mihály Makai
Nuclear Science and Engineering | Volume 82 | Number 3 | December 1982 | Pages 338-353
Technical Paper | doi.org/10.13182/NSE82-338
Articles are hosted by Taylor and Francis Online.
Solving problems of reactor physics is well developed for typical pressurized water and boiling water reactor geometries but less developed for high-temperature gas-cooled reactor, liquid-metal fast breeder reactor, and WWER (BBP) geometries. Several problems of reactor physics can be formulated in a geometry-independent fashion with the help of symmetry considerations, which allows the solution to be decomposed into eigenfunctions of the symmetry operations. An analytic coarse-mesh solution is derived without resorting to the cross leakage concept. The method is applicable to arbitrary geometries. A second-stage homogenization based on the Bloch theorem is presented. It is shown that the solution of the transport equation can always be made up from a cell problem set (microfunctions) and from an overall solution to the diffusion equation (macrofunction).