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.
M. Rajagopalan, H. S. Pruys, A. Grütter, H. R. von Gunten, E. A. Hermes, R. Richmond, E. Rössler, A. Schmid, P. Wydler
Nuclear Science and Engineering | Volume 58 | Number 4 | December 1975 | Pages 414-419
Technical Paper | doi.org/10.13182/NSE75-A26796
Articles are hosted by Taylor and Francis Online.
The yields of 27 mass chains in the fission of 235U and the ratio of fast-neutron to thermal-neutron fission yields (the “R” value) of 21 mass chains in the fission of 239Pu induced by fast neutrons (median energy ∼180 keV) have been measured in the reactor PROTEUS. The yields were obtained by a comparison method using gamma-ray spectroscopy. The data show that, in agreement with other authors, yields in the peaks of the mass distribution do not change compared to thermal-neutron-induced fission.