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.
R. J. Jiacoletti, W. K. Brown, H. G. Olson
Nuclear Science and Engineering | Volume 48 | Number 4 | August 1972 | Pages 412-419
Technical Paper | doi.org/10.13182/NSE72-A22509
Articles are hosted by Taylor and Francis Online.
The 237Np(n,f) cross section has been measured relative to the 235U(n,f) cross section from 20 eV to 7 MeV, including the range where no data previously existed (4 to 24 keV). Energies of the source neutrons from the Physics 8 underground nuclear explosion were determined by measuring the time-of-flight from the source to the neptunium target foil. The current signals produced in solid-state detectors by fission fragments were photographically recorded and converted to cross sections using the neutron flux measured with 235U(n,f)and 6Li(w,α)T reactions. Subthreshold resonances were observed in the 237Np(n,f) cross section. The maximum value of the cross section observed just above threshold is 1.9 b at 2.26 MeV. A comparison of results with some previously reported values is presented.Present address: University of Wyoming, Laramie, Wyoming 82070.
