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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.
L. F. Hansen, J. D. Anderson, E. Goldberg, J. Kammerdiener, E. Plechaty, C. Wong
Nuclear Science and Engineering | Volume 40 | Number 2 | May 1970 | Pages 262-282
Technical Paper | doi.org/10.13182/NSE70-A19688
Articles are hosted by Taylor and Francis Online.
Using the sphere transmission and time-of-flight techniques, the neutron spectra emitted from 0.58 and 3.0 mfp of nitrogen and from 0.72 mfp of oxygen have been measured for a 14-MeV neutron source. The analysis of the data has been done using the Livermore Monte Carlo Neutron-Transport Program (SORS). Good agreement was obtained for nitrogen with a revised SORS calculation, where five inelastic levels are explicitly included in the computational routine for the (n,n′) cross sections. To obtain agreement between calculations and measurements for oxygen, the computational model had to be extended so that it could account for the presence of inelastic levels. A revision of the cross sections was also carried out. With these new versions of SORS, excellent fits to the experimental measurements for nitrogen and oxygen were obtained. Using the revised SORS program, calculations for the transport of neutrons in air from a 14-MeV point neutron source were obtained.