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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.
M. Hayashi, T. Nishigori, R. G. Alsmiller, Jr., R. A. Lillie
Nuclear Science and Engineering | Volume 109 | Number 4 | December 1991 | Pages 391-400
Technical Paper | doi.org/10.13182/NSE91-A23864
Articles are hosted by Taylor and Francis Online.
Calculational studies are conducted of neutron and gamma-ray transport in the beam tubes of a proposed high-flux reactor for the Advanced Neutron Source. To avoid excessively long computing times, the calculations were carried out by coupling two, two-dimensional discrete ordinates calculations. The calculational methodology used is briefly described. Calculated results are presented of the thermal neutron, nonthermal neutron, and gamma-ray fluxes in a radial and a tangential beam tube. Both scalar and angular fluxes in and at the exit of the beam tubes are given. When compared with the radial beam tube, the tangential beam tube shows a lower flux of high-energy neutrons and a much lower flux of gamma rays. The spectral characteristics of the particle fluxes at the exits of the beam tubes are similar to those at the entrances.