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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.
Yoshihiko Kanemori, Yutaka Furuta
Nuclear Science and Engineering | Volume 36 | Number 2 | May 1969 | Pages 238-245
Technical Paper | doi.org/10.13182/NSE69-A19721
Articles are hosted by Taylor and Francis Online.
Dose rates of gamma rays from a 60Co cylindrical source surrounded coaxially by a cylindrical shield were measured in the radial direction in a plane passing through the midpoint of the axis of the source. The 60Co was uniformly distributed in a water-like medium. The shield was composed of water and iron, each in a single layer, and of water and iron in a double layer. The concept of the dose buildup factor for a volume source was introduced and the behavior of gamma rays scattered from the shielded cylindrical source was considered. The variation of the dose buildup factor for the shielded cylindrical source as a function of the distance from the source is less than the variation for the unshielded source. The dose buildup factor for a cylindrical source, with and without shields, shows many features that differ from those generally observed, i.e., an infinite medium surrounding a point source and one obtained from the total gamma-ray dose rates calculated by integration of an attenuation kernel with dose buildup factors for a point isotropic source. The unique behavior of the dose buildup factor for the cylindrical source with a cylindrical shield is shown by supplemental experiments with a 60Co point source to be due to the cylindrical shape of the source and shields.
