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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.
E.A. Straker
Nuclear Science and Engineering | Volume 46 | Number 3 | December 1971 | Pages 334-355
Technical Paper | doi.org/10.13182/NSE71-A22371
Articles are hosted by Taylor and Francis Online.
Calculations have been made of the space, energy, angle, and time dependence of the neutron and secondary gamma-ray fields produced in the atmosphere by several neutron sources, and the results for a 12.2- to 15-MeV source and a fission source are compared in this paper. They include steady-state and time-dependent results at ranges out to 1500 m for both an infinite air medium and an air-over-ground medium, the latter for source heights of 15 and 343 m. The data show that the neutron doses and dose rates from the 12.2- to 15-MeV source are higher than those from the fission source in all geometries and time intervals. While the secondary gamma-ray doses produced by the 12.2- to 15-MeV source also are higher than those produced by the fission source in all geometries, the secondary dose rates are higher only for times less than 10-3 sec, after which the dose rates from the two sources are comparable. The effects of the ground are to enhance both the neutrons and the secondary gamma rays at ranges close to the source and to act as an absorber at ranges far from the source. These effects decrease with increasing source height.
