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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.
U. Malik, L. S. Kothari, A. Kumar
Nuclear Science and Engineering | Volume 81 | Number 1 | May 1982 | Pages 137-143
Technical Note | doi.org/10.13182/NSE82-A19600
Articles are hosted by Taylor and Francis Online.
Neutron diffusion in graphite containing 1/v and non-1/v absorbers has been studied in the diffusion theory approximation using a multigroup (30-group) approach and the neutron scattering kernel proposed earlier by the authors. It is observed that, in this case as in the case of water investigated earlier, the behavior of neutrons in graphite poisoned with gadolinium is different from that in graphite poisoned with samarium or cadmium. To explain the reason for this difference, a hypothetical model for the energy variation of the absorption cross section has been constructed that closely resembles samarium in one limit and goes over to gadolinium in the other. The effect of varying the concentration of non-1/v absorbers on the flux of sub-Bragg and epicold neutrons has been studied for this model, and some interesting results are obtained.