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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.
K. Shure, J. A. O'Brien, D. M. Rothberg
Nuclear Science and Engineering | Volume 35 | Number 3 | March 1969 | Pages 371-375
Technical Paper | doi.org/10.13182/NSE69-A20016
Articles are hosted by Taylor and Francis Online.
Effective removal cross sections for iron and lead that can be applied to fast-neutron dose rate calculations have been determined from calculated spatial-spectral neutron distributions as a function of succeeding polyethylene thickness. These cross sections increase with polyethylene thickness, and for large polyethylene thicknesses, they are in agreement with those derived from experiment. From the spatial-spectral neutron distributions, relative contributions of various neutron energy ranges to the neutron dose rate have been calculated as a function of succeeding polyethylene thickness. For polyethylene thicknesses > 30 cm, fast (E > 302 keV), epithermal (302 keV > E > 0.625 eV), and thermal (E < 0.625 eV) neutrons contribute 83, 6, and 11%, respectively, to the neutron dose rate.
