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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.
A. Trkov, G. L. Molnár, Zs. Révay, S. F. Mughabghab, R. B. Firestone, V. G. Pronyaev, A. L. Nichols, M. C. Moxon
Nuclear Science and Engineering | Volume 150 | Number 3 | July 2005 | Pages 336-348
Technical Paper | doi.org/10.13182/NSE05-A2520
Articles are hosted by Taylor and Francis Online.
The precise value of the thermal capture cross section of 238U is uncertain, and evaluated cross sections from various sources differ by more than their assigned uncertainties. A number of the original publications have been reviewed to assess the discrepant data, corrections were made for more recent standard cross sections and other constants, and one new measurement was analyzed. Because of the strong correlations in activation measurements, the gamma-ray emission probabilities from the - decay of 239Np were also analyzed. As a result of the analysis, a value of 2.683 ± 0.012 b was derived for the thermal capture cross section of 238U. A new evaluation of the gamma-ray emission probabilities from 239Np decay was also undertaken.
