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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.
W. N. McElroy, R. J. Armani, E. Tochilin
Nuclear Science and Engineering | Volume 48 | Number 1 | May 1972 | Pages 51-71
Technical Paper | doi.org/10.13182/NSE72-A22456
Articles are hosted by Taylor and Francis Online.
Previously reported inconsistencies between activation detector and n, p scattering/time-of-flight (TOF) measurements of the thermal-neutron-induced 235U fission spectrum prompted a comparison of such measurements in the core center and on the surface of a bare 235U assembly, referred to as Godiva. For the present study, TOF measurements and multiple foil measurements of the core and surface spectra of the APFA-III-Godiva are compared. Comparison of the integral fluxes above specified energies for the two methods shows agreement to within ∼5% at core center. Results obtained at in. from the core surface, however, show disagreement between the multiple foil and TOF (and previously reported photo-plate data) which is similar to that found for measurements in the fissionspectrum. Results for the fission spectrum are re-analyzed using the same evaluated energy-dependent cross sections as used for the Godiva study but with a larger number of foil reactions than previously available. A Monte Carlo error analysis code is used for the assignment of errors for the activation results for the Godiva and fission spectrum studies. It is concluded that if the activation measurements of the Godiva and fission spectrum remain firm, and significant changes in current evaluated reaction cross sections are not effected, then increases up to as much as 10 to 15% in the mean energy of the Godiva leakage and fissionspectrum must be considered.