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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. E. Abbott, E. J. Allen
Nuclear Science and Engineering | Volume 108 | Number 3 | July 1991 | Pages 278-288
Technical Note | doi.org/10.13182/NSE91-A23825
Articles are hosted by Taylor and Francis Online.
Two new difference schemes are derived for numerically solving the transport equation in spherical geometry. The first difference method is positive; i.e., the calculated fluxes are never negative. Furthermore, for the first method, the error expansion is suitable for applying Richardson extrapolation with respect to both spatial and angular variables to increase the accuracy of the approximate fluxes. Numerical experiments illustrate the accuracy obtained using this procedure, as well as demonstrate that the accuracy of the second difference method is significantly improved through application of Richardson extrapolation. In addition, the numerical results indicate that the second method is significantly more accurate than the standard nonextrapolated diamond-difference method for numerically solving the transport equation in spherical geometry.