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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.
M. M. R. Williams
Nuclear Science and Engineering | Volume 174 | Number 2 | June 2013 | Pages 172-178
Technical Paper | doi.org/10.13182/NSE12-45
Articles are hosted by Taylor and Francis Online.
A new approach is developed for solving stochastic eigenvalue problems that arise when uncertainty is present in the cross-section data in a critical assembly. The method has been shown to agree with values obtained from a direct quadrature. The new approach, which uses a polynomial chaos expansion (PCE), does not involve the nonlinear equations associated with the classical method of PCE, but rather a linear equation obtained by considering an equivalent time-dependent problem; it therefore leads to much simpler calculational procedures. The convergence of the method is rapid, and it is illustrated by numerical examples based upon a criticality problem and also by comparison with a problem that uses the nonlinear method.