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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.
Seungsu Yuk, Nam Zin Cho
Nuclear Science and Engineering | Volume 181 | Number 1 | September 2015 | Pages 1-16
Technical Paper | doi.org/10.13182/NSE14-88
Articles are hosted by Taylor and Francis Online.
In this paper, we present two novel approaches to reactor core analysis: (1) whole-core fine-group deterministic transport calculations are accelerated by a partial-current-based coarse-mesh finite-difference (p-CMFD) method, and (2) a whole-core domain is decomposed into nonoverlapping local problems, with local problem transport solutions then embedded within the p-CMFD methodology in a two-level iterative scheme to provide a whole-core transport solution. To solve three-dimensional (3-D) reactor problems, both approaches use the two-dimensional/one-dimensional (2-D/1-D) fusion method as a solution kernel, which employs a 2-D method of characteristics in the radial direction and a 1-D SN-like method in the axial direction. A refinement sensitivity study of a 3-D boiling water reactor assembly problem shows the stability and accuracy of the 2-D/1-D fusion method. We report the results of these two approaches as applied to three whole-core configurations of the C5G7 OECD/NEA 3-D benchmark problem and to a modified C5G7 benchmark problem with explicitly modeled cladding.