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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.
Hangbok Choi
Nuclear Science and Engineering | Volume 137 | Number 1 | January 2001 | Pages 38-51
Technical Paper | doi.org/10.13182/NSE01-A2174
Articles are hosted by Taylor and Francis Online.
The fuel composition heterogeneity effect on reactor performance parameters was assessed by refueling simulations for three DUPIC fuel options of fuel composition heterogeneity control: fissile content adjustment, reactivity control by slightly enriched and depleted uranium, and reactivity control by natural uranium. For each DUPIC fuel option, the simulations were performed using 30 heterogeneous fuel types, which were determined by the agglomerative hierarchical clustering method. The heterogeneity effect was considered during the refueling simulation by randomly selecting fuel types for the refueling operation. The refueling simulations of the heterogeneous core have shown that the key performance parameters, such as the maximum channel power (MCP), maximum bundle power (MBP), and channel power peaking factor (CPPF), are close to those of the core that has a single fuel type. For the three DUPIC fuel options, the uncertainties of MCP, MBP, and CPPF due to the fuel composition heterogeneity are <0.6, 1.5, and 0.8%, respectively. This study has shown that the three DUPIC fuel options reduce the composition heterogeneity effectively, and the zone power control system has a sufficient margin to adjust the perturbations caused by fuel composition heterogeneity.