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NRC unveils Part 53 final rule
The Nuclear Regulatory Commission has finalized its new regulatory framework for advanced reactors that officials believe will accelerate, simplify, and reduce burdens in the new reactor licensing process.
The final rule arrives more than a year ahead of an end-of-2027 deadline set in the Nuclear Energy Innovation and Modernization Act (NEIMA), the 2019 law that formally directed the NRC to develop a new, technology-inclusive regulatory approach. The resulting rule—10 CFR Part 53, “Risk-Informed, Technology-Inclusive Regulatory Framework for Advanced Reactors”—is commonly referred to as Part 53.
John F. Carew, David J. Diamond
Nuclear Technology | Volume 50 | Number 3 | October 1980 | Pages 252-256
Technical Paper | Fuel | doi.org/10.13182/NT80-A32528
Articles are hosted by Taylor and Francis Online.
An evaluation of the relationship between operating limit uncertainty allowance and fuel performance has been made. A simple analytic relation between uncertainty allowance and the number of fuel rods exceeding fuel limits due to measurement uncertainties has been derived. An evaluation of this relation for selected and bounding power distributions indicates that the expected fraction of the core challenging fuel limits is strongly dependent on (a) the operating power distribution and (b) the estimates of measurement uncertainties used in determining the operating limit uncertainty allowance. Also, the various (1-sigma, 2-sigma, 95/95, etc.) criteria used in selecting uncertainty allowance are found to differ significantly in terms of the number of rods that exceed fuel limits.
