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2025 annual assessments out for U.S. reactors
The Nuclear Regulatory Commission has released its 2025 annual performance assessments of the country’s 95 operating commercial nuclear reactors. And of the 95 reactors, all but five earned the highest marks.
Nuclear power plant assessments can fall under one of five categories: Licensee Response, Regulatory Response, Degraded Cornerstone, Degraded Performance, and Unacceptable Performance. Ninety reactors fell under Licensee Response, the highest performance category in safety and security. Plants that achieve this level of performance are subject to a Reactor Oversight Process (ROP) baseline inspection.
Carolyn McGraw, Germina Ilas
Nuclear Technology | Volume 183 | Number 3 | September 2013 | Pages 436-445
Technical Paper | Fission Reactors / Radiation Transport and Protection | doi.org/10.13182/NT13-A19431
Articles are hosted by Taylor and Francis Online.
New pressurized water reactor (PWR) cross-section libraries were generated for use with the ORIGEN-ARP depletion sequence in the SCALE nuclear analysis code system. These libraries are based on ENDF/B-VII.0 nuclear data and were generated using the two-dimensional depletion sequence, TRITON/NEWT, in SCALE 6.1. The libraries contain multiple burnup-dependent cross sections for seven PWR fuel designs, with enrichments ranging from 1.5 to 6 wt% 235U and burnups from 0 to 90 GW(d)/tonne U. The computational methodology and studies performed to establish an optimal depletion model for cross-section library generation are discussed in this paper. Verification against detailed TRITON simulations for the considered assembly designs showed that depletion calculations performed in ORIGEN-ARP with the pregenerated libraries provide results similar to those obtained with direct TRITON depletion while greatly reducing the computation time. Validation of the libraries, carried out using radiochemical assay measurements and decay heat measurements for PWR spent fuel, showed good agreement between calculated and experimental data.