Oconee 3 completes Spring refuel in 23 days, caps 686-day B2B run

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Oconee 3 completed its spring refueling outage in 23 days, finishing one day ahead of the 24-day schedule. This performance represents a reduction of 13.9 days compared to the average duration of the unit's 15 previous refueling outages.

The 23-day duration ranks as the 13th-longest among the 16 tracked refuels for this 859-MW Babcock and Wilcox pressurized water reactor. The unit entered this maintenance period following a 687-day unscheduled-outage-free streak and a 2025 capacity factor of 99.8 percent. Duke Energy Carolinas operates this unit along with six other nuclear units in the United States. Across the broader fleet, 94 units are currently operating at a 94 percent capacity factor, with four other units currently in outage.

23 days outage · 1 day ahead of schedule · third B2B run complete · 859 MW back online

After 23 days offline for its Spring 2026 refueling outage, Oconee 3 returned to the grid on May 28, 2026. The outage began on May 6, 2026.

The published schedule had it at 24 days (May 1, 2026 to May 25, 2026), so the actual ran 1 day shorter than planned.

The outage ran about 14 days shorter than the unit's 15-cycle average of 36.9 days. It also capped a 686-day breaker-to-breaker run, the unit's third qualified B2B run. Going into the refueling, the unit had run for about 23 months without an unscheduled outage. NukeWorker's duration projection scores 97% accuracy for this unit.

The 23-day outage removed roughly 436,000 MWh from the grid, worth approximately $17 million at recent wholesale prices, equivalent to a year's electricity for about 40,000 homes.

Across the U.S. fleet of 94 commercial reactors, today's combined capacity factor is 94.0% (2 currently in refueling, 1 in unscheduled outages), above the 87.0% baseline for this month over the past five years. At the same site, Oconee 1 and Oconee 2 are both running at full power. Comanche Peak 2, Palisades, Surry 2, and Saint Lucie 2 also completed refueling outages within the past week.

Oconee 3 is an 859-MW Babcock & Wilcox PWR operated by Duke Energy Carolinas (commercial operation since 1974). At full power, it supplies enough electricity for roughly 687,000 homes. The utility operates 6 other U.S. nuclear units. Its operating license runs through 2054 (renewed in 2025). The unit ran at a 99.8% capacity factor in 2025, among the unit's strongest cycles.

View Oconee 3's ratings, history, projections, and current status on NukeWorker.

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Sources: NRC Daily Reactor Power Status reports, utility-published outage schedules, and NukeWorker's projections.