Watts Bar 1 completes Spring refueling outage in 28 days

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Watts Bar 1 finished its refueling outage in 28 days, completing the work one day ahead of the 29-day schedule. This duration is 11.4 days shorter than the average of the unit's 18 prior refuels. The unit entered this maintenance period following an unscheduled-outage-free streak of 691 days.

28 days outage · 1 day ahead of schedule · 1,123 MW back online

Watts Bar 1 completed its Spring 2026 refueling outage on May 15, 2026, returning to service after 28 days. The outage began on Apr 18, 2026.

The published schedule had it at 29 days (Apr 17, 2026 to May 16, 2026), so the actual ran 1 day shorter than planned.

The outage ran about 11 days shorter than the unit's 18-cycle average of 39.4 days. Going into the refueling, the unit had run for about 23 months without an unscheduled outage.

The 28-day outage removed roughly 694,000 MWh from the grid, worth approximately $28 million at recent wholesale prices, equivalent to a year's electricity for about 64,000 homes.

Across the U.S. fleet of 94 commercial reactors, today's combined capacity factor is 91.3% (5 currently in refueling), above the 87.0% baseline for this month over the past five years. At the same site, Watts Bar 2 is running at full power. Vogtle 3, Catawba 1, Millstone 2, and Saint Lucie 2 also completed refueling outages within the past week.

Watts Bar 1 is a 1,123-MW Westinghouse 4-loop PWR operated by Tennessee Valley Authority (commercial operation since 1996). At full power, it supplies enough electricity for roughly 898,000 homes. The utility operates 6 other U.S. nuclear units. Its operating license runs through 2035. The unit ran at a 68.5% capacity factor in 2025, with some downtime through the year.

View Watts Bar 1's ratings, history, predictions, and current status on NukeWorker.

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