South Texas 1 completes Spring refuel in 33 days, caps 497-day B2B run

[News Wire]

South Texas 1 completed its refueling outage in 33 days, which was one day longer than the planned 32-day schedule. This duration is 13.2 days below the average of the unit's 17 prior refuels. The outage concluded following a 747-day unscheduled-outage-free streak for the 1,280-MW Westinghouse 4-loop PWR.

33 days outage · 1 day past schedule · ninth B2B run complete · 1,280 MW back online

South Texas 1 resumed power production on Apr 22, 2026 after a 33-day Spring 2026 refueling outage that began Mar 21, 2026.

The published schedule had it at 32 days (Mar 20, 2026 to Apr 21, 2026), so the actual ran 1 day longer than planned.

The outage ran about 13 days shorter than the unit's 17-cycle average of 46.2 days. It also capped a 497-day breaker-to-breaker run (over the 454-day threshold for an 18-month cycle), the unit's ninth qualified B2B run. Going into the refueling, the unit had run for more than 2 years without an unscheduled outage. NukeWorker's predictive model scores 95% on duration accuracy for this unit.

The 33-day outage removed roughly 933,000 MWh from the grid, worth approximately $37 million at recent wholesale prices, equivalent to a year's electricity for about 86,000 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, South Texas 2 is running at full power. Quad Cities 2, Ginna, and McGuire 2 also completed refueling outages within the past week.

South Texas 1 is a 1,280-MW Westinghouse 4-loop PWR operated by STP Nuclear Operating (commercial operation since 1988). At full power, it supplies enough electricity for roughly 1 million homes. The utility operates 1 other U.S. nuclear unit. Its operating license runs through 2047 (renewed in 2017). The unit ran at a 100.0% capacity factor in 2025, among the unit's strongest cycles.

View South Texas 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.