Limerick 1 completes Spring refuel in 23 days, caps 731-day B2B run

[Core Content]

Limerick 1 finished its refueling outage one day ahead of the 24-day schedule. The 23-day duration marks the fifth-longest among the unit's 14 tracked refuels. This performance follows an 844-day unscheduled-outage-free streak for the unit.

23 days outage · 1 day ahead of schedule · fifth B2B run complete · 1,120 MW back online

After 23 days offline for its Spring 2026 refueling outage, Limerick 1 returned to the grid on May 19, 2026. The outage began on Apr 27, 2026.

The published schedule had it at 24 days (Apr 20, 2026 to May 14, 2026), so the actual ran 1 day shorter than planned.

It also capped a 731-day breaker-to-breaker run (over the 628-day threshold for a 24-month cycle), the unit's fifth 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 97% on duration accuracy for this unit.

The 23-day outage removed roughly 569,000 MWh from the grid, worth approximately $23 million at recent wholesale prices, equivalent to a year's electricity for about 53,000 homes.

Across the U.S. fleet of 94 commercial reactors, today's combined capacity factor is 91.9% (4 currently in refueling, 1 in unscheduled outages), above the 87.0% baseline for this month over the past five years. At the same site, Limerick 2 is running at full power. Palisades, Surry 2, Saint Lucie 2, and Comanche Peak 2 also completed refueling outages within the past week.

Limerick 1 is a 1,120-MW General Electric BWR/4 operated by Constellation Nuclear (commercial operation since 1986). At full power, it supplies enough electricity for roughly 896,000 homes. The utility operates 20 other U.S. nuclear units. Its operating license runs through 2044 (renewed in 2014). The unit ran at a 99.9% capacity factor in 2025, among the unit's strongest cycles.

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

Want the full picture? Subscribe to the NukeWorker outage schedule for every current and upcoming U.S. nuclear outage: refueling, forced, and the 18-month rolling forecast.

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