Millstone 2 completes Spring refuel in 31 days, caps 522-day B2B run

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Millstone 2 completed its refueling outage in 31 days, which was 3 days longer than the planned 28 days. This duration was 10.8 days below the average of 17 prior refuels. The unit entered this outage with an unscheduled-outage-free streak of 1538 days.

31 days outage · 3 days past schedule · fifth B2B run complete · 853 MW back online

Millstone 2 completed its Spring 2026 refueling outage on May 13, 2026, returning to service after 31 days. The outage began on Apr 13, 2026.

The published schedule had it at 28 days (Apr 9, 2026 to May 7, 2026), so the actual ran 3 days longer than planned. NukeWorker's predictive model came closer, anticipating about 31 days based on the unit's recent cycles, within a day of the actual.

It is the unit's third-shortest refueling outage of 18 cycles tracked since 2000. It also capped a 522-day breaker-to-breaker run (over the 452-day threshold for an 18-month cycle), the unit's fifth qualified B2B run. Going into the refueling, the unit had run for more than 4 years without an unscheduled outage.

The 31-day outage removed roughly 584,000 MWh from the grid, worth approximately $23 million at recent wholesale prices, equivalent to a year's electricity for about 54,000 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, Millstone 3 is running at full power. Catawba 1, Watts Bar 1, Turkey Point 3, and Fermi 2 also completed refueling outages within the past week.

Millstone 2 is an 853-MW COMB CE PWR operated by Dominion Energy Nuclear Conn (commercial operation since 1975). At full power, it supplies enough electricity for roughly 682,000 homes. The utility operates 1 other U.S. nuclear unit. Its operating license runs through 2035 (renewed in 2005). The unit ran at a 100.0% capacity factor in 2025, among the unit's strongest cycles.

View Millstone 2'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.