Prairie Island 1 begins Fall 2026 refueling outage

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Prairie Island 1, Welch, Minnesota.

Prairie Island 1 began a routine refueling outage on October 3, 2026, starting one day later than its scheduled October 2 start date. The Northern States Power Company of Minnesota operates the 521-megawatt Westinghouse two-loop pressurized water reactor, which entered commercial operation in 1973.

The unit entered this maintenance window following a 438-day unscheduled-outage-free streak and after completing about 93 percent of its typical 669-day operating cycle. The prior 2025 cycle achieved a capacity factor of 92.1 percent, while historical refuel operations average 47.6 days across 15 prior refuels. Across the United States, the nuclear fleet operates at an 85.2 percent capacity factor with 94 units online.

WELCH, MN. Refueling activities began at Prairie Island 1 on Oct 3, 2026. The published schedule had a Oct 2, 2026 start; actual is 1 day later than planned. Planned outage length is 30 days (back to service around Nov 1, 2026).

Going into the refueling, the unit had run for about 15 months without an unscheduled outage. NukeWorker's start-date projection scores 100% accuracy for this unit.

Across the U.S. fleet of 94 commercial reactors, today's combined capacity factor is 85.2% (12 units currently refueling, 1 unit in an unscheduled outage), above the 81.8% baseline for this month over the past five years. At the same site, Prairie Island 2 is running at full power. Palo Verde 1, Robinson 2, Sequoyah 2, and Salem 1 also began refueling outages within the past week. With the unit offline for refueling, that takes about 417,000 homes' worth of generation off the grid.

Prairie Island 1 is a 521-MW Westinghouse 2-loop PWR operated by Northern States Power Co - Minnesota (commercial operation since 1973). The utility operates 2 other U.S. nuclear units. Its operating license runs through 2033 (renewed in 2011). The unit ran at a 92.1% capacity factor in 2025, a solid year of operation.

Heading to Welch, MN for outage work? Current per-diem averages $113/night lodging plus $68/day meals (total $181/day), and Unemployment Benefits are $914 weekly. See open nuclear jobs in Minnesota on NukeWorker.

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