Maintenance Schedules

Nuclear Power Plant Picture Besides occasional unexpected repairs, generators require periodic scheduled maintenance. Nuclear units must be refueled every 12 to 18 months, and fossil fuel units require boiler maintenance outages of 3 to 6 weeks in length about every 12 to 18 months. Most maintenance is scheduled during seasons when the load is relatively low--typically in the spring and fall. But, there is always the risk of unseasonable "freak weather" that could increase demand unexpectedly during a scheduled maintenance outage.