Operators shut down the Unit 1 reactor at the Susquehanna nuclear power plant in northeastern Pennsylvania early Friday after 282 days of consecutive operation to begin a planned refueling and maintenance outage, PPL Susquehanna says.

Each of the two units at the Susquehanna nuclear plant is taken out of service for refueling and maintenance every 24 months. The company said this outage will include "an inspection of the Unit 1 main turbine to confirm that there is no recurrence of the cracks discovered in 2011 that led PPL to replace affected turbine blades."

Workers will replace about 40 percent of the uranium fuel and complete hundreds of scheduled equipment maintenance tasks and upgrades. Unit 2 at the plant continues to operate at full power.