FirstEnergy Nuclear Operating Company (FENOC), a subsidiary of FirstEnergy, announced its Davis-Besse Nuclear Power Station in Oak Harbor, Ohio, shut down at for scheduled refueling and maintenance.

While the unit is offline, about a third of the unit’s 177 fuel assemblies will be replaced. Preventative maintenance and safety inspections to ensure continued safe and reliable operations also will be performed on major components including various pumps, valves, reactor vessel, steam generators and the cooling tower.

A major project during the outage is replacement of two of the plant’s four reactor coolant pump motors. These 50-ton, 16-foot tall, 9,000-horsepower motors drive large pumps capable of pushing more than 100,000 gallons of water per minute through the reactor vessel, helping control reactor power and ensuring the fuel remains cooled. Davis-Besse received a 20-year license extension from the Nuclear Regulatory Commission in December 2015, and this work, along with the other outage inspections and preventative maintenance, will ensure the plant continues to operate safely and reliably during the period of extended operation.

More than 1,000 temporary contractor workers and FENOC and FirstEnergy employees will supplement the Davis-Besse workforce during the outage.

The 908-megawatt Davis-Besse Nuclear Power Station has operated safely and reliably, generating more than 14.5 million megawatt hours of electricity since the completion of its last refueling in May 2014.