Londonderry Township, PA - Three Mile Island Unit 1 returned to service today at 9:12 a.m. EDT when operators connected the plant's turbine generator to the regional power grid. The unit automatically shut down on Sept. 20 due to an unexpected actuation of a relay switch on a reactor coolant pump. Plant personnel replaced the relay, installed additional monitoring capabilities of the relay and tested the pump prior to restarting the plant.
"We performed the necessary repairs safely and efficiently and are committed to a reliable operating cycle," said Rick Libra, TMI Site Vice President.
Three Mile Island is located about 12 miles south of Harrisburg, Pa. The plant generates 852 megawatts of carbon free power - enough electricity for about 800,000 homes. Electric customers were not affected by the plant being off-line.