After a brief forced outage, Indiana Michigan Power’s Cook Nuclear Plant Unit 2 was returned to service just after midnight, at 12:44 a.m., Thursday, July 25.
At 8:26 a.m. on July 21, Cook’s Unit 2 was safely taken offline after operators noted a gradual decline in performance of both of the unit’s two non-essential service water pumps. Non-essential service water is used to maintain cooling for the main turbine’s lube oil system as well as other non-nuclear and non-safety-related systems. In order to make the necessary pump repairs, Cook Plant operators made the conservative decision to execute the safe, controlled shutdown of Unit 2.
Cook’s Unit 1 remained full power throughout the duration of the Unit 2 forced outage. Subsequent system inspection following the shutdown found that the pump strainers had become clogged with lake debris. The clogged components were cleaned, re-inspected and returned to service. A full causal analysis has been initiated to develop further actions to prevent the issue from recurring.
At full capacity, the 1,084-net MW Unit 1 and 1,194-net MW Unit 2 combined produce enough electricity for more than one and one half million average homes.
Indiana Michigan Power is a wholly owned subsidiary of American Electric Power (NYSE:AEP).
