BRIDGMAN, Mich., June 6, 2002 — Wednesday night, during routine surveillance testing of American Electric Power’s Cook Nuclear Plant Unit 1, the unintended opening of a valve resulted in the transfer of approximately 100 gallons of reactor coolant system water to a holding tank for the system.
Plant operators manually closed the valve after about 15 seconds.
Because reactor coolant system level changed by greater than 25 gallons per minute, the situation was classified as an unusual event, the lowest of four levels in the plant’s emergency plan. Notification of the brief entry and exit into the emergency plan was made to the Nuclear Regulatory Commission.
The holding tank is intended for storage of reactor coolant system water, and no radioactive water was released from the system, to the inside of the Containment Building, or to the atmosphere.
The valve to the holding tank should have been blocked from opening during the test. The testing procedure has been revised to prevent recurrence.
The unit was off-line for a scheduled refueling outage and should return to service by early next week. Cook Unit 2 remains at 100 percent power.
American Electric Power is a multinational energy company with a balanced portfolio of energy assets. AEP, the United States’ largest electricity generator, owns and operates more than 42,000 megawatts of generating capacity in the U.S. and select international markets.
AEP is a wholesale energy marketer, ranking among North America’s top providers of wholesale power and natural gas with a growing wholesale presence in European markets. In addition to electricity generation, AEP owns and operates natural gas pipeline systems, natural gas storage, coal mines, and the fourth-largest inland barge company in the U.S. AEP is also one of the largest electric utilities in the United States, with almost 5 million customers linked to AEP’s wires. The company is based in Columbus, Ohio.