Pinhole leak of radioactive coolant found at the Davis-Besse nuclear power plant

Engineers at the Davis-Besse nuclear reactor near Toledo found a pinhole coolant leak in a pipe weld Wednesday evening while doing a walk-down inspection of the plant.

Engineers were preparing to resuming operations after more than a month-long reactor shutdown for refueling and maintenance. They were conducting the inspection while the reactor was in "hot standby" mode. The coolant system was running at normal operating temperatures and pressures.

In a report early Thursday to the Nuclear Regulatory Commission, plant owner FirstEnergy Corp. estimated the leak of radioactive coolant inside the reactor containment building at the about one-tenth gallon per minute.
The report noted that the coolant was spraying from a pinhole in the socket weld of a three-quarter inch pipe at a 90 degree elbow between the reactor coolant pump and a safety valve.

Reactor operators immediately began shutting down the reactor as engineers began repair preparations.
Spokeswoman Jennifer Young today said the leaked coolant was cleaned up and no radioactivity escaped into the atmosphere. There were no injuries.

FirstEnergy shut down the 908-megawatt reactor on May 6 for normal refueling, inspections and maintenance. More than 1,000 contractors worked with Davis-Besse employees to replace 68 of the reactor's 177 fuel rods.

Contractors also were involved with preventive maintenance of major components including pumps, valves and the emergency diesel generators. Others also worked on the power plant's cooling tower to improve efficiency.

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