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'Extremely small' radiation release at Calif. plant possible, utility says

Mike Blake / Reuters

The San Onofre Nuclear Generating Station sits on the shore of the Pacific Ocean in San Diego County, Calif.

Updated at 9:25 p.m. ET: In a statement Wednesday evening, Southern California Edison said it was still working on plans for repair of the leak in a steam generator tube that had prompted the shutdown of a reactor in the San Onofre nuclear plant. The statement said that monitoring instruments showed no change in radiation levels that would be detectable outside the plant.

The statement said operators shut down the plant Tuesday "and isolated the component that contained the leaking tube within four hours of detecting the indications."

More from the statement:

Currently, operators are cooling down Unit 3 and reducing pressure in the plant, which is the method to stop the tube from leaking. They are meticulously following prescribed procedures written specifically for addressing a tube leak condition.

"There was no threat then, nor is there now any danger to the public or to plant workers," said Pete Dietrich, senior vice president and Chief Nuclear Officer for Southern California Edison.

"Our operators performed exactly as they are trained to perform and took prompt action to ensure we did not create a situation involving any challenge to the health and safety of the public," Dietrich said.

Original post: An "extremely small" amount of radiation could have escaped into the atmosphere from a Southern California nuclear power plant after a water leak prompted operators to shut down the reactor, a utility spokesman said Wednesday.

Nuclear Regulatory Commission spokesman Victor Dricks echoed that, saying a small amount of radioactive gas "could have" escaped the San Onofre Nuclear Generating Station on the northern San Diego Coast.

Southern California Edison spokesman Gil Alexander said the amount would have been "extremely small" and possibly not detectable by monitors.

The company and federal regulators say the release would not have posed a safety risk for the public.

A reactor at the plant was shut down Tuesday night after a possible leak was detected in one of the unit's steam generator tubes.

Southern California Edison on Tuesday said in a statement that "a precautionary shutdown of Unit 3" at the electricity generating plant was under way, but that there had been no release of radiation to the atmosphere and there was no danger to employees or the public.

The San Onofre plant is on the Pacific Ocean coast near San Clemente north of San Diego. It consists of two units, No. 2 and No. 3. No. 1 was shut down permanently in 1992. It is one of two nuclear plants that generate electricity in Southern California; the other is the Diablo Canyon plant in San Luis Obispo County.

Unit No. 2 at San Onofre was already offline for maintenance and refueling, but Southern California Edison said the shutdown of No. 3 would not affect the supply of electricity to customers.

In September, the failure of a major tranmission line between Arizona and California caused the Onofre reactors to go offline automatically.

The Associated Press and Reuters contributed to this report.

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