San Onofre nuclear plant closure not permanent, Edison says
The extended closure of the San Onofre nuclear plant due to equipment issues has led some to speculate -- or hope -- that the plant will be shuttered for good, but the chief nuclear officer for plant operator Southern California Edison said he doesn't believe the current problems signal the plant's demise.
“There’s nothing I’m aware of today that would make me conclude that,” SCE Senior Vice President Peter Dietrich said in a telephone interview Monday, speaking to the Times for the first time since safety concerns forced the plant's closure.
The plant has been shuttered for nearly three months due to unexpected wear in tubes that carry radioactive water in the plant's recently replaced steam generators. The problem came to light when one tube sprang a small leak on Jan. 31. Since then, hundreds of tubes have been found with excessive wear, apparently as a result of vibrations that caused the tubes to rub against each other and against support structures.
Dietrich said after "intensive study" of thermohydraulic conditions, eddy testing and visual inspections using cameras that snake inside the tubes, "We have made great progress in gaining an understanding of the situation."
He did not say what officials believe might be causing the problems and did not give a timeline for the continuing testing, inspections and analysis at the plant. Edison wrapped up its latest round of inspections Friday, during which it found two tubes in the plant's reactor Unit 2 showing tube-to-tube wear. Hundreds of tubes in Unit 3 had already been discovered with the same type of wear, but officials initially said the pattern of wear on the Unit 2 tubes appeared to be different.
A pair of reports commissioned by advocacy group Friends of the Earth have charged that design changes in the new steam generators -- particularly the addition of more tubes -- led to the problems, and that Edison misled federal regulators about the extent of the changes. Dietrich said Edison had kept the Nuclear Regulatory Commission informed using the same process followed by other nuclear plants and that the design changes were made to update technology "designed in the 1960s and '70s, built in the '70s and installed in the '80s."
Dietrich did not say whether he expects the plant to remain out of service through the summer. But, he said, Edison is pushing forward with contingency plans to avoid power shortages in Southern California if the plant does remain shuttered, including transmission and distribution improvements.
And in Irvine, the City Council was preparing to vote Tuesday on a letter to the Nuclear Regulatory Commission calling for the commission to examine safety issues at the plant, including seismic and tsunami hazards and spent fuel storage, and to extend the emergency planning zone around the plant from a 10- to 50-mile radius.
-- Abby Sewell
Photo: The San Onofre Nuclear Generating Station is seen from the beach south of San Clemente. Credit: David McNew/Getty Images.