San Onofre not expected to close for good, Edison says

Apr 24 - McClatchy-Tribune Regional News - Abby Sewell Los Angeles Times

The extended closure of the San Onofre nuclear plant due to safety concerns 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 problems signal the plant's demise.

"There's nothing I'm aware of today that would make me conclude that," Southern California Edison Senior Vice President Pete Dietrich said in a telephone interview Monday, speaking to The Times for the first time since the plant was forced to close.

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. Since then, 509 of the plant's nearly 39,000 tubes have been taken out of service because of excessive wear, apparently a result of vibration that caused the tubes to rub against each other and against support structures.

Dietrich said after "intensive study" of thermohydraulic conditions, eddy current testing and visual inspections using cameras that snake inside the tubes, "we have made great progress in gaining an understanding of the situation."

But he did not say what officials believe might be causing the issues and did not give a timeline for wrapping up the testing, inspections and analysis at the plant. Edison finished 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 contend 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.

While he did not say whether he expects the plant to remain out of service through the summer, Dietrich 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.

abby.sewell@latimes.com