The presentation to the NRC reviewed the extensive analysis by SCE and its independent global experts of causes of tube wear in San Onofre Unit 3 and the corrective actions to eliminate those causes in Unit 2.
“After extensive analysis from three independent experts, we are confident that we understand the causes of the tube wear and have taken the appropriate steps to prevent it in Unit 2,” said Pete Dietrich, SCE senior vice president and chief nuclear officer. During the NRC meeting in Rockville, Md, other nuclear industry vendors and the Electric Power Research Institute also made presentations on steam generator issues.
SCE determined the tube-to-tube wear in the Unit 3 steam generators was caused by a phenomenon known as fluid elastic instability. This phenomenon stems from three factors: high steam velocity, low-moisture conditions in specific locations of the tube bundles, and ineffective tube supports in the same locations. SCE has proposed operating Unit 2 at 70 percent to decrease velocity, increase damping and prevent fluid elastic instability.
San Onofre is the largest source of baseload generation and voltage support in the region and is a critical asset in meeting California’s clean energy needs. Both units at San Onofre are currently safely shut down. Unit 2 remains shut down since it was taken out of service Jan. 9, 2012, for a planned outage. Unit 3 was safely taken offline Jan. 31, 2012, after station operators detected a leak in a steam generator tube.
NRC approval is required before SCE can restart Unit 2. The repair, corrective action and restart plan for Unit 2, along with additional technical information to address questions from the NRC, are available to the public at www.SONGScommunity.com
More information is available at www.edison.com/SONGSupdate and at www.SONGScommunity.com.
San Onofre is jointly owned by SCE (78.21 percent), San Diego Gas & Electric (20 percent) and the city of Riverside (1.79 percent). Follow us on Twitter (www.twitter.com/SCE) and like us on Facebook (www.facebook.com/SCE).
About Southern California Edison
An Edison International (NYSE:EIX) company, Southern California Edison is one of the nation’s largest electric utilities, serving a population of nearly 14 million via 4.9 million customer accounts in a 50,000-square-mile service area within Central, Coastal and Southern California.
1:00 PM Eastern 2/9/2013
ATOMIC POWER REVIEW