San Onofre Study

CONTACT: Daniel Hirsch, Committee to Bridge the Gap: (831) 336-8003

Hundreds of Times More Damaged Tubes in Either Reactor Than Typical for New Replacement Steam Generators

LOS ANGELES, CA, Sept. 12 – An exhaustive analysis of data from nuclear plants nationwide reveals that critical safety components in both reactors at the San Onofre nuclear power plant –– the damaged replacement steam generators  –– are in far worse shape compared to typical U.S. reactors than previously admitted by federal regulators and the plant’s operator.

• San Onofre’s Unit 2 reactor has about 400 times as many damaged steam generator tubes as the median number at comparable plants over the same operational period, and Unit 3 has more than 450 times as many.  
• Each San Onofre reactor has greater than 1,000 times as many indications of wear on the tubes than the typical reactor in its first cycle of operation. 
• Each San Onofre unit has had to plug more tubes than all replacement steam generators nationwide combined.

The newly unearthed data refute claims of the U.S. Nuclear Regulatory Commission that the tube damage in Unit 2 is “similar” to that found at comparable reactors and of plant operator Southern California Edison that the damage was “not unusual,” just a normal “settling in” of the equipment. The data also show that despite Edison’s claims that problems with Unit 2 are not as severe as in Unit 3, both reactors have comparable levels of damage—1595 worn tubes in Unit 2 compared with 1806 in Unit 3.

“San Onofre Unit 2 and 3 are both very ill nuclear plants.  They are far, far outside the norm of national experience,” writes Daniel Hirsch, report co-author.  “Restarting either San Onofre reactor with crippled steam generators that have not been repaired or replaced would be a questionable undertaking at best.”  Hirsch is President of the Committee to Bridge the Gap, the nuclear policy organization that prepared the report, and a Lecturer on nuclear policy at the University of California, Santa Cruz.

Both San Onofre reactors have been shut down since January, after a leak from one of the thousands of thin, tightly packed tubes that transfer heat from radioactive water to produce steam to turn the plant’s electricity turbines. The findings of today’s report are critical because Edison claims that Unit 2 is far less seriously damaged than Unit 3 and should be allowed to restart and operate at reduced power. Edison has acknowledged that Unit 3 may never restart.