The REAL CAUSE of San Onofre's Unit 3 massively expensive failure...
It appears that a complacent SCE and the inexperienced Mitsubishi engineers did not perform proper academic research and industry comparisons about the potential adverse consequences of the reducing the pressures in the original steam generators. Lowering the pressures were the primary cause of shortening the life of the Original Generators due to increased tube wear and plugging caused by random vibrations and also caused the destruction of the new Unit 3 Replacement Steam Generators due to the same thing.
In addition, Edison engineers prepared a defective NRC report and design specifications, which were not challenged by Mitsubishi, the manufacturer, and/or adequately reviewed by NRC Region IV. Mitsubishi then at the direction of SCE engineers made numerous untested and unanalyzed design changes to the steam generators under the pretense of “like for like”, exchange and even NRC Region IV Director Elmo Collins said, “The guts of the machinery look …. Different.”
So based on a review of the AIT Report and some of the World’s Experts, the three potential causes, which were significant contributors to the “fatigue damage” in San Onofre Unit 3 and the tube-to-tube wear resulting in the tube leak are as follows:
A. Insufficient internal supports and differences in manufacturing or fabrication of the tubes and other components between Units 2 & 3.
B. Due to modeling errors, the SONGS replacement generators were not designed with adequate thermal hydraulic margin to preclude the onset of fluid-elastic instability.
C. Differences between Unit 2 and Unit 3’s Operational Factors
CONCLUSIONS: Until the NRC can determine that San Onofre is 100% safe to operate at its approved rated power, granting any Unit 2 Restart testing is unacceptable, because if a nuclear accident occurred during testing who would be held liable, the Nuclear Utilities, the Insurance Carriers, the Federal Government, the State of California, the CPUC, the NRC Commissioners, NRC Region IV, EIX/SCE Shareholders & Employees or just the millions of affected southern Californians? The DAB Safety Team believes that once the true amount of existing tube fatigue and all other associated damage is KNOWN, anything short of a total steam generator rebuild and/or replacement will be unacceptable prior to any restart being authorized by the NRC.
2013 is the year to Decommission San Onofre
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