FOR IMMEDIATE RELEASE
The DAB Safety Team: November 19, 2012
Media Contact: Don Leichtling (619) 296-9928 or Ace Hoffman (760) 720-7261
SCE is now in Violation of 10 CFR 50, Appendix A, GDC 14, 15, 30 and 32 Requirements
SONGS is required to inspect its steam generators (SG's) and repair or remove from use any tubes found to contain flaws exceeding 35% of the nominal tube wall thickness. SCE was operating SONGS Unit 3 RSG E-088 for 11 months with eight tubes with flaws ranging from 72-100% in violation of the above law. Now SCE wants to jeopardize the safety of 8.4 Million Southern Californians by restarting their degraded Unit 2 RSGs with 2 flawed tubes exceeding 28% of their nominal tube wall thickness along with thousands of other fatigue damaged tubes that may have undetected, untested, undiscovered, unmeasured, undocumented and or un-quantified cracks and run it for 5 months! SCE is desperately trying to justify the restart of Unit 2 based on conflicting, confusing and erroneous Operational Assessments prepared by Westinghouse, AREVA, Intertek and MHI with Inscrutable (Undecipherable) Data and under-conservative computer models, which are not applicable to 100% Steam Voiding caused by a Main Steam Line Break and sub-cooled feed water flashing conditions due to Steam generator depressurization. The nominal tube wall thickness "flaw" of 28% of these tubes is projected to be > 31% during the 5 month trial restart of Unit 2 based on untested data, that may be applicable to other plants, but not to SONGS. Based on the history of the catastrophic and unprecedented failure of eight Unit 3 SG E-088 tubes, Unit 2 SG design deficiencies and incomplete tube inspections, these flaws can exceed the 35% plugging limit at any time prior to the end of 5 months trial period due to any abnormal plant operations or transients [e.g., loss of offsite power, adverse local thermal-hydraulic conditions (like high Steam voids of > 99.6% due to narrow tube pitch to tube diameter ratio, low tube clearances), etc.], all of which are beyond the control of the operator. Hence, the Public and the Regulators will never know, until it is too late, when Unit 2 again will be operating in violation of the Technical Specifications Limit. Unit 2's Restart Effort is just an unapproved and desperate experiment, which is not permitted by law. The only legal option SCE has is to apply for a thorough NRC 10 CFR 50.90 License Amendment, along with transparent and trial-like public hearings. Anything less, would be a regulatory failure by the NRC, to protect public safety and a violation of the authority and the privileges granted by the President and Congress of the United States.
Background: Steam Generator (SG) tubes form 50 percent of the Reactor's Highly Radioactive Coolant Pressure Boundary. SONGS Technical Specifications states, "SG tube integrity shall be maintained by meeting the performance criteria for tube structural integrity (SIPC) and accident induced leakage (AILPC) over the full range of normal operating conditions and design basis accidents." SONGS Technical Specification Limiting Condition of Operation 3.7.14 states, "All SG tubes satisfying the tube repair criteria shall be plugged in accordance with the Steam Generator Program. If one or more SG tubes satisfying the tube repair criteria (35%) is not plugged in accordance with the Steam Generator Program, then the reactor should be in Mode 5 (Cold Shutdown in 6 hours)." SONGS Technical Specification 184.108.40.206.c.1 states, "Tubes found by in-service inspection to contain flaws with a depth equal to or exceeding 35% of the nominal tube wall thickness shall be plugged." During the "in-situ" pressure testing of SONGS Unit 3 SG 3E-088, out of eight tubes, three tubes (Flaw Depth 99-100%) failed both the AILPC and SIPC SG Tube Integrity Performance Criteria; and 5 tubes (Flaw Depth 72-81%) passed the AILPC but failed the SIPC. The discovery of not one but eight Replacement Steam Generator (RSG) tube failures now, not only means that SCE was operating Unit 3 beyond their Current (Technical Specifications) Licensing Basis Limit (CLB), (which they have yet to be penalized for by the NRC, as required by law), but also offers real proof, for the very first time, that had a Main Steam Line Break (MSLB) accident happened, at least eight RSG tubes would have leaked/ruptured at once and thereby could very well have caused the SONGS reactor to Meltdown, due to loss of radioactive core coolant, an event which has not ever before been computer modeled by either the Industry or the NRC! 100% Void Fraction in SG U-Tube Bundle with sub-cooled Feedwater flashing, happened with complete severance of one tube along with damage to many neighboring tubes in Mihama Japan in 1991. One main steam isolation valve and one pressurizer relief valve could not be operated by remote control to stop the radioactive steam flow to the environment. The amounts of radioactive rare gas and iodine discharged to the atmosphere were about 2.3E10 and 3.4E8 Becquerel's, respectively. This single tube rupture caused the first INES level 3 nuclear incident in Japan, which ignited social concerns all over Japan because it shattered the nuclear industry's myth of 100% safe reactors!
Questions: Because of its variable and often complex morphology, tube cracking can be difficult to detect and size by the conventional inspection techniques used by SCE, and the failure pressure and leak-rate behaviors of degraded tubes are not readily predictable; so why has SCE, in its rush to Restart Unit 2, not inspected thousands of Unit 2 Steam Generator tubes with T/R single-pass array probes, laser-scanned penetrant inspection and/or ultrasonic detection technologies to accurately determine the depth, extent and location of flaws (circumferential, radial and axial cracks) at U-bends, tube-support intersections and/or the clearances between these tubes? Furthermore, why has SCE not made use of the world's best remote video-inspection technology (which is not available in-house to Westinghouse, AREVA, Edison and/or MHI) to confirm the gaps between the tubes-AVBs-TSPs and condition of the TSPs for any structural deformation? SCE has blatantly refused to use state-of-the-art remote visual and/or mechanical inspection techniques to cut costs and save time. By not doing this, SCE has not performed a thorough inspection and accurately assessed the condition of the entire degraded RSG tube bundle, the weakened AVB structure and/or the damaged tube support plates.
Answers: These inspections along with the detailed manufacturer's drawings would have accurately determined the condition of the gaps between Tubes/AVB and TSP of the entire degraded Unit 2 RSG's to identify all regions with narrow tube pitch to diameter ratio, low tube clearances, damaged tube support plates and potential steam dry-out areas. Furthermore, these RSG's, as designed by SCE's in-house designers, do not have any in-plane vibration protection to prevent cascading tube ruptures during a MSLB accident! Now Westinghouse is projecting the wear of 2 additional active tubes in SG 2E089 may be from 28% to ~31% by the end of 5 months assuming everything goes as planned, without any transients or MSLB. In light of SONGS Unit 3 poor operating experience, the projection of this number based on empirical formulas and data derived from other plants/tests is highly questionable and does not meet the intent of Deterministic Analysis. This 31% number is "shaving things too close" to the NRC's plugging limit of 35% and these 2 degraded tubes due to the RSGs design deficiencies described above present a formidable challenge to the Safe Restart of Unit 2 by making these tubes highly vulnerable to ruptures during any unanticipated operational occurrences and/or Main Steam Line Breaks. Therefore, these 2 active tubes and all their neighboring tubes should also be plugged consistent with the previous SCE Press Statement on Unit 2 RSGs, "Edison said it plugged six tubes in Unit 2 that had wear of better than 35 percent and plugged more than 500 other tubes preventively."
Result: By not doing full inspections of all RSG tubes, nor plugging these additional 2 questionable tubes along with hundreds of their surrounding tubes as a preventive, SCE has failed BOTH the public's trust and has not met the performance criteria as specified in Appendix A, "General Design Criteria for Nuclear Power Plants," (GDC 14, 15, 30 and 32) to 10 CFR Part 50, which establishes the fundamental regulatory requirements for the integrity of their RSG tubes.
Additional technical information read The DAB Safety Team's: SONGS MSLB Analysis
Glossary of Acronyms and Abbreviations:
· AIPC: performance criteria for accident induced leakage
· AREVA: Nuclear engineering firm owned by French Atomic Energy Commission
· AVB: Anti Vibration Bar
· CFR: Code Of Federal Regulations
· CLB: Current (Technical Specifications) Licensing Basis Limit
· GDC: General Design Criterion
· MHI: Mitsubishi Heavy Industry
· MSLB: Main Steam Line Break
· NRC: Nuclear Regulatory Commission
· RSG: Replacement Steam Generators
· SCE: Southern California Edison
· SIPC: Performance criteria for tube structural integrity
· SG: Steam Generator
· SONGS: San Onofre Nuclear Generating Station, whose majority Owner is SCE
· TSP: Tube Support Plate
Copyright November 19, 2012 by The DAB Safety Team. All rights reserved. This material may not be published, broadcast or redistributed without crediting the DAB Safety Team. The contents cannot be altered without the Written Permission of the DAB Safety Team Leader and or the DAB Safety Team's Attorneys.