ML12179A447
| ML12179A447 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 06/26/2012 |
| From: | Greg Werner NRC/RGN-IV/DRS/PSB-2 |
| To: | Peter Dietrich Southern California Edison Co |
| vlm/Werner G | |
| References | |
| Download: ML12179A447 (8) | |
Text
June 26, 2012 Mr. Peter Dietrich Senior Vice President and Chief Nuclear Officer Southern California Edison Company San Onofre Nuclear Generating Station P.O. Box 128 San Clemente, CA 92674-0128
SUBJECT:
MEETING
SUMMARY
FOR AUGMENTED INSPECTION TEAM EXIT MEETING WITH SOUTHERN CALIFORNIA EDISON COMPANY
Dear Mr. Dietrich:
On June 18, 2012, NRC personnel met with representatives of Southern California Edison at the San Juan Capistrano Community Center Community Hall, located in San Juan Capistrano, California to present the Augmented Inspection Team exit issues and observations.
In accordance with 10 CFR 2.390 of the NRCs Rules of Practice, a copy of this letter and its enclosure will be available electronically for public inspection in the NRC Public Document Room or from the Publicly Available Records (PARS) component of NRC's document system (ADAMS). ADAMS is accessible from the NRC Web site at http://www.nrc.gov/reading-rm/adams.html (the Public Electronic Reading Room).
Sincerely,
/RA/
Gregory Werner, Chief Plant Support Branch 2 Division of Reactor Safety Docket Nos. 0500050361, 0500050362 License Nos. NPF-10, NPF-15
Enclosure:
- 1. NRC Presentation
- 2. Southern California Edison Presentation Electronic Distribution for SONGS UNITED STATES NUCLEAR REGULATORY COMMISSION REGION IV 1600 EAST LAMAR BLVD ARLINGTON, TEXAS 76011-4511
SUNSI Rev Compl.
Yes No ADAMS Yes No Reviewer Initials GEW Publicly Avail Yes No Sensitive Yes No Sens. Type Initials GEW C:PSB2 PAO RSLO C:PSB2 GEWerner VLDricks WAMaier GEWerner
/RA/
/RA/
/E/
/RA/
6/20/2012 6/21/12 6/26/12 6/26/2012
NRC PRESENTATION 1
San Onofre Nuclear Generating Station Augmented Inspection Team Public Exit Meeting Nuclear Regulatory Commission - Region IV June 18, 2012 2
Purpose of Todays Meeting Present the Status of the Augmented Inspection Discuss Activities Going Forward Answer Questions from the Audience 3
Agenda Introduction Augmented Inspection Team Decision Augmented Inspection Team Charter NRC Discussion on Augmented Inspection Status Licensee Response to AIT Status Path Forward NRC Closing Remarks Question and Answer Session 4
NRC Representatives Elmo Collins, Regional Administrator, Region IV Thomas Blount, Acting Director, Division Reactor Safety Greg Werner, Branch Chief, AIT Team Lead Greg Warnick, Senior Resident Inspector 5
NRC Representatives (Cont)
Michele Evans, Director, Division of Operating Reactor Licensing Ryan Lantz, Branch Chief, Region IV Victor Dricks, Senior Public Affairs Officer, Region IV John Reynoso, Resident Inspector, AIT Team Member Emmett Murphy, Senior Materials Engineer, Office of Nuclear Reactor Regulation, AIT Team Member Carl Thurston, Reactor Systems Engineer, Office of Research, AIT Team Member Joel Rivera-Ortiz, Senior Reactor Inspector, Region II, AIT Team Member Michael Bloodgood, Operations Engineer, Region IV 6
SONGS Representatives Peter Dietrich, Senior Vice President and Chief Nuclear Officer, SONGS, SCE Douglas Bauder, Vice President and Station Manager, SONGS, SCE Thomas Palmisano, Vice President of Nuclear Engineering, Projects and Site Support, SONGS, SCE
NRC PRESENTATION 7
NRC Opening Remarks Elmo Collins, Regional Administrator, Region IV Thomas Blount, Acting Director, Division of Reactor Safety 8
Steam Generator Tube Leak Actual tube leak was of minor safety significance.
Offsite radiation release was minimal.
The plant operators responded properly and minimized the release.
9 10 AIT Decision Management Directive 8.3 Pre-Planning Criteria NRC Response 11 AIT Charter Team Members - 7 inspectors/engineers from 5 NRC offices Key Objectives Additional information and observations provided by the resident inspectors 12 AIT Issues and Observations Eight tubes failed pressure testing.
SONGS used multiple independent consultants and S/G manufacturers.
NRC PRESENTATION 13 AIT Issues and Observations (cont)
Mitsubishis thermal/hydraulic computer simulation model did not accurately predict the behavior of the steam and water in the steam generators.
Manufacturing differences between the steam generators contributed to the difference in tube degradation.
14 AIT Follow-up Items Ten items identified for follow-up:
- 1. Post trip/transient procedure
- 2. Evaluation and disposition of numerous Unit 3 loose parts monitor alarms
- 3. Retainer bar design not evaluated for vibration impacts
- 4. Evaluation of and control of Unit 3 divider plate repair
- 5. Unit 3 steam generator shipping requirements 15 AIT Follow-up Items (cont)
- 6. Lack of tube bundle support for steam generators during shipment
- 7. Evaluation and disposition of shipping accelerometer data
- 8. 50.59 evaluation
- 9. Control of manufacturing differences
- 10. Adequacy of Mitsubishis computer simulation model 16 AIT Summary
- The NRC understands the steam generator thermal hydraulic conditions that resulted in the tube degradation.
- The thermal hydraulic conditions were not accurately predicted during design.
- Additional actions to fix and prevent any additional tube-to-tube degradation due to excessive vibration are being evaluated and developed. The NRC has additional inspections to perform.
- The NRC will take as much time as needed to ensure the safety of the public.
17 SONGS Response Peter Dietrich Senior Vice President and Chief Nuclear Officer 18 Path Forward - Key NRC Activities
- Continue review of steam generator tube wear
- Confirmatory Action Letter inspections
- Augmented Inspection followup inspection
- Additional public meetings
- NRC decision about the acceptability of the resumption of power operations
- Routine process to recommend improvements to the inspection program
NRC PRESENTATION 19 NRC Closing Remarks Elmo Collins Regional Administrator Region IV 15 Minute Break 20 21 Questions and Answers Contacting the NRC
- Report an emergency (301) 816-5100 (24/7 NRC Headquarters Operation Center) (call collect)
- Report a safety concern:
(800) 695-7403 (Toll-free Safety Hotline)
Allegation@nrc.gov
- General information or questions www.nrc.gov
- Victor Dricks, Public Affairs Officer, RIV 817-200-1128 Victor.Dricks@nrc.gov 22
SOUTHERN CALIFORNIA EDISON PRESENTATION SONGS EXCELLENCE 2012 Steam Generator Recovery Update Nuclear Safety in Action June 18, 2012 SONGS EXCELLENCE 2012 We operate San Onofre Nuclear Generating Station (SONGS) safely and reliably to the highest standards to protect the health and safety of the public and our employees We will not restart either Unit 2 or Unit 3 until we and the NRC are satisfied it is safe to do Southern California Edison Commitment SONGS EXCELLENCE 2012 Current Status
- Unit 2 Status:
- Shutdown on Jan. 9 for routine refueling and maintenance outage &
reactor vessel head replacement
- Unit 3 Status:
- Operators safely shutdown Unit 3 after steam generator tube leak identified on January 31
- Shared learning with industry 3
SONGS EXCELLENCE 2012 4
Pressurized Water Reactor Layout SONGS EXCELLENCE 2012 Steam Generator Cut-Away Elevation View 5
SONGS EXCELLENCE 2012 Actions Taken to Date
- Discovered unexpected tube-to-tube wear in limited portions of Unit 3 steam generators
- Deferred Unit 2 restart pending investigation
- Assembled team of experts to inform, assist and challenge
- Completed extensive tests and analysis on both units in all steam generators to support determining cause 6
SOUTHERN CALIFORNIA EDISON PRESENTATION SONGS EXCELLENCE 2012 Technical Expertise Supporting SCE
- Mitsubishi Heavy Industries
- AREVA
- B&W Canada
- EPRI 7
- Other industry personnel, recognized academics and specialized consultants SONGS EXCELLENCE 2012 Cause of Unexpected Tube-to-Tube Wear
- Specific mechanism is Fluid Elastic Instability causing excessive tube vibration
- Most excessive wear occurring in limited area of Unit 3 steam generators
- This is due to:
- High steam flow velocities
- Very dry steam
- Inadequate tube support structure in the U bend region for the tubes experiencing the wear 8
SONGS EXCELLENCE 2012 Next Steps
- Follow up on Augmented Inspection Teams additional requests
- Implement our corrective actions
- Develop additional information as stated in Confirmatory Action Letter
- Continue work to develop intermediate and long term solutions
- Will require extensive analysis, mock-ups and testing 9
SONGS EXCELLENCE 2012 10 There is no timeline on safety