ML13303A910
| ML13303A910 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 08/18/1988 |
| From: | Hickman D Office of Nuclear Reactor Regulation |
| To: | Baskin K, Cotton G SAN DIEGO GAS & ELECTRIC CO., SOUTHERN CALIFORNIA EDISON CO. |
| References | |
| TAC-68329, TAC-68330, NUDOCS 8808240087 | |
| Download: ML13303A910 (6) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 lop August 18, 1988 Docket Nos.: 50-361 and 50-362 Mr. Kenneth P. Baskin Mr. Gary D. Cotton Vice President Senior Vice President Southern California Edison Company Engineering and Operations 2244 Walnut Grove Avenue San Diego Gas and Electric Company Post Office Box 800 101 Ash Street Rosemead, California 91770 Post Office Box 1831 San Diego, California 92112 Gentlemen:
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION REGARDING MSIV ROOT CAUSE ANALYSIS AND INSPECTION RESULTS, SAN ONOFRE UNITS 2 AND 3 (TAC NOS. 68329 AND 68330)
By letter dated July 13, 1988 you submitted your "Root Cause Analysis for the Guide Rail/Lev-R-Lock Interaction Problem for MSIVs" and your "Inspection Results of SONGS-3 MSIV-8205." We have reviewed these documents and have discussed them with yoV and with Region V personnel by telephone. As we stated in our telephone conversation with you on July 19, 1988, the staff has con cluded that continued operation of Unit 2 and startup of Unit 3 following the current refueling outage are acceptable. This is based primarily upon your disassembly of Unit 3 MSIV-8205. You found that valve to have sustained much less damage than either of the MSIVs at Waterford 3; and, even with a signifi cant number of broken bolts and, in one case, two guide rails missing, the Waterford MSIVs were nevertheless apparently capable of performing their safety function. Therefore, we conclude that the as-found condition of your MSIVs does not constitute a significant safety hazard. However, the condition of the valves upon disassembly was significantly different from what you concluded based upon your borescopic examination of the valve. These differences are not addressed in either of your reports. Therefore, the staff has little confidence in your long term program which relies principally upon borescopic SS;S240087 80-0818 PDR ADOCK 05000361 PDC
-2 examinations. Accordingly, we do not agree with the conclusions and recommend ations contained in your two reports. To assist in resolving this issue, we request that you provide the information described in the enclosure to this letter.
Should you have any questions regarding this request, please call me.
Sincerely, D. E. Hickman, Project Manager Project Directorate V Division of Reactor Projects -
- III, IV, V and Special Projects Office of Nuclear Reactor Regulation
Enclosure:
As stated cc:
See next page
00 2 -
August 18, 1988 examinations. Accordingly, we do not agree with the conclusions and recommend ations contained in your two reports. To assist in resolving this issue, we request that you provide the information described in the enclosure to this letter.
Should you have any questions regarding this request, please call me.
Sincerely, original signed by D. E. Hickman, Project Manager Project Directorate V Division of Reactor Projects -
- III, IV, V and Special Projects Office of Nuclear Reactor Regulation
Enclosure:
As stated cc:
See next page DISTRIBUTION Docket File OGC (for info only)
NRC & Local PDRs PD5 Reading GMHolahan JLee EJordan BGrimes ACRS (10)
DEHickman 5
NRR/EMEB
.R PD5 DEHickman:dr LBMarsh mell for GKnighton 8//7/88 8/11/88 10 /88
Mr. Kenneth P. Baskin San Onofre Nuclear Generating Southern California Edison Company Station, Units 2 and 3 cc:
Mr. Gary D. Cotton Mr. Hans Kaspar, Executive Director Senior Vice President Marine Review Committee, Inc.
Engineering and Operations 531 Encinitas Boulevard, Suite 105 San Diego Gas & Electric Company Encinitas, California 92024 101 Ash Street Post Office Box 1831 San Diego, California 92112 Mr. Mark Medford Southern California Edison Company Charles R. Kocher, Esq.
2244 Walnut Grove Avenue James A. Beoletto, Esq.
P. 0. Box 800 Southern California Edison Company Rosemead, California 91770 2244 Walnut Grove Avenue P. 0. Box 800 Mr. Robert G. Lacy Rosemead, California 91770 Manager, Nuclear Department San Diego Gas & Electric Company Orrick, Herrington & Sutcliffe P. 0. Box 1831 ATTN:
David R. Pigott, Esq.
San Diego, California 92112 600 Montgomery Street San Francisco, California 94111 Richard J. Wharton, Esq.
University of San Diego School of Alan R. Watts, Esq.
Law Rourke & Woodruff Environmental Law Clinic 701 S. Parker St. No. 7000 San Diego, California 92110 Orange, California 92668-4702 Charles E. McClung, Jr., Esq.
Attorney at Law Mr. S. McClusky 24012 Calle de la Plaza/Suite 330 Bechtel Power Corporation Laguna Hills, California 92653 P. 0. Box 60860, Terminal Annex Los Angeles, California 90060 Regional Administrator, Region V U.S. Nuclear Regulatory Commission Mr. C. B. Brinkman 1450 Maria Lane/Suite 210 Combustion Engineering, Inc.
Walnut Creek, California 94596 7910 Woodmont Avenue, Suite 1310 Bethesda, Maryland 20814 Resident Inspector, San Onofre NPS c/o U. S. Nuclear Regulatory Commission Mr. Dennis F. Kirsh Post Office Box 4329 U.S. Nuclear Regulatory Commission San Clemente, California 92672 Region V 1450 Maria Lane, Suite 210 Mr. Sherwin Harris Walnut Creek, California 94596 Resource Project Manager Public Utilities Department Mr. Dennis M. Smith, Chief City of Riverside Radiological Programs Division City Hall Governor's Office of Emergency Services 3900 Main Street 2800 Meadowview Road Riverside, California 92522 Sacramento, California 95832
UNITED STATES A
NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 ENCLOSURE MSIV ROOT CAUSE ANALYSIS AND INSPECTION REPORT SAN ONOFRE UNITS 2 AND 3 REQUEST FOR ADDITIONAL INFORMATION TAC NOS. 68329 AND 68330
- 1. On page 15 of your Root Cause Analysis, you state that all the broken capscrews at Waterford except one were found in either the bottom of the MSIV body cavity or the turbine stop valve strainers.
Where was the remaining capscrew found?
- 2. The borescope inspection results on page 16 of the Root Cause Analysis conflicts with the inspection results on page 2 of the Inspection Results. Address these conflicts and their significance relative to the reliability of the borescopic examination.
- 3. The conclusions and recommended actions of the Root Cause Analysis state that MSIVs which stroke slower than 3.0 seconds are not subject to the Waterford 3 failure. It also states that a valve which strokes in 3.0 seconds with one dump valve open will stroke in 2.5 seconds with both dump valves open. Yet you make no commit ment to do anything about this situation. Explain what, if anything, you will do about this.
- 4. Discuss what improvements can be made to the borescopic examination to increase the staff's confidence that damage to shoes and rails as well as severed bolts will be detected. Address what the cap abilities of the examination will be once these improvements have been implemented.
- 5. Provide a schedule for future actions such as examinations, inspections, and completion of studies.
- 6. Provide a commitment to either inspect the Unit 2 valves or examine both and inspect one to verify the capabilities of the borescopic examination.
- 7. Discuss the polishing of the gate and segment back angles and of the gate and seat surface of MSIV-8205.
-2
- 8. Discuss the self-aligning feature of the skirt installation and the role of this feature on the capscrew failures in MSIV-8205.
- 9. Discuss how a galled surface gets smoothed out, as stated on page 14 of your Inspection Results. You have assumed that the coefficient of friction starts at 1.0 and becomes 0.35 as the valve is cycled. What causes this to happen and why?