ML19344E076
| ML19344E076 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 08/20/1980 |
| From: | Mills L TENNESSEE VALLEY AUTHORITY |
| To: | |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, NCR-SQN-EEB-801, NUDOCS 8008260593 | |
| Download: ML19344E076 (2) | |
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TENNESSEE VALLEY AUTHOR!TY l
CH ATTA NCCG A. TENNESSEE 37401 400 Chestnut Street Tower II August 20, 1980 Mr. James P.
'Reilly, Director Office of Insp tion and Enforcement U.S. Nuclear Re latory Consission Region II - Suit 3100 101 Marietta Stre Atlanta, Georgia 2 03
Dear Mr. O'Reilly:
SEQUOYAH NUCLEAR PLANT UNIT 2 - SEISMID' SUPPORTS FOR AUXILIARY FEEDWATER CONTROL VALVES - NCR SQN EEB 8017 - FINAL REPORT The subject deficiency was initially reported to NRC-0IE Inspector M. Thomas en July 21, 1980, in accordance with 10 CFR 50.55(e). Enclosed is our final report.
If you have any questions concerning this matter, please get in touch with D. L. Lambert at FTS 857-2581.
Very truly yours, TENNESSEE VALLEY AUTHORITY L. M. Mills, Manager Nuclear Regulation and Safety l
Enclosure y
cc:
Mr. Victor Stello, Jr., Director (Enclosure)/
Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Wasnington, DC 20555 l
30/7
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9 ENCLOSURE SEQUOYAH NUCLEAR PLANT UNIT 2 SEISMIC SUPPORTS FOR AUXILIARY FEEDWATER CONTROL VALVES NCR SQN EEB 8017 10 CFR 50.55(e)
FINAL REPORT Description of Deficiency Ten control valves in the auxiliary feedwater system were installed without some required seismic support struts. TVA accepted shipment of the valves prior to completion of the seismic test pro 6 ram being conducted by the vendor with the agreement that the necessary struts would be supplied when-the testing was completed. The valves involved are the eight steam generator level control valves and the.. pres sure control valve on the discharge of both auxiliary feedwater motor-driven pumps. Some support struts for two control valves cannot be installed due to interferences with other TVA equipment. The absence of the struts and the interferences were discovered when the struts were delivered to the site and installation was attempted. Without the. struts, the valves are not seismically qualified.
Safety Implication All of the affected valves are classified as active valves. Because the valves were not seismically qualified, one or more of them may have failed during a seismic event. Failure of these valves could lead to the loss of the auxiliary feedwater system which could adversely affect plant safety.
Corrective Action Those supports that have no interference problem have been installed.
All of the required struts which have not been installed are being field l
fabricated to alleviate the interference problem. TVA will perform a seismic analysis to ensure that the altered supports are adequate to meet the seismic requirements. The supports will be fabricated and installed by fuel loading.
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