ML20003F534
| ML20003F534 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 04/15/1981 |
| From: | Mills L TENNESSEE VALLEY AUTHORITY |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, SQRD-50-328-81, NUDOCS 8104220315 | |
| Download: ML20003F534 (2) | |
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April 15, 1981 f<-
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A SQRD-50-328/81-04 APR 211981 =.-Q EmT* $
Mr. J P. O'Reilly, Director g
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Office of Ihepection and Enforcement tA U.S. Nuclear hogulatory Comtission Region II - Suig 3100 101 Marietta Str Atlanta, Georgia 03
Dear Mr. O'Reilly:
SEQUOTAH NUCLEAR Pulff UNIT 2 - ENYIRONMENTAL QUALIFICATION OF SAFETY-RELATED ELECTRICAL. EQUIPENT - SQRD-50-328/81 FINAL REPORT The subject deficiency was initially reported to NRC-0IE Inspector R. W. Wright en December 8,1980, in accordance with 10 CFR 50 55(e) as NCR SQN EEB 8044R1. Interia reports were submitted on January 8, February 12, and March 17, 1981. Enclosed is our final report.
If you have any questions, please get in touch with D. L. Lambert at FTS 857-2581.
Very truly yours, TENNESSEE VALLEY AUTHORITI i
r L. M. Mills, Manager Nuclear Regulation and Safety Enclosure co:
Mr. Victor Stello, Director (Enclocum)
Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, DC 20555 foil s
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ENCLOSURE v
SEQUOYAH NUCLEAR PLANT UNIT 2 ENVIRONMENTAL QUALIFICATION OF ELECTRICAL EQUIPMENT SQRD 50-328/81-04 10 CFR 50.55(e)
FINAL REPORT Description of Deficiency Automatic Switch Company (ASCO) solenoid valves (models HB8300C58RU, HB8262C22, HTx8320A22V, and.*:3316C15) are used to centrol various containment isolation valves in the plant control air, radiation menitoring, and ventilation systems. The subject valves are -located in the annulus region.
Information obtained fecm ASCO indicated that the solenoids in question were not qualified for the following post accident environment in the annulus:
Temperature:
150 F Pressure:
Atmospheric Relative Humidity:
100 peycent Radiation:
7 X 10 rads Safety Implications Post accident operability of these valves is required for a period of one year. The solenoids are normally energized, thereby allowing air pressure to open the isolation valve. Upon loss of electrical signal, the solenoid deenergizes and allows the isolation valve to close. Failure of the solenoid valves as a result of the post accident environment would result in loss of function of the associated containment isolation valves.
Corrective Action The solenoids in the control air and ventilation system ( ASCO models HB8300C58RU, EB8262C22, and HT8316C15) will be replaced with qualified valves. A TVA engineering change notice has been written which requires the replacement of these valves before unit 2 fuel loading. This work will be accomplished within the specified implementation schedule. As for the solenoids in the radiation monitoring system ( ASCO model HTX8320A22V), TVA has reviewed the solenoid valve design against the calculated accident environment and has concluded that the present valves are acceptable for service on an interim basis. However, in accordance with the guidelines in l
NUREG-0588, these valves will be either type-tested to verify full l
qualificaticn or replaced before Jund 30, 1982.
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