ML19338G043
| ML19338G043 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 10/23/1980 |
| 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, NCR-2292R, NUDOCS 8010280368 | |
| Download: ML19338G043 (2) | |
Text
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i 400 Chestnut Street Tower II October 23, 1980 Mr. James P b 'Reilly, Director Office of Insp tien and Enforcement U.S. Nuclear Re 'atory Comissicn Regicn II - Suite 100 101 Marietta Street Atlanta, Georgia 303
Dear Mr. O'Reilly:
SEQUOYAH NUCLEAR PLANT UNIT 2 - CONTAINMENT VACUUM RELIEF VALVE PNEUMATIC OPERATORS - NCR 2292R - FINAL REPORT The subject deficiency was initially reported to NRC-0IE Inspector M. Thomas on September 23, 1980, in accordance with 10 CFR 50.55(e).
Enclosed is our final report.
If you have any questions, please get in touch with D. L. Lambert at FTS 357-2581.
Very truly yours, TENNESSES VALLEY AUTHORITY L. M. Mills, Manager Nuclear Regulation and Safety Enclosure
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cc:
Mr. Victor Stello, Director (Enclosure)V Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, DC 20555 0/9 S/ f 8 0102 803(8~
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.a ENCLOSURE SEQUOYAH NUCLEAR PLANT UNIT 2 CONTAINMENT VACUUM RELIEF ISOLATION VALVE PNEUMATIC OPERATORS NCR 2292R 10 CFR 50.55(e)
FINAL REPORT Description of Deficiency An' excessive corrosion problem was identified in all three of the contain-ment vacuum relief isolation valve pneumatic operators. The pistons, piston seals, return springs, and cylinders of the operators were damaged by corrosion to the point that operation of the operators was inhibited.
The corrosion was apparently caused either by improper storage of the operators which allowed wate:' to enter the components or by the use of moisture containing air for valve operation auring construction.
Safety Implications Valve failure in either the closed-or open position could have adverse safety implications. If the' valves failed closed, an inadvertent contain-ment spray or operation of an air return fan could have led to a negative pressure in the containment, which could have damaged the containment..If the valves failed open, a failure of the outboard check valves would then be a breach of containment.
Corrective Action Repair parts or suitable replacements for the operators were not available so the entire _ valve and operator assemblies are being replaced by valves that have been transferred from Hartsville Nuclear Plant. The installa-tion of the new valves is in Tcogress and is expected to be complete by December 1, 1980.
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