ML19281A750

Forwards Final Rept Re Installation of Essential Raw Cooling Water Drain Valve TVA Class G Instead of TVA Class C

ML19281A750
Person / Time
Site:	Sequoyah
Issue date:	03/23/1979
From:	Gilleland J TENNESSEE VALLEY AUTHORITY
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
NUDOCS 7904040083
Download: ML19281A750 (2)

Text

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e TENNESSEE VALLEY AUTHORITY \_,

E CH ATTANOOGA. TENNESSEE 37401 _

500C Chestnut Street Tower II .

MAR 2 31979 Mr. Jam a P. O'Reilly, Director Office o Inspection and Enforcement U.S. Nuc1 r Regulatory Comission Region II Suite 3100 101 Mariett Street ,

Atlanta, Geo gia 30303 -

Dear Mr. O'Reilly:

f SEQUOYAH PLANT UNITS 1 AND 2 - INSTALLED ERCU DRAIN VALVE TVA CLASS l G INSTEAD OF TVA CLASS C - NCR SWP-79-S FINAL REPORT l The subject deficiency was initially reported to NRC-OIE Inspector 5 C. R. McFarland on February 22, 1979. Enclosed is our final report.

If you hava any questione concerning this matter, please get in touch f with M. R. Wisenburg at FTS 854-2581.

Very truly yours, F

J. E, Gilleland Assistant Manager of Power .

Enclosure  !.

cc: Mr.JohnG. Davis,ActingDirector(Enclosurek  ;

Office of Inspection and Enforcement U.S. Nuclear Regulatory Comission  ;

Washington, DC 20555 i

I

@9\ i 790404o033 g An Equal Opportunity Employer

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ENCLOSURE SEQUOYAll NUCLEAR PLANT UNITS 1 AND 2 INSTALLED ERCW DRAIN VALVE TVA CLASS G INSTEAD OF TVA CLASS C NCR SWP 79-s-3 FINAL REPORT Description of Deficiency During final review of design drawings by Power Production, it was found that eight drain valves on the ERCW side (tube side) of the diesel generator heat exchangers (one valve per heat exchanger) were designated TVA Class G instead of Class C as required for components of the ERCW system. As a result, Clacs G valves were installed. The error was apparently due to an oversight by the design organization.

Safety Implications The eight valves originally installed were Class G and therefore not seismically qualified. If failure of these valves is postulated as a result of a seism *c event, the ERCW system would be unable to with-stand the consequential inventory losses. Since the ERCW system supplies cooling water to safety-related equipment, the safe operation of the p1 ant could have been adversely affected.

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i Corrective Action The deficient Class G valves are to be replaced with Class C valves now availab.e at the construction site. Design drawings have been corrected to show proper valve classification. The valve replacement will be done before fuel load of unit 1. Engineers and designers have been instructed to thoroughly review the design criteria and all other applicable documents before the design of systems.

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