ML19323G971

Final Deficiency Rept Re Ruskin Fire Dampers.Ruskin Developed Alternate Fix to Correct Problem W/Vertical Spring Closure & Potential for Jammed Blades

ML19323G971
Person / Time
Site:	Sequoyah
Issue date:	06/02/1980
From:	TENNESSEE VALLEY AUTHORITY
To:
Shared Package
ML19323G968	List: ML19323G967 ML19323G971
References
NCR-SQN-MEB-800, NUDOCS 8006090336
Download: ML19323G971 (3)

Text

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ENCLOSURE SEQUOYAH NUCLEAR PLANT UNITS 1 Ah3 2 RUSKIN FIRE DAMPERS NCR SQN MEB 8004 AND NCR SQN MEB 8001 (FORMERLY NCR MEB 80-4) 10 CFR 50.55(e) ,

FINAL REPORT Description of Deficiency In the final report on NCR SQN MEB 8001 (formerly NCR MEB 80-4) dated March 28, 1980, a problem relating to Ruskin vertical, spring close, IBD Fire Dampers was addressed. The corrective action stated that a

1. 6 screw would be fastened in the narrow portion of the slot in the spring brackets. Although this method should have eliminated the problem, Ruskin has found that some of the screws worked loose during shipment.

Ruskin has developed an alternate fix for the problem.

Ruskin has since notified TVA of a second problem with the IBD Fire Dampers (NCR SQN MEB 8004). If the blade package in vertical units less than 9" high is shifted such that the leading edge of the bottom blade rests higher than the trailing edge, the blades may jam when released.

Safety Implications This deficiency does not alter the ability of Ruskin Fire Dampers to remain intact and operable after a seismic event. However, it can affect the complete closure of the damper and could allow a fire to spread resulting in damage to the plant greater than that for which the plant was designed.

Corrective Action To correct the problem cited in NCR SQN MEB 8001, Ruskin has developed an alternate fix consisting of a small metal clamp which rr: aches to the spring bracket and provides a positive stop for the spr .sg (see attached drawing 1).

Ruskin has developed a snap-in strip to correct the problem cited in ,

NCR SQN MEB 8304, which when installed will hold the bottom blade in the

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proper orientation and ensure complete and consis' tent closure of the damper (see attached drawing 2). - -

Since the initial reporting of these deficiencies, we have determined that the dampers are installed or intended-for installation in unit 1 or in the part of the plant common to both units. This problem was reported for unit 1 as SQko-50-327/80044 under Technical Specification 6.9.1.12. The corrective action is expected to be complete by June 10, 1980.

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