ML20053D824

Interim Deficiency Rept Re Design of Horizontal Fire Dampers,Initially Reported on 820323.Air Balance Horizontal Dampers Cleaned.Blade Locks Secured & Damaged Closer Springs Replaced.Completion Expected by 820801

ML20053D824
Person / Time
Site:	Comanche Peak
Issue date:	05/28/1982
From:	Gary R TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC)
To:	Madsen G NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
References
10CFR-050.55E, 10CFR-50.55E, TXX-3523, NUDOCS 8206070356
Download: ML20053D824 (3)

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1 TEXAS UTILITIES GENERXflNG CO.TilnNY 20t>l lif tYAN TOWEli IJAIJ.AM."I EX AM 752fn

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TXX-3523

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3 i Mr. G. L. Madsen, Chief

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Reactor Projects Branch U.S. Nuclear Regulatory Commission Office of Inspection and Enforcement 611 Ryan Plaza Drive, Suite 1000 Docket Nos. 50-445 Arlington, TX 76012 50-446 COMANCHE PEAK STEAM ELECTRIC STATION DESIGN OF HORIZONTAL FIRE DAMPERS FILE N0. 10110

Dear Mr. Madsen:

In accordance with 10 CFR 50.55(e), we are submitting the attached report of actions taken to correct a deficiency regarding the design of horizontal fire dampers supplied by Pacific Air Products Company. We previously made a verbal report to your Mr. T. Westerman on February 25, 1982, and we submitted an interim report logged TXX-3496 on March 23, 1982.

Supporting documentation is available at the CPSES site for your Inspector's review.

We anticipate completion of the corrective action by August 1,1982.

Very truly yours,

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R. . Gary RJG:pko Attachment cc: NRC Region IV - (0 + 1 copy)

Director, Inspection and Enforcement - (15 copies) c/o Distribution Services Branch, DDC, ADM.

U.S. Nuclear Regulatory Commission X Washington, DC 20555

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'k 8206070356 820528 DR ADOCK 05000

TXX-3523 May 28, 1982 ATTACHMENT DESIGN OF HORIZONTAL FIRE DAMPERS DESCRIPTION OF DEFICIENCY During preoperational startup testing, several horizontal fire dampers failed to operate. Preliminary investigations by the site engineering group revealed additional operability concerns with other dampers performing various functions provided by a common supplier (PAPCO).

The supplier and site engineering group have concluded subsequent evaluations of the dampers. The specific description, safety impact, and corrective actions for each type of damper are as follows.

Horizontal dampers failed to close properly dislodging the blade lock and closer spring. The cause of the malfunction is not related to design but to debris and corrosion typical to long term construction projects. The problem is not typical in operation considering the placement of filters. Several dampers provided by a subtier manufacturer (Air Balance) were found to have blade locks mounted by tabs bending in the opposite direction than specified by the supplier. This deficiency causes reduced tab strength resulting in dislodged blade locks after damper operation.

Vertical dampers fail to close properly due to blade and track debris typical to long term construction projects. In addition, testing by the supplier has indicated the damper may fail or close slowly due to air velocity pressure.

Larger (60" x 60") horizontal dampers fail to close properly due to cleanliness control typical to long term construction, minor damage to damper parts, and frame deflection which occurs in installation (grouting) activities. The supplier, subtier manufacturer (Advanced Air), and site engineering concur the deficiency cannot be attributed to a single factor but a combination of these conditions.

ANALYSIS OF SAFETY IMPLICATIONS In the event of fire, the failure of certain horizontal dampers to close would compromise the fire barrier and jeopardize the adjacent fire zone. A fire in two adjacent zones could affect both trains of safety equipment and impair the ability to safely shut-down the plant.

In the event of fire, the failure of all other fire dampers to close would compromise the fire barrier and jeopardize the adjacent fire zone. However, the ability to safely shut-down the plant would not be impacted due to the design of the ventilation system.

I Attachment TXX-3523 May 28, 1982 Page 2 CORRECTIVE ACTIONS Corrective actions for the deficient conditions will include the following.

Horizontal dampers manufactured by Air Balance will be cleaned and lubricated as required with a dry, non-oil lubricant. Blade locks will be secured with additional fasteners. Damaged closer springs will be replaced.

Vertical dampers representative of plant size and velocity requirements will be tested. Based upon test results, closer springs will be adaed as required.

All dampers will be cleaned and lubricated.

Large horizontal dampers will be replaced with multipanel dampers.

DATE OF IMPLEMENTATION All corrective actions should be completed by August 1,1982.

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