ML20046C366

Special Rept:On 930629,seven Blockout Type Penetration Fire Barriers & on 930713,six Sleeve Type Penetration Fire Barriers Determined to Be Nonfunctional.Repairs Completed & Fire Barriers Restored to Functional Status

ML20046C366
Person / Time
Site:	North Anna
Issue date:	08/05/1993
From:	Stewart W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
93-481, NUDOCS 9308100189
Download: ML20046C366 (2)

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VinoiNIA EI.ECTHIC AND POWER COMPANY 1I Ricunown,Vmorm 23261 August 5, 1993 l i

i U.S. Nuclear Regulatory Commission Serial No.93-481 Attention: Document Control Desk MPW/EJW R9  :

Washington, D.C. 20555 Docket Nos. 50-338  !

50-339 1 License Nos. NPF-4  !

NPF-7 _

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Gentlemen: 1 i

VIRGINIA ELECTRIC AND POWER .QOMPANY  !

NORTH ANNA POWER STATION UNITS 1 & 2 -

PENETRATION FIRE BARRIERS SPECIAL REPORT (

Pursuant to Updated Final Safety A'nalysis Report (UFSAR) Technical Requirement 16.2.1.3.B.2.2, a Special Report is hereby submitted because seven blockout type. .i penetration fire barriers and six sleeve type penetration fire barriers were determined j to be' nonfunctional. Subsequently, repairs were completed and the penetration fire  !

barriers were restored to functional status.

On June 29,1993, during the performance of inspections for blockout type penetration  !

fire barriers, marinite boards covering one blockout type cable tray penetration were ,

removed to verify foam adequacy. A fire watch was established upon removal of the i marinite board to satisfy the technical requirement actions. During inspections,- the  ;

penetration between the Unit 1 Cable Spreading Room and the. Turbine Building was found to contain gaps in the foam material. The deficiencies are believed to be the result of inadequate initial installation and/or inspection. Subsequently, repairs to the -

foam and marinite board were completed and the penetration was restored to a functional status.

An investigation was immediately initiated to determine the extent of the problem. A-review of station drawings and walk downs of the plant determined that similar Appendix R blockout type cable tray penetration fire barriers are limited to nineteen throughout the station including the one mentioned above. A roving fire watch was established, as a conservative measure, upon discovery of several similar deficiencies on other penetrations. These penetrations are located between the Normal Switchgear to Turbine Building for Units 1 & 2, Normal Switchgear to Mechanical 1

g Equipment Room for Units 1 & 2, Cable Spreading Room to Turbine Building for Units o 1 & 2, and Unit 1 Charging Pump Cubicle 1 A to 1B, and 1B to 1C. Inspections of six o- penetrations identified gaps and voids in the foam material. Repairs to the foam CD material and marinite boards for five penetrations were completed satisfactorily.-

00 Repairs for the sixth penetration are in progress. Two penetrations were inspected  ;

and found to be acceptable. Inspections of the ten remaining blockout type cable tray g) y!

930810o189 930805 E /4J<

DR ADOCKOSooge qg

.- r, penetrations are in progress and repairs will be made if required. The roving fire watch will continue until completion of the inspection and repairs. Any similar deficiencies will be documented by station deviation reports. No additianal Special +

Reports will be made.

On July 13,1993, during performance of the annual Fire Barrier inspection Periodic Test for sleeve type penetrations (a separate evolution from the inspections on June 29, 1993) addiiional foam deficiencies were found. Six sleeve type fire barrier penetrations, approximately 1.5 inches in diameter, one in. each charging pump cubicle, were identified with inadequate foam depth. Subsequently, repairs were '

performed and the fire penetrations were restored to functional status. It is believed, based on engineering inspections, that these penetration fire barriers were deficient since initial installation. Approximately 500 sleeve type penetrations have been inspected during 1993 with only three other deficiencies found.

This Special Report has beso reviewed by the Station Nuclear Safety and Operating Committee and will be provided to the Management Safety Review Committee.

Should t,ou have any questions regarding this report, please contact us.

t Very truly yours, TS W ,

l4 ) A i t

W. L. Stewart Senior Vice President - Nuclear cc: U.S. Nuclear Regulatory Commission Region 11 101 Marietta Street, N.W.

Suite 2900 Atlanta, Georgia 30323 NRC Senior Resident inspector North Anna Power Station I