ML20045G639

Special Rept 93-11:on 930624,portion of Fire Header in Auxiliary Bldg Removed from Svc as Result of Maint Activities & Water Flooded Penetration Room.Fire Suppression Sys Declared Inoperable & LCO 3.7.11.1 Entered

ML20045G639
Person / Time
Site:	Sequoyah
Issue date:	07/07/1993
From:	Fenech R TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
93-11, NUDOCS 9307140242
Download: ML20045G639 (3)

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Tenneuse Valley Autb oty. Post Offic.e Oct 20CO. Soddy Das Tennensee 37379 2000 I

Robert A. Fenech Vce PrWdent Sequuvah Nuclear Plant July 7, 1993 U.S. Nuclear Regulatory Conunission ATTN:

Document Control Desk Washington, D.C. 20555 Gentlemen:

in the Matter of

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Docket Nos. 50-327 Tennessee Valley Authority

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50-328 SEQUOYAll NUCLEAR PLANT (SQN) - UNITS 1 AND 2 - DOCKET NUMBERS 50-327 AND 50-328 - FACILITY OPERATING LICENSES DPR-77 and DPR-79 The enclosed special report provides details concerning the inoperability of the fire suppression water system in the Unit 2 reactor building as initially reported by telephone at 1515 Eastern daylight time on June 25, 1993, and confirmed by facsimile on the same day in accordance with Action Statement (b)(2) of Technical Specification 3.7.11.1.

Details are provided in the enclosure.

The condition involves only the Unit 2 reactor building.

If you have any questions concerning this submittal, please telephone C. II. Whi ttemore at (615) 843-7210.

Sincerely, h

&A-t!obert A. Fenech Enclosure cet See page 2 130063 9307140242 930707 U l gDR ADDCK 05000328 PDR

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E U.S. Nuclear Regulatory Conunission Page 2 July 7, 1993 cc (Enclosure):

Mr. D. E. LaBarge, Project Manager U.S. Nuclear Regulatory Commission One White Flint, North 1

11555 Rockville Pike Rockville, Maryland 20852-2739 NRC Resident Inspector Sequoyah Nuclear Plant 2600 Igon Ferry Road Soddy-Daisy, Tennessee 37379t3624 i

Regional Administrator e

U.S. Nuclear Regulatory Commission Reglon'11 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323-2711 9

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4 ENCLOSURE e

l 14-DAY FOLLOW-UP REPORT SPECIAL REPORT 93-11

.Sequoyah Nuclear Plant Technical Specification Limiting Condition for Operation (LCo.) 3.7.11.1 requires that the fire suppression water system be operable through the last valve ahead of the water-pressure alarm device on each sprinkler or hose standpipe and the last valve ahead of the deluge valve on each deluge or spray system in the Unit 2 reactor building.

-1 Descrlplion_sLSondliion j

J on June 24, 1993, at 2200 Eastern daylight time (EDT), with Unit 2 in Mode 5 for a maintenance outage and Unit 1 in Mode 6 for a refueling ontage, LCOs 3. 7.11.1, 3. 7.11. 2, and 3. 7.11.4 were entered.

A portion of the fire header in the nux111ary building was removed from serv ice (isolated) as a result of maintenance activities in the process of repairing and replacing leaking lines.

The initial attempt to isolate the leaking section was unsuccessful in that a valve (Valve 0-26-496) on one side of the problem area was leaking through.

The next valve upstream of the leaking valve was then isolated (closed). Tnis valve (Valve 0-26-697) was also leaking through. The decision was made to break the flange on the 697 valve and install a. blind flange. JIowever, when the craft broke the flange open, a significant amount of' water Ilooded the Unit 2 penetration room where the valve was located.

The next isolation valve (Valve 0-26-696) upstream of the 697 valve waslthen

-c1nsed.

This atopped the leak, but it also isolated the. fire header going to the Unit 2 reactor building. The-situation was corrected (within an hour), and LCOs 3.7.11.1, 3.7.11.2, and 3.7.11.4 were exited at 2251 EDT.

Correc tlys._ Action The immediate corrective action was to declare the Unit 2 reactor building fire suppression system inoperabic and enter LCO 3.7.11.1.

The blind flange was then. installed and Valve 0-26-696 reopened..

Stibsequently, within the hour, the Unit 2 reactor building fire suppression system was returned to operable status and LCOs 3.7.11.1, 3.7.11.2, and 3.7.11.4 were exited.

This event is being reported in accordance with the requirements of Action Statement (b)(2)(c) of LCO 3. 7.11.1.

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