ML20024H273

Ro:Vital Fire Suppression Water Sys Equipment Not Available for Greater than Seven Days.Caused by Prolonged Preventive Maint.Diesel Driven Fire Pump Was Declared Operable on 910503

ML20024H273
Person / Time
Site:	Vermont Yankee File:NorthStar Vermont Yankee icon.png
Issue date:	05/23/1991
From:	Murphy W VERMONT YANKEE NUCLEAR POWER CORP.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
BVY-91-55, NUDOCS 9105310093
Download: ML20024H273 (2)

Text

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VERMONT YANKEE NUCLEAR POWER CORPORATION

. n, [ Ferry Road, Brattleboro. vT 05301-7002 yh yg ENGINEERING OrnCE se ,.4.m .

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May 23,1991 U.S. Nuclear Regulatory Commission

- Washington,_ D.C. 20555 Attn: Document Control Desk

Reference:

a) Operating License DPR 28 (Docket No. 50 271)

Subject:

Report of Inoperable Equipment in the Vital Fire Suppression Water System l In accordance with Vermont Yankee Technical Specifications Section

! 3.13.B.2, this report is submitted as notification that the required Vital Fire Suppression Water system equipment was not available for greater than seven days. The diesel doven fire pump was out of service for seventeen days.

The diesel driven fire pump was removed from service on Tuesday, April 16, 1991 for preventive maintenance. The scope of the work undertaken i included disassembly, inspection, refurbishing, and restoration to service. These l activities did not reveal any_ condition which could have immediately affected the

!- operability of the pump prior to the performance of the work. The diesel driven l fire pump was declared operable on Friday, May 3,1991.

During the period when the diesel driven fire pump was unavailable, alternate provisions were made to supply the Vital Fire . Suppression Water System. These provisions are detailed in Attachment A to this letter.

Very truly yours, Vermont Yankee Nuclear Power Corporation y &

Vw[dy M Warren P. Murphy Senior Vice President, Operations I

/dm l cc: USNRC Regional Administrator, Region i USNRC Resident inspector, VYNPS USNRC Project Manager, VYNPS <

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ATTACHMENT A Provisions for Vital Fire Suppression Water System Based on the results of preventive maintenance performed on the four station service water pumps, maintenance personnel recommended that the diesel driven fire pump undergo similar preventive maintenance measures. Corrosion product build-up and impeller wear was noted in the service water pumps.

Based on _ these findings, it was determined that the diesel driven fire pump should also be inspected.

To ensure that the ?reventive maintenance work was completed in an expeditious manner, the fol;owing actions were taken;

1) Appropriate procedures, manuals, and repair documents were identified and made ava!!able.

2) Repair personnel were dedicated to the fire pump maintenance activities.

3) Support equipment required for the removal and installation of the fire pump was scheduled and reserved for the project.

4) Anticipated replacement parts were identified, located, and verified as available.

Tech Spec Section 3.13.B.1 specifies the minimum equipment requirements for an operable Vital Fire Suppression Water System. Section 3.13.B.1.a requires that two fire pumps are operable and lined up to the fire suppression loop. Since the diesel oriven fire pump preventive maintenance work placed this pump out of service, the following compensatory measures were established;

1) The electrically driven fire pump remained operable as the primary Vital Fire Suppression Water supply pump.

2) The plant service water system, which can be cross connected to the fire l water main, was utilized as the secondary source for the Vital Fire Suppression Water system.

3) The four plant service water pumps were verified as operable prior to the l start of work on the diesel driven fire pump. During the work effort, the four plant service water pumps remained operable.

l These actions ensured that an adequate Vital Fire Suppression Water system was maintained and that an independent water source was available at all times to supply all fire suppression systems within the plant. Based on this information, the preventive maintenance activities associated with the diesel driven fire pump did not significantly impact the operability of the Vital Fire Suppression Water system.

l /dm