ML20086S265

AO-S1-74-06:on 740507,emergency Svc Water Pump SW-P-1A Diesel Tripped on High Cooling Water Temp.Caused by Disengaged Clutch.Clutch Manually Engaged,Diesel Restarted & Pump Run for 1 H

ML20086S265
Person / Time
Site:	Surry
Issue date:	06/27/1974
From:	Stallings C VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	Moseley N NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
AO-S1-74-06, AO-S1-74-6, NUDOCS 8403010476
Download: ML20086S265 (7)

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!!r. !!orn:an C. Moscicy, Director Scrial No. 177 Directorate of Reguintory Operations P0&M/JTB:clw United States Atornic Energy Coc: mission Region II - Suite 818 Docket No. 50-280

'230 Peachtree Street, Northwest License No. DPR-32 Atlanta, Georgia 30303

Dear Mr. Moscicy:

Purcuant to Surry Power Station Technical Specification 6.6.B.1, the Virginia Elcetric and Power Company hereby submits forty (40) copics of Abnormal Occurrence Report No. A0-SI-74-06.

The substance of this report has been reviewed by the S.tation Nuclear Safety and Operating Committee and will be placed on the agenda for the next meeting of the System Nuclear Safety and Operating Comnittee.

Very truly yours, ,

$2.lM.)d5MtG9sJ C. M. Stallings

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Vice President-Power Supply and Productica Operations Enclosures 40 copics of A0-SI-74-06

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cc: Mr. K. R. Coller, Assistant Director for Operating _Pe2ctors ,

Mr. Stanley Ragone .. t a

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ABNORMAL OCCURRENCE REPORT REPORT NO. A0-SI-74-06 FAILURE OF TWO E!!ERGENCY SERVICE WATER PUMPS MAY 17, 1974 DOCKET NO. 50-280 LICENSE NO. DPR-32 SURRY POWER STATION VIRGINIA ELECTRIC AND POWER COMPANY 6

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- 1. INTRODUCTION .

In accordance with Technical Specification 6.6.B.1 for Surry Power Station, Operating License No. DPR-32, this report describes an abnormal occurrence which occurred on May 7, 1974. The Directorate of Regulatory Operations, Region II, was notiffed on May 8, 1974.

The occurrence reported herein is classifled an an abnormal occurrence pursuant to Technical Specification 1.0.1.2 which states that "An abnormal occurrence is defined as: Any unit cendition that results in violation of a limiting condition for operation as established in these Technical Specifications." The occurrence reported herein resulted in two out of three emergency service water pumps being inoperable which is in violation of Technical Specification 3.14.A.4.

II.

SUMMARY

OF OCCU1111ENCE On May 7 1974 Unit. No. ? wan in the cold chutdava condition and Unit No. I was operating at 86 per cent of rated power and 720 MWe generator output. The monthly test of the station's diesel driven emergency service water pumps was being performed in accordance with Periodic Test 25.3,

" Emergency Service Water Pumps."

The test commenced at approximately 1820 hours0.0211 days <br />0.506 hours <br />0.00301 weeks <br />6.9251e-4 months <br />. Emergency service water punp SW-P-1A diesel vas remotely started from Unit No. 1 Control Room. After twenty (20) minutes of operation, the diesel tripped on high cooling water temperature. The operator attempted to start emergency ,

service water pump SW-P-1B diesel, but it failed to start. Pump SW-P-lC was tested satisfactorily. Therefore, two of the three emergency service water pumps were inoperabic. Technical Specification 3.li.A.4 requires that at least two pumps be operable.

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, Investic on of the pumps revealed that clutch for pump SW-P-1A was disen~g aged. The failure of pump SW-P-1B to start was caused by a dead cell, in one of the diesel's starting batteries.

i Following appropriate corrective action de' scribed hereinbelow, the monthly PT of the emergency service water pumps was resumed and completed satisfactorily.

III. ANALYSIS OF OCCURRENCE Three emergency service water pumps with a design capacity of 15,000 gpm each are provided to supply water to the high level intake canal in the event of a loss of offsite power. Each pump (SW-P-1A, IB and IC) is driven by a diesel engine through a clutch and a set of reduction gears. In addition, pump SW-P-1A can also be driven by means of a direct coupled electric motor. Each diesel dr'lve has a starting motor run by batteries, closed cooling system, indirectly cooled through a heat exchanget aupplied 'uy waiei fium the pump diochatsu, u..d local / I remote means of starting.

The diesel drive of emergency service water pump SW-P-1A had been removed from service for maintenance prior to the occurrence described herejn. During a test on April 16, 1974, the diesel was run for approximately two (2) minutes to verify operability, but the disengaged clutch was not detected.

The scheduled monthly test of the emergency service water pumps, PT-25.3, was performed on May 7, 1974. According to PT-25.3, the diesel drive pumps are first started remotely from Unit No. I control room and then localJy at the pump. The motor drive of pumo SW-P-1A, is similarly tested. The Control Room Operator, following PT-25.3 k' _J

• (3 O procedure, started pump SW-P-1 A from the contr'or room. With the

, p' ump disengaged from the drive, the temperature of the cooling system increased for approximately twenty (20) minutes af ter starting i the pump and the diesel tripped on high temperature.

The control room operator then attempted to remotely start pump SW-P-1B, but the diesel failed to start. Investigation revealed there was a defective cell in the starting battery for the pump diesel drive.

Preliminary investigation indicates that there was an internal short within the battery. The reason for the failure has not been determined and is under investigation.

Each diesel is equipped with two (2) 12 volt batteries in series.

The failed battery is manufactured by National Battery Company, recently renamed Gould National Battery Company.

IV. CORRECTIVE ACTION TO purvENT REritRRENCE The immediate corrective action on pump SW-P-1A following the trip of the diesel drive was to investigate the pump locally. It was discovered that the clutch was disengaged. The clutch was manually engaged, the diesel was restarted and the pump was run for one (1) hour to complete PT-25.3 satisfactorily for "A" pump.

For the occurrence reported herein, the test following the i

maintenance was not of sufficient duration to allow the disengaged }

clutch to be detected, and there was no maintenance procedure requiring a complete test of the pump. To reduce the probability of  ;

i a recurrence of a similar event, staff personnel have been cautioned 1 that complete maintenance procedures, including provisions for testing, H l

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V are required when performing maintenance of safety related equipment, and the test should be complete and adequate to verify operability of the affected equipment after performance of maintenance.

The immediate corrective action taken in regard to the failed battery was to replace it. Additional investigation of the failed battery is being performed to ascertain the cause of failure. In addition, the surveillance requirements for these, and similar batteries, are being reviewed to determine the adequacy to detect failures of the type experienced. Appropriate additional corrective action, commensurate with the results of these investigations, will be' initiated.

V. ANALY_ SIS AND EVALUATION OF SAFFTY IMPLICATIONS OF Tile OCCURRENCE Three diesel driven emergency service water pumps with a design capacity or 13,000 gpm eacn arc provicea to supply water to Line liigli Icvel intake canal during a loss-of-station power incident. The long term service water requirement for the loss-of-coolant accident in one unit with simultaneous loss-of-station power and the second unit being maintained in a safe condition is 15,000 gpm. Therefore, one emergency service water pump would have been sufficient to meet the requirements of the design basis accident.

In addition, the length of time the two pumps were inoperabic was short. Due to the storage capacity of the high icvel intake canal, there would have been sufficient time to make the affected pumps operable.

Thert rcre no safety implications associated with the occurrence described herein.

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. O VI. C.ONCI,US ION S The licensee concludes that:

1. The failure of craergency service water pump SW-P-I A was caused by Ita clutch being disengaged.

2. The clutch was disengaged because of the failure to

' allow station administrative procedurcs.

3. The failure of emergency service water pump SW-P-1B was caused by a defective cell in one of the dicsci starting batteries.

4. The occurrence described herein did not affect the safe operation of the station.

S. The occurrence described herein did not adversely affect the health or safety of the general public.

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