ML19354E164

LER 89-021-00:on 891218,when Operator Directed to Stop Svc Water Pump C by Positioning Handswitch to auto-after Stop Position,Pump Started,Causing ESF Actuation.Caused by Failed Circuit Board.Board replaced.W/900117 Ltr

ML19354E164
Person / Time
Site:	Summer
Issue date:	01/17/1990
From:	Bradham O, Higgins W SOUTH CAROLINA ELECTRIC & GAS CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-89-021, NUDOCS 9001290130
Download: ML19354E164 (4)

Text

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' 10CFR50.73 7 ,

th C;rolina El;ctric & Gas C,mpany _ 01 ) S. radhom l J:nkinsville. SC 29065 Hucliar Operations (803) 345 4040

iSCE&G.

i January 17, 1990 -

Document Control Desk U. S. Nuclear Regulatory Commission Washington, DC 20555 i

SUBJECT:

Virgil C. Summer Nuclear Station Docket No. 50/395 Operating License No. NPF-12 LER 89-021 .

Gentlemen:

Attached is Licensee Event Report No.89-021 for the Virgil C. Summer Nuclear-Station. This report is submitted pursuant'to the requirements of 10CFR50.73(a)(2)(iv).

Should there be any questions, please call us at your convenience.

Very truly yours, O. S. Bradham DCH/0SB: led Attachment c: D. A. Nauman/0. W. Dixon, Jr./T. C. Nichols, Jr.

! E. C. Roberts R.-V. Tanner J. C. Snelson S. D. Ebneter R. L. Prevatte J..J. Hayes, Jr. J. B. Knotts, Jr.

General Managers INP0 Records Center C. A. Price ANI Library G. J. Taylor Marsh & McLennan J. R. Proper NPCF R. B. Clary NSRC F. H. 7ander RTS (ON0890110)

T. L. Matlosz Files (818.05 & 818.07)

K. E. Hodland 9001290130 900117

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X BI i i Pci i i i N i i i i i i i i l i I I I I l i I I I I I SUPPlahttNTAL fitP0af 4xPSCTED nel MONTM DAY YtAR YES (I, v.e ..w.ar $K*tCTgf gygne,$$10N DA tty NO l l l A T . ACT ,v ,, .. ... . e.,v ,,, . .-,.o , n.i During surveillance testing on December 18, 1989, Surveillance Test Procedure (STP) 123.003A, " Train A Service Water System Valve Operability Test," was being performed.

During the performance of the procedure, the operator was directed to stop the "C" Service Water Pump. However, when the operator stopped the pump by positioning the handswitch to the " Auto-After-Stop" position, the pump restarted for no observable reason. It was determined that the restart of the "C" Service Water Pump could be considered as an inadvertent ESF actuation.

A Maintenance Work Request (MWR) resulted in the discovery of a failed circuit board which sealed in an automatic start signal to the "C" service water pump.

The following corrective actions were taken:

The NRC was notified within four hours per 10CFR50.72(b)(2)(ii).

The "C" Service Water Pump was returned to its normal "out of service" condition.

The failed circuit board was replaced and the low discharge pressure bistable was calibrated.

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IMIC Form SetA U.S. NUCLEM EEIUL&TOXY COMMIB810N

. LICENSEE EVENT REPORT (LER) TEXT CONTINUATION annovio ove no atsomoi exnnes mms FActLeiv NAME til DOCEtY NUMBER (21 ggR NUMBER (6) PAGE (3) naa "St!;rt' 3".Y Virgil C. Summer Nuclear Station- o is lo Io lo 13 l 9 l5 819 -

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010 01 2 0F 013 TEKT (# more space a mn#EN4 Was edEheons/ NRC form Jil6AW {1M PLANT IDENTIFICATION:-

Westinghouse - Pressurized Water Reactor E0VIPMENT IDENTIFICATION:  :

"C" Service Water Pump: XPP39CSW EIIS-BI IDENTIFICATION OF EVENT:

A failed circuit board caused the "C" Service Water Pump to sense a false low  !

discharge pressure resulting in an inadvertent start of the pump.  !

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'fVENT DATE: 1 December 18, 1989 i

REPORT DATE:

January 17, 1990 i This report was initiated by Off-Normal Occurrence Report 89-110.

CONDITIONS PRIOR TO EVENT: I

-Mode 1, 100% power.

Surveillance testing of service water system valves per STP 123.003A.

DESCRIPTION OF EVENT:

I

'During surveillance testing on December 18, 1989 Surveillance Test Procedure (STP) 123.003A, " Train A Service Water System Valve Operability Test," was being performed. In order to permit stroking the discharge valve for the "A" Service Water Pump, the procedure aligns the "C" (Swing) Service Water Pump to Train A.

For administrative reasons, this causes Train A to be declared inoperable. During the performance of the procedure, the operator was directed to stop the "C" Service  !

Water Pump. However, at approximately 2200 when the operator stopped the pump by i positioning the handswitch to the " Auto-After-Stop" position, the pump restarted for no observable reason. The operator stopped the pump by placing the handswitch in the " Pull-to-Lock" position. 1 Even though Train A was currently inoperable, it was determined that the restart of the "C" service water pump could be considered as an inadvertent ESF actuation.

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.. LICENSEE EVENT REPORT (LER) TEXT CONTINUATION A*enowo ous so moe t noints am e r ACittiv NAME (16 puck 41 NUMDER til ttR NJM8tR 166 PAGE (3)

SIN l', -y'((,N vtAm Virgil C. Summer Nuclear Station  ! o ls lo jo lo l3l 9 15 8 l9 __

0l 2[1 ._ 0;O 0l3 or 0[3 nxm -.. .-. - acw w.nni CAUSE OF EVENT:

A Maintenance Work Request (MWR) was issued; this resulted in the discovery of a  ;

failed circuit board which caused a low discharge pressure bistable to remain in the tripp :d condition thus sealing in an automatic start signal to the "C" Service Water Pump.

ANALYSIS OF EVENT: ,

The inadvertent restart of the "C" Service Water Pump reestablished the system configuration to that which had previously existed prior to stopping the pump.

This arrangement is a procedurally acceptable configuration; therefore, the restart of the pump did not present any compromise to the safe operation of the Service Water System or to the plant.

IMMEDIATE CORRECTIVE ACTION:

The NRC was notified within four hours per 10CFR50.72(b)(2)(ii). ,

The "C" Service Water Pump was returned to its normal "out of service" condition.

The failed circuit board was replaced and the low discharge pressure bistable was calibrated.

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ADDITIONAL CORRECTIVE ACTION:

None.

PRIOR OCCURRENCES:

None.

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