ML18005A643

LER 88-029-00:on 880915,short Equipment Start Pulses Generated,Causing Safety injection,motor-driven Auxiliary Feedwater & Emergency Svc Water Pumps to Start.Caused by Failure of Relay in Sequencer Test circuit.W/881012 Ltr

ML18005A643
Person / Time
Site:	Harris
Issue date:	10/12/1988
From:	Schwabenbauer, Watson R CAROLINA POWER & LIGHT CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
HO-880212-(O), LER-88-029, LER-88-29, NUDOCS 8810170161
Download: ML18005A643 (6)

Text

ACCESSION NBR:8810170161 DOC.DATE: 88/10/12 NOTARIZED: NO DOCKET FACIL:50-400 Shearon Harris Nuclear Power Plant, Unit 1, Carolina 05000400 AUTH. NAME AUTHOR AFFILIATION SCHWABENBAUER Carolina Powe & Light Co.

WATSON,R.A. Carolina Power & Light Co.

RECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER 88-029-00:on 880915,unexpected start of 1B-SB emergency svc water pump occurred. Caused by failure of relay.

W/8 ltr.

DISTRIBUTION CODE: IE22D COPIES RECEIVED:LTR J ENCL TITLE: 50.73 Licensee Event Report (LER), Incident Rpt, etc.

g SIZE:

NOTES:Application for permit renewal filed. 05000400 RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD2-1 LA 1 1 PD2-1 PD 1 1 BUCKLEY,B 1 1 INTERNAL: ACRS MICHELSON 1 1 ACRS MOELLER 2 2 ACRS WYLIE 1 1 AEOD/DOA 1 1 AEOD/DSP/NAS 1 1 AEOD/DSP/ROAB 2 2 AEOD/DSP/TPAB 1 1 ARM/DCTS/DAB 1 1 DEDRO 1 1 NRR/DEST/ADS 7E 1 '0 NRR/DEST/CEB 8H 1 1 NRR/DEST/ESB 8D 1 1 NRR/DEST/ICSB 7 1 1 NRR/DEST/MEB 9H 1 1 NRR/DEST/MTB 9H 1 1 NRR/DEST/PSB 8D 1 1 NRR/DEST/RSB 8E 1 1 NRR/DEST/SGB 8D 1 1 NRR/DLPQ/HFB 10 1 1 NRR/DLPQ/QAB 10 1 1 NRR/DOEA/EAB 11 1 1 NRR/DREP/RAB 10 1 1 NRR/DREP/RPB 10 2 2 NRR/DRI S/S I B 9A 1 1 NUDOCS-ABS RACT 1 02 1 1 RES TELFORD,J 1 1 RES/DSIR DEPY 1 1 RES/DSIR/EIB 1 1 RGN2 FILE 01 1 1 EXTERNAL: G&G WILLIAMS,S 4 4 FORD BLDG HOYgA 1 1 H ST LOBBY WARD 1 1 LPDR 1 1 NRC PDR 1 1 NSIC HARRISgJ 1 1 NSIC MAYSiG 1 1 TOTAL NUMBER OF COPIES REQUIRED: LTTR 46 ENCL 45

NRC Form 355 U.S. NUCLEAR REOULATORY COMMISSION 104LI)

APPROVED OMB NO. 31$ 00104 EXPIRES: 5/31/BS LICENSEE EVENT REPORT (LER)

FACILITY NAME (1) DOCKET NUMBER 12) PA E 3 SHEARON HARRIS NUCLEAR POWER PLANT UNIT 1 0 5 0 0 0 4 0 0 1 OF 0 3

' '" 1B-SB EMERGENCY SERVICE WATER PUMP START DUE TO A DEFECTIVE REL'AY IN THE EMERGENCY SE UENCER TEST CIRCUIT.

EVENT DATE (Sl LER NUMBER (m REPORT DATE (7) OTHER FACILITIES INVOLVED ISI MONTH DAY YEAR YEAR P SEQUENTIAL MONTH OAY YEAR FACILITYNAMES DOCKET NUM 5 E R (SI kN NUMBER NO NUMBER 0 5 0 0 0 O 915 88 8 8 029 00 101 2 8 8 0 5 0 0 0 OPERATINO THIS REPORT IS SUBMITTED PURSUANT TO THE REOUIREMENTS OF 10 CFR ii: (Check onr ot morr ot the foIIovttnpl (11)

MODE (5) 20.402(tr) 20.405(c) 50,73(e) (1HIv) 73.71(II)

POWER 20A05(el(1)(ll 5025(c)(1) 50.73(e) (2)(vl 73.71(c)

LEYEL O O O (10) 20A05( ~ )(1)(4) 50.35(c) (2) 50.73(el(2) (v4) OTHER (Specify In Atrrtrect below rnd In Trrrt, NRC Form 20.405( ~ l(1)(BI) 50,73(e I (21(I) 50.73(e) (1)(vBI)(A) 3SSAI 20A05( ~ ) (I )(lvl 50.73(e) (2)(4) 50.73( ~ ) (2wvBI)(B) 20A05( ~ l(1)(vl 50.734) (2)BII) 50.73(e)(2)(n)

LICENSEE CONTACT FOR THIS LER (12)

TELEPHONE NUMBFR R. SCHWABENBAUER REGULATORY COMPLIANCE TECHNICIAN AREA CODE 9 19 36 2-2 669 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)

MANUFAC. REPORTABLE NN . MANUFAC.

CAUSE SYSTEM COMPONENT TURER TO NPRDS g . !.c?

CAUSE SYSTEM COMPONENT TURER EPORTABLE TO NPRDS RI g J E Y P 297 M...m R.

c ceo NIÃN SUPPLEMENTAL REPORT EXPECTED (lm MONTH R%

N DAY

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YEAR EXPECTED SUBMISSION DATE (15)

YES IIIyer, completr EXPECTED SUBMISSION DA TEI NO ABSTRACT ILImlt to 1400 rpecrr, l.r., epptonlmetely IIItren Wnpreepecr rypewrinrn IInrrI (15)

ABSTRACT:

The plant was shutdown in Mode 6, Refueling, at 0 percent reactor power on September 15, 1988, Plant Change Request (PCR)-1089 had been installed which made a change to the IB-SB Emergency Sequencer actuation relay output contact monitoring lights for the containment fan cooler high speed start relays.

At 0900 hours0.0104 days <br />0.25 hours <br />0.00149 weeks <br />3.4245e-4 months <br /> the sequencer was run in the TEST mode to verify design and completion of the PCR. The sequencer test start button was pressed and released and ihe blocking relays rolled and the TEST START light illuminated'owever, In lieu of continuing the test cycle, the sequencer reset after a delay of nine seconds, The sequencer test permissive interlocks were observed as being available, but the test start circuit did not seal in. The TEST START button was pressed and released again and this time the sequencer reset all relays at one time.

OD (1IEf ~This rapid reset caused the simultaneous movement of the blocking relays to return to 'their normally closed

~30-posltionr the actuation program relays returning to their normally open positions, and the one-shot relays returning to their normally closed positions All this resulted in short equipment start pulses being generated mg that caused trouble alarms for the IB-SB Safety Injection Pump, the IB-SB Motor Driven Auxiliary Feedwater Pump, a)C and the unexpected start of the IB-SB Emergency Service Water Pumps The cause of the event was the failure of a relay in the test circuit which is supposed to block fhe start signal to the pumps while in the test mode.

OQ Corrective actions include the changing out of the defective relay and the performance of tests verifying the correct performance of the sequencer.

MQ There were no safety consequences as a result of this event as the relay ls part of the test mode circuitry only and would not have prevented normal operation of the sequencer in response to a safety injection or loss of off-site power signals This event is being reported in accordance with IOCFR50,75 (a)(2)(iv) as an Engineered Safety System Feature actuation'RC Form 355 IB4)3)

NRC Form 355A U.S. NUCLEAR REGULATORY COMMISSION (943)

LICENSEE EVENT REPORT ILER) TEXT CONTINUATION APPROVED OMS NO. 3)50&)GO EXPIRES: 8/31 )88 FACILITY NAME (11 DOCKET NUM8ER (2) LER NUMBER (5) PAGE (3I YEAR SEQUENTIAL +>':. IISVISION NVMSSR  :.:M NVMSSII SHEARON HARRIS NUCLEAR POWER PLANT UNIT 1 0500040 088 0 2 9 0 0 02pFO 3 TEXT (II more Aofce )I )rRr 'rE rrfe drOO'r'oo ~ HRC Form 3854'f) (IT)

DESCRIPTION:

The plant was shutdown in Mode 6, Refueling, at 0 percent reactor power on September 15, 1988. A Plant Change Request (PCR)-1089 had been installed which made a change to the 1B-SB Emergency Sequencer (EIIS:JE) actuation relay output contact monitoring lights for the containment (EIIS:NH) fan cooler high speed start relays (EIIS:BK).

At 0900 hours0.0104 days <br />0.25 hours <br />0.00149 weeks <br />3.4245e-4 months <br /> the sequencer was run in the TEST mode to verify design and completion of the PCR via a modification acceptance test. The sequencer TEST START pushbutton was pressed and released, the blocking relays rolI.ed and the TEST START light illuminated. In lieu of continuing in the test cycle, the sequencer reset after a delay of nine seconds. The sequencer test permissive interlocks were observed as being available, but the start circuit did not seal-.in.

Technicians at the sequencer, who were present to assist in verifying the modification, monitored the seal-in relays while the TEST START pushbutton was pressed again. Upon releasing the start pushbutton, at about forty-five seconds into the test, no change was noted, then nine seconds later the sequencer reset all the relays at one time.

This rapid reset caused the simultaneous movement of the blocking relays returning to their normally closed positions, the actuation (program) relays returning to their normally open positions, and the one-shot relays returning to their normally closed position. This sequence of events resulted in short equipment start pulses being generated that caused trouble alarms for the 1B-SB Safety Injection (SI) Pump (EIIS:BQ) and the 1B-SB Motor Driven Auxiliary Feedwater (AFW) Pump (EIIS:BA) and the unexpected start of 1B-SB Emergency Service Water (ESW) Pump (EIIS:BI). The correct resetting sequence at the end of a test is for the actuation and one-shot relays to reset first with the blocking relays resetting nine seconds later.

CAUSE:

Subsequent investigation of the sequencer immediately following the event revealed the cause of the event was the testing relay PIA1/1183 (POTTER BRUMFIELD MODEL SMDR137-8) was not actuating although the armature was trying to rotate. It was discovered that one set of contacts on the relay had burned causing the contact finger to weld itself to the'lastic armature. Thi's welding impeeded proper rotation of the armature.

NRC FOIIM SSSA *U.S GPO,)958-0.52A.538/455 5983)

NRC Form 366A U.S. NUCLEAR REOULATORY COMMISSION (983(

LICENSEE EVENT REPORT (LERI TEXT CONTINUATION APPROVED OMS NO. 3(SOW104 EXPIRES: 8/31/88 FACILITYNAME ill DOCK ET NUMBE R l2( LER NUMBER (SI PACE (3I SHEARON HARRIS NUCLEAR POWER PLANT SEQUENTIAL NVMSER REVISION NVMSER UNIT 1 TEXT /// more Eaece CAUSE

• reEMred. Iree (continued)

~ H/IC /orrrr 3684'4/ (ITI o 5 o o o 4 0088 0 2 9 0 003 0F0 3 This relay provides .part of the seal-in circuit for the TEST START pushbutton. Other contacts on the relay, including the burnt contacts, provide power to the program relays during a test sequence and are intended to open at the end of a test prior to the closing of the blocking relays. If this relay does not reset when the coil is de-energized, the entire sequencer will reset at one time as previously described.

The contacts on the relay that showed burning supply power to Program A Loss of Off-Site Power. This was the sequence which was running in test when the sequencer improperly reset and started the 1B-SB ESW pump.

ANALYSIS:

There were no safety consequences as a result of this event. The failed relay is part of the test mode circuitry only and would not have prevented normal operation in response to a SI or loss of off-site power signal. While in test the sequencer is and was declared inoperable.

This event is being reported in accordance with 10CFR50.73 (a)(2)(iv) as an Engineered Safety System (EIIS:JE) feature actuation.

A similar event was reported in LER-88-008-00 where an inadvertent actuation of the Engineered Safety System Feature occurred during testing of the 1B-SB Emergency Sequencer.

CORRECTIVE ACTION/ACTION'TO PREVENT RECURRENCE:

1. The defective relay has been replaced.

2~ Engineering Periodic Test (EPT)-033, Emergency Safeguards Sequencer System Test, which performs a thorough checkout of the sequencer logic including the ability to interrupt the testing mode, was satisfactorily completed and the sequencer declared operable at 1540 hours0.0178 days <br />0.428 hours <br />0.00255 weeks <br />5.8597e-4 months <br /> on September 15, 1988..

3. Engineering Surveillance Test (EST)-317, Emergency Sequencing System 1B-SB Response Time Test, which. runs the sequencer through two complete test sequences, was successfully completed on September 16, 1988.

NRCFORM 346A o U.S.OPO:1988 0 824.638/465 (943 I

Carolina Power & Light Company HARRIS NUCLEAR PROJECT P.O. Box 165 New Hill, NC 27562 OCT $ 21988 File Number'SHF/10-13510C Letter Number: HO-880212 (0)

U.S. Nuclear Regulatory Commission ATTN: NRC Document Control Desk Washington, DC 20555 SHEARON HARRIS NUCLEAR POWER PLANT UNIT 1 DOCKET NO. 50-400 LICENSE NO. NPF-63 LICENSEE EVENT REPORT 88-029-00 Gentlemen.'n accordance with Title 10 to the Code of Federal Regulations, the enclosed Licensee Event Report is submitted. This report fulfills the requirement for a written report within thirty (30) days of a reportable occurrence and is in accordance with the format set forth in NUREG-1022, September 1983.

Very truly yours, R. A. Watson Vice President Harris Nuclear Project RAW:lem Enclosure cc.'r. W. H. Bradford (NRC SHNPP)

Mr. B. Buckley (NRR)

Mr. M. L. Ernst (NRC RII)

MEM/LER-88-029/1/OS1

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