ML18004B886

LER 87-011-01:on 870307,breaker Tripped Open Causing de-energization of Auxiliary Bus 1E.Caused by Procedural Inadequacy.Defective PIC Card in Power Supply to LT-112 Relay Replaced & Procedure revised.W/870722 Ltr

ML18004B886
Person / Time
Site:	Harris
Issue date:	07/22/1987
From:	Schwabenbauer, Watson R CAROLINA POWER & LIGHT CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
HO-870459-(O), LER-87-011, LER-87-11, NUDOCS 8707280188
Download: ML18004B886 (8)

Text

EGULA ORY INFORMATION DISTRIBUTl SYSTEM <BIDS)

ACCESSION NBR: 8707280188 DOC. DATE: 87/07/22 NOTARIZED: NO'OCKET 0 FACIL: 50-400 Shearon Harv is Nucleav Power Plantr Unit ii Carolina '5000400 AUTH. NAME AUTHOR AFFILIATION SCHWABENBAUER. Carolina Power 8c Light Co.

WATSON'. A. Carolina Power 5 Light Co.

RECIP. NAME RECIPlENT AFFILIATION

SUBJECT:

LER 87-011-01: on 870307'reakev tv ipped open causing de-energ ization of auxiliary bus 1E. Caused bg pv ocedural inadequacy. Defective PIC card in powev'upply to LT-112 v clay v eplaced h pv ocedure revised. W/8 DISTRIBUTION CODE: IE22D COPIES RECEIVED: LTR I ENCL I SIZE:

TITLE: 50. 73 Licensee Event Repov t (LER)r Incident Rpti etc.

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'S B 1 INTERNAL: ACRS MICHELSON 1 1 ACRS MOELLER 2 2 AEOD/DOA 1 1 AEOD/DSP/NAS 1 1 AEOD/DSP/ROAB 2 2 AEOD/DSP/TPAB 1 1 DEDRO 1 1 NRR/DEST/ADE 1 0 NRR/DEST/*DS 1 '0 NRR/DEST/CEB 1 1 NRR/DEST/ELB 1 1 NRR/DEST/ICSB 1 1 NRR/DEST/MEB 1 1 NRR/DEST/MTB 1 1 NRR/DEST/PSB 1 1 NRR/DEST/RSB 1 1 NRR/DEST/SGB 1 1 NRR/DLPG/HFB 1 1 NRR/DLPQ/GAB 1 1 NRR/DOEA/EAB 1 NRR/DREP/RAB 1 1 NRR/DREP/RPB 2 2 NRR/PMAS/ ILRB 1 1 NRR/PMAS/PTSB 1 1

~RE~QrRC 02 1 1 RES DEPY GI 1 1 RES TELFDRDr J 1 1 RES/DE/EIB 1 1 RQN2 FILE 01 1 1 EXTERNAL: EGSQ GROH> M 5 5 H ST LOBBY WARD 1 LPDR 1 1 NRC PDR 1 NSIC HARRIS. J 1 1 NSIC MAYST G 1 1 TOTAL NUMBER OF COPIES REQUIRED: LTTR 45 ENCL 43

~ ~ ~ 0 NR>> Form 36F, U.S. NUCLEAR REGULATORY COMMISSION (903)

APPROVED OMB NO. 3)600104 EXPIRES: 5/31/SB LICENSEE EVENT REPORT (LER)

FACILITY NAME (I) DOCKET NUMBER (2) PA E 3 SHEARON HARRIS PLANT UNIT 1 o s o o o 4 0 1 OF 0 TITLE (4)

"6.9 KV ONSITE DISTRIBUTION" EVENT DATE (5) LER NUMBER LBI REPORT DATE (7) OTHER FACILITIES INVOLVED (5)

MONTH DAY YEAR YEAR SEQUENTIAL NUMBER o NUMBER MONTH OAY YEAR FACILITY NAMES DOCKET NUMBER(3) 0 5 0 0 '0 03 07 8 7 8 7 0 1 1 0 1 7 2 2 8 7 0 5 0 0 0 OPERATING THls REPQRT Is sUBMITTED PURsUANT To THE REQUIREMENTs oF 10 cFR g: fcheck one or morr of thr folio~/no) (ll)

MODE (0) 4 20.402(b) 20AOS(c) 60.73(e) (2)(lv) 73.71(5)

POWE R 20.405( ~ )(1)(l) 60.35 (e) (1) 50,73(e)(2)(v) 73.71(c)

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~g,.~;.j, 20.406( ~ ) (1) (v) 60.73(e) (2) (lll) 50.73( ~ ) (2)(x)

LICENSEE CONTACT FOR THIS I.ER (12I NAME TELEPHONE NUMBER R. SCHWABENBAUER REGULATORY COMPLIANCE AREA CODE 9 19 362 -26 9 COMPLETE ONE LINE fOR EACH COMPONENT FAILURE OESCRIBEO IN THIS REPORT (13)

MANUFAC REPORTABLE MANUFAC. am "N'PORTABL CAUSE SYSTEM COMPONENT TO NPRDS CAUSE SYSTEM COMPONENT TURER TVRER TO NPRDS>>g.

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SUPPLEMENTAL REPORT EXPECTED (14) MONTH OAY YEAR EXPECTED SUBMISSION DATE 116)

YES flfyer, complrre EXPECTED SVBhtISSIOIV DATEI NO ABSTRACT ILlmir ro tr00 rpeceL I.r., epproximerely fifrren rlnrrr rpere typenm'tron liner) (16)

ABSTRACT On March 7, 1987, an Auxiliary Operator (AO) was performing a weekly surveillance test (OST-1023) which is for offsite power verification. One of the requirements of the OST is to ensure the breaker release lever is in the neutral position with the breaker closed. When the AO checked Auxiliary Bus IE feeder breaker 121, the breaker was inadvertently tripped open causing the de-energization of Auxiliary Bus IE and Safety Bus 1B-SB. This occurred at 2230 hours0.0258 days <br />0.619 hours <br />0.00369 weeks <br />8.48515e-4 months <br /> on March 7, 1987.

The de-energization of Bus 1B-SB caused the 1B-SB Diesel Generator to start and the actuation of Sequencer 1B-SB on Bus undervoltage. The AO immediately closed the breaker cabinet and notified the Control Room of the incident. The Senior Control Operator (SCO) then initiated AOP-025 for the loss of one emergency bus and all plant systems were then returned to normal.

At the time of the incident, the plant was in Mode 4 at 345'F.and 350 psig.

There were no adverse 'consequences. due to this event and safety systems performed as required. To prevent recurrence, the applicable procedure has been revised.

8707280188 870722 PDR ADOCK 05000400 pn g

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NRC Form 366 (94I3)

NRC Form 388A U.S. NUCLEAR REGULATORY COMMISSION (940 I LI NSEE ENT REPORT (LER) TEXT CONTINU ON APPROVED OMB NO. 3(50&104 EXPIRES: 8/31/88 FACILITYNAME (1) OOCKET NUMBER (21 LER NUMBER (5) PAGE (3)

YEAR SEOUENTIAL REVISION NUMBER '.od NUMSER SHEARON HARRIS PLANT UNIT 1 o s o o o 400 8 7 011 0 1 0 2 OF 0 3 TEXT //P/r>>rs <<>>cr /4 s///Irsd, I/rr dd/ddo>>/ //RC Fcrrn 38543/ (17)

TEXT DESCRIPTION On March 7, 1987, an Auxiliary Operator (AO) was performing a weekly surveillance test OST-1023 entitled "OFFSITE POWER AVAILABILITYVERIFICATION WEEKLY INTERVAL MODES 1-2-3 & 4." One of the requirements of the OST is to ensure the breaker release lever is in the neutral position with the breaker closed. The AO did this by checking the release lever with his foot for freedom of movement. The AO had used this method without incident in the past. When the AO went to check the Auxiliary Bus 1E feeder breaker 121, the breaker tripped open causing the de-energization of Auxiliary Bus lE. This also de-energized the 1B-SB safety bus thereby activating the 1B-SB Sequencer and starting the 1B-SB Diesel Generator.

The AO immediately closed the breaker cabinet and notified the Control Room.

Upon notification, the Senior Control Operator (SCO) entered Abnormal Operating Procedure AOP-025, entitled "Loss of One Emergency AC Bus (6.9KV) or One Emergency DC (125V) Bus" for the loss of emergency bus and restored all plant systems to normal operation. At the time of the incident, the plant was in Mode 4 at 345'F and 350 psig.

The de-energization of non-safety related Auxiliary Bus lE also caused the Charging Safety Injection Pumps (CSIP) suction source to automatically transfer from the Volume Control Tank (VCT) to the Refueling Water Storage Tank (RWST). This transfer occurs automatically when both VCT level channels (LT-115 and LT-112) are less than 5X (low low level) or when Safety Injection occurs. This transfer of suction source was due to the de-energization of relays K701 (for LT-115) and K706 (for LT-112) which caused the associated contacts to close and generate a signal to re-position th'e valves. Relay K701 lost power due to a 7.5 KVA Inverter (the normal power supply) being out of service for a maintenance function', the alternate power supply was via Auxiliary Bus 1E. Relay K706 lost power due to a faulty pin on the PIC card which failed to pass the normal power from an uninterruptible source; the backup source was powered via the Auxiliary Bus 1E.

The VCT/RWST transfer was caused by a combination of both the 7.5 KVA Inverter being out of service, a defective PIC card in the power supply to the LT-112 relay, and the black out of power panels supplied via Auxiliary Bus 1E.

CAUSE The incident was caused by a procedural inadequacy. The procedure did not clearly state how the check was to be performed. The AO had performed th'is by using a slight amount of pressure on the release pedal.

NRC FORM 344A *U.S.GPO:1 988.0 824 538/455

($4)3)

NRC Form 366A U.S. NUCLEAR REGULATORY COMMISSION (983)

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~ LI SEE ENT REPORT (LER) TEXT C TINU ON APPROVED OMB NO, 3150-0104 EXPIRES: 8/31/88 FACILITY NAME (I) DOCKET NUMBER (2) LER NUMBER (61 PAGE (3)

UNIT YEAR PNO SEOUENT/AL NUM E rr gf REVIE/ON

.Ã NUMBER SHEARON HARRIS PLANT 1 TEXT /6 mroo Eooof /4/P///ood, re ///orro/HRC Form 35843/ (IT) 05000400$ 7 0 1 1 0 1 03 "0 3 ANALYSIS There were no adverse consequences due to this incident. The event resulted in actuation of components on the 1B-SB bus as required by plant design.

The event is reportable per 10CFR50.73(a)(2)(iv) which requires reporting of manual or automatic initiation of any Engineered Safety Feature.

CORRECTIVE ACTION The defective PIC card in the power supply to LT-112 relay has been replaced.

ACTION TO PREVENT RECURRENCE To prevent a recurrence of this event, a change to OST-1023 has been completed. The procedure now contains the caution statement, NDo not depress the breaker release pedal when breaker'is closed, pedal will trip breaker."

'NRC fORM 3EEA w U.S.GPO:1986W624 538/455

'(94(3)

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C SQE Carolina Power & Light Company HARRIS NUCLEAR PROJECT P.O. Box 165 New Hill, NC 27562

'JUL 22 ]qRT File Number'SHF/10-13510C Letter Number: HO-870459 (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 87-011-01 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.

Revision 1 is being submitted due to a change in why the K706 relay lost power and the corrective action taken.

Very truly yours, R. A. Watson Vice President Harris Nuclear Project RAW:skm Enclosure cc: Dr. J. Nelson Grace (NRC RII)

Mr. B. Buckley (NRR)

Mr. G. Maxwell (NRC SHNPP)

MEM/HO-8704590/PAGE 1/OS1

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