ML18004B749

LER 87-011-00:on 870307,auxiliary Bus IE Feeder Breaker 121 Tripped Open,Causing de-energization of Auxiliary Bus IE & Safety Bus 1B-SB.Caused by Procedural Inadequacy.Work Ticket Initiated to Replace diode.W/870406 Ltr

ML18004B749
Person / Time
Site:	Harris
Issue date:	04/06/1987
From:	Schwabenbauer, Watson R CAROLINA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
HO-870395-(), HO-870395-(0), LER-87-011, LER-87-11, NUDOCS 8704130111
Download: ML18004B749 (5)

Text

REGULA Y INFORNATION DISTR IBUTI0 YSTEN (R IDS>

ACCESSION NBR

8704130111 DOC. DATE: 87/04/06 NOTARIZED: NO DOCKET FACIL: 50-400 Shearon Harris Nuclear Power Plant> Unit 1> Carolina 05000400 AUTH. NANE AUTHOR AFF ILIAT I ON BCHWABENBAUER Carol in a P over 8c Light C o.

WATSON> R. A. Carolina Poeer 5 Light Co..

RECIP. NAME RECIPIENT AFFILIATION

SUBJECT:

LER 87-011-00: on 870307> auxiliary bus IE feedeY breaker 121 tripped open> causing de-energization of auxiliary bus IE 5 safety bus 1B-SB. Caused bg procedural inadequacy. Work tic ket initiated to replace diode. W/870406 ltr.

DISTRIBUTION CODE: IESSD COPIES RECEIVED: LTR I ENCL I SIIE:

TITLE: 50. 73 Licensee Event Report (LER)> Incident Rpt> etc.

NOTES: App lication for permit reneu'al f iled. 05000400 RECIPIENT COPIEB RECIPIENT COPIES ID CODE/NANE LTTR ENCL ID CODE/NAME LTTR ENCL PD2-1 L* 1 1 PD2-1 PD 1 BUCKLEY> B 1 INTERNAL: ACRS MICHELSON 1 1 ACRB NOELLER 1 1 ACRB WYLIE 1 AEOD/DOA 1 1 AEOD/DBP/ROAB 2 2 AEOD/DSP/TAPB 1 NRR/ADT 1 NRR/DEBT/ADE 0 NRR/DEBT/ADS 1 0 ERR/DEBT/CEB 1 1 NRR/DEBT/ELB 1 1 ERR /DEBT/ I CSB 1 1 NRR/DEST/MEB 1 NRR/DEST/MTB 1 1 NRR/DEBT/PSB 1 1 NRR/DEST/RSB 1 NRR/DEBT/SGB 1 NRR/DLPG/HFB 1 1 NRR/DLPG/GAB 1 1 NRR/DOEA/EAB 1 1 NRR/DREP/EPB 1 1 NRR/DREP/RAB 1 1 BR /ILRB 1 NRR/PNAS/PTSB 1 1 REG FIL 02 RES SPEIS> T 1 1 RGN2 FILE 01 1 EXTERNAL: EQ8cG GROH> N 5 5 H ST LOBBY WARD LPDR 1 NRC PDR NSI C HARRIS> J 1 1 NSIC MAYS> G TOTAL NU >HER OF COP IES REQUIRED: LTTR 41 ENCL 39

NRC Form 3FS U rL NUCLEAR REQULATORY COMMISSION (94)3) APPROVED OMB NO. 31504104 EXPIRES) 5/31/SS LICENSEE EVENT REPORT (LER)

FACILITY NAME (I) DOCKET NUMBER (2) PA E 3I SHEARON HARRIS PLANT UNIT 1 0 5 0 0 0 4 0 1 QF 0 3 TITLE (4)

"6.9 KV ONSITE DISTRIBUTION" EVENT DATE (5) LER NUMBER (6) REPORT DATE (7) OTHER FACILITIES INVOLVED IS)

YEAR SEQUENTIAL Mb Rt VISION MONTH DAY YEAR FACILITYNAMES DOCKET NUMBER(S)

MONTH DAY YEAR NUMBER 5M NUMBER 0 5 0 0 0 0 3 0 7 8 7 011 0 04 6 87 0 5 0 0 0 THIS REPORT IS SUBMITTED PURSUANT T 0 THE REQUIREMENTS OF 10 CFR (): (Check one or more of the follovy'npl (11)

OPERATINQ MODE (9) 20A02(II) 20.405(c) 50.73 (e) (2) (Iv) 73.71(5)

POWER 20.405 [v) (I ) (I) 50.35(c) (I ) 50.73(e)(2)(v) 73 71(c)

LEVEL 20A05( ~ )(I ) (il) 50,73(s) (2) (vii) DTHER (specify ln Aortrect

00) 0 0 0 50.35(c) (2) helow end ln Test, NRC Form 20.405( ~ ) (1)(ill) 50.73(e) (2)(l) 50.73(e) (2) (vill)(A) 366A) 20A05( ~ ) (I ) (I v) . 50.73(s) (2) (Ii) 50.7 3(e) (2) (vill)(5) 20.405 (e) (I ) (v) 50.73(s) (2) (lii) 50.73( ~ )(2)(s)

LICENSEE CONTACT FOR THIS LEA (12I NAME TEI.EPHONE NUMBER AREA CODE R. SCHWABENBAUER REGULATORY TECHNICIAN 919 362 -26 69 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCAIBED IN THIS REPORT (13) i.

MANUFAC EPOATABLE

!NM5 MANUFAC.

PORTABLE CAUSE SYSTEM COMPONENT CAUSE SYSTEM COMPONENT TVRER .. TO NPRDS TVRER TO NPADS h:. Ihr ARIx..

B E E JX W12 0 N c

X N~.~. '"P hk hA:cNkprg ~. whirr h48X h, SVPPLEMENTAI. REPORT EXPECTED (14) MONTH DAY YEAR EXPECTED SUBMISSION DATE (15)

YES llf yet, complNe EXPECTED SUBMISSION DATE)

ABsTRAGT ILlmlr to tcOO tpecer, l.e., epproxlmetely fifteen tfnpleepece typewritten linnl (15)

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 lB-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 3450F 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.

8704130111 870406 PDR *DOCI('5000400 S PDR NRC Form 355 (94)3)

NRC Form 366A U.S. NUCLEAR REOULATORY COMMISSION (94)3)

LICENSEE EVENT REPORT (LER) TEXT CONTINUATION APPROVED OMB NO, 3150-0)04 EX PIR ES: 8/31/BS FACILITY NAME (1) DOCKET NUMBER (2) LER NUMBER (6) FACE (3)

YEAR :R+: SEQUENTIAL

,8 NUMBER '1'UMBER SHEARON HARRIS PLANT UNIT 1 0 5 0 0 0 4 0 0 011 0 0 02 "0 3 TEXT //F'moro FPoco /4 /or/rokod, Iroo /I/Ooro///RC %%d 36649/ (13 I 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 6 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 1E 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 the 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 lE. Relay K706 lost power due to a faulty diode which failed to pass the normal power from an uninterruptible source', the backup source was powered via the Auxiliary Bus lE.

The VCT/RWST transfer was caused by a combination of both the 7.5 KVA Inverter being out of service, a defective diode 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 this by using a,slight amount of pressure on the" release pedal.

NRC FORM BBBA *U.S.GPO;1986 0-624 538/455 (94)3)

NRC Form 366A U.S. NUCLEAR RECULATORY COMMISSION (963)

LICENSEE EVENT REPORT (LER) TEXT CONTIN'ION APPROVEO OMB NO. 3150&)04 EXPIRES: 8/31/88 FACILITY NAME (I) DOCKET NUMBER (2) LER NUMBER (6) PACE (3)

YEAR SEOVENTIAL REVISION NVMSER RroI/ NUMBER SHEARON HARRIS PLANT UNIT 1 40 OS7 0 1 1 00 03 OF 0 TEXT /O'IRors 4/Moo /4 o/O/ISIL Iroo o//SooM/HRC Fo/RI 35546/ ((7)

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 A work ticket has been initiated to replace the faulty diode.

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 SSSA *U.S.CPO.'1986 0.624 538/455 (963)

~4/

Carolina Power 8 Light Company HARRIS NUCLEAR PROJECT P.O. Box 165 New Hill, NC 27562 APR 0 6 1987 File Number'SHF/10-13510C Letter Number'HO-870395 (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"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:skm Enclosure cc.'r. J. Nelson Grace (NRC RII)

Mr. B. Buckley (NRR)

Mr. G. Maxwell (NRC SHNPP)