ML17221A584

LER 87-017-00:on 871221,reactor Tripped Due to Protective Sys Hi Startup Rate B Channel in Trip & Loss of 1MD 120-volt Ac Instrument Bus.Caused by Personnel Error.Personnel Counseled on Following procedures.W/880120 Ltr

ML17221A584
Person / Time
Site:	Saint Lucie
Issue date:	01/20/1988
From:	Green W, Woody C FLORIDA POWER & LIGHT CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
L-88-30, LER-87-017-02, LER-87-17-2, NUDOCS 8801260221
Download: ML17221A584 (5)

Text

REGULATE.. INFORMATION DISTRIBUTION ~STEM (RIDS)

ACCESSIOhb NBR: 8801260221 DOC. DATE: 88/01,/20 NOTAR IZFD: NQ DOCKET FACIL: 50-335 St. Lucie Planti Unit ii Florida Poeer S. Light Co. 05000335 AUTH. NAME AUTHOR AFFILIATION GREENi W. C. Florida Poeer 8. Light Co.

WOODYi C. Q. Florida Power 5 Light Co.

REC IP. NAME REC IP IENT AFFILIATION

SUBJECT:

LER 87-017-00: on 871221'eactor tripped due to protective sos hi startup rate B channel in trip 5 loss o8 1MD 120-volt ac instrument bus. Caused bg personnel error. Personnel counseled on following procedures. W/880120 ltr.

DISTRIBUTION CODE: IE22D COPIES RECEIVED: LTR ENCL SIZE:

TITLE: 50. 73 Licensee Event Report (LER) i Incident Rpti etc.

NOTES:

REC IP IENT CQP IES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD2-2 LA 1 1 PD2-2 PD 1 TQURIGNYi E 1 1 INTERNAL: ACRS MICHELSQN 1 1 ACRS MQELLER 2 2 AEOD/DOA 1 1 AEOD/DSP/NAS 1 1 AEOD/DSP/RQAB 2 2 *EOD/DSP/TPAB 1 1 ARM/DCTS/DAB 1 1 DEDRO 1 NRR/DEST/ADS 0 NRR/DEST/CEB 1 1 NRR/DEST/ELB 1 1 NRR/DEBT/ I CSB 1 NRR/DEST/MEB 1 1 NRR/DEBT/MTB 1 1 NRR/DEST/PSB 1 NRR/DEST/RSB 1 1 NRR/DEST/SGB 1 NRR/DLPG/HFB 1 1 NRR/DLPG/GAB 1 1 NRR/DOEA/EAB 1 NRR/DREP/RAB 1 NRR/DREP/RPB 2 2 SIB 1 1 NRR/PMAS/ ILRB 1 1 REG FI 02 RES TEI FORDS J 1 1 R DE/EIB 1 1 RES/DRPS DIR 1 1 RGN2 FILE 01 1 1 EXTERNAL: EGS.G GROHi M 5 5 FORD BLDG HOYLE A 1 1 H ST LOBBY WARD 1 LPDR 1 1 NRC PDR 1 1 NSIC HARRIS' 1 1 NSIC MAYST G 1 1 TOTAL NUMBER OF COPIES REQUIRED: LTTR 46 ENCL 45

P. O. B 4000, JUNO BEACH, FL 3340B 0420 rAVuARX 2 0 >98e L-88-30 10 CFR 50.73 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C. 20555 Gentlemen:

Re: St. Lucie Unit 1 Docket No. 50-335 Reportable Event: 87-17 Date of Event: December 21, 1987 Reactor Trip Due to Reactor Protective System HI Start-up "Rate B Channel in Trip and the Loss of 1MD 120V AC Instrument Bus Due to Personnel Error attached Licensee Event Report I'he is being submitted pursuant to the requirements of 10 CFR 50.73 to provide notification of the subject event.

Very truly yours, C. O.

Exec t' o y Vice President COW/GRM/gp Attachment cc: Dr. J. Nelson Grace, Regional Administrator, Region II, USNRC Senior Resident Inspector, St. Lucie Plant USNRC, GRM/003 an FPL Group company

NRC Form 365 U.S. NUCLEAR REGULATORY COMMISSION r9 83r APPROVED OMS NO 31500101 LICENSEE EVENT REPORT (LER) EXPIRES ~ r3) 88 FACILITY NAME (11 DOCKET NUMBER (2( PAGE (3r TITLE Ie)

St. Lucie, Unit 1 050003351OF3 REACTOR TRIP DUE TO REACTOR PROTECTIVE SYSTEM HI START-UP RATE B CRANNEL AND THE LOSS OF 1MD 120V AC INSTRUMENT BUS DUE TO PERSONNEL ERROR IN TRIP EVENT DATE(5) LER NUMSER IS) REPORT DATE (7) OTHER FACILITIES INVOLVED (8)

MONTH OAY Yf.AR YEAR SEQUENTIAL REYiCIQN I'ACILITYNAMES NuaneEA NUMSEII MONTH DAY YEAR DOCKET NUMSER(SI N/A 0 5 0 0 0 1 2 2 1 8 7 0 1 7 0 0 01 208 8 0 5 0 0 0 THIS REPORT IS SUSMITTEO PURSUANT T 0 THE REQUIREMENTE of 10 cFR (): Ichtct oi nieve or rht Ioriomnol OPERATINO oia ~ (11 MODE (8) 20.c02(o) 20.405(c) 50.73(ell2)livl 73.7'I I)a I POWE R LEVEL 20 e05 I ~ I I I I (il S0.38 Ic I llI 50.7 3(e I I 2)H I 73.71(cl 1 p p 20.405( ~ I I I I (ii) 50.35(cl(21 50.73(e)121I vO I OTHER ISptcr(y rn Aorutc(

otioiv tno in Tetr. IYRC Four 20.o05( ~ I llI (iii) 50.73( ~ l(1)(il 50.73(t l(2l(viii)(Al 344AI 20.C05( ~ I(1) (it) 50.73( ~ I(2)(ii) 50.73(el(2) lvriil(SI 20AOS(el)i)(v) 50.73(el(1Hiii) 50.73( ~ l(2)(x)

LICENSEE CONTACT FOR THIS LER l)2)

NAME TELEPaaONE 4UMSER AREA COPE W. C. Green Shift T Ad 3 0546 5-3 5 50 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE OESCRISED IN THIS REPORT 113)

CAUSE SYSTEM COMPONENT MANUFAC REPORTAS(.E MANUFAC. EPORTAS LE TURER TO NPROS CAUSE SYSTEM COMPONENT TURER TO NPROS n

N/A J SUPPLEMENTAL REPORT EXPECTED Ilo) 4IO4, >> DAY YEAR EXPECTED SUSMISSiovr YES III yer. comprtrt EXPECTED SUEMISSIOiV OATEI DATE IISI NO N A AssTRAcT ILimir ro Ieoo Iptctr, It.. tpprotrmtrtry hrrttn unort.rptct type>>ninon (anti) I)SI On December 21, 1987, while operating in Mode 1 at 100 percent power, St. Lucie Unit Nl tripped due to the loss of the 1MD 120 volt AC bus. With the Reactor Protective System (RPS) Hi Start-up Rate B channel Bistable in trip, the RPS logic for HI Start-up Rate was 1 of 3. The loss of the 1D Instrument Inverter caused the subsequent loss of the 1MD 120 volt AC bus, which resulted in the actuation of the deenergize to actuate function of the RPS D channel trip Bistables thus satisfying the RPS trip logic.

The root cause of the event was a cognitive personnel error by a utility non-licensed operator not adequately following a plant approved procedure for operation of the 120 volt Instrument AC Class 1E System.

The non-licensed operator was counseled by his supervisor on the importance of adequately following approved procedures and the need for greater attention to detail while performing critical job responsibilities. A procedure for infrequent operations or manipulations is being drafted. This is to assure a detailed review and briefing by the shift supervisor with appropriate personnel for safe and satisfactory performance. The plant Training Department will evaluate this item to determine appropriate training methods and requirements.

A Human Performance Evaluation is being conducted to identify any areas that may be of concern.

8801260221 880120 PDR ADOCK 05000335 NRC Form 358 S PDR a9 83i

NRC FeIm SddA US. NUCLEAR REGULATORY COMMISSION (9.83)

LICENSEE EVENT REPORT (LER) TEXT CONTINUATION APPROVEO OMS NO 3(50-OIOS EXPIRES; 8/31/88 FACILITY NAME (ll OOCKET NUMSER (3( LER NUMSER Id( PAGE (31 YEAR SEOVENTIAL REVISION Qg NVM ER NVMSER St. Lucie, Unit 1 0 5 0 0 0 3 3 8 7 0 1 7 0 0 0 2 OF 0 3 TEXT ////I>>/S S>>csis /s//w'rsd. vss sddeoI>>/ Hi(C %%d/m 38EA's/ (17(

DESCRIPTION OF EVENT At 1646 hours0.0191 days <br />0.457 hours <br />0.00272 weeks <br />6.26303e-4 months <br /> on Monday, December 21, 1987, with a utility non-licensed operator in the process of returning the 1D Instrument Inverter (EZZSEEF) to service following the completion of preventive maintenance to the system, St. Lucie Unit Nl tripped while operating in Mode 1 at 100 percent power. By not adequately following a plant approved procedure, the operator inadvertently placed the static transfer switch to the inverter position, thus removing the 1B maintenance bypass bus (EZISEED) from service without having the inverter input breaker closed. This resulted in the loss of power to the 1MD 120 volt AC bus. With the Reactor Protective System (RPS) (EZIS:JC) Hi start-up Rate B channel bistable in trip, the RPS Hi Start-up Rate logic was in 1 of 3. When power was lost to the RPS D channel, the deenergize to actuate trip bistables actuated, thus satisfying the RPS logic for tripping the reactor. The plant was immediately stabilized in hot standby Mode 3. The Auxiliary Feedwater Pumps (AFP) (EZZS:BA) started because the Steam Generator levels reached the Engineering Safety Feature Actuation System (ESFAS) (EZZSEJE) set point.

CAUSE OF THE EVENT The root cause of the event was a cognitive personnel error by a utility non-licensed operator for not adequately following a plant approved procedure for operation of the 120 volt Instrument AC Class 1E System. There were no unusual characteristics of the work location which contributed to the personnel error.

ANALYSIS OF THE EVENT This event is reportable under 10 CFR 50.73 (a)(2)(iv) as any event or condition that results in an automatic actuation of the (RPS) or (ESFAS). The plant response to this event was as expected for existing plant conditions. Zt has been concluded that no safety consequences resulted from this event because all safety functions were maintained throughout the event and plant equipment operated as expected with no component failures. The 1MD 120 volt AC bus was restored by properly placing the 1D instrument inverter in service with the 1B maintenance bypass bus as an alternate source. The health and safety of the public were not affected by this event.

NRC PORM lddA (943)

NRC Fosm 366A V.S. NUCLEAR REGULATORY COMMISSION (94) 31 LICENSEE EVENT REPORT (LER) TEXT CONTINUATION APPROVEO OMB NO 3(60-0104 4 EXPIRES: 8431(68 r

FACILITY NAME (I) OOCKET NUMBER (3) LER NVMBER (6) PAGE (3I YEA(I SEGUENTIAL - REVISION N(4MSER NVMSSR St. Lucie, Unit 1 o s o o o 3 3 5 8 7 1 7 0 3OF 03 TEXT llfmP4s spsssis ss644Nsd. 44ss sdd4P644sl Hi(C Fom4 3664'sl (IT)

CORRECTIVE ACTIONS:

1. The non-licensed operator was counseled by his supervisor on the importance of following approved procedures and the need for greater attention to detail while performing critical job responsibilities.

2. The plant Training Department will evaluate this item to determine appropriate training methods and requirements.

3. A Human Performance Evaluation of the event is being conducted to identify any areas that may be of concern.

4. A procedure for infrequent operations and manipulations is being drafted to assure a review and briefing by the shift supervisor with the appropriate personnel. This will insure adequate expertise and experience is present, the correct sequence and expected results are understood, and the impact on the plant is known before beginning.

ADDITIONAL INPORMATIONE FAILED COMPONENT INFORMATION:

All components functioned normally during this event.

PREVIOUS SIMILAR EVENTS:

See LER 335-87-010 and 335-82-071 for previous reactor trips caused by a loss of an instrument, inverter.

NRC SORM 366A 1983)