ML17223B121

LER 91-001-00:on 910128,inadvertent Actuation of Reactor Protection Sys Occurred During Testing.Caused by Personnel Error.Operator counselled.W/910226 Ltr

ML17223B121
Person / Time
Site:	Saint Lucie
Issue date:	02/26/1991
From:	Sager D, Treadwell J FLORIDA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
L-91-56, LER-91-001, LER-91-1, NUDOCS 9103050506
Download: ML17223B121 (10)

Text

ACCELERATED DEMONST]+TION SYSTEM DILUTION REGULATORY XNFORMATXON DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:9103050506 DOC.DATE: 91/02/26 NOTARIZED: NO DOCKET FACIL:50-335 St. Lucie Plant, Unit 1, Florida Power & Light Co. 05000335 AUTH. NAME AUTHOR AFFXLIATION TREADWELL,J. Florida Power & Light Co.

SAGER,D.A. Florida Power & Light Co.

RECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER 91-001-00:on 910128,inadvertent actuation of reactor protection sys occurred during testing. Caused by personnel D error. Operator counselled.W/910226 ltr.

DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR TITLE: 50.73/50.9 Licensee Event Report (LER),

2 ENCL 3 Incident SIZE:

Rpt, etc.

NOTES: A RECXPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL D PD2-2 LA 1 1 PD2-2 PD 1 1 NORRIS,J 1 1 D INTERNAL: ACNW 2 2 ACRS 2 2 AEOD/DOA 1 1 AEOD/DSP/TPAB 1 1 AEOD/ROAB/DS P 2 2 NRR/DET/ECMB 9H 1 1 NRR/DET/EMEB 7E 1 1 NRR/DLPQ/LHFB11 1 1 NRR/DLPQ/LPEB10 1 1 NRR/DOEA/OEAB 1 1 NRR/DREP/PRPBll 2 2 NRR DST/SELB 8D 1 1 NRR/DST/SICB 7E 1 1 LB8D1 1 1 NRR/DST/SRXB 8E 1 1 FILE 02 1 1 RES/DSIR/EIB 1 1 RGN2 E 01 1 1 EXTERNAL: EG&G BRYCE, J. H 3 3 L ST LOBBY WARD 1 1 NRC PDR 1 1 NSIC MAYS,G 1 1 NSXC MURPHY,G.A 1 1 NUDOCS FULL TXT 1 1 D

S D

D NOTE TO ALL "RIDS" RECIPIENTS'LEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM Pl-37 (EXT. 20079) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!

FULL TEXT CONVERSION REQUIRED TOTAL NUMBER OF COPIES REQUIRED: LTTR 33 ENCL 33

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P.O. Box 128, Ft. Pierce, FL 34954-0128 February 26, 1991 L-91-56 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: 91-01 Date of Event: January 28, 1991 Inadvertent Actuation of Reactor Protection System Durin Mode 3 Testin Due to Personnel Error The attached Licensee Event Report is being submitted pursuant to the requirements of 10 CFR 50.73 to provide notification of the subject event.

Very truly yours, D. A. ager Vice P esident St. L ie Plant DAS:GRM kw Attachment cc: Stewart D. Ebneter, Regional Administrator, USNRC Region Senior Resident Inspector, USNRC, St. Lucie Plant II DAS/PSL 4361 91030gCya06 9y02P6 PDR ADOCK 05000335

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(143'lCENSEE FPL fecaew ol MlC fees Xl EVENT REPORT (LER)

U.S. NUCLEAR REGULATORY COMMISSCN APP ROVE 0 OM B NO. 315001 04 EXPIRES SI31/85 FACILITYNAME (1) DOCKET NUMBER (2 PAGE 3 St. Lucie Unit 1 0 500033 51OF03 TITLE (4) INADVERTENTACTUATION OF REACTOR PROTECTION SYSTEM DURING MODE 3 TESTING DUE TO PERSONNEL ERROR EVENT DATE (5) LER NUMBER (6) REPORT DATE (7) OTHER FACILITIES INVOLVED(8)

MONTH DAY YEAR YEAR MONTH DAY YEAR FACILITYNAMES DOCKET NUMBER(S)

NUMBER NUMBER N/A 0 5000 0 1 289 1 9 1 0 0 1 0 0 0 2 2 6 9 1 THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR OPERATING Check one or more of the foiiowin 11 MODE (9) 20.402(b) 20.405(c) 50.73(a)(2)(iv) 73.71(b)

POWER 20.405(a)(1)(i) 50.36(c)(1) 50.73(a)(2)(v) 73.71(c)

LEVEL (10) 0 00 20.405(a)(1)(ii) 50.36(c)(2) 50.73(a)(2)(vii) OTHER (Specify In Abstract 20.405(a)(1)(iii) 50.78(a)(2)(i) 50.73(a)(2)(viii)(A) below and in Text 20.405(a)(1)(iv) 50.73(a) (2)(ii) 50.73(a)(2)(viii)(B) NRC Form 366A) 20.405(a)(1)(v) 50.73(a)(2)(iii) 50.73(a)(2)(x)

LICENSEE CONTACT FOR THIS LER (12)

NAME AREA CODE J. Treadwell, Shift Technical Advisor 4 0 7 465-3 550 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT 13 CAUSE SYSTEM COMPONENT MANUFAC- TURER REPORTABLE TO NPRDS CAUSE SYSTEM COMPONENT MANUFAC- TURER REPORTABLE TO NPRDS SUPPLEMENTAL REPORT EXPECTED 14 EXPECTED AR SUBMISSION YES (lfyes, complete EXPECTED SUBMISSION DATE) NO DATE (15)

ABSTRACT (Limit to 1400 spaces. I.e. approximately fifteen single-space typewritten lines)(1 6)

On January 28, 1991, at 1136, with Unit 1 in mode 3 for scheduled Control Element Assembly testing, an inadvertent actuation of the Reactor Protection System occurred during Reactor Protection System testing. TheactuationoccurredonHighStartup Rate,channelsAandB. The TripCircuit Breakers opened, and one Control Element Assembly inserted. The reactor was already subcritical, and the event had no effect on plant operation.

The root cause of the event was cognitive personnel error. A utility licensed operator inadvertently adjusted the wrong trip test potentiometer during Reactor Protection System Loss of Turbine testing.

Corrective actions: Utility licensed operators restored the incorrectly positioned potentiometer to its correct position and closed the Trip Circuit Breakers. Scheduled testing was resumed. An INPO Human Performance Enhancement System review was performed on this event. The operator was counseled.

An Operator Self Verification program had recently been introduced in order to reduce personnel error.

As this policy is fully implemented and all operators become familiar with it, the frequency of such errors should be reduced.

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APL FecereN rl U.S. NUCLEAR REGULATORY COMM1SSlON IRC F~ SN

(~ LICENSEE EVENT REPORT (LER) TEXT CONTINUATION APPROVEO 0MB NO. 31504104 EXPIRES 8011SS

, FACILITYNAME (1) DOCKET NUMBER (2) LER NUMBER (6) PAGE (3)

YEAR SEQUENTIAL REVISION St. Lucie Unit 1 NUMBER . NUMBER 0 500 0335 9 1 0 0 1 0 0 0 2 03 TEXT (lfmore spaceis required, use additional NRC Form 366A's)(17)

DESCRIPTION OF THE EVENT On January 28, 1991, Unit 1 was in Mode 3 for scheduled Control Element Assembly (CEA) (EIIS:AA) testing. Reactor Protection System (RPS) (EIIS:JC) channel A High Startup Rate had previously been placed in a tripped condition, due to Wide Range Safety Channel A Nuclear Instrument (Nl) (EIIS:IG) being out of service.

CEA testing was in progress with one CEA partially withdrawn. All other CEA's were fully inserted. In preparation for startup, RPS testing;.<as being performed in accordance with Operations procedure 1-1400054, REACTOR PROTECTION SYSTEM - LOSS OF TURBINE - HYDRAULICFLUID PRESSURE LOW. Per procedure, a trip test potentiometer is adjusted on the linear range power Nl drawer. At 1136; while testing channel B, the operator inadvertently adjusted a similarly labeled trip test potentiometer on the adjacent wide range power Nl drawer. This was seen by RPS as a High Startup Rate on channel B. With channel A already in a tripped condition, this satisfied the RPS 2/4 logic. The Trip Circuit Breakers (TCB's) opened and one CEA inserted. This was the only CEA not already fully inserted. The reactor was subcritical.

CAUSE OF THE EVENT The root cause of this event was cognitive personnel error. An INPO Human Performance Enhancement System (HPES) review was performed. There were no adverse environmental conditions with respect to lighting, noise or equipment labeling. A utility licensed operator did not adequately follow an approved procedure. The wrong trip test potentiometer was adjusted on the RPS cabinet.

Self-checking was not applied to ensure location of the correct component before it was operated. A contributing factor was the channel A High Startup Rate already being in a tripped condition. This changed the RPS logic from 2/4 to 1/3, thus eliminating the normal single-failure tolerance for actuation on a spurious signal.

ANALYSIS OF THE EVENT This event is reportable under the requirements of 10CFR50.73.a.2.iv as an event that resulted in manu"I or automatic action of any Engineered Safety Feature.

I The portion of the testing being performed involved simulating a turbine trip on one RPS channel at a time. With channel A High Startup Rate already in a tripped condition, the error resulted in a false High Startup Rate on 2 out of 4 RPS channels, satisfying the RPS actuation logic. The TCB's opened and one CEA inserted. The reactor was already subcritical and in Mode 3, thus the event had no effect on plant operation. The RPS actuated correctly and properly as called upon. All TCB's were open within 40 milliseconds. Therefore, there were no equipment operability concerns. If the same test were run with the unit above 15% power, this event would not have occurred, as adjustment of the trip test potentiometer would not have been necessary. If this test had been done with the reactor critical but less than 15% power, the event would have resulted in a reactor trip.

The health and safety of the public were not at risk at any time during this event.

fPL FocawN U.S. NUCLEAR REGULATORY COMM ISS ION

~C IHCF~ APPROVEO 0MB NO. 3150410l ONP4$ I UCENBEE EVENT REPORT (LER) TEXT CONTINUATION EXPIRES 8I31ISS FACILITYNAME (1) DOCKET NUMBER (2) LER NUMBER (6) PAGE (3)

YEAR EQUENTIAL REVISIO NUMBER NUMBE St. Lucie Unit 1 0 50 0 0335 9 1 0 0 1 0 0 0 3 0 3 TEXT (Ifmore space is required, use additional NRC Form 366A's) (1 7)

CORRECTIVE ACTIONS

1. A post trip review was conducted to verify proper equipment response and determine the specific cause of this event. Scheduled testing was resumed.

2. An INPO HPES review was performed on this event.

3. The requirements of the operator self verification program were reviewed with the operator involved.

4..Introduction of an Operator Self Verification program had begun just prior to this event in order to reduce personnel errors. As this program is fully implemented and operators become familiar with it, the frequency of such errors will be reduced.

5. Training of all licensed operators on the importance of self verification in reducing this type of error will

-be conducted.

6. The Wide Range Channel A Nl will be repaired by the end of the next refueling outage.

ADDITIONALINFORMATION NONE LER 389-89-003 describes an inadvertent Containment Isolation actuation due to a Licensed Operator mistakenly resetting one channel while a second channel was in the tripped condition.

LER 389-90-004 describes an inadvertent actuation of Engineered Safeguards Equipment during Engineered Safeguards testing due to Instrument and Control personnel depressing the wrong pushbut ton.

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