ML17223A534

LER 90-001-00:on 900124,discovered Low Steam Generator Pressure Trip to Main Steam Isolation Signal Setpoint Below Tech Spec Min Value.Caused by Procedural Error in Setpoint Adjustment.Pressure Input Settings adjusted.W/900221 Ltr

ML17223A534
Person / Time
Site:	Saint Lucie
Issue date:	02/21/1990
From:	Sager D, Weeks J FLORIDA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
L-90-66, LER-90-001-02, LER-90-1-2, NUDOCS 9003060224
Download: ML17223A534 (5)

Text

ACCELERATED I+TRJBUTION DEMONSATION SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:9003060224 DOC.DATE: 90/02/21 NOTARIZED: NO DOCKET FACIL:50-335 St. Lucie Plant, Unit 1, Florida Power & Light Co. 05000335 AUTH. NAME AUTHOR AFFILIATION WEEKS,J.W. Florida Power & Light Co.

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

RECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER 90-001-00:on 900124,low steam generator pressure trip to main steam isolation signal set below TS allowed min value.

W/8 lt DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR ENCL SIZE:

TITLE: 50.73/50.9 Licensee Event Report (LER), Incident'. Rpt, etc.

NOTES:

RECIPIENT COPIES RECIPIENT 'COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD2-2 LA 1 1 PD2-2 PD 1 1 NORRIS,J 1 1 INTERNAL: ACNW 2 2 ACRS 2 2 AEOD/DOA 1 1 AEOD/DS P/TPAB 1 1 AEOD/ROAB/DSP 2 2 DEDRO 1 1 NRR/DET/ECMB 9H 1 1 NRR/DET/EMEB9H3 1 1 NRR/DET/ESGB 8D 1 1 NRR/DLPQ/LHFBl1 1 1 NRR/DLPQ/LPEB10 1 1 NRR/DOEA/OEAB1 1 1 1 NRR/DREP/PRPB11 2 2 NRR/DST/SELB 8D 1 1 NRR/DST/SICB 7E 1 1 NRR DST S B 1 1 NRR/DST/SRXB 8E 1 1 1 1 RES/DSIR/EIB 1 1 RGN2 FILE 01 1 1 EXTERNAL: EG&G WILLIAMS,S 4 4 L ST LOBBY WARD 1 1 LPDR 1 1 NRC PDR 1 1 NSIC MAYS,G 1 1 NSIC MURPHY,G.A 1 1 NUDOCS FULL TXT 1 1 NOTE TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTEl CONTACT THE,DOCUMENI'ONTROL DESK, ROOM Pl-37 (EXT. 20079) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISIS FOR DOCUMENTS YOU DON'T NEED!

FULL TEXT CONVERSION REQUIRED TOTAL NUMBER OF COPIES REQUIRED: LTTR, 37 ENCL 37

F'.0. Box14000,Juno Beach, FL 33408 0420 FEBRUARY,2 1 199C L-90-66

.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: 90-01 Date of Event: January 24, 1990 Low Steam Generator Pressure Trip to Main Steam Isolation Signal Set BeloW Technical Specification Allowed Minimum Value Due To Procedural 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. ger Vice sident St. Lucie Plant DAS/GRM/slh Attachment cc: Stewart D. Ebneter, Regional Administrator, Region II, USNRC Senior Resident Inspector, USNRC, St. Lucie Plant

>00=040224 W002-g PDt AOOCK 05000 3 1='DC an FPL Group compur~

o FPL Facarrrr'Ie oi U.S. NUCLEAR REGULATORY COMMISSION NRC f.orm 388 APPROVED OMS NO. 31530104 t8.83) LICENSEE EVENT REPORT (LER) EXPIRES 8/31/85 FACILITYNAME (1) DOCKET NUMBER (2) PAGE 3 ST. LUGIE, UNIT 1 0 50003 35 1OFO 3 LOW STEAM GENERATOR PRESSURE TRIP TO MAIN STEAM ISOLATION SIGNAL SET BELOW TECHNICAL SPECIFICATION ALLOWED MINIMUMVALUE DUE TO PROCEDURAL ERROR EVENT DATE (5) LER NUMBER (6) REPORT DATE (7) OTHER FACILITIES INVOLVED(8)

MONTH DAY YEAR FACILITY NAMES DOCKET NUMBER(S)

MONTH DAY YEAR YEAR NUM E NUM N/A 05000 0 1 2 4 9 0 0 0 1 0 0 0 2 9 0 THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR OPERATING Che k neor oreof e ollowin 11 MODE (9) 50.73(a)(2)(iv) 73.71(b) 20.402(b) 20.405(c)

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

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

LICENSEE CONTACT FOR THIS LER (12)

NAME AREA CODE JAY W. WEEKS, SHIFT TECHNICAL ADVISOR 4 0 7 465-3550 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT 13 CAUSE SYSTEM COMPONENT MANUFAC- R/POQTAgLE CAUSE SYSTEM COMPONENT Mg@AC- R/PORTIIrBLE TURER SUPPLEMENTAL REPORT EXPECTED 14 EXPECTED YYA 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 24 January, 1990, St. Lucie Unit 1 was in Mode 5 and preparing for a refueling outage when an Instrumentation and Controls (I & C) supervisor discovered a discrepancy in an I & C procedure when compared to the Technical Specification. Technical Specification 3.3.2, Table 3.34 states that the minimum allowable setpoint for the low Steam Generator (SG) pressure input to the Main Steam Isolation Signal (MSIS) of the Enginccred Safety Features Actuation System (ESFAS) is 585 psig. The I & C procedure had the sctpoint set to 585+/- 7.5 psig.

The root cause of the event was a procedural error in that thc setpoint adjustments in the ESFAS calibration procedure were not in accordance with the requirements of the Technical Specifications. The I & C procedure will be revised to reflect the correct settings for the low SG pressure inputs to the MSIS. The procedures have been thoroughly reviewed and independently verified by qualified I & C personnel to ensure no other setpoint problems exist on either Unit 1 or Unit 2 procedures. The actual settings of the low SG pressure inputs to the MSIS will be adjusted to the correct setpoints prior to entering Mode 3. Mode 3 is the first mode after the outage that the MSIS is required to be operable and in service.

acarm NRC Form 358 t8 83)

FPL Faorirrib ol U.S. NUCLEAR REGULATORYCOMMISSION NRC Form 368 I8 83)-

LICENSEE EVENT REPORT (LER) TEXT CONTINUATION APPROVEO OM 8 NO. 31500104 EXPIRES 8/31/85 r FACILITYNAME (1) DOCKET NUMBER (2) LER NUMBER (6) PAGE (3)

YEAR SEI(IUENTIAL RFVI/IP ST. LUCIE, UNIT1 0500033590 0 0 1 0 0 0 2 OF 0 3 TEXT (Ifmore space ls required, use additional NRC Form 366A's) (17)

DESCRIPTI N F THE EVENT:

On 24 January, 1990, St. Lucie Unit 1 was in Mode 5 and preparing for a refueling'outage. A plant Instrumentation and Control (I &, C) supervisor discovered that a discrepancy existed in one of the I & C Maintenance procedures to a requirement of the Technical Specifications. Technical Specification 3.3.2, Table 3.3A states that the minimum allowable value of Steam Generator (EIIS:AB) (SG) low pressure trip setpoint to the Main Steam Isolation Signal (MSIS) of thc Engineered Safety Features Actuation System (EIIS:JE) (ESFAS) is 585 psig.

The I & C Maintenance procedure that tests and calibrates the ESFAS inputs had an erroneous value for setting the SG low prcssure trip inputs to thc MSIS. The SG pressure instrument setpoint has a variable range of -15 to 1185 psig. The instrument providing this signal has an output of 4 to 20 milliamps. 'Ibis is a linear instrument where the pressure of -15 psig corresponds to 4 milliamps output and the 1185 psig corresponds to 20 milliamps.

The midpoint of the range is 585 psig (corresponding to 12 milliamps). 585 psig is the Technical SpeciTication minimum, therefore the minimum allowable instrument output would be 12.00 milliamps. However, the procedure required that the MSIS trip setting be set at 12.00 milliamps+/- 0.10 milliamps. This allowed the actual setpoint to be 585+/- 7.5 psig (577.5 to 592.5 psig). While some of these setpoints were set correctly to agree with the Technical SpeciTications, at times some were set below the Technical Specification minimum.

This event was discovered while the unit was in Mode 5. Thc Technical Specification requirement for the MSIS to be operable is for Modes 1, 2, and 3. Therefore, the unit did not enter into any Action Statcmcnt.

The root cause of the event is a procedural error in that the approved procedure for testing and calibrating- the ESFAS trip signals speciTied MSIS sctpoints less conservative than the requirements of the Technical SpeciTications. The error was not discovered during the original preparation and review of thc procedure by plant I & C personnel. No unusual characteristics of the work location were known to have contributed to this event.

Y I FTHEE E T'nit 1 Technical Specification requires that the SG low pressure trip setting for the MSIS be >/= 585 psig.

The procedure for testing and calibrating this setpoint allowed the trip to be set as low as 577.5 psig. Upon review of previously performed calibration data sheets, it was determined that the setpoint had in fact been set between 577.5 and 585 psig. At no time was the setpoint set below 577.5 psig.

This event was reportable to the NRC under 10CFR50.73.a.2.i.B as any operation or condition prohibited by the plant's Technical Specifications.

Though the setpoint was below the Technical SpeciTication Minimum, it was still bounded by the analysis of thc limiting accident, Steam Line Rupture Event, in the Final Updated Safety Analysis Report (FUSAR).

This analysis assumes the MSIS trip to actuate at a pressure of 578 psia (563.3 psig). Therefore, the actual sctpoint was at least 14.2 psi above that of the limiting accident analysis.

Thus, the health and safety of the public was not endangered at any time before this event was discovered.

FPL Facsimb ot NRC Form 366 (8.83]

FPL Facolrnb ol U.S. NUCLEAR REGULATORY COMMISSION NRCForrnSN ~ APP ROVED 0M B NO. 31504104 t8 83) LICENSEE EVENT REPORT (LER) TEXT CONTINUATION EXPIRES 8/31/85 FACILITYNAME (1) DOCKET NUMBER (2) LER NUMBER (6) PAGE (3)

YEAR SEQUENTIAL NUMBER REVISION NUMBER ST. LUCIE, UNIT1 05000335 9 0- 0 0 0 0 0 3 F 0 3 TEXT(Ifmore space is required, use additional NRC Form 366A's)(17)

1. I & C Procedure No. 1-1400052 will bc changed to correct the setpoints for MSIS low SG pressure trip.

2. The actual sctpoints on the ESFAS cabinet will be corrected prior to Mode 3 following the refueling outage.

Mode 3 is the first mode entry which requires the MSIS to be operable and in service.

3. QualiTied I & C personnel have independently checked and verified that no other ESFAS or Reactor Protection System setpoints are in violation of their Technical SpeciTication requirements for either Unit 1 or Unit 2.

T R F il d m 'n nt Identificai n There werc no component failures associated with this event.

Pr vi u imil rEv n There have been no previous Licensee Event Reports involving incorrect ESFAS sctpoints due to procedural error at this facility.

FPL Faorlrnb ol NRC Form 388 t8-83)