ML17227A754

LER 93-003-00:on 930201,discharge Occurred from Safety Injection Tanks to Rcs.Caused by Personnel Error.Operators Closed SIT Discharge Isolation Valves,Deenergized Motor Operators & Personnel Involved counselled.W/930302 Ltr

ML17227A754
Person / Time
Site:	Saint Lucie
Issue date:	03/03/1993
From:	Sager D, Sarah Turner FLORIDA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
L-93-063, L-93-63, LER-93-003-01, LER-93-3-1, NUDOCS 9303090376
Download: ML17227A754 (5)

Text

ACCEI ERAT DOCVMENT DIST VTION SYSTEM REGULATORY INFORMATION DISTRIBUTIO SYSTEM (RIDS)

ACCESSION NBR:9303090376 DOC.DATE: 93/03/03 NOTARIZED: NO 'OCKET g f$ FACIL:50-389 8t. Lucie Plant, Unit 2, Florida Power a Light Co. 05000389 AUTH. NAME AUTHOR AFFILIATION TURNERFS.E. Florida Power & Light Co.

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

RECIP.NAME REC1PIENT AFFILIATION

SUBJECT:

LER'93-003-00:on 930201,discharge occurred from safety injection tanks to RCS.Caused by personnel error. Operators closed SIT discharge isolation valves,deenergi'zed motor operators & personnel involved counselled.W/930302 ltr.

DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR ENCL SIZE:

TITLE: Bulletin Response (30,40,70 DKT)

P 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/DSP/TPAB 1 1 AEOD/ROAB/DSP 2 . 2 NRR/DE/EELB 1 1 NRR/DE/EMEB 1 1 NRR/DORS/OEAB 1 1 NRR/DRCH/HHFBHE 1 1 NRR/DRCH/HICB ~ 1 1' NRR/DRCH/HOLB 1 1 NRR/DRIL/RPEB 1 NRR/DRSS/PRPB 2 2 NRR DSSA/SPLB 1 1 NRR/DSSA/SRXB 1 1 - EG-FZc- 02 1 1 RES/DSIR/EIB .'1 1 RGN2 FILE 01 1 1 EXTERNAL: EG&G BRYCEFJ.H 2 2 L ST LOBBY WARD 1 1 NRC PDR 1 1 NSIC MURPHY,G.A 1 1 NSIC POOREFW. 1 1 NUDOCS FULL TXT 1 1 NOTE TO ALL"RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM PI-37 (EXT. 504-2065) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!

FULL TEXT CONVERSION REQUIRED TOTAL NUMBER OF COPIES REQUIRED: LTTR 32 ENCL 32

0 P.O. Box 128, Ft. Piorco, FL 34954-0128 March 2, 1993 L-93-063 10 CFR 50.73 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C. 20555 Re: St. Lucie Unit 2 Docket No. 50-389 Reportable Event: 93-003 Date of Event: February 1, 1993 Discharge from the Safety Injection Tanks to the Reactor Coolant System due to Personnel Error while Shutdown 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, Q. d. spy~~+

Zd <55'y D. A. Sager Vice President

.St. Lucie Plant DAS/JWH/kw Attachment cc: Stewart D. Ebneter, Regional Administrator, USNRC Region II Senior Resident Inspector, USNRC, St. Lucie Plant DAS/PSL f875-93 OBOO~O 9303090376 'rr30303 PDR ADOCK 05000389 S PDR an FPL Group company

AAITTOTTOCAST Nrk 4 \ 44 4 144 FFL Fscsrrk'Hk ol U.S. NUCLEAR REGULATORY COMMISSION SARIS: ASCII NRC Form SOS TSTSAATT0 TAT%XN ATTT RTSPCHSS To CCINkT kklTHTITS SSOISIATICH CCkkfCTION LICENSEE EVENT REPORT (LER) ISCSSSTl 444 ITIS ICRNAI44 CCASNNTS IHCNSNHC TAATXNTSRNATS TOTIR ISCkSOS NO IHIORTS NANACSlS NT TTlANCHTA444k TAS HASE Nl RT OITATONT OQM48SCK 1 ANNNTCTCTI, OC TTINk NSI TO THE SAATRWCRA ISSVC TON IRON C'I p1SI414kkOITICTOI IAANAfHISNTAAOIAOCST,WARNTCTOACCTOITS FACILITYNAME (1) DOCKET NUMBER (2) PAGE 3 St. Lucie Unit 2 050003891 0 3

'~ ( ) Discharge from the Safety Injection Tanks to the Reactor Coolant System due to Personnel Error while Shutdown.

EVENT DATE (5) LER NUMBER (6) REPORT DATE (7) OTHER FACILITIES INVOLVED(8)

S IAL DAY YEAR FACILITYNAMES DOCKET NUMBER(S)

DAY YEAR YEAR N/A 0 0 2 019 3 9 3 0 0 3 0 0 0 3 0 3 9 3 NIA 05000 THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR:

OPERATING Check one or more of the followin (11l MODE (9) 73.71(b) 20.402(b) 20.405(c) X 50.73(a)(2)(iv)

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 in Abstract 20.405(a)(1)(iii) 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 TELEP ONE NUMBER AREAGODE S. E. Turner, Shift Technical Advisor 4 0 7 4 6 5 - 3 5 5 0 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT 13 REPORTABLE MANUFAC- REPORTABLE .

CAUSE SYSTEM COMPONENT TURER TO NPRDS CAUSE SYSTEM COMPONENT TURER TO NPRDS I I I SUPPLEMENTAL REPORT EXPECTED 14 EXPFGTED MONTH DAY YEAR SUBMISSION YES (Ifyes, complete EXPECTED SUBMISSION DATE) NO DATE (15)

ABSTRACT (Limit to 1400 spaces.i.e. approximately fifteen single-space typewritten lines) (16)

On 1 February, 1993 St. Lucie Unit 2 was in Mode 5 and preparing for a normal plant cooldown and depressurization. Operations personnel were performing a stroke time test of the Safety Injection Tank (SIT) discharge valves. The SIT discharge valves were shut at the start of this test because the SITs are not required to be operable in Mode 5. After the stroke testing was complete the four SIT discharge valves were erroneously left open. When the Reactor Coolant System (RCS) was intentionally depressurized below the SIT pressure of 260 psia, approximately 2200 gallorIs of SIT inventory was transferred to the RCS. Operators noted the increase in pressurizer level and stopped the plant depressurization. The open SIT discharge valves were determined to be the cause, and they were shut and de-energized. The normal cooldown and depressurization was then completed.

The root cause of this event is personnel error. While cooling down and depressurizing the plant an operator erroneously placed the SIT discharge valves in a position contrary to that required by plant conditions. A contributing factor is that the cooldown and depressurization procedure was not specific on what was required for 'as left'alve position after the SIT valve test.

The corrective actions taken include: 1) to place the plant in the required condition by closing the SIT discharge valves, 2) update valve stroke data sheet to clarify which procedure is used for the valve position required after testing, 3) change the cooldown procedure to clarify the SIT discharge valves post test position, 4) Operations supervision counselled the personnel involved in this event on the importance of understanding plant conditions.

FPL Facsimile of NRC Form 366 (6-89)

FPL Fscsflff f0 or U.S. NUCLEAR REGULATORY COMMISION AttNOIEO CAST Kk SN04100 NRC Form %8 EftSEW 4004l

+89) I ESTWATEOOROQI tE Il ESAKISITE 0 COANET WITH TISS ttrÃWAllCNCCAIECOEAI LICENSEE EVENT REPORT (LER) INI1NST: 00 0 IITE CSINAfEINSANNT0 ISCNTOWC N/STEN ESONATE TO TIN IE CON00 f

NST tEAONT0NANNNINNTSNANCN 00000EIAa IANETAN IEISAATCNTAaaNTSESE TEXT CONTINUATION WANNNTNTI.OC TISIE ANTTO TIE tAfl I WNSN ISOVCOON tNOECT TSII0410AT Cf NE Cf NANAOENENTNST NAXNT.WANNICTONOC 00001 FACILITYNAME (1) DOCKET NUMBER (2) LER NUMBER (6) PAGE (3)

YEAR EQUENTIAL REVISIO NUMBER NUMBER St. Lucie Unit 2 0 5 0 0 03 89 9 3 0 0 3 0 0 0 2 0 3 TEXT (Ifmore spaceis required, use additional NRC Form 366A's) (17)

On 1 February 1993, with Unit 2 in mode 5, the operating shift was performing a cooldown of the reactor coolant system as per OP 2-0030127, "Reactor Plant Cooldown -, Hot Standby to Cold Shutdown." This procedure requires the Safety Injection Tank (EIIS:BP) (SIT) motor operated discharge isolation valves to be stroke time tested in the-closed direction. These motor operated valves are normally open and their breakers racked out during power operations to prevent inadvertent closure. As per OP 2-0030127, the breakers were closed and all four SIT discharge valves were stroke timed in the closed direction. The operator recorded the data in another procedure and then deenergized the SIT discharge valves. The operator recorded the data on Data Sheet 10, "Non-check Valves Cycled During Cooldown, Cold and Heatup Conditions" of AP 2-0010125A, "Surveillance Data Sheets." This data sheet has a column that specifies post test valve position required after valve stroke. For the SIT discharge valves this column is blank. The operator performing the test opened the four SIT discharge valves then wrote 'open'n the blank for each of the SIT discharge valves post test position. The SIT discharge valves were independently verified to be in the open position by a second operator. The operator performing the test then returned to OP 2-0030127 and had the four SIT valves deenergized as required by the procedure. In this condition, both the open and closed valve position indicating lights are extinguished and the only indication of valve position is from a linear scale indicating meter.

On the next shift the cooidown and depressurization of the reactor coolant system (EIIS:AB) (RCS),

was recommenced. During depressurization the operators noticed that pressurizer level was increasing. Depressurization was stopped and an investigation initiated to determine the cause of the unexpected pressuiizer level increase. The operators noted that the SIT pressures had decreased during depressurization and that the linear valve position indicators indicated that the SIT discharge valves were open. The motor operators for the SIT discharge valves were reenergized and then the valves were closed, and deenergized. The normal depressurization and cooidown were recommenced and completed without futher incident.

TH E T The root cause of this event was cognitive personnel error by utility licensed operators. At the completion of SITdischarge isolation valve testing, a licensed operator reopenedthese valves and did not restore them to their originally closed position, as required by the plant conditions. A contributing factor was that the Reactor Plant Cooldown Procedure did not specify a post test valve position for the SIT isolation valves.

FPL Facsimile of NRC Form 366 (6-89)

fPL fOCSIITSSI Ol U.S. NUCLEAR REGULATORY COMMISION AttAOITDCSSI NCS SII04104 NRC faITISa6 fSSNNW IO44 1 401SIATTOOJlOCNSTNINSSONSC TOCOSNSTTNTNTHSttOIWATIONCCUSCDON LICENSEE EVENT REPORT(LER) INaN ST I 100 HNL faSNANS COSNNNTS INOANDWOTSSTXN 44DNATC TO TIC INCaCS lt AHI 14tONT 0 NANA04SC NT DNANCN SSCS IAS IAOSTANINCRAATCSTT OCMaLKK a

TEXT CONTINUATION WANNSSTON. DC TOSNS NCS TO TIN tN4SSNatl INOVCTON tNONCT IS I SS 4 'ISIS 1 ICC Cf NANNXSCNT AI41 ISSSCCT. WANNSSTOK DC TOSCL FACILITYNAME (1) DOCKET NUMBER (2) LER NUMBER (6) PAGE (3)

YEAR . EQUENTIAL REVISIO NUMBER NUMBER St. Lucie Unit 2 05000389 9 3- 0 0 3 0 0 0 3 0 3 TEXT (Ifmore spaceis required, use additional NRC Form 366A'sf (17)

Plant personnel originally concluded that this event was not reportable because there was no valid Engineered Safety Feature Actuation Signal. This event was later reported under 10CFR50.72(b)

(1)(iv), as an "Emergency Core Cooling System discharge to the reactor coolant system", after plant personnel received additional clarification from the NRC on 22 February 1993. This event is also being reported under 10CFR50.73(a)(2)(iv) as "Any event or condition that resulted in manual or automatic actuation of any Engineered Safety Feature."

The Safety Injection Tanks are not required to be in service in modes 5 and 6, and may be isolated when the Reactor Coolant System is below 276 psia. During this event, the four SITs had a small level drop from approximately 57% to 53% of tank volume. Approximately 2200 gallons of water

'as discharged from the SITs to the RCS causing a negligible drop in RCS temperature. Because the SITs were at a significantly higher boron concentration than the RCS, the overall reactivity addition was negative from the water added to the RCS from the SITs.

Therefore, the health and safety of the public was not affected by this event.

1) Operations closed the SIT discharge isolation valves, and deenergized their motor operators.

2) The personnel involved in this event have been counselled by Operations supervision on the importance of awareness of plant conditions.

3) Unit One and Unit Two procedures for OP 1/2-0030127, "Reactor Plant Cooldown", have been clarified as to the required post test valve position after a SIT valve test.

4) The Data Sheets for Unit One and Unit Two procedures of AP 1/2-0010125A have been clarified for applicable valve position required after testing of the SIT isolation valves.

There were no component failures involved in this event.

There have been no previous Licensee Event Reports on Inadvertant discharge from the Safety Injection Tanks to the Reactor Coolant System.

FPL Facsimile of NRC Form 366 (6-89)