ML18038B880

LER 97-002-00:on 970410,HPCI Declared Inoperable.Caused by Personnel Error.Operations Personnel Stopped Instrument Mechanics Testing & Returned HPCI to Standby Readiness. W/970508 Ltr

ML18038B880
Person / Time
Site:	Browns Ferry
Issue date:	05/08/1997
From:	Crane C, Jay Wallace TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-97-002-03, LER-97-2-3, NUDOCS 9705190199
Download: ML18038B880 (16)

Text

CATEGORY REGULA Y INFORMATION DISTRIBUTIO SYSTEM (RIDS)

ACCESSION lNBR:9705190199 DOC.DATE: 97/05/08 NOTARIZED: NO DOCKET ¹ FACIE:50-296 Browns Ferry Nuclear Power Station, Unit 3, Tennessee 05000296 AUTH. NAME AUTHOR Tennessee Valley Authority AFFILIATION'ALLACE,J.E.

CRANE,C.M. Tennessee Valley Authority RECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER 97-002-00:on 970410,HPCI declared inoperable. Caused by personnel error. Operations personnel stopped instrument mechanics testing s returned HPCI to standby read:.iness.W/

970508 ltr.

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 PD2-3-PD 1 1 WILLIAMS,J. 1 1 INTERNAL: ACRS 1 1 BD, B 2 2 AEOD/SPD/RRAB 1 1 PKK I~ggg@ 1 1 NRR/DE/ECGB 1 1 NRR/DE/EELB 1 1 NRR/DE/EMEB 1 1 NRR/DRCH/HHFB 1 1 NRR/DRCH/H I CB 1 1 NRR/DRCH/HOLB 1 1 NRR/DRCH/HQMB 1 1 NRR/DRPM/P"CB 1 1 NRR/DSSA/SPLB 1 1 NRR/DSSA/SRXB 1 1 RES/DET/EIB 1 1 RGN2 FILE 01 1 1 I

EXTERNAL: L ST LOBBY WARD 1 1 LITCO BRYCE,J H 1 1 1 1 NOAC QUEENER,DS 1 1

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NOAC POORE,W.

NRC PDR 1 1 NUDOCS FULL TXT 1 1 NOTE TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE. TO HAVE YOUR NAME OR ORGANIZATION REMOVED FROM DISTRIBUTION LIST'R REDUCE THE NUMBER OF COPIES RECEIVED BY YOU OR YOUR ORGANIZATION, CONTACT THE DOCUMENT CONTRO:

DESK (DCD) ON EXTENSION 415-2083 FULL TEXT CONVERSION REQUIRED TO AL NUMBER OF COPIES REQUIRED: LTTR 25 ENCL 25

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Tennessee Valley Authority. Post Office Box 2000. Decatur, Alabama 35609-2000 Christopher M. (Chris) Crane Vice President, Browns Ferry Nuclear Pfant May 8, 1997 U. S. Nuclear Regulatory Commission 10 CFR 50.73 ATTN: Document Control Desk Washington, D.C. 20555

Dear Sir:

BROWNS FERRY NUCLEAR PLANT (BFN) UNIT 3 - DOCKET NO. 50-296 FACILITY OPERATING LICENSE DPR-68 -LICENSEE EVENT REPORT 50-296/97002 The enclosed report provides details regarding the isolation of the Unit 3 High Pressure Coolant Injection (HPCI) system.

The isolation was a result of personnel error due to a lack of self checking and second party verification. lrt Submittal of this report is in accordance with CFR 50.73(a) (2) (iv) as an event or condition that requited in manual or automatic actuation of an Engineered Safety Feature and 10 CFR 50.73(a)(2)(v) as an event or condition that alone could have prevented the fulfillment of the safety function of a system needed to mitigate the consequences of an accident.

Sincerely,

( I C. M. C ane j/

Enclosure cc: See page 2 llllllllllllllllllllllllllllllllllllll 190007 9705i90l'P9 'tf70508 PDR ADOCK 050002'tf6 S PDR

UPS. Nuclear Regulatory Commission Page 2" May 8, 1997 Enclosure cc (Enclosure):

Mr. Mark S. Lesser, Branch Chief U. S. Nuclear Regulatory Commission Region II Atlanta Federal Center 601 Forsyth St.,SW. Suite 23T85 Atlanta, Georgia 30303 NRC Resident Inspector Browns Ferry Nuclear Plant 10833 Shaw Road Athens, Alabama 35611 Mr. J. F. Williams, Project Manager U. S. Nuclear Regulatory Commission One White Flint, North 11555 Rockvil'le Pike Rockville, Maryland 20852

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NRC FORM 366 U.S. NUCLEAR REGULATORY COIVMSSION APPROVED BY OMB NO. 3160%104 (445) EXPIRES 04/30/88 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS MANDATORYINFORMATION COLLECTION REQUEST:

LICENSEE EVENT REPORT (LER) 50.0 HRS. REPORTED LESSONS LEARNED ARE INCORPORATED INTO THE UCENSING PROCESS AND FED BACK TO INDUSTRY. FORWARD COMMENTS REGARDING (See reverse for required number of BURDEN ESTIMATE TO THE INFORMATION AND RECORDS digits/characters for each block) MANAGEMENT BRANCH IT% F33), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON. DC 2055&4001.

FAcILITYNAMs Il) DOCKETNUMSCRI1) I'Aos ts)

Browns Ferry Nuclear Plant (BFN) Unit 3 05000296 1OF5 TITLE Ie)

Unit 3 HPCI system unexpectedly isolated resulting in an ESF by the actuation of the isolation logic. The cause of this event was personnel error.

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

FACIUTY NAME DOCKET NVMSER MONTH DAY YEAR SEQUENTIAL REVISION MONTH DAY NUMBER NUMBER N/A FACIUTY NAME DOCKET NVMSER 10 97 97 002 00 05 08 N/A OPERATING THIS REPORT IS SUBIVETTED PURS UANT TO THE REQUIREMENTS OF 10 CFR: (Chock ono or moro (11)

MODE (8) N 20.2201(b) 20.2203(a)(2)(v) 50.73(a)(2)(i) 50.73(a)(2)(viii)

POWER 20.2203(a)(1) 20.2203(a)(3)(I) 50.73(a)(2)(ii) 50.73(a)(2)(x)

LEVEL (10) 100 20.2203(a)(2)(l) 20.2203(a)(3)(ii) 50.73(a)(2)(iil) 73.71 20.2203(a)(2)(ii) 20.2203(a)(4) X 50.73(a)(2)(iv) OTHER 20.2203(a)(2)(iii) 50.36(c)(1) X 50.73(a)(2)(v) Specify In Abstract below or In NRC Form 368A 20.2203(a)(2)(iv) 50.36(c)(2) 50.73(a)(2)(vii)

LICENSEE CONTACT FOR THIS LER (12)

TELEPHONE NVMSER (Indude htes Code)

James E. Wallace, Licensing Engineer (205) 729-7874 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT(13)

CAUSE SYSTEM COMPONENT MANUFACTURER REPORTABLE TO NPRDS CAUSE SYSTEM COMPONENT MANUFACTURER REPORTABLE TO NPRDS SUPPLEMENTAL REPORT EXPECTED (14) EXPECTED MONTH DAY YEAR YES SUBMISSION (If yos, complete EXPECTED SUBMISSION DATE). No DATE (16)

ABSTRACT (Limit to 1400 spaces, I.o., approximately 15 singlo-spaced typowr)Iten lines) (16)

On April 10, 1997, Unit 3 and Unit 2 were operating at 100 percent power, and Unit 1 was shutdown and defueled.

While performing a surveillance instruction for the functional testing of the Unit 3 HPCI steam supply low pressure switches, a volt-ohm meter (VOM) was inadvertently placed across a wrong pressure switch contacts. When the pressure switch under test actuated, the VOM completed a HPCI isolation logic circuit causing the actuation of the logic circuitry. As a result of this configuration, HPCI was declared inoperable since it could not perform its intended function. The cause of this event was personnel error as a result of mispositioning a volt-ohm meter lead due to a lack of self checking and second party verification. Corrective actions included personnel corrective actions and training of personnel involved to heighten their awareness of the consequences of this event.

This report is being submitted in accordance with 10 CFR 50.73 (a)(2)(iv) as an event or condition that resulted in the automatic actuation of an Engineered Safety Feature. Additionally, this event is also reportable in accordance with 10 CFR 50.73(a)(2)(v) as an event or condition that alone could have prevented the fulfillment of the safety function of a system that is needed to mitigate the consequences of an accident. Three previous LERs (259/95001, 296/95005, and 296/95004) on similar events were identified.

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NRC FORMQQCA U.S. NUCLEAR REOULA'IQRY COMMISSION (44)5)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACZLZTX NAME 1) DOCKET Bzowns Ferry Unit 3 05000296 2 of 5 97 002 00 T mora space rs requ>re, usa s oes capes orm (1 )

Z. PLANT CONDZTZONS At the time of discovery, 'Unit 3 and, Unit 2 were operating at 100 percent power, and Unit 1 was shutdown and defueled.

zz. DESCRZPTZON OF EVENT A. Eveet On April 10 at 0018'ours Central Daylight time (CDT), Instrument Mechanics (IMs), (utility, nonlicensed) were authorized to perform a functional test of the. High Pressure Coolant Injection (HPCI) [BJ) system steam supply low pressure circuitry. At 0058 hours6.712963e-4 days <br />0.0161 hours <br />9.589947e-5 weeks <br />2.2069e-5 months <br />, HPCI pressure switch (3-PS-73-1A) [PS] was taken out of service for testing. At 0059 hours6.828704e-4 days <br />0.0164 hours <br />9.755291e-5 weeks <br />2.24495e-5 months <br />, a HPCI isolation occurred. At 0100 hour0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br />sr the 1A pressure switch was returned to service after testing. At 0104 hours0.0012 days <br />0.0289 hours <br />1.719577e-4 weeks <br />3.9572e-5 months <br />, Control Room Unit Operator (UO) (utility, licensed) was performing a board walkdown and noticed that the HPCI steam line isolation valves [FCV) (3-FCV-73-2 and 3) were closed. The UO notified the Unit Supervisor (US) of a Group 4 HPCI isolation while another UO notified the IMs of the plant's condition and told them to stop their testing until further investigation could identify the cause of the two, closed HPCI valves. At that time, the HPCI was declared inoperable. At 0112 hours0.0013 days <br />0.0311 hours <br />1.851852e-4 weeks <br />4.2616e-5 months <br />, the UO who identified the isolation took recovery actions for the HPCI isolation in accordance with plant procedure 3-AOI-64-2B, Group 4 - High Pressure Coolant Injection. The HPCI-steam lines were warmed and the isolation valves were reopened. 'The system was returned to standby readiness and declared operable when the isolation valves were opened in accordance with Operating Instruction (3-0I-73), High Pressure Coolant Injection.

At 0420 hours0.00486 days <br />0.117 hours <br />6.944444e-4 weeks <br />1.5981e-4 months <br />, a 4-hour 10 CFR 50.72 notification was made to the NRC for the actuation of an ESF and for HPCI's inability to fulfillits safety function to mitigate the consequences of an accident. In addition, this 30-day report is being submitted in accordance with 10 CFR 50.73(a)(2)(iv) as an event or condition that resulted in the

,automatic actuation of an ESF. Additionally, this event is also reportable in accordance with 10 CFR 50.73(a)(2)(v) as an event oz condition that alone could have prevented the fulfillment of the safety function of a system that is needed to mitigate the consequences of an accident.

B. ~Zno arable Structures, Co onents, or S stems that Contributed to the Event:

None.

f hRC CRM 568A (4-95)

0 NRC FORM 666A U.S. NUCLEAR REOULATQRY COIVMSSION (485)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILZTX NAME DOCKET NUMBER NUMBER Browns Ferry Unit 3 05000296 3 of 5 97 -- 002 -- 00 TE T more spree rs requ<r ruse s ons copes orm (17)

C. Dates and A roximate Times of Ma or Occurrences:

Apri1 10, 1997 At 0018 hours2.083333e-4 days <br />0.005 hours <br />2.97619e-5 weeks <br />6.849e-6 months <br />, CDT SI to test HPCI began.

At 0058 hours6.712963e-4 days <br />0.0161 hours <br />9.589947e-5 weeks <br />2.2069e-5 months <br />, CDT Pressure switch 1A taken out of service for testing.

At 0059 hours6.828704e-4 days <br />0.0164 hours <br />9.755291e-5 weeks <br />2.24495e-5 months <br />, CDT HPCI isolation occurred.

At. 0100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br />, CDT Pressure switch 1A returned to service after testing.

At 0104 hours0.0012 days <br />0.0289 hours <br />1.719577e-4 weeks <br />3.9572e-5 months <br />, CDT Unit Operator discovered isolated valves.

At 0112 hours0.0013 days <br />0.0311 hours <br />1.851852e-4 weeks <br />4.2616e-5 months <br />, CDT HPCI returned to standby readiness.

At 0420'ouzs, CDT A 4-hour notification for the HPCZ isolation was made.

DE Other S stems or Seconda Functions Affected:

None.

E. Method of Discove The HPCI isolation was discovered when an UO performed a board walkdown and identified 'that the HPCZ steam line isolation valves were closed.

F. erator Actions:

Operators notified the ZMs of the isolation and requested the IMs to stop further testing. The UO performed recovery steps in 3-AOI-64-2B Using 3-OI-73, the UO returned HPCZ to standby

~

readiness.

6. Safet S stem Res onses:

None.

zzz. CAUSE OF THE EVENT A. Zmmediate Cause:

The immediate cause of this event was the initiation of the HPCI low pressure logic circuitry that resulted in the closure of two HPCI isolation valves.

NRC FORM 366A (4%5)

0 NRC FORM SCCA U.S. NUCLEAR REOULATORY COMVISSION (4<5)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAME DOCKET LER NUMBER NUMBER NUMBER Browns Ferry Unit 3 05000296 4of5 97 -- 002 -- 00 TEXT ( more space is require, use a iuona copes orm (17)

B. Root Cause:

The cause of this event was personnel error due to a lack of self checking and second party verification.

IMs performing the SI mispositioned volt-ohm meter (VOM) leads to the wrong pressure switch contacts. When the pressure switch under test was valved out and its contacts closed, the VOM completed the circuitry which actuated the isolation logic resulting in HPCI's inability to perform its intended function.

C. Contributin Factors:

None.

zv. ANALYSZS OF THE EVENT The HPCI system provides makeup water to the reactor under emergency conditions. During this event, due to the isolation of the HPCI steam line isolation valves, HPCI was out of service for 14 minutes.

Technical Specifications allowed continued reactor operations for up to seven (7) days if HPCI is inoperable provided Automatic Depressurized System [SB], Core Spray [BM], Residual Heat Removal system [BO] in the low pressure injection mode and Reactor Core Isolation Cooling system [BN] are operable. During this event these systems were operable and would have performed their required functions if called upon.

The HPCI low steam line pressure isolation logic energizes the following relays to accomplish the functions listed when a low steam3-line pressure condition is sensed or simulated: (1) 23A-K12 closes FCV-73-3, energizes turbine trip solenoid, provides ICS with trip signal, and provides CISS A with a trip signal; (2) 23A-K12A closes 3-FCV-73-2 only; (3) 23A-K13 closes 3-FCV-73-26, 3-FCV-73-27, and 3-FCV-73-81; and (4) 63-73-4'rovides CISS trip signal only. In this event, the above functions were verified except the 23A-K13 initiations which could not because the valves actuated by this relay did not change state since they were already closed.

All safety-related components operated as expected during this event.

Therefore, the safety of the plant, its personnel, and the public were not compromised.

v. ~ CORRECTZVE ACTIONS A. Zmmediate Corrective Actions:

Operations personnel stopped the IMs testing and returned HPCI to standby readiness.

NRC FORM 366A (4W5)

il NRC FORM 866A U.S. NUCLEAR REOULATORY COIVMSSION (4+S)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAME I DOCKET PAGE NUMBER NUMBER Browns Ferry Unit 3 05000296 5 of 5 97 -- 002 -- 00 TEXT,( more space rs requir, use a rrona copes orm (1T)

B. Corrective Actions To Prevent Recurrence:

Corrective actions included personnel corrective actions andabout the training of personnel involved to heighten their awareness negative consequences of this event on plant operations.

Additionally, plant stand-down meetings were conducted to ensure plant personnel understood management expectations for self checking and second party verification.

VI. ADDITIONAL INFORMATION A. Failed Co onents:

None.

B. Previous LERs on Similar Events:

TVA has reviewed previous BFN LERs which resulted from ESF actuations due to lack of self checking or verification. Three IERs (259/95001, 296/95005, and'96/95004) were identified.

However, the corrective action taken in these previous LERs would not have pzecluded this (296/97002) event.

VII. COMMITMENTS None.

Energy Industry Identification System (EIIS) system and component codes are identified in the text with brackets (e.g., [XX]).

NRC FORM 366A (4%5)

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