ML18036A725

LER 92-003-00:on 920423,unexpected Group 4 Primary Isolation Signal Received,Resulting in Closure of HPCI Steam Supply Isolation Valves.Caused by Inadvertent Installation of Test Plug.Test Plug marked.W/920526 Ltr

ML18036A725
Person / Time
Site:	Browns Ferry
Issue date:	05/26/1992
From:	Austin S, Zeringue O TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-92-003-02, LER-92-3-2, NUDOCS 9206010218
Download: ML18036A725 (16)

Text

ACCELERATED DISTRIBUTION DEMONST TION SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:9206010218 DOC.DATE: 92/05/26 NOTARIZED: NO DOCKET ii FACIL:50-260 Browns Ferry Nuclear Power Station, Unit, 2, Tennessee 05000260 AUTH. NAME AUTHOR AFFILIATION AUSTIN,S. Tennessee Valley Authority ZERINGUE,O.J. Tennessee Valley Authority RECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER 92-003-00:on 920423,unexpected Group 4 primary isolation signal received,resultinq in closure of HPCI steam D supply isolation valves. Caused by inadvertent installation of test plug. Test plug marked.W/920526 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 D ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL SANDERS,M. 1 1 HEBDON,F 1 1 D ROSS,T. 1 1 INTERNAL: ACNW 2 2 ACRS 2 2 AEOD/DOA 1 1 AEOD/DSP/TPAB 1 1 AEOD/ROAB/DSP 2 2 NRR/DET/EMEB 7E 1 1 NRR/DLPQ/LHFB10 1 1 NRR/DLPQ/LPEB10 1 1 NRR/DOEA/OEAB 1 1 NRR/DREP/PRPB11 2 2 NRR/DST/SELB 8D 1 1 NRR/DST/SICB8H3 1 1 N 4Dgg SPLB8D1 1 1 NRR/DST/SRXB 8E 1 1 REG F 02 1 1 RES/DSIR/EIB 1 1 ILE 01 1 1 EXTERNAL EG &G BRYCE i J H~ 3 3 L ST LOBBY WARD 1 1 NRC PDR 1 1 NSIC MURPHY,G.A 1 1 NSIC POORE,W. 1 1 NUDOCS FULL TXT 1 1 D

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NOTE TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL DESK,

'ROOihl Pl-37 (EXT. 20079) TO ELIMINATEYOUR'AME FROiil DISTRIBUTION LISTS FOR DOCUil!ENTS YOU DON'T NEED!

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

Tennessee Vattey Authority, Post Office Box 2000. Decatur, 'Alabama 35609 O. J. 'Ike'eringue Vice President, Browns Ferry Operations NAY 26 l992 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555

Dear Sir:

TVA BROWNS FERRY NUCLEAR PLANT (BFN) UNIT 2 DOCKET NO. 50-260 FACILITY OPERATING LICENSE DPR-52 LICENSEE EVENT REPORT LER-50-260/92003 The enclosed report provides details concerning inadvertent Group 4 isolation during performance of the High Pressure Coolant High Temperature Functional Test. This report is submitted in accordance with 10 CFR 50.73(a)(2)(iv) and 10 CFR 50.73(a)(2)(v).

Sincerely, Enclosure cc: see page 2 PDR S

ADOCK virus't~206010218 920526 05000260 PDR

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U.S. Nuclear Regulatory Commission

. NAY 2 6 1992 cc (Enclosure):

INPO Records Center Suite 1500 1100 Circle 75 Parkway Atlanta, Georgia 30339 Paul Krippner American Nuclear Insurers Town Center, Suite 300S 29 South Main Street West Hartford, Connecticut 06107 NRC Resident Inspector Browns Ferry Nuclear Plant Route 12, P.O. Box 637 Athens, Alabama 35609-2000 Regional Administrator U.S. Nuclear Regulatory Commission Region II 101 Marietta Street, Suite 2900 Atlanta, Georgia 30323 Thierry M. Ross U.S. Nuclear Regulatory Commission One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852

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(6-89) Expires 4/30/92 LICENSEE EVENT REPORT (LER)

FACILITY NAHE (1) DOCKET NUHBER (2)

TITLE (4) v SE()UENTIAL REVISION FACILITY NAMES DOCKET NUHBER 5)

OPERATING TH 5 REPORT IS SUBHITTED PURSUANT TO THE RE()UIREHENTS OF 10 CFR 5:

HODE 20.402(b) 20.405(c) 50.73(a)(2)(iv) 73.71(b)

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

LEVEL 20.405(a)( l)(ii) 50.36(c)(2) 50.73(a)(2)(Vii) OTHER (Specify in 20.405(a)(1)(iii) '0.73(a)(2)(i) 50;73(a)(2)(viii)(A) Abstract below and in 20.405(a)( l)(iv) 50.73(a)(2)(ii) 50.73(a)(2)(viii )(8) Text, NRC Form 366A)

NAHE Steve Austin, Compliance Licensing Engineer AREA CODE REPORTABLE REPORTABLE Y T H P NT NF T EXPECTED SUBHISS ION ABSTRACT (Limit to 1400 spaces, i.e., approximately fifteen single-space typewritten lines) (16)

On April 23, 1992 at 0440 hours0.00509 days <br />0.122 hours <br />7.275132e-4 weeks <br />1.6742e-4 months <br /> during performance of the High Pressure Coolant (HPCI) High Temperature Functional Test, an unexpected Group 4 Primary Containment Isolation Signal was received, resulting in closure of the HPCI steam supply isolation valves.

The root cause of this event was inadvertent installation of a test plug, an "Amphenol Connector," 120 degrees out of orientation. This resulted in the concurrent heating and subsequent activation of three temperature detectors which

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satisfied the system logic for a Group 4 isolation.

Corrective actions to prevent recurrence will be marking of the test plug to provide indication of correct installation, adding precautions to procedures, replacement of the test plug, and operations personnel review of the incident investigation issued as a result of this event.

NRC Form 366(6-89)

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(6-89) Expires 4/30/92 LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAME (1) (DOCKET NUMBER (2)

I ( (SE()UENTIAL ( (REVISION( ( ( ( (

Browns Ferry Unit 2 ( I I I I

. TEXT (If more space is required, use additional NRC Form 366A's) (17)

C.

April 23, 1992 at 0440 CST Inadvertent HPCI isolation received and subsequent Group 4 valve isolati.on.

April 23, 1992 at 0500 CST HPCI isolation reset and subsequent Group 4 valves were opened, HPCI declared operable'pril 23, 1992 at 0745 CST A four-hour nonemergency notification was made to NRC in accordance with 10 CFR 50.72(b)(2)(ii) and 10 CFR 50.72(b)(2)(iii).

None.

B.

The problem was identified by the Unit 2 operator when he noted the valve position lights indicated valve position had changed.

None.

None.

III. CAUSE OF THE EVENT The immediate cause of the event was the installation of the test plug in an incorrect orientation.

NRC Form 366(6-89)

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(6-89) Expires 4/30/92 LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAHE (1) IOOCKET NUHBER (2)

I I I SEQUENTIAL I IREVISIONI I I I I Browns Ferry Uni t 2 I I I I I TEXT (If more space is required, use additional NRC Form 366A's) (l7)

B- RaMme-The root cause of the event was inadvertent installation of the test plug 120 degrees out of orientation. This incorrect installation resulted in the concurrent heating and subsequent actuation of three temperature detectors which satisfied the system logic for the Group 4 isolation.

C.

Poor ergonomic design contributed to the event. (The design of the test plug, the cable, the keyway in the test .plug, and lack of indication of the correct orientation once the test plug is installed contributed to this event.,) The plug installation is difficult due to size and stiffness of the cable. The size of the key is small and difficult to see and no other orientation markings exits. Once installed, the user has no indication that the test plug is installed correctly.

IV. ANALYSIS OF THE EVENT

'The HPCI system provides makeup water to the reactor under emergency conditions. During the event, due to the isolation of the steam supply valves to the HPCI turbine, HPCI was out of service for 20 minutes.

Technical specifications allow continued reactor operation for up to seven days if HPCI is inoperable provided Automatic Depressurization System

[SB], Core Spray System [SM], Residual Heat Removal System [BO] in the Low Pressure Injection mode and Reactor Core Isolation Cooling System [BN] are operable. During the event, these systems were operable and would have performed their required function if called upon.

All safety related components operated as expected during the event.

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

V. CORRECTIVE ACTIONS A.

The Unit 2 Leak Detection Temperature Switch Test Panel was inspected for problems. When no problems were identified, the High Pressure Coolant High Temperature Functional Test was successfully performed.

NRC Form 366(6-89)

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(6-89) Expires 4/30/92 LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAME (1) (OOCKET NUMBER (2)

I I I I SEQUENTIAL I IREVISIONI I I I I Browns Ferry Unit 2 I I I I I TEXT (If more space is required, use additional NRC Form 366A's) ( 17)

B.

1. The Leak Detector Temperature Switch Test panels will be clearly marked to provide correct indication of test plug installation.

2. Procedures involving the installation of the test plug on the Leak Detection Temperature Switch Test panels will be revised to include precautions to ensure matching of the test plug keyway in the receptacle key during installation.

3. Operations personnel will review the incident investigation issued as a result of this event.

4. The test plug, "Amphenol Connector," on the Heat Detector Temperature Test panel and equivalent panels on Units 1 and 3 will be inspected.

Those that have indications of improper installation will be replaced.

VI. ADDITIONAL INFORMATION None.

B.

None.

VII.

1. The Leak Detection Temperature Switch Test panels will be clearly marked to provide correct indication of test plug installation. This will be completed by June 20, 1992.

2. Procedures involving the installati.on of the test plug .on the Leak Detection Temperature Switch Test panels will be revised to include precautions to ensure matching of the test plug keyway in the receptacle key during installation. This will be completed by September 4, 1992.

3. Operations personnel will review the incident investigation issued as a result of this event. This will be completed by September 11, 1992.

4. The test plug, "Amphenol Connector," on the Heat Detector Temperature Test panel and equivalent panels on Units 1 and 3 will be inspected. Those that have indications of improper installation will be replaced. This will be completed by September ll, 1992.

Energy Industry Identification System (EIIS) codes are identified in the text as [XX].

NRC Form 366(6-89),

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