ML18036A742

LER 92-003-01:on 920423,during Performance of HPCI Test,An Unexpected Group 4 PCIS Received,Resulting in Closure of Inboard & Outboard HPCI Valves.Caused by Incorrect Plug Installation.Test Plug replaced.W/920608 Ltr

ML18036A742
Person / Time
Site:	Browns Ferry
Issue date:	06/08/1992
From:	Austin S, Zeringue O TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-92-003-03, LER-92-3-3, NUDOCS 9206120122
Download: ML18036A742 (16)

Text

REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:9206120122 DOC DATE: 92/06/08 NOTARIZED: NO DOCKET 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 R

SUBJECT:

LER 92-003-01:on 920423,during performance of HPCI test, an unexpected group 4 PCIS received,resultinq in closure of inboard & outboard HPCI valves. Caused by a.ncorrect plug installation. Replacement of test plug.W/920608 ltr.

DISTRIBUTION'ODE: IE22T COPIES RECEIVED:LTR ENCL SIZE:

TITLE: 50.73/50.9 Licensee Event Report (LER),'ncident 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 - - SPLB8D1 1 1 NRR/DST/SRXB 8E 1 1 02 1 1 RES/DSIR/EIB 1 1' RGN2 FILE 01 1 1 EXTERNAL: EG&G BRYCE,J.H 3 3 L ST LOBBY WARD 1 NRC PDR 1 1 NSIC MURPHY,G.A 1 1 NSIC POORE,W. 1 1 NUDOCS FULL TXT 1 1 D

D D

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PLEASE HELP US TO REDUCE WAS'ONTACT THE DOCUMENT CONTROL DESK, ROOM Pl-37 (EXT. 20079): TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'-NEED!

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4l ~I L.

Tennessee Vailey Authority. Post Office Sox 2000, Decatur.'Alabama 35609 O. J.'Ike'eringue Vice President..sro(Nns Ferry Operations JUN 08 1992 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, REVISION 1 The enclosed report provides details concerning inadvertent Group 4 isolation during performance of'he 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).

is revising 'this

'VA LER because of errors identified in the Nay 26, 1992 letter. In the letter previously provided, TVA inadvertantly. omitted the report date and indicated the wrong event, time in Paragraph 3 of Description of Event on Page .2. Furthermore, the last sentence: of Paragraph 1 in the Abstract 'has been clarified.

Sincerely, i

0. J. Zeringue

~used<

Encl'osure cc:, see page 2 9206i20i22 920608 PDR ADOCK .05000260 S PDR

'2' U.S. 'Nucl'ear Regulatory Commission JUN 08 I<9) cc (Enclosure):

INPO Records Center Sui;te 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, Al'abama 35609-2000 Regional'dministrator U.S. Nuclear Regulatory Commission Region .II 101 Marietta Street, Suite 2900 Atlanta, Georgia 30323 Thierry M. Ross U.S. Nuclear R'egulatory Commission One White Flint, North 11555 Rockville Pike

'Rockville, Maryland. 20852

NRC Form 366 U NUCLEAR REGULATORY COMMISSION Approved OMB No. 3150-0104 (6-89) Expires 4/30/92 LICENSEE EVENT REPORT (LER)

FACILITY NAME (1) DOCKET NUMBER (2) P TITLE (4)

SE()UENTIAL REVISION FACILITY NAMES DOCKET NUMBER S) 0 60 892 OPERATING, THIS REPORT IS SUBMITTED PURSUANT TO THE RE()UIREMENTS OF 10. CFR g:

MODE 1 w 20.402(b) 20.405(c) 50.73(a)(2)(iv) 73.71(b)

POWER 20.405(a)( 1)(i) 50.36(c)(l) 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 1 20.405(a)(l)(iii) 50.73(a)(2)(i) 50.73(a)(2)(viii)(A) Abstract below and in 20.405(a)( 1)(iv) 50.73(a)(2)(ii) 50.73(a)(2)(viii.)(B) Text, NRC Form 366A) v .7 1

'NAME Steve Austin, Compliance Licensing Engineer AREA CODE REPORTABLE REPORTABLE NT EXPECTED T .AY YA SUBMISSION Y f m P D 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 inboard and outboard HPCI 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 satisfied the system logic for a Group 4 isolation.

Corrective actions to prevent recurrence will include 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)

0 NRC Form 366A (6-.89)

FACILITY NAME (1)

U.NUCLEAR PENSEE REGULATORY COMMISSION EVENT REPORT (LER)

TEXT CONTINUATION IOOCKET NUMBER (2) t Approved OMB No. 3150-0104 Expires 4/30/92 I I I I SEQUENTIAL I I REVI SION I 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),

I. PLANT CONDITIONS Unit 2 was at 2214 megawatts thermal or 67 percent power. Units 1 and 3 were defueled.

II. DESCRIPTION OF EVENT A- Ex<mt=

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) [BI] High Temperature Functional Test, an unexpected Group 4 Primary Containment Isolation Signal (PCIS) [JE] was received.

,On April 23, 1992 at approximately 0435 hours0.00503 days <br />0.121 hours <br />7.19246e-4 weeks <br />1.655175e-4 months <br />, a nonlicensed utility Assistant Unit Operator (AUO) initiated the test by installing the test plug, "Amphenol Connector," on the Unit 2 Leak Detection Temperature Switch Test Panel. He then energized the, panel, placing the selector switch in position to energize the heating element associated with one temperature switch and depressed the test button. However, he installed

'the test plug connector 120 degrees out of orientation which resulted in the concurrent heating of three temperature switches instead of one. Upon reaching the setpoint temperature, the temperature switches activated relays 23A-KS and 23A-K34 thus satisfying the logic for HPCI isolation.

At 0440 hours0.00509 days <br />0.122 hours <br />7.275132e-4 weeks <br />1.6742e-4 months <br /> the Group 4 isolation occurred, closing the inboard and outboard'PCI isolation valves. At 0500 hours0.00579 days <br />0.139 hours <br />8.267196e-4 weeks <br />1.9025e-4 months <br /> 'HPCI was returned to standby readiness and declared operable when the isolation signal was reset and the isolation valves were opened.

TVA reports this event in accordance with 10 CFR 50.73(a)(2)(iv), as an unplanned actuation of an Engineered Safety Feature and 10 CFR 50.73(a)(2)(v), as any event or condition that alone could have prevented the fulfillment of the safety function of structures or systems needed,to shutdown the reactor and maintain it in a safe shutdown condition.

B.

EKcKLC o None.

NRC Form 366(6-89)

Ik 41 (r

NRC Form 366A U. NUCLEAR REGULATORY COMMISSION Approved OMB No. 3150-0104 (6-89) Expires 4/30/92 PENSEE EVENT REPORT (LER)

TEXT'ONTINUATION FACILITY NAME (1) )DOCKET NUMBER (2)

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

C.

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

,April 23, 1992 at 0500 CDST HPCI isolation reset and subsequent Group 4 valves were opened, HPCI declared operable.

April 23, 1992 at 0745 CDST 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).

D.

None.

E.

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

F.

None.

G.

None.

III. CAUSE OF THE EVENT A.

The immediate cause of the event was. the installation of the test plug in an incorrect orientation.

NRC Form 366(6-89)

4l I

NRC Form 366A (6-89),

FACILITY NAME (1)

U. NUCLEAR REGULATORY COMMISSION PENSEE EVENT REPORT (LER)

TEXT CONTINUATION IDOCKET NUMBER (2) t Approved OMB No. 3150-0104 Expires 4/30/92 I ( / SE()UENTIAL / i REVISION(

Browns Ferry Unit 2 I I I I I TEXT (If more space is required, use additiona1 NRC Form 366A's) (17)

B- Huaf&auae=

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 exists. Once installed, the user has no indication that the. test plug is installed correctly.

IV. ANALYSIS OF THE EVENT A.

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

NRC Form 366(6-89)

0 NRC 'Form 366A U. S~UCLEAR REGULATORY COMNISSION Approved ONB No. 3150-0104 (6-89) Expires 4/30/92 HFENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NANE (1) IDOCKET NUNBER '(2)

I /SE()UENTIAL i /REVISION/ J J )

Browns Ferry Uni t 2 I I I I I TEXT (If more space is required, use additional'RC 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 ADDITIOMAL 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 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. 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 ll, 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 11, 1992.

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

NRC Form 366(6-89)

0 .

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