ML17342A848

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LER 87-013-00:on 870710,power Operations of 480 Volt Load Ctr Continued When Inoperable Channel Not in Tripped Condition.Caused by Failure of Relay in Undervoltage Protection Scheme.Evaluation underway.W/870810 Ltr
ML17342A848
Person / Time
Site: Turkey Point NextEra Energy icon.png
Issue date: 08/10/1987
From: Hart R, Woody C
FLORIDA POWER & LIGHT CO.
To:
NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
L-87-328, LER-87-013-02, LER-87-13-2, NUDOCS 8708130177
Download: ML17342A848 (7)
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Text

REGULATORY FORMATION DISTRIBUTION SY M (RIDS>

ACCESSION NBR: 8708130177 DOC. DATE: 87/08/10 NOTARIZED: NO DOCKET FACIL 50 251 Turkey Point Planti Unit 4. Florida Poeer and Light C 05000251 AUTH. NAME AUTHOR AFFILIATION HART'. D. Florida Poeer 8c Light Co.

NOODYz C. Q. Florida Power 5 Light Co.

RECIP. NAME RECIPIENT AFFILIATION

SUBJECT:

LER 87-013-00: on 870710'ech Spec 3. 5-2i Item 3. 2b exceeded requirements. Caused bg Failure o% relay 327TX4C2 in undervoltage protection scheme for 4C 480 volt load ctr.

Relay 327TX/4C2 replaced. M/870810 itr.

DISTRIBUTION CODE: IE22D COPIES RECEIVED: LTR i ENCL TITLE: 50. 73 Licensee Event Report (LER)i Incident Rpti g etc.SIZE:

NOTES:

REC IP IENT COPIES REC IP IENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD2-2 LA 1 1 PD2-2 PD 1 1 McDQNALDi D 1 INTERNAL: ACRS MICHELSON 1 1 ACRS MOELLER AEOD/DOA 1 1 AEOD/DSP/NAS 1

  • EQD/DSP/RQAB 2 2 AEQD/DSP/TPAB 1 DEDRO 1 1 NRR/DEST/ADE 1 0 NRR/DEST/ADS 1 0 NRR/DEST/CEB 1 1 NRR/DEST/ELB 1 NRR/DEST/ I CSB 1 1 NRR/DEST/MEB 1 NRR/DEST/MTB 1 1 NRR/DEST/PSB 1 1 NRR/DEST/RSB 1 1 NRR/DEST/SGB 1 NRR/DLPG/HFB 1 NRR/DLPG/GAB 1 1 NRR/DQEA/EAB 1 1 NRR/DREP/RAB 1 1 NRR/DREP/RPB 2 2 NRR/PMAS/ILRB 1 0 1 RES DEPY GI 1 E DiJ 1 RES/DE/E IB 1 1 . RGN2 FILE 01 1 EXTERNAL: EGSG GROHz M 5 5 H ST LOBBY NARD 1 1 LPDR 1 1 NRC PDR 1 1 NSIC HARRIS' 1 1 NSIC MAYSi G 1 1 TOTAL NUMBER OF COPIES REQUIRED:, LTTR 44 ENCL 42

I NAC Form 366 V.S. NUCLEAR AEOVLATORY COMMISSION I9 83)

APPROVEO OMB NO. 3160410S LICENSEE EVENT REPORT (LER) EXPIRES: 8/31/88 FACILITY NAME (II DOCKET NUMBER (2) PA E I Turke Point Unit 4 0 5 0 0 0 25 1 > oF03 Technical Speci icat on . . Entere When 480 Volt Undervoltage Relay Failed Periodic Testing EVENT DATE IBI LER NUMBER (6) REPOR1'ATE (TI OTHER FACILITIES INVOLVED (8)

MONTH OAY YEAR YEAR SEQUENT/AL rr 1 V/SIOrs OAY YEAR FACILITYNAMES DOCKET NUMBER(S) rrUMSEII NUMB Err MONTH N A 0 5 0 0 0 710 8787 013 0 0 0 8 1 0 N A 0 5 0 0 0 THIS REPORT IS SUBMITTED PURSUANT T 0 THE REQUIREMENTS OF 10 CFR (): ICnscp ons or more of tps fopowinp/ (11)

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NAME TELEPHONE NUMBER AREA CODE Randall D. Hart, Licensing Engineer 305 246- 55.9 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DFSCRIBEO IN THIS REPORT (13)

CAUSE SYSTEM COMPONENT MANUFAC REPORTABLE MANUFAC. EPOATABLE TURER TO NPRDS CAUSE SYSTEM COMPONENT TVRER TC N4ROS J E R LIY G08 SUPPLEMENTAL REPORT EXPECTED (Ie) MONTH OAV <<EAA EXPECTED SV 8 M I SS I 0 N YES III yN, comp/<<e DATE (ISI EXPECTED SVSMISSION DATE/ tvO ABSTRACT ILrmR to /c00 totcst, r ~,. spprommsrsiy 0/rttn tinpis specs tyoswnrrsn /ms// IISI On July 10, 1987, the requirements of Technical Specification (TS) Table 3.5-2, item 3 .2.b were exceeded . During the performance of operating procedure (OP) 9404.2, 4160 volt and 480 volt switchgear undervoltage test, the undervoltage protection circuit for the 4C 480 volt load center would not pass the test. This channel was declared out of service and maintenance was requested to investigate the occurrence. TS section 3.5, Table 3.5-2 (Engineered Safety Features Actuation), item 3.2.b requires that for the 480V load centers power operation may continue with one channel inoperable as long as the inoperable channel is placed in the tripped condition. Operations attempted to place the channel in the tripped mode but were unable to do this due to the failure and the design of the system. TS Table 3.5-2, item 3.2.b does not provide an action statement for this condition. This required Unit 4 to be placed into TS 3.0.1 which requires the unit to be in hot standby in 7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br />.

Maintenance replaced relay 327TX4C2 at 1523. OP 9404.2 was recommenced and the replaced relay was satisfactorily tested at 1528. This took the unit out of TS 3.0.1. The cause of the event was a failure of relay 327TX/4C2 in the undervoltage protection scheme for the 4C 480 volt load center. Our Engineering Department has been requested to evaluate this failure to determine root cause and appropriate corrective actions.

PDR ADOCK 05000~DR~1 0251 NRC Form 366 I983) S

NRC Form 366A

)983)

LICENSEE EVENT ORT ILER) TEXT CONTINUATION ~ US. NUCLEAR REGULATORY COMMISSION APPRGYED oMS No. 3)50MIOE EXPIRES: 8/31/88 FACILITYNAME ('ll COCKET NUMSER (2) LER NUMBER (6) PAGE (3)

YEAR ~'EOUENTIAL girl REVISION NUMdEII 'NO NUMEER Turkey Point 4 o s o o o 2 5 1 8 7 0 l 3 0 0 TEXT Ã/IKV>><<MC>> N r>>do)>>EI I>>>> Odd5>>rm/NRC %%dnn ARLll/(Ill EVENT:

On July 10, 1987, the requirements of Technical Specification (TS) Table 3.5-2, item 3.2.b were exceeded. At 1430 during the performance of operating procedure (OP) 9404.2, 4160 volt and 480 volt switchgear undervoltage test, the undervoltage protection circuit for the 4C 480 volt load center would not pass the test. The red indicating light did not come on as required by the procedure. This channel was declared out of service and the Electrical Maintenance Department was requested to investigate the occurrence. They discovered that relay 327TX4C2 had failed. This relay is one of two instantaneous relays that sense'ndervoltage on the 4C 480 volt load center.

TS section 3.5, Table 3.5-2 (Engineered Safety Features Actuation), item 3.2.b requires that for the 480V load centers, power operation may continue with one channel inoperable as long as the inoperable channel is placed in the tripped condition. Operations attempted to place the channel in the tripped mode but

.were unable to do this because of the relay failure and the design of the circuit. TS Table 3.5-2, item 3.2.b does not provide an action statement for this condition. This required Unit 4 to be placed into TS 3.0.1 which requires the unit to be in hot standby in 7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br />. Electrical Maintenance replaced relay 327TX4C2 at 1523. OP 9404.2 was recommenced and the replaced relay was satisfactorily. tested at 1528. This took the unit out of TS 3.0.1.

CAUSE OF EVENT:

The cause of the event was a failure of relay 327TX/4C2 in the undervoltage protection scheme for the 4C 480 volt load center..

ANALYSIS OF EVENT:

Upon identification of the failure, the affected relay was replaced and returned to service within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> so no unit shutdown was commenced. Our Engineering Department has been requested to evaluate this failure to determine root cause, appropriate corrective actions and the safety significance of this event. Should this evaluation significantly change the information provided in this LER, a LER update will be sent accordingly.

CORRECTIVE ACTIONS:

1) Relay 327TX/4C2 was replaced and satisfactorily tested within 1 hour of the initial failure.
2) Our Engineering Department has been requested to evaluate this concern to assist in identifying the root cause and appropriate corrective actions.

Engineering will schedule the completion of this request in accordance with the Integrated Schedule.

NRC FORM EddA o U.S GPO:198&).824 538/455 (94)3)

NRC fork 388A U.S. NUCLEAR RECULATORY COMMISSION 194)3)

LICENSEE EVEN EPORT (LERI TEXT CONTINUATIO APPROVED OMB NO 3)SOMI04 EXPIR ES: 8/31/88 PAC)LITT NAME l)) DOCKET NUMBER 12) LER NUMBER )B) PACE 13)

YEAR eQ 880UEkTrAL kUM884 Qj REVISIOk

'.4 kUM884 Turkey Point 4 p g p p p 2 5 l 8 7 0 1 3 0 0 03 0FO 3 TACT /P rr488 <<Moo k roqM)or/, rroo ~ )35ona/ ArRC Forrrr 3/ÃAk/ 117)

ADDITIONAL DETAILS:

The affected relay is manufactured by General Electric and is model number CR120BD04341.

Similar Occurrences: none kRC PORM 348A oU S GPO.1988 0 824 538/455

$ 83)

P. O. BO '000,'UNO BEACH. FL 3340B FLORIDA POWER 5 LIGHT COMPANY AUGUSTI 1 0 1987 L-87-328 IO CFR 50.73 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C. 20555 Gent lemen:

Re: Turkey Point Unit 4 Docket No. 50-251 Reportable Event: 87-I 3 Dote of Event: July, IO, l 987 Technical Specification 3.0. I Entered When 480 Volt Undervolta e Rela Failed Periodic Testin The attached Licensee Event Report is being submitted pursuant to the requirements of IO CFR 50.73 to provide notification of the subject event.

Very truly yours, C. O. W o Group President Nuclear Energy COW/SDF/gp Attachment cc: Dr. J. Nelson Grace, Regional Administrator, Region II, USNRC Senior Resident Inspector, USNRC, Turkey Point Plant SDF I /049/ I PEOPLE... SERVING PEOPLE

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