ML18010A731

LER 92-012-00:on 920802,one of Three Secondary Relays Failed to Actuate,Causing TS 3.0.3 to Be Entered.Caused by Failure of under-voltage Relay to Actuate.Procedure Will Be Revised to Provide Guidance for Tripped condition.W/920831 Ltr

ML18010A731
Person / Time
Site:	Harris
Issue date:	09/01/1992
From:	Hinnant C, Verrilli M CAROLINA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
HO-920127, LER-92-012-02, LER-92-12-2, NUDOCS 9209040154
Download: ML18010A731 (6)

Text

'CCELERATED DIy~RIBUTIOYDEMOYSyRATIOH SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR: 9209040154 DOC. DATE: 92/O'V/01 NOTARIZED: NO DOCKET 0 FACIL: DO-400 Shearon Harv is Nucleav Power Planti Unit li Cav olina 05000400 AUTH. NAME AUTHOR AFF ILI ATIQN VERRILLI M.

> Carolina Power 5 Light Co.

HINNANT. C. S. Carol ina Powev'c Ll g h t Co.

REC IP. NAME RECIPIENT AFFILIATION

SUBJECT:

LER 92-012-00: on 9'20802'ne of three secondav g relays Failed to actuate. causing TS 3. 0. 3 to be entev ed. Caused bg failure of under-voltage velar to actuate. Procedure will be v evised to provide guidance fov. tv ipped condition. 8/920831 ltr.

DISTRIBUTION CODE: IE22T COPIES RECEIVED: LTR ~

ENCL g SIZE:

TITLE: 50. 73/50. 9 Licensee Event Repov t (LER)i

/

Incident Rpti etc.

NOTES: Application f ov permit renewal f iled. 05000400 A

REC IP IENT COPIES REC I P I ENT CQP IES ID CODE/NAMiE LTTR ENCL ID CODE/NAME LTTR ENCL PD2-1 L* 1 1 PD2-1 PD 1 1 LEi N 1 1 INTERNAL: ACNE 2 2 ACRS 2 2 AEOD/DQA AEODrDserTPAB 1 1 AEOD/ROAB/DSP 2 NRR/DET/EMEB 7E 1 I I

NRR DLP 8/LHF 9 1 0 I 1 NRR/DLP6/LPEB 10 1 NRR /DOEA/.OEAB 1 NRR/DREP/PRPB1 1 2 NRR/DST/SELB BD 1 NRR/DST/SICBBH3 1 1' LBBD 1 1 1 NRR/DST/SRXB SE REG LE 02 1 1 RES/DSIR/EIB I ILE Ol 1 1 EXTERNAL: EG~~cG BRYCE. J H L ST LOBBY NARD 1 NRC PDR NSIC MURPHY'. A 1 NSIC POOREi4l, NUDOCS FULL TXT 1 Qr2C/'ii~/+&~Pi~ ~ dN 6'nddr/zz/- ddt'k/-+-

A NOTE TO ALL RIDS RECIPIENTS:

PLEASE HELP US TO REDUCE V'ASTE! CONTACT THE DOCUMENT CONTROL DESK.

ROOM P!-S7 (EXT. 504-2065) TO ELIMiNATEYOUR NAME FROM DISTRIBUTIOiN I ISTS FOR DOCUMENTS YOU DON'T NEED!

FULL TEXT CONVERSION REQUIRED TOTAL. NUMBER QF COP IES REQUIRED: LTTR 31 ENCL 31

Carolina Power & Light Company P.O. Box 165 ~ New Milt, NC 27562 G. E. VAUGHN Vice President Marris Nuctear Project AUG 3 1 1992 Letter Number: HO-920127 U.S. Nuclear Regulatory Commission ATTN: NRC Document Control Desk Washington, DC 20555 SHEARON HARRIS NUCLEAR POWER PLANT UNIT 1 DOCKET NO. 50-400 LICENSE NO. NPF-63 LICENSEE EVENT REPORT 92-012-00 Gentlemen:

In accordance with Title 10 t:o the Code of Federal Regulations, the enclosed Licensee Event Report is submitted. This report fulfills the requirement for a written report within thirty (30) days of a reportable occurrence and is in accordance with the format set forth in NUREG-1022, September 1983.

Very truly yours C. S. Hinnant'eneral Manager Harris Nuclear Project MV:dmw Enclosure cc: Mr. S. D. Ebneter (NRC - RII)

Mr. N. B. Le (NRC - RII)

Mr. J. E. Tedrow (NRC - SHNPP)

Mr. G. E. Vaughn 040050 MEM/LER92-012/1/Osl 9209040154 05000440 it20901 PDR ADOCK

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED OMB NO. 31604104 (509)

EXPIRES: C/30/92 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS INFORMATION COLLECTION REGUEST: 50.0 HRS. FORWARD LICENSEE EVENT REPORT (LER) COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS AND REPORTS MANAGEMENT BRANCH (P430), U.S. NUCLEAR REGULATORY COMMISSION. WASHINGTON, DC 20566, AND TO THE PAPERWORK REDUCTION PROJECT I3150010C), OFFICE OF MANAGEMENTAND BUDGET. WASHINGTON, OC 20503.

DOCKET NUMBER (2) PA FACILITY NAME (I)

Shearon Harris Nuclear Power Plant Unit //1 0 5 0 0 0 4pp 1OF 4 Technical Specification 3.0.3 entry due to failure of 1B-SB Emergency Bus Undervolta e Rela EVENT DATE LS) LER NUMBER (SI REPORT DATE (7) OTHER FACILITIES INVOLVED ISI C) O: DDOVENTIAL DAY YEAR FACILITYNAMES DOCKET NUMBER(SI MONTH DAY YEAR YEAR NUMBER NUMDDR MONTH 0 5 0 0 0 0 8 292 92 0 1 2 0 9 0 1 9 2 oi tne Ioirowinpl (I'l 0 5 0 0 0 THIS REPORT IS SUBMITTED PURSUANT TO THE RLDUIREMENTS OF 10 CFR (I: ICnecc one or more OPERATING MODE (D) 20.602 (5) 20AOS(cl 50.73(e I (2 I (N) 73.7)(r))

POWER 20AOS( ~ l(1) li) SOW(cl(11 50.73(el(2)lv) 73.71(cl 0 50.73(e) (2) lvii) OTHER ISpecrry In Aorvect 1 0 20AOS(e l(1) (Sl 50.36(c) (2)

Oeiow erxy in Tert, IIIICForm 20AOS(e l(1) liii) 50.73(el(2) Ii) 50.73(el(2)Niiil(A) 3$ SAI 20AOS(e) (I l(iv) 50.73(e I (2)(ii) 50.73(el(2((vitri(BI 20AOS( ~ ) (I l(v) 50.73(e) l2)(i(il 50.73(el(2)(el LICENSEE CONTACT FOR THIS LER (12I NAME TELEPHONE NUMBER Michael Verrilli Specialist Regulatory Compliance AREA CODE COMPLE'TE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPOR'7 (13I MANUFAC. REPORTABLE v'

'P. AUSE SYSTEM COMPONENT MANUFAC EPORTABLE ~455%@:

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TURER TO NPRDS )cog?g~

B J E 2 7 B4 55 g5~44 SUPPLEMENTAL REPORT EXPECTED (11) MONTH DAY EXPECTED SUBMISSION YEAR'n DATE (15)

YES III yer, comp/ere EXPECTED SVSMISSIOII DATE/ x NO ABSTRACT ILimit to Ic00 rpecer, I ~ ., Fpproximetely Iiireen tinple epece typewritten liner/ (16)

ABSTRACT:

August 2, 1992, while performing Operational Surveillance Testing on the.lB-SB 6.9KV Safety Bus Under Voltage Devices (OST-1124), one of the three SECONDARY relays failed to actuate. Efforts to place this relay in the tripped condition exceeded the one hour time limit allowed by the Technical Specification (TS) action statement. This resulted in entering TS 3.0.3. This was caused by the failure of the under-voltage relay to actuate during testing and difficulty experienced in tripping the channel. The faulty relay was replaced and tested within approximately two hours and TS 3.0.3 was exited. Corrective act'ion to prevent recurrence will be a procedure revi'sion that will provide guidance for

~

placing the relay in the tripped condition.

On August 12, 1992, during a review of the event, it was identified that OST-1124 did not positively verify the operability of all three PRIMARY under voltage relays. This test had previously been deemed satisfactory, if the appropriate alarms were annunciated at the main control board. This was due to the systems two out of three logic making it possible to receive the required alarm with one of the relays not operating properly. Upon this determination, one of the three primary relays was considered inoperable until OST-1124 was revised to physically verify operability of all three. The revised version of OST-1124 was completed one hour and twenty minutes later, thus causing TS 3.0.3 to be entered for twenty minutes. This was caused by a deficient surveillance procedure and an

'inadequately designed relay test circuit. Corrective actions to prevent recurrence will include a procedure revision and a relay test circuit design change.

NRC Form 365 (6 59)

NRC FORM 358A VS. NUCLEAR REGULATORY COMMISSION APPROVED DMS NO. 3)500)04 (MS)

EXPIRES! O/30/92 TOTHER WTH THIS ESTIMATED SVRDEN PER RESPONSE TO COMPLY LICENSEE EVENT REPORT {LER) INFORMATION COLLECTION REOVEST: 501) HRS. FORWARD COMMENTS REGARD)NO SURDEN ESTIMATE RECORDS TEXT CONTINUATION ANO REPORTS MANAGEMENTSRANCH IP430), US. NVCLEAR REGULATORY COMMISSION. WASHINGTON, OC 20555, AND TO THE PAPERWORK REDUCTION PROJECT (l150010ll. OFFICE OF MANAGEMENTAND SUDGET,WASHINGTON, DC 20503.

FACILITY NAME (I) DOCKET NUMSER (2) LER NUMSER (Sl PAGE (3)

YSAA SSOVENTiAL WK OSVL1ION mg HVMSSR NUM OA Shearon Harris Nuclear Power Plant Unit 8l 0 5 0 0 0 4 0 0 9 2 0 20 0 0 2 0F0 4 TEXT /I/ oKoO Opoco Io oopo)oPL ooo aetio'ooo/ H/IC %%de 35SA 8/ (12)

EVENT DESCRIPTION:

On August 2, 1992 the plant was in Mode-1 at 100% power. Operations Surveillance Test (OST-1124) was being conducted on the 1B-SB Safety Bus Under Voltage Relays (EIIS: JE/27). Step ¹7.2.10 of this test requires the target flags for the secondary under voltage relays to be reset. This step assumed that the relays had successfully actuated. At 0237 hours0.00274 days <br />0.0658 hours <br />3.918651e-4 weeks <br />9.01785e-5 months <br />, operators observed that the target flag for one of the three relays was not in the tripped condition. This indicated that the relay had not actuated to the tripped position as required by the test. This information was immediately conveyed to the Shift Supervisor in the main control room, Technical Specification (TS) 3.3.2.c action statement ¹15 requires the relay to be placed in the tripped condition within one hour or enter TS 3.0.3. At 0315 the relay assembly was physically removed from its cabinet.

This action was initially determined to comply with the TS requirement. However, additional investigation revealed that removing the relay did not place the channel in the tripped condition and at 0449 hours0.0052 days <br />0.125 hours <br />7.423942e-4 weeks <br />1.708445e-4 months <br />, TS 3.0.3 was entered due to exceeding the one hour time limit. Plans were made to be in Mode-3 by 0900 hours0.0104 days <br />0.25 hours <br />0.00149 weeks <br />3.4245e-4 months <br /> if the relay could not be tripped or replaced with a spare and satisfactorily tested. Approximately two hours later replacement of the relay was completed and at 0658 hours0.00762 days <br />0.183 hours <br />0.00109 weeks <br />2.50369e-4 months <br />, satisfactory testing allowed the plant to exit TS 3.0.3.

During subsequent review of the event and development of corrective actions, it was identified that procedure OST-1124 did not positively verify the operability of all three primary under voltage relays. The test had previously been deemed satisfactory if the appropriate alarms were annunciated at the main control board, but due to the systems Htwo out of three logic",'t was possible to receive the required alarm with one of the three relays not operating properly.

This determination was made at 1200 on August 12, 1992, at which time one of the three primary relays was considered inoperable until adequate testing could be developed and completed to verify operability of all three. This condition once again invoked the one hour time limit of TS 3.3.2.c action statement ¹15. Plans were made at this point to begin plant shutdown at 1500, based on the potential for entry into TS 3.0.3, if testing could not verify operability. A revised version of OST-1124, that included physical verification of contact actuation, was developed to resolve the operability 'concern for the primary relays. Thi's test was completed satisfactorily at 1320 on August 12, 1992. TS 3.0.3 was entered at 1300 and exited at 1320 upon completion of this test.

CAUSE:

There were two causes for the initial 3.0.3 entry. The first was a failure of the 1B-SB 6.9KV Safety Bus Under Voltage Secondary Relay (27A-1/1712) to actuate during surveillance testing. Investigation revealed that the relay's actuation setpoint had drifted outside the required band and prevented the relay from tripping at the specified voltage. This relay was calibrated during the past refueling outage which ended in May 1991 and had demonstrated satisfactory NRC Form 355A (589)

~ 2 NRC FOAM 356A US. NUCLEAR REGULATORY COMMISSION (669) APPROVED OMB NO. 3(500104 EXPIRES! 4/30/92 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS LICENSEE EVENT REPORT ILER) INFORMATION COLLECTION REOUESTI 50A) HAS. FOAWAAD COMMENTS REGARDING BURDEN FSTIMATE TO THE RECORDS TEXT CONTINUATION AND REPORTS MANAGEMENT BRANCH (F430), U.S. NUCLEAR REGULATORY COMMISSION. WASHINGTON. DC 20555. AND TO THE PAPERWOAK REDUCTION PROJECT (31500104). OFFICE OF MANAGEMENTAND BUDGET. WASHINGTON, DC 20503.

FACILITY NAME (I I DOCKET NUMBER (21 LER NUMBER (SI PAGE IS)

YEAR SSOVENTIAL NVMPOR 4') REVISION NVMOOII hearon Harris Nuclear Power Plant nit 81 0 5 0 0 0 4 p p 9 2 012 00 03 OF p 4 TEXT illmore opoco /1 roeooerL Iree Or/IFo'ooo/HRC Form 35643/112)

CAUSE: (continued) performance during each of.the 17 monthly surveillance tests conducted up to this event. The second cause that contributed to entering TS 3.0.3 was 'that a pre-developed plan for placing the relay in the tripped condition was not available. The initial action taken to comply with the TS requirement for tripping the relay was to r'emove the relay from the cabinet. Subsequent investigation which included additional voltage readings, revealed that this action did not place the circuit in the tripped condition. By the time this determination was made,,a large portion of the one hour time limit had been consumed.

The cause for the TS 3.0.3 entry that occurred on August 12, 1992 was the inadequacy of surveillance test OST-1124 and the design for the relay test circuitry, The acceptance criteria for OST-1124 had previously been satisfied upon receipt of alarms at the main control board and Auxiliary Equipment Panel ¹2. The procedure did not require observation or verification of the relays actuation during testing. The test circuit was designed to generate these alarms if two of the three relays actuate. This design configuration was inadequate in that one of the three relays could be potentially inoperable, yet allow the alarms to actuate. and meet the required acceptance criteria. To positively verify operability of all three relays, testing was developed to confirm relay actuation upon loss of voltage. Development and performance of this testing took longer than one hour and therefore resulted in TS 3.0.3 entry.

SAFETY SIGNIFICANCE:

There were no safety consequences as a result of this event. Two of the three relays (both primary and secondary) were operable as indicated by previous successful surveillance testing. This ensures that the intended Engineered Safety Feature actuation would have occurred in the event of an actual safety bus under voltage condition.

These events are being reported as TS violations (3.0.3 entry) per 10CFR50.73 (a)(2)(i)(B). There have been no previous similar..reports submitted.

CORRECTIVE ACTIONS:

The faulty relay was replaced and satisfactory performance of OST-1124 veri. fied its operability on August 2, 1992.

OST-1124 was revised to ensure that all three primary and secondary relays trip as required.

NAC Form 355A (5691

NRC FORM 365A US. NUCLEAR REGULATORY COMMISSION (509) APPROVED OMS NO. 3150010E E XP I R ES: E/30/92 TOTHER ESTIMATED SURDEN PER RESPONSE TO COMPLY WTH THIS LICENSEE EVENT REPORT (LER) INFORMATION COLLECTION REQUEST: 60.0 HRS. FORWARD COMMENTS REGARD)NO SURDEN ESTIMATE RECORDS TEXT CONTINUATION AND REPORTS MANAGEMENTBRANCH (P430). U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON. DC 20555. AND TO THE PAPERWORK REDUCTION PROIECT (31500104). OFFICE OF MANAGEMENTAND BUDGET,WASHINGTON. DC 20503.

FACILITYNAME (1) DOCKET NUMSER (2) LER NUMSER (6) PAGE (3)

YEAR SEQUENTIAL 4EVOION Shearon Harris Nuclear Power Plan NUM E4 NUM E4 Unit Pl TEXT /lfmom EPACT lI nqukpd, UPP Add/5544/P/RC Form 35543/ (12) 0600040P92 0 1 2 0 0 4 oF p4 CORRECTIVE ACTIONS: (continued)

3. Clarification will be provided on how to effectively place these relays in the tripped condition.

During review and discussion of this evolution, it was discovered that the relay circuit resistance was too high to actuate'he primary relay target flag coils. This had no impact on the relays trip function, operability or capability to annunciate the control board alarm. A plant modification will be impl(emented to ensure that. these target flags properly indicate that the relay has actuated.

EIIS Information:

Engineered Safety Feature Actuation System - JE (U.V. Relay - 27)

NRC FON4 355A (64)9)