ML17261B146

LER 90-008-01:on 900524,safeguards Buses Degraded Voltage Relays Miscalibrated.Caused by Wrong Setpoint Tolerance Being Specified in Calibr Procedure.Degraded Voltage Relays Calibr to Conservative Tolerance setpoint.W/900820 Ltr

ML17261B146
Person / Time
Site:	Ginna
Issue date:	08/20/1990
From:	BACKUS W H, MERCREDY R C ROCHESTER GAS & ELECTRIC CORP.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-90-008, LER-90-8, NUDOCS 9008290105
Download: ML17261B146 (14)

Text

ACCELERATED DISTRIBUTION DEM REGULATORY XNFORMATION DISTRIBUTION SYSTEM (RIDS)ACCESSION NBR:9008290105 DOC.DATE: 90/08/20 NOTARIZED-NO DOCKET FACIL:50-244 Robert Emmet Ginna Nuclear Plant, Unit 1, Rochester G 05000244 AUTH.NAME AUTHOR AFFILIATION BACKUS,W.H.

Rochester Gas S ElectricCorp.MERCREDY,R.C.

Rochester Gas 6 Electric.Corp.RECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER 90-008-01:on 900524,safeguards buses degraded voltage relays miscalibrated due to procedure inadequacy.

W/9 ltr.DISTRXBUTION CODE: IE22T COPIES RECEXVED:ILTR ENCL SIZE: TITLE: 50.73/50.9 Licensee Event Report (L NOTES:License Exp date in accordance with 10CFR2,2.109(9/19/72)

~/05000244 p RECIPIENT ID CODE/NAME PD1-3 LA JOHNSON,A COPIES LTTR ENCL 1 1 1 1 PD RECIPXENT D CODE/NAME-3 PD COPIES LTTR ENCL 1 1 INTERNAL: ACNW AEOD/DS P/TPAB NRR/DET/ECMB 9H NRR/DLPQ/LHFB11 NRR/DOEA/OEAB11 NRR/DST/SELB 8D-DS LB8D1 G 02 RGN1 FILE 01 EXTERNAL: EGGG BRYCE,J.A LPDR NSIC MAYS,G NUDOCS FULL TXT 2 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 3 3 1 1 1 1 1 1 AEOD/DOA AEdD/ROAB/DSP NR6/DET/EMEB9H3 NRR/DLPQ/LPEB10 NRR/DREP/PRPB11 NRR/DST/SICB 7E NRR/DST/SRXB 8E RES/DSIR/EIB L ST LOBBY WARD NRC PDR NSgC MURPHY,G.A I 1 1 2 2 1 1 1 1 2 2 1 1 1 1 1 1 1 1 1 1 1 1 D NOTE TO ALL"RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE IVASTE!CONTACT THE DOCUMENT CONTROL DESK, ROOM P l-37 (EXT.20079)TO ELIMINATE YOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!A ,D D FULL TEXT CONVERSION REQUIRED TOTAL NUMBER OF COPIES REQUIRED: LTTR 32 ENCL 32 tiDQ

ROCHESTER GAS AND ELECTRIC CORPORATION nt~V i"s relic'c'tare~89 EAST AVENUE, ROCHESTER N.Y.14649-0001 ROBERT C.MECREOY Vice President Cinna Nuclear Production TELEPHONE AstEACOOE71B 546 27CO August 20, 1990 U.S.Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 Sub)ect: LER 90-008 (Revision 01), Safeguards Buses Degraded Voltage Relays Miscalibrated Due To.Procedure Inadequacy Causes a Condition Prohibited By Plant Technical Specifications R.E.Ginna Nuclear Power Plant Docket No.50-244 In accordance with 10CFR50.73, Licensee Event Report System, Item (a)(2)(i)(B), which requires*a report of any operation prohibited by the Plant,'s Technical Specifications", the attached Licensee Event Report LER 90-008 (Revision 01)is hereby submitted.

This revision is necessary to address applicable Technical Specification action statements and to clarify recalibration methodology.

Very truly yours, Robert C.Mecredy xc: U.S.Nuclear Regulatory Commission Region I 475 Allendale.Road King of Prussia, PA 19406 Ginna USNRC Senior Resident Inspector.

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OATCI aktf AAcf IU>>o>>e Io>>NI aooo>>.l1, aooroooaao>>rt III>>oo aa>>at>>~Ittoorra>>o o>>>>a>>ll 4 lstlCTIO LUINICSION OATI IIII aaONTN C*T T CA1 On May 24, 1990 at 1604 EDST with the reactor at approximately 984 full power, an evaluation of undervoltage relay test;data revealed that five (5)of the eight (8)Degraded Voltage Relays on 480 volt safeguard buses were calibrated such that relay actuation would not occur within the limits of Technical Specifi-cations.As this was a setpoint problem with the Degraded Voltage Relays, no immediate plant.or operator responses were necessary.

1 The underlying cause.of the event was attributed to the wrong setpoint and setpoint tolerance being specified in a calibration procedure.

Immediate corrective action was to calibrate the Degraded Voltage Relays to a setpoint on the conservative side of the tolerance.

Subsequent to the calibration, the Degraded Voltage Relays were tested satisfactorily and returned to service.11C tae SN QADI I

IIAC 4'~444A raeSI LICENSEE EVENT REPORT ILER)TEXT CONTINUATION COCKET IIVMACA Ill V.4.AVCLCAA ASCVLATOAY COMMIS4IOH 444AOv40 OM4 vO SISO&IOs 4IItIA44 4IS)%$R.E.Ginna Nuclear Power Plant rEXr nr~SOSCe e~~OaeeOW+AC~~'SS I ITS o 5 o o o 2 4490 LSA AVM44A I~I SSOVSHTtIL VVU A-0 0 8 AIVISIQH vtIU 4 A-0 1 02o~0 8 I~PRE-EVENT PLANT CONDIT10NS The unit was at approximately 984 reactor power.The Results and Test Department and an Electrical Engineering representative were observing the Relay Department performing protective relay calibration procedure PR-1.1 (480 Volt Undervoltage And Ground Alarm Scheme For Buses 14;16, 17 and 18.)II.DESCRIPTION OF EVENT A.DATES AND APPROXIMATE TIMES OF MAJOR OCCURRENCES:

0 Modification installation in 1982: Event date 0 0 May 24, 1990, 1115 EDST: Discovery date and time of the first of five relays found below the limit of Technical Specifications.

May 244 19904 1604 EDST, All affected relays recalibrated, tested satisfactorily.

and restored to service.B.EVENT: On May 24, 1990 at 1604 EDST, with the reactor ht approximately 984 full power PR-1.1 was completed.

Evaluation of the PR-l.l data revealed that five (5)of the eight.(8)Degraded Voltage Relays on 480 volt safeguards buses 14, 16, 17, and 18 had been calibrated such that relay actuation would not occur within the limits of Technical Specifications, page 2.3-10, Figure 2.3-1.The relays affected were as follows: relays 27/14 on Bus 14, 27B/16 on Bus 16, 27/17 and 27B/17 on Bus 17 and 27/18 on Bus 18.This determination occur-red after evaluation and analysis of test data and Technical Specification recpxirements as follows: vaC eOsM S44g MAC/elm SSSA 1$41l LICENSEE EVENT REPORT (LERI TEXT CONTINUATION V.S.NVCLSAA AlOVLATOAV CCSSAIISSIOII ASPAOV$0 OMS HO 11$0&IOs/$)ISIA$$SI$I%$OOCIICT HVMOSA ITI LCA HVSSCIA ISI S S Q U S N T I 4 L~0 M A IIS v IS lO N H M R.E.Ginna Nuclear Power Plant o s o o o 2 4 4 90-00 8 0 103 OFQ 8 TKXT IIT~aWCe S waver,~~lV AC Ann~'ll I I TI 0 o 0 The current 480 volt safeguards bus undervoltage system was first put in service in 1982.Setpoints were specified by Corporate Electrical Engineering, and these setpoints (with tolerances established by the Relay and Test, Department) were used to calibrate these relays over the past eight years.On April 4, 1990 the normal annual calibration was performed on the 480 volt safeguards buses Degraded Voltage Relays, per PR-l.l.This procedure checks and calibrates the dropout voltage of the relays.The procedure specified a+54 calibration toler-ance on the dropout, setpoint with a"desired$'pecified setpoint of 103.5'olts.

All Degraded Voltage Relays were calibrated to these specifica-tions.Because of the+tolerance allowed by the procedure some of the relays were calibrated to less than the"desired" 103.5 volts which was considered acceptable.

I On April 12, 1990 the normal post calibration test was performed on the 480 volt safeguards buses Degraded Voltage Relays per periodic test procedure PT-9.1 (Undervoltage Protection

-480 Volt Safeguard Buses)., This procedure checks the reset voltage of the relays and also the dropout response time, but does not check the dropout voltage.All Degraded Voltage Relays were found to be within the specifications of the procedure.

Prior to April 26, 1990 a review of the calibration data from April 4, 1990 and a review of plant Technical Specifications was performed by the ISI/IST Coordinator and an Electrical Engineering representative.

Following this review, these in-dividuals requested that all Degraded Voltage

>>AC tv>>SSSA W4S I LICENSEE EVENT REPORT ILER)TEXT CONTINUATION I>S.>>I>CLCAi ASOI>LATOIIY CO>>MISSIO>I A>TAOVSD OMS>>0 SISOWI04/S)ttI>ISS S>SI'SS R.E.Ginna Nuclear Power Plant nXr>>>~a>>Ce>>~.~~>>>IC a~'>>Im o 5 o o o 2 4 4 LCII MI>>>Sill III S~QUl>>T>AL%VU A 90-00 8 i'IV>>IOU HVU TA-0 1 04 ov Relays that were found at or below 103.5 volts be adjusted to greater than 103.5 volts.The greater than 103.5 volts was requested to ensure that all relays were within the Technical Specification limit of 103.5 volts prior to entering the plant mode for which these relays are required to be operable.Five Degraded Voltage Relays were adjusted on April 26, 1990.On May ll, 1990 the normal monthly PT-9.1 was performed on all 480 volt safeguards buses Degraded Voltage Relays.This test was witnessed by an Electrical Engineering representative.

After review of the test data, the Electrical Engineering representative expressed a concern that, based on the test reset data, actual dropout voltage of, 5 of the Degraded Voltage Relays may be below the Technical Specification 103.5 volt limit.Since, the PT-9.1 only tested the reset voltage for each relay an actual recalibration must be performed to determine the"as found" dropout voltage.On May 24, 1990 PR-l.l was reperformed on the 5 Degraded Voltage Relays to verify their dropout voltage setpoint.At 1115 EDST, the dropout voltage of the first relay was checked and found below the Technical Specification limit of 103.5 volts.The degraded voltage relay was recalibrated and tested prior to being declared operable, then the four additional relays in question were tested in the same manner.Technical Specification Table 3.5-1, action statement 7, was entered.prior to the calibration of each relay and the calibrated relay was subsequently deemed operable following successful completion of PT-9.1.A review of the"as found" calibration date showed that the dropout voltages..of the other 4 relays were also below the Technical Specification limit of 103.5 volts.This condition was determined to be reportable in accordance with 10CFR50.73 (a)(2)(i)(B).

0 On May 29, 1990 PT-9.1.was reperformed on all 480 volt safeguards buses Degraded Voltage Relays to check for possible setpoint drift.All relays tested satisfactorily.

IIAC Sacro$$$A N4$l LICENSEE EVENT REPORT (LER)TEXT CONTINUATION V.$.MVCLCA1 AlOULAYOAY CCAOMI$$101 ASSAOVCO OM$14 3150MIOO S$)rSI1$$"$r$I%$SACILltY 1AM 0 Ill OOCIIlf rlUM0$1 Ill<<$AA L$1 rIVM4$1 1$l Soaulrr TrAL'r rr A rrt Y l5 IO rr rrrrM SA4$I$I R.E.Ginna Nuclear Power Plant TEXT IIS'rroro ance rl rOOrrooC rroo sororrol rr SIC Srorrr~$I I ITI o 5 o o o 2 4 4 90-00 8-0 1 050FQQ C.INOPERABLE STRUCTURES, COMPONENTS, OR SYSTEMS THAT CONTRIBUTED TO THE EVENT: None.D.OTHER SYSTEMS OR SECONDARY FUNCTIONS AFFECTED: None.METHOD OF DISCOVERY:

The event was made apparent during the performance of PR-1.1 on May 24, 1990.F.OPERATOR ACTION: As this was a setpoint problem with the Degraded Voltage Relays, no immediate operator action was necessary.

G.SAFETY SYSTEM RESPONSES:

None., III.CAUSE OF EVENT A.IMMEDIATE CAUSE'he immediate cause of the event was due to 5 of 8 Degraded Voltage Relays on 480 volt safeguard buses 14, 16, 17, and 18 being calibrated such that relay actuation would not, occur within the limits of Technical Specifi-cations.B.ROOT CAUSE: The root cause of the event discovered on May 24', 1990, was attributed to the calibration conditions that existed on April.26, 1990, during the previous calibra-tion of the five Degraded Voltage Relays.The underlying vol rgorr ooOJ HAC Setm 1SSA.l$4$l LICENSEE EVENT REPORT ILERI TEXT CONTINUATION U.S.HUCLSAA AlOULATOIIY COMMISSIOH ASSAOYSO OMS HO)I$0&IOS 1)It<A$5~I1I'SS I'ACILITY HAMI I'l OOCIIST HUMISII ITI Llll HUM'II I~I S S OU S H T I A L U A ting Y IS lO H M R.E.Ginna Nuclear Power Plant TSIT IN mme Swee e nOrreK~aAKanet HIIC Arm~'M I ITI o s o o o 2 4490-00 8-0 10 60'8 cause of finding, setpoints below limits (in the past)is now evident and is due to the wrong setpoint and setpoint tolerance being specified in a calibration procedure.

The calibration procedure for the safeguard bus Degraded Voltage Relays (PR-1.1)specified an acceptance criteria of 103.5 volts+5%.Ginna Technical Specification figure 2.3-1 requires the Degraded'oltage Relays to actuate when the relay voltages drop to 103.5 volts.(AC)which corresponds to 414 volts on the'480 volt safeguard bus.The relay setpoint of 103.5 volts was determined by RGGE Corporate Engineering and provided to Relay and Test Department for use,.in the calibration of these relays.However, no definitive tolerance band was provided with the desired setpoint;-

Normal vendor recommended tolerances were applied upon development of the calibration procedure.

This resulted in the actual setpoint of these relays to be acceptable when left below the, required minimum dropout voltage of 103.5 volts.I IV ANALYSIS OF&lENT This event is reportable in accordance with 10 CFR 50.73, Licensee Event Report System, item (a)(2)(i)(B), which requires a report of,"any operation prohibited by the plant's Technical Specifications." The 5 out of 8 Degraded Voltage Relays being calibrated such that relay actuation would not occur within the limits of Technical Specifications was an, operation prohibited by the plant Technical Specifica-tions..An assessment was performed considering both the safety consequences and implications of this event with the following results and conclusions:

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NNC evttt SSSA I94JI LICENSEE EVENT REPORT (LERI TEXT CONTINUATION V.S.NVCLTAA AlOVLATONY COMMISSION

/AIteAOvlO OMl 40 JISOWIOS lNItIA$$SI$1 1$FACILITY NANO III OOCNST NVMOSII ITI L$1 NVMllN ISI s e o v s tt T t A L V U tte tt IS tO tt 4 U~A R.E.Ginna Nuclear Power Plant TTXT u'tten Secre r newer.tre taeertt NAC Aetttt~1I I I TI o s o o o 2 4490-00 8 0 l 0 80r-08 B.ACTION TAKEN OR PLANNED TO PREVENT RECUE&ENCE:

o The test conditions that existed on April 26, 1990, will be evaluated.

As a result of this evaluation, it is expected that improvements will be recommended., 0 Any relays calibrated after April 25, 1990, will be identified.

The results of these calibrations will be reviewed for generic concerns with test conditions.

An analysis will be, performed to obtain the optimum setpoint and setpoint tolerance for the Degraded Voltage Relays., o Calibration procedure PR-l.l will be revised to-incorporate

-these new setpoints and setpoint tolerances.

o A new methodology for testing these relays will be incorporated into Periodic Test procedure PT-9.1.VI ADDITIONAL INFORMATION A.AFFECTED COMPONENTS:

The Degraded Voltage Relays are a Model 211B1175D Type ITE-27 relay manufactured by ITE Corporation.

B.PREVIOUS LER'S ON SIMILAR EVENTS: A similar.LER event historical search was conducted with the following results: no documentation of similar LER events with the same root cause at Ginna Station could be identified.

C.SPECIAL COMMENTS: None.