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{{#Wiki_filter:ACCELERATEDUTIONDEMONS'ATIONSYSTEMREGULATORYINFORMATIONDISTRIBUTIONSYSTEM(RIDS)ACCESSIONNBR:9007020032DOC.DATE:90/06/22NOTARIZED:NODOCKETFACIL:50-316DonaldC.CookNuclearPowerPlant,Unit2,Indiana&05000316AUTH.NAMEAUTHORAFFILIATIONBEILMAN,T.P.IndianaMichiganPowerCo.(formerlyIndiana&MichiganEleBLIND,A.A.IndianaMichiganPowerCo.(formerlyIndiana&MichiganEleRECIP.NAMERECIPIENTAFFILIATION
{{#Wiki_filter:ACCELERATED UTIONDEMONS'ATION SYSTEMREGULATORY INFORMATION DISTRIBUTION SYSTEM(RIDS)ACCESSION NBR:9007020032 DOC.DATE:
90/06/22NOTARIZED:
NODOCKETFACIL:50-316 DonaldC.CookNuclearPowerPlant,Unit2,Indiana&05000316AUTH.NAMEAUTHORAFFILIATION BEILMAN,T.P.
IndianaMichiganPowerCo.(formerly Indiana&MichiganEleBLIND,A.A.
IndianaMichiganPowerCo.(formerly Indiana&MichiganEleRECIP.NAME RECIPIENT AFFILIATION


==SUBJECT:==
==SUBJECT:==
LER88-003-08:on880111,repetitiveviolationofESFinstrumentationLCOtolerancesduetohighlyRAvalues.W/9DISTRIBUTIONCODE:IE22TCOPIESRECEIVED:LTRENCLSIZE:TITLE:50.73/50.9LicenseeEventReport(LER),IncidentRpt,etc.NOTES:RECIPIENTIDCODE/NAMEPD3-1LAGIITTER,J.INTERNAL:ACNWAEOD/DSP/TPABDEDRONRR/DET/EMEB9H3NRR/DLPQ/LPEB10NRR/DREP/PRPB11NRR/DST/SICB7ENRR/DST/SRXB8ERES/DSIR/EIBEXTERNAL:EG&GSTUART,V.ALPDRNSICMAYS,GNUDOCSFULLTXTCOPIESLTTRENCL11'122111111112211111144111111RECIPIENTIDCODE/NAMEPD3-1PDAEOD/DOAAEOD/ROAB/DSPNRR/DET/ECMB9HNRR/DLPQ/LHFB11NRR/DOEA/OEAB11NRR/DST/SELB8DLB8D1EGFILE0201LSTLOBBYWARDNRCPDRNSICMURPHY,G.ACOPIESLTTRENCL111'2211111111111111111111NOTETOALL"RIDS"RECIPIENTS:PLEASEHELPUSTOREDUCEWASTE!CONTACTTHEDOCUMENTCONTROLDESK,ROOMPl-37(EXT.20079)TOELIMINATEYOURNAMEFROMDISTRIBUTIONLISTSFORDOCUMENTSYOUDON'TNEEDFULLTEXTCONVERSIONREQUIREDTOTALNUMBEROFCOPIESREQUIRED:LTTR34ENCL34 IndianaMichiganPowerCompanyCookNuclearPlantP.O.Box458Bridgman.Ml491066164655901INDIANANfCHIGiANPOWERJune22,1990UnitedStatesNuclearRegulatoryCommissionDocumentControlDeskRockville,Maryland20852OperatingLicensesDPR-58DocketNo.50-316DocumentControlManager:Inaccordancewiththecriteriaestablishedby10CFR50.73entitledLicenseeEventReortinSstem,thefollowingreportisbeingsubmitted:88-003-08Sincerely,~~A.A.BlindPlantManagerAAB:clwAttachmentCC9OO/O2QQiI-Di~D.H.Williams,Jr.A.B.Davis,RegionIIIM.P.AlexichP.A.BarrettJ.E.BorggrenR.F.KroegerB.Walters-Ft.WayneNRCResidentInspectorJ.G.Giitter,NRCJ.G.KepplerM.R.PadgettG.Charnoff,Esp.DottieSherman,ANILibraryD.HahnINPOS.J.Brewer/B.P.Lauzau9t.Cyr'..";<)"i(iC)O>>jqqW(pgII NRCFORM366(569)V.S.NUCLEARREGULATORYCOMMISSIONLICENSEEEVENTREPORTILER)APPROVEDOMBNO,31500104EXPIRES:4/30/92ESTIMATEDBURDENPERRESPONSETOCOMPLYWTHTHISINFORMATIONCOLLECTIONREQUESTt500HRS.FORWARDCOMMENTSREGARDINGBURDENESTIMATETOTHF.RECORDSANOREPORTSMANAGEMENTBRANCH(F630>,U.S.NUCLEARREGULATORYCOMMISSION,WASHINGTON.OC20555,ANDTOTHEPAPERWORKREDUCTIONPROJECT(31500104).OFFICEOFMANAGEMENTANOBUDGET,WASHINGTON,OC20503.FACILITYNAME(I)D.C.COOKNUCLEARPLANT-UNIT2DOCKETNUMBER(llPA050003]61OF0REPETITIVEVIOLATIONOFESFINSTRUMENTATIONLIMITINGCONDITIONSFOROPERATIONTOLERANCESDUETOHIGHLYRESTRICTIVEALLOWABLEVALUESEVENTDATE(5)LERNUMBER(6)REPORTDATE(TIOTHERFACILITIESINVOLVED(SlMOIITHOAYYEARYKARSEOUENTIAINVMBEII:rvor','EVtSKMON'THOAYYEARNUMBEIIFACILITYNAMES.C.COOK-UNIT1DOCKETNUMBER(5)05000018800006229005000THISREPORTISSUBMITTEDPURSUANTT0THERLQUIREMENTSOF10CFR():(CheckOneormoreotthetorrorrino>(11OPERATINGMODK(9)120.405(c)60.36(c)(Il50.36(c)(2>X5073(~l(2)R)50.73(c>12)lii)64.73(cI(2)(ii(I20.402(tr>10.405(~l(1III)20.405(el(1)(ii)20405(~l(1l(iiil20.406(c)(I1(iv)10.405(~Illl(vlPOWERLEVEL050.73(e)(2)(>v)50.73(c)(2)(v)50.73(~)(2)(v9)50.73(el(21(viii)(A)50.73(c)(2>(vi(1)(6)50.73(~)(2>(c)73.71(II)73.71(c)OTHER(SoecitytnAOttrectOererr~ndIn7eefhtRCForm366A)LICENSKKCONTACTFORTHISLER(12)*T.P.BEILMANMAINTENANCEDEPARTMENTSUPERINTENDENTTELEPHONENUMBERAREACODE61665-591COMPLETE.ONELINEFOREACHCOMPONE)4TPAILVREDESCRIBEDIHTHISREPORT(13)CAUSESYSTEMCOMPONENTMANUFAC.TVRERTOHFROSIy",~gg@r'Pk>FWmCp~CAUSESYSTEMCOMPONENTPereIrrpr,";.-:iPNMAHUItAC.TVREREPORTABLETONPRDSa>pWPP~,i~lyP~SUPPLEMENTALREPORTEXPEC'TED(14)MONTHDAYYEARYESIityn,COmnretefXPfCyfDSVSMISSIOtyOATfINOEXPECTEDSUBMISSI0NDATE(15)ABSTRACTILrmtttote(k>tercet.r,~,,eooroeimetelyAfteentinpretoecetyoerrrrttenhnetl(16)Thisrevisionisbeingsubmittedtoreflectanupdateontheresultsoftheincreasedfrequency(monthly)calibrationchecksperformedtodate.OnMarch11,1988anequipmenttrendinvestigationwasbeingperformedon4KVBusLossofVoltagerelaysandthe4KVBusDegradedVoltagerelays(EIIS/EK-27).The'asfound'onditionoftheserelays.duringpastcalibrationcheckshasgenerallybeenfoundtobebeyondtheTechnicalSpecification(T.S.)allowablevalues.Eachrelaywasadjustedtowithinallowablevaluesatthetimeitwasdiscoveredoutofspecification.AllrelayswerefunctionalandwouldhaveperformedtheESFfunction,althoughataslightlydifferentvoltagethanspecifiedinT.S.Anengineeringreviewhasdeterminedaplusorminus3percenttolerance(asopposedtothecurrent0.5percent)tobeacceptablefortheLossofVoltageapplication.TheDegradedVoltageapplicationwillacceptaplusorminus1.5percenttoleranceandwillr'equireinstallationofmoreaccurateundervoltagerelays(DesignChangecurrentlyunderway),AT.S.changerequesthasbeensubmitted.AsstatedintheoriginalLER,wehaveincreasedthecalibrationfrequencyfromeveryeighteenmonthstomonthly.NRCForm366(64)91 NRCFORM366A)669)US.NUCLEARREGULA'TORYCOMMISSIONLICENSEEEVENTREPORT(LERITEXTCONTINUATIONAPPROVEOOMBNO.31500104EXPIRESI4/30/62ESTIMATEDBURDENPEARESPONSETOCOMPLYWTHTHISINFORMATIONCOLLECTIONREQUEST;500HRS.FORWARDCOMMEN'TSREGARDINGBURDENESTIMATETOTHERECORDSANDREPOATSMANAGEMENTBRANCH(P.530).U.S,NUCLEARREGULATORYCOMMISSION,WASHINGTON.DC20555,ANDTO1HEPAPERWORKREDUCTIONPROJECT13')500)04),OFFICEOFMANAGEMFNTANDBUDGET,WASHINGTON,DC20503.FACILITYNAME11)D.C.COOKNUCLEARPLANT"UNIT2DOCKETNUMBER12)YEARLERNUMBERLS).'<."ISEQUENTIALNUMSRIll45VISIONNI/M64PAGE13)TEXTl///44/4SPPCeJI/PFVPPd.I/>>Pdd/Pe/M//YRCFP//4366A3/l)Tlosooo31688-030802oFOThisrevisionisbeingsubmittedtoreflectanupdateontheresultsoftheincreasedfrequency(monthly)calibrationchecksperformedtodate.ConditionsPriortoOccurrenceUnit1andUnit2wereoperatingat90percentand80percentreactorthermalpower,respectively,throughouttheevent.Therewerenoinoperativestruc-tures,components,orsystemsthatcontributedtothisevent.DescritionofEventOnMarchll,1988,anequipmenttrendinvestigationwasbeingperformedonthe4KVBusLossofVoltagerelays(EIIS/EK-27)andthe4KVBusDegradedVoltagerelays(EIIS/EK-27).ThesetpointsfortheserelayshavebeenfoundtobeoutsideoftheTechnicalSpecification(T.S.)allowablevalues(T.S.3.3.2.1Table3.3-4,items8aand8b).Of144individualcalibrationsonthelossofvoltagerelaysoverasevenyearperiod,68werefoundtobeoutsideoftheT.S.tolerances.Ofthe66individualcalibrationsperformedonthedegradedvoltagerelaysoverasevenyearperiod,41'erefoundtobeoutsideoftheT.S.tolerances.Theamountofdeviationfromtheallowablesetpointbandwaslimitedanddistributionamongtherelayswasrandom,indicatingnoparticularrelaytobedefective.Asurveyofotherutilitieswhichusethistypeofrelayrevealedthattheperformanceofourrelaysisconsistentwiththeirexperienceandwithinmanufacturer'sspecifications.Eachrelaywasreadjustedtowithinallowablevaluesatthetimeitwasdiscoveredoutofspecification.TheLossofVoltagerelaysareinstalledtosensealossofoffsiteornormalauxiliarypowertotheESS4KVbuses.Oncethelossofvoltagehasbeensensedandafteratwo-secondtimedelay,theserelaysina2/3phaseslogicinitiateloadsheddingandemergencydieselgeneratorstarting.TheDegradedBusVoltagerelaysareinstalledtosensedegradedreservepowerfeedtotheESS4KVbusesand,ona2/3phaseslogicwithatwo-minutetimedelay,tripopenthereserveSeedbreakersandstarttheemergencydieselgenerators.Oncetheemergencydieselgeneratorhasrestoredbusvoltagetonormal,safetyloadsaresequencedontothesafetybuses.TheTechnicalSpecificationsforUnits1and2haveexistingsetpointsof80percent(+.5%,-1.0%)fortheLossofVoltageand90percent(+1.0%,-.5%)fortheDegradedGriddetection.Thetoleranceonthesesetpointsaretighterthantherelayscanobtain,andmoreimportantly,tighterthanrequiredforperformingtheirintendedfunction,i.e.,sensinglossofnormalvoltage,initiatingloadshedding,anddieselstarting.NRCFon4366A168S)
LER88-003-08:on 880111,repetitive violation ofESFinstrumentation LCOtolerances duetohighlyRAvalues.W/9DISTRIBUTION CODE:IE22TCOPIESRECEIVED:LTR ENCLSIZE:TITLE:50.73/50.9 LicenseeEventReport(LER),IncidentRpt,etc.NOTES:RECIPIENT IDCODE/NAME PD3-1LAGIITTER,J.
NRCFORMS66A(689(V.S,NUCI.EARREGULATORYCOMMISSIONLlCENSEEEVENTREPORT(LER)TEXTCONTINUATIONAPPROVEDOMB'NO,S(50010<EXPIRES;ol50(99EST(MA'TEOBUROFNPERRESPONSETOCOMPLYWTHTHISINFORMATIONCOLLECTIONREQUEST.'00HRS.FORWARDCOMMENTSREGARDINGBURDEN'ESTIMATETOTHERECORDSANDREPORTSMANAGEMENTBRANCH(P5501.U.S.NUCLEARREGV(.ATORYCOMMISSION.WASHINGTON.DC90555,ANDTO1HEPAPERWORKREDUCTIONPROJECTIS(500(OOI.OFFICEOFMANAGEMENTANDBUDGET,WASHINGTON,DC90509.FACILITYNAIAE(11D.C.COOKNUCLEARPLANT"UNIT2TEXTillmoroAoocolo(ouuwod.uppoddidooollVRCFounJESA'Jl(IT)DOCKETNVMBER(EIYEARosooo3188LERNUMBERL61SEQUENTIALNUMOER03ggSREVISIONouNVMSSR08PAGE(Sl030F04CauseofEventCalibrationhistoryshowsaperformancerecordinlinewithundervoltagerelaysusedatotherplants.Wehavereviewedtheapplicationofundervoltagerelaysforthisfunctionwithotherutilitiesandvariousrelaymanufacturers.Wehaveconcludedthattheundervoltagerelaysarebeingproperlyappliedinthismodeasaconventionalprotectiverelay.Thisusewouldnotnormallyinvolvehavinganacceptanceband.HanyutilitiesconsultedhadnoTechnicalSpecificationrequiredtolerancesforthisfunctionandothershadbroaderallowancevalueswhichmorecloselyreflectthemanufacturer'sexpectedperformancetolerances.AnalsisofEventAmericanElectricPower'sSystemvoltagestudieshavebeenperformedandindicatethattheworstcasevoltageontheESSbusesattheCookNuclearPlantwouldbe87.3percent.WedonotexpecttheESSbusvoltagetodroptoalowervoltagethanthisunlessacompleteplantblackoutconditionoccurred.Underablackoutcondition,theESSbusvoltagewouldquicklydropwellbelowthe80percentundervoltagerelaysetpointandinitiateloadsheddinganddieselstart.ESSusvTheonlyfunctionofthe80percentvoltagerelaysistosemeatotallfoss0busvoltage.Therefore,thesetpointdeviationswe'eexperiencedtranslateintoadifferentlinevoltageandtimethantheTechnicalSpecificationcallsfor,butthetimeinvolvedforthisadditionalvoltagedropisinsignificant.Thefunctionofthedegradedbusrelaysaretodisconnecttheplantfromthegridforasustaineddegradedcondition,i.e.,lessthan90percent.voltageforatleast.twominutes.Theyarearmedonlywhentheplantisfedfromoffsite.power.Plantnormalconfigurationistobefedfromthegeneratorauxiliarytransformersexceptforshortperiodsduringstartupandshutdown.Therefore,theserelaysarenotnormallyactiveduringunitoperation.Again,relatingtooursystemstudies,wedonotbelievetheshiftoutoftolerancetobeasafetyproblemforthedegradedbusrelays.Ourstudiesindicatethatthelowestpossibleoffsitevoltagetoourbuseswouldbe93.3percentexceptfortheshortperiodduringReactorCoolantPump(RCP)starting,whichislessthanoneminute.DuringRCPstarting,thebusvoltagecandipto87.3percent,however,weareprotectedfromanunnecessarytripbythetwo-minutetimedelayonthiscircuit.N8CFounS66A(6$91 NRCFORM366A(689IV.S.NUCLEARREGULATORYCOMMISSIONLICENSEEEVENTREPORT(LER)TEXTCONTINUATIONAPPROVEDOM8NO,3I500106EXPIRES:A/30/93ESTIMATED8VRDENPERRESPONSETOCOMPLYWTHTHISINFORMATIONCOLLECTIONREOVEST-,500HRS.FORWARDCOMMENTSREGARDING8URDENESTIMATETOTHERECORDSANDREPORTSMANAGEMENTBRANCHIP630).U.S.NUCLEARREGULATORYCOMMISSION.WASHINGTON.DC30555,ANDTo1HEPAPERWORKREDUCTIONPROJECTI31504104I,OFFICEOFMANAGEMENTAND8VDGET,WASHINGTON,DC30503,FACILITYNAMEIIID.C.COOKNUCLEARPLANT-UNIT2DOCKETNUMBERI2/LERNUMBERIEIYEAR':966QUENNAL'".n<Y'6&#x17d;NUM668r'NUM6nPAGEIS)TEXT/llnuuppnpco/FPuquuud,upppddnenp//YRC%%d366A9/IITI050003188-03080Anengineeringreviewhasdeterminedaplusorminus3percenttolerance(asopposedtothecurrent0.5percent)tobeacceptablefortheLossofVoltageapplication.Mostofthecalibrationhistorydataiswithin3percentoftherequiredsetpoint.Thefewexceptionsareconsiderednqrmalrandomfailures.TheDegradedVoltageapplicationwillacceptaplusorminus1.5percenttolerance.Thisvalueissuitablefortheinstallationofmoreaccurateundervoltagerelays.Basedontheabove,ithasbeenconcludedthatthereisnojeopazdytothehealthandsafetyofthepublicasaresultofthisevent.CorrectiveActionTherelayswererecalibratedtowithintheallowablevaluesatthetimeofdiscoveryduringthecalibration.Anengineeringreviewhasdeterminedaplusorminus3percenttolerancetobeacceptablefortheLossofVoltageapplicationandaplusorminus1.5percenttolerancefortheDegradedVoltageapplication.ATechnicalSpecificationchangerequesthasbeensubmitted.Inaddition,aDesignChangeregardingthereplacementofthecurrentlyinstalledDegradedVoltagerelayswithmoreaccuraterelaysisscheduledtobecompletedatthenextrefuelingoutagesforbothunits.AsstatedintheoriginalLER,wehaveincreasedthecalibrationfrequencyfromeveryeighteenmonthstomonthlyuntilthetrendindicatesadifferentfrequencyisjustified.Monthlycalibrationcheckshaveyieldedthefollowingresultstodate:4KVLossofVoltage-528calibrations65failures12.3percent4KVDegradedVoltage-264calibrations41failures15.5percentFailedComonentIdentificationNone.PreviousSimilarEventsLER316/81-015LER315/81-017LER315/82-051LER315/82-059LER316/82-100LER316/82-108LER315/83-069L'ER315/83-094NRCForm366AI669)}}
INTERNAL:
ACNWAEOD/DSP/TPABDEDRONRR/DET/EMEB9H3 NRR/DLPQ/LPEB10 NRR/DREP/PRPB11 NRR/DST/SICB 7ENRR/DST/SRXB 8ERES/DSIR/EIB EXTERNAL:
EG&GSTUART,V.A LPDRNSICMAYS,GNUDOCSFULLTXTCOPIESLTTRENCL11'122111111112211111144111111RECIPIENT IDCODE/NAME PD3-1PDAEOD/DOAAEOD/ROAB/DS PNRR/DET/ECMB 9HNRR/DLPQ/LHFB11 NRR/DOEA/OEAB11 NRR/DST/SELB 8DLB8D1EGFILE0201LSTLOBBYWARDNRCPDRNSICMURPHY,G.A COPIESLTTRENCL111'2211111111111111111111NOTETOALL"RIDS"RECIPIENTS:
PLEASEHELPUSTOREDUCEWASTE!CONTACTTHEDOCUMENTCONTROLDESK,ROOMPl-37(EXT.20079)TOELIMINATE YOURNAMEFROMDISTRIBUTION LISTSFORDOCUMENTS YOUDON'TNEEDFULLTEXTCONVERSION REQUIREDTOTALNUMBEROFCOPIESREQUIRED:
LTTR34ENCL34 IndianaMichiganPowerCompanyCookNuclearPlantP.O.Box458Bridgman.
Ml491066164655901INDIANANfCHIGiANPOWERJune22,1990UnitedStatesNuclearRegulatory Commission DocumentControlDeskRockville, Maryland20852Operating LicensesDPR-58DocketNo.50-316DocumentControlManager:Inaccordance withthecriteriaestablished by10CFR50.73entitledLicenseeEventReortinSstem,thefollowing reportisbeingsubmitted:
88-003-08 Sincerely,
~~A.A.BlindPlantManagerAAB:clwAttachment CC9OO/O2QQiI-Di~D.H.Williams, Jr.A.B.Davis,RegionIIIM.P.AlexichP.A.BarrettJ.E.BorggrenR.F.KroegerB.Walters-Ft.WayneNRCResidentInspector J.G.Giitter,NRCJ.G.KepplerM.R.PadgettG.Charnoff, Esp.DottieSherman,ANILibraryD.HahnINPOS.J.Brewer/B.P.
Lauzau9t.Cyr'..";<)"i(iC)O>>jqqW(pgII NRCFORM366(569)V.S.NUCLEARREGULATORY COMMISSION LICENSEEEVENTREPORTILER)APPROVEDOMBNO,31500104 EXPIRES:4/30/92ESTIMATED BURDENPERRESPONSETOCOMPLYWTHTHISINFORMATION COLLECTION REQUESTt500HRS.FORWARDCOMMENTSREGARDING BURDENESTIMATETOTHF.RECORDSANOREPORTSMANAGEMENT BRANCH(F630>,U.S.NUCLEARREGULATORY COMMISSION, WASHINGTON.
OC20555,ANDTOTHEPAPERWORK REDUCTION PROJECT(31500104).
OFFICEOFMANAGEMENT ANOBUDGET,WASHINGTON, OC20503.FACILITYNAME(I)D.C.COOKNUCLEARPLANT-UNIT2DOCKETNUMBER(llPA050003]61OF0REPETITIVE VIOLATION OFESFINSTRUMENTATION LIMITINGCONDITIONS FOROPERATION TOLERANCES DUETOHIGHLYRESTRICTIVE ALLOWABLE VALUESEVENTDATE(5)LERNUMBER(6)REPORTDATE(TIOTHERFACILITIES INVOLVED(SlMOIITHOAYYEARYKARSEOUENTIAI NVMBEII:rvor','EVtSK MON'THOAYYEARNUMBEIIFACILITYNAMES.C.COOK-UNIT1DOCKETNUMBER(5) 05000018800006229005000THISREPORTISSUBMITTED PURSUANTT0THERLQUIREMENTS OF10CFR():(CheckOneormoreotthetorrorrino>
(11OPERATING MODK(9)120.405(c) 60.36(c)(Il50.36(c)(2>X5073(~l(2)R)50.73(c>12) lii)64.73(cI(2)(ii(I20.402(tr>
10.405(~l(1III)20.405(el(1)
(ii)20405(~l(1l(iiil20.406(c)
(I1(iv)10.405(~Illl(vlPOWERLEVEL050.73(e)(2)(>v)50.73(c)(2)
(v)50.73(~)(2)(v9)50.73(el(21(viii)(A) 50.73(c)(2>(vi(1)
(6)50.73(~)(2>(c)73.71(II) 73.71(c)OTHER(SoecitytnAOttrectOererr~ndIn7eefhtRCForm366A)LICENSKKCONTACTFORTHISLER(12)*T.P.BEILMANMAINTENANCE DEPARTMENT SUPERINTENDENT TELEPHONE NUMBERAREACODE61665-591COMPLETE.
ONELINEFOREACHCOMPONE)4T PAILVREDESCRIBED IHTHISREPORT(13)CAUSESYSTEMCOMPONENT MANUFAC.TVRERTOHFROSIy",~gg@r'Pk>FWmCp~
CAUSESYSTEMCOMPONENT PereIrrpr,";.-:iPN MAHUItAC.
TVREREPORTABLE TONPRDSa>pWPP~,i~lyP~
SUPPLEMENTAL REPORTEXPEC'TED (14)MONTHDAYYEARYESIityn,COmnretefXPfCyfDSVSMISSIOty OATfINOEXPECTEDSUBMISSI0NDATE(15)ABSTRACTILrmtttote(k>tercet.r,~,,eooroeimetely Afteentinpretoecetyoerrrrtten hnetl(16)Thisrevisionisbeingsubmitted toreflectanupdateontheresultsoftheincreased frequency (monthly) calibration checksperformed todate.OnMarch11,1988anequipment trendinvestigation wasbeingperformed on4KVBusLossofVoltagerelaysandthe4KVBusDegradedVoltagerelays(EIIS/EK-27).
The'asfound'ondition oftheserelays.duringpastcalibration checkshasgenerally beenfoundtobebeyondtheTechnical Specification (T.S.)allowable values.Eachrelaywasadjustedtowithinallowable valuesatthetimeitwasdiscovered outofspecification.
Allrelayswerefunctional andwouldhaveperformed theESFfunction, althoughataslightlydifferent voltagethanspecified inT.S.Anengineering reviewhasdetermined aplusorminus3percenttolerance (asopposedtothecurrent0.5percent)tobeacceptable fortheLossofVoltageapplication.
TheDegradedVoltageapplication willacceptaplusorminus1.5percenttolerance andwillr'equireinstallation ofmoreaccurateundervoltage relays(DesignChangecurrently underway),
AT.S.changerequesthasbeensubmitted.
AsstatedintheoriginalLER,wehaveincreased thecalibration frequency fromeveryeighteenmonthstomonthly.NRCForm366(64)91 NRCFORM366A)669)US.NUCLEARREGULA'TORY COMMISSION LICENSEEEVENTREPORT(LERITEXTCONTINUATION APPROVEOOMBNO.31500104EXPIRESI4/30/62ESTIMATED BURDENPEARESPONSETOCOMPLYWTHTHISINFORMATION COLLECTION REQUEST;500HRS.FORWARDCOMMEN'TS REGARDING BURDENESTIMATETOTHERECORDSANDREPOATSMANAGEMENT BRANCH(P.530).U.S,NUCLEARREGULATORY COMMISSION, WASHINGTON.
DC20555,ANDTO1HEPAPERWORK REDUCTION PROJECT13')500)04),
OFFICEOFMANAGEMFNT ANDBUDGET,WASHINGTON, DC20503.FACILITYNAME11)D.C.COOKNUCLEARPLANT"UNIT2DOCKETNUMBER12)YEARLERNUMBERLS).'<."ISEQUENTIAL NUMSRIll45VISIONNI/M64PAGE13)TEXTl///44/4SPPCeJI/PFVPPd.I/>>Pdd/Pe/M//YRC FP//4366A3/l)Tlosooo31688-030802oFOThisrevisionisbeingsubmitted toreflectanupdateontheresultsoftheincreased frequency (monthly) calibration checksperformed todate.Conditions PriortoOccurrence Unit1andUnit2wereoperating at90percentand80percentreactorthermalpower,respectively, throughout theevent.Therewerenoinoperative struc-tures,components, orsystemsthatcontributed tothisevent.DescritionofEventOnMarchll,1988,anequipment trendinvestigation wasbeingperformed onthe4KVBusLossofVoltagerelays(EIIS/EK-27) andthe4KVBusDegradedVoltagerelays(EIIS/EK-27).
Thesetpoints fortheserelayshavebeenfoundtobeoutsideoftheTechnical Specification (T.S.)allowable values(T.S.3.3.2.1Table3.3-4,items8aand8b).Of144individual calibrations onthelossofvoltagerelaysoverasevenyearperiod,68werefoundtobeoutsideoftheT.S.tolerances.
Ofthe66individual calibrations performed onthedegradedvoltagerelaysoverasevenyearperiod,41'erefoundtobeoutsideoftheT.S.tolerances.
Theamountofdeviation fromtheallowable setpointbandwaslimitedanddistribution amongtherelayswasrandom,indicating noparticular relaytobedefective.
Asurveyofotherutilities whichusethistypeofrelayrevealedthattheperformance ofourrelaysisconsistent withtheirexperience andwithinmanufacturer's specifications.
Eachrelaywasreadjusted towithinallowable valuesatthetimeitwasdiscovered outofspecification.
TheLossofVoltagerelaysareinstalled tosensealossofoffsiteornormalauxiliary powertotheESS4KVbuses.Oncethelossofvoltagehasbeensensedandafteratwo-second timedelay,theserelaysina2/3phaseslogicinitiateloadsheddingandemergency dieselgenerator starting.
TheDegradedBusVoltagerelaysareinstalled tosensedegradedreservepowerfeedtotheESS4KVbusesand,ona2/3phaseslogicwithatwo-minute timedelay,tripopenthereserveSeedbreakersandstarttheemergency dieselgenerators.
Oncetheemergency dieselgenerator hasrestoredbusvoltagetonormal,safetyloadsaresequenced ontothesafetybuses.TheTechnical Specifications forUnits1and2haveexistingsetpoints of80percent(+.5%,-1.0%)fortheLossofVoltageand90percent(+1.0%,-.5%)fortheDegradedGriddetection.
Thetolerance onthesesetpoints aretighterthantherelayscanobtain,andmoreimportantly, tighterthanrequiredforperforming theirintendedfunction, i.e.,sensinglossofnormalvoltage,initiating loadshedding, anddieselstarting.
NRCFon4366A168S)
NRCFORMS66A(689(V.S,NUCI.EARREGULATORY COMMISSION LlCENSEEEVENTREPORT(LER)TEXTCONTINUATION APPROVEDOMB'NO,S(50010<EXPIRES;ol50(99EST(MA'TEO BUROFNPERRESPONSETOCOMPLYWTHTHISINFORMATION COLLECTION REQUEST.'00 HRS.FORWARDCOMMENTSREGARDING BURDEN'ESTIMATE TOTHERECORDSANDREPORTSMANAGEMENT BRANCH(P5501.U.S.NUCLEARREGV(.ATORY COMMISSION.
WASHINGTON.
DC90555,ANDTO1HEPAPERWORK REDUCTION PROJECTIS(500(OOI.
OFFICEOFMANAGEMENT ANDBUDGET,WASHINGTON, DC90509.FACILITYNAIAE(11D.C.COOKNUCLEARPLANT"UNIT2TEXTillmoroAoocolo(ouuwod.uppoddidooollVRCFounJESA'Jl(IT)DOCKETNVMBER(EIYEARosooo3188LERNUMBERL61SEQUENTIAL NUMOER03ggSREVISIONouNVMSSR08PAGE(Sl030F04CauseofEventCalibration historyshowsaperformance recordinlinewithundervoltage relaysusedatotherplants.Wehavereviewedtheapplication ofundervoltage relaysforthisfunctionwithotherutilities andvariousrelaymanufacturers.
Wehaveconcluded thattheundervoltage relaysarebeingproperlyappliedinthismodeasaconventional protective relay.Thisusewouldnotnormallyinvolvehavinganacceptance band.Hanyutilities consulted hadnoTechnical Specification requiredtolerances forthisfunctionandothershadbroaderallowance valueswhichmorecloselyreflectthemanufacturer's expectedperformance tolerances.
AnalsisofEventAmericanElectricPower'sSystemvoltagestudieshavebeenperformed andindicatethattheworstcasevoltageontheESSbusesattheCookNuclearPlantwouldbe87.3percent.WedonotexpecttheESSbusvoltagetodroptoalowervoltagethanthisunlessacompleteplantblackoutcondition occurred.
Underablackoutcondition, theESSbusvoltagewouldquicklydropwellbelowthe80percentundervoltage relaysetpointandinitiateloadsheddinganddieselstart.ESSusvTheonlyfunctionofthe80percentvoltagerelaysistosemeatotallfoss0busvoltage.Therefore, thesetpointdeviations we'eexperienced translate intoadifferent linevoltageandtimethantheTechnical Specification callsfor,butthetimeinvolvedforthisadditional voltagedropisinsignificant.
Thefunctionofthedegradedbusrelaysaretodisconnect theplantfromthegridforasustained degradedcondition, i.e.,lessthan90percent.voltageforatleast.two minutes.Theyarearmedonlywhentheplantisfedfromoffsite.power.Plantnormalconfiguration istobefedfromthegenerator auxiliary transformers exceptforshortperiodsduringstartupandshutdown.
Therefore, theserelaysarenotnormallyactiveduringunitoperation.
Again,relatingtooursystemstudies,wedonotbelievetheshiftoutoftolerance tobeasafetyproblemforthedegradedbusrelays.Ourstudiesindicatethatthelowestpossibleoffsitevoltagetoourbuseswouldbe93.3percentexceptfortheshortperiodduringReactorCoolantPump(RCP)starting, whichislessthanoneminute.DuringRCPstarting, thebusvoltagecandipto87.3percent,however,weareprotected fromanunnecessary tripbythetwo-minute timedelayonthiscircuit.N8CFounS66A(6$91 NRCFORM366A(689IV.S.NUCLEARREGULATORY COMMISSION LICENSEEEVENTREPORT(LER)TEXTCONTINUATION APPROVEDOM8NO,3I500106EXPIRES:A/30/93ESTIMATED 8VRDENPERRESPONSETOCOMPLYWTHTHISINFORMATION COLLECTION REOVEST-,
500HRS.FORWARDCOMMENTSREGARDING 8URDENESTIMATETOTHERECORDSANDREPORTSMANAGEMENT BRANCHIP630).U.S.NUCLEARREGULATORY COMMISSION.
WASHINGTON.
DC30555,ANDTo1HEPAPERWORK REDUCTION PROJECTI31504104I, OFFICEOFMANAGEMENT AND8VDGET,WASHINGTON, DC30503,FACILITYNAMEIIID.C.COOKNUCLEARPLANT-UNIT2DOCKETNUMBERI2/LERNUMBERIEIYEAR':966QUENNAL
'".n<Y'6&#x17d; NUM668r'NUM6nPAGEIS)TEXT/llnuuppnpco/FPuquuud,upppddnenp//YRC%%d366A9/IITI050003188-03080Anengineering reviewhasdetermined aplusorminus3percenttolerance (asopposedtothecurrent0.5percent)tobeacceptable fortheLossofVoltageapplication.
Mostofthecalibration historydataiswithin3percentoftherequiredsetpoint.
Thefewexceptions areconsidered nqrmalrandomfailures.
TheDegradedVoltageapplication willacceptaplusorminus1.5percenttolerance.
Thisvalueissuitablefortheinstallation ofmoreaccurateundervoltage relays.Basedontheabove,ithasbeenconcluded thatthereisnojeopazdytothehealthandsafetyofthepublicasaresultofthisevent.Corrective ActionTherelayswererecalibrated towithintheallowable valuesatthetimeofdiscovery duringthecalibration.
Anengineering reviewhasdetermined aplusorminus3percenttolerance tobeacceptable fortheLossofVoltageapplication andaplusorminus1.5percenttolerance fortheDegradedVoltageapplication.
ATechnical Specification changerequesthasbeensubmitted.
Inaddition, aDesignChangeregarding thereplacement ofthecurrently installed DegradedVoltagerelayswithmoreaccuraterelaysisscheduled tobecompleted atthenextrefueling outagesforbothunits.AsstatedintheoriginalLER,wehaveincreased thecalibration frequency fromeveryeighteenmonthstomonthlyuntilthetrendindicates adifferent frequency isjustified.
Monthlycalibration checkshaveyieldedthefollowing resultstodate:4KVLossofVoltage-528calibrations 65failures12.3percent4KVDegradedVoltage-264calibrations 41failures15.5percentFailedComonentIdentification None.PreviousSimilarEventsLER316/81-015 LER315/81-017 LER315/82-051 LER315/82-059 LER316/82-100 LER316/82-108 LER315/83-069 L'ER315/83-094 NRCForm366AI669)}}

Revision as of 08:51, 29 June 2018

LER 88-003-08:on 880111,repetitive Violation of ESF Instrumentation Limiting Condition for Operation Tolerances Occurred.Caused by Highly Restrictive Allowable Values. Calibr Frequencies Increased to monthly.W/900622 Ltr
ML17328A301
Person / Time
Site: Cook American Electric Power icon.png
Issue date: 06/22/1990
From: BEILMAN T P, BLIND A A
INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-88-003, LER-88-3, NUDOCS 9007020032
Download: ML17328A301 (6)


Text

ACCELERATED UTIONDEMONS'ATION SYSTEMREGULATORY INFORMATION DISTRIBUTION SYSTEM(RIDS)ACCESSION NBR:9007020032 DOC.DATE:

90/06/22NOTARIZED:

NODOCKETFACIL:50-316 DonaldC.CookNuclearPowerPlant,Unit2,Indiana&05000316AUTH.NAMEAUTHORAFFILIATION BEILMAN,T.P.

IndianaMichiganPowerCo.(formerly Indiana&MichiganEleBLIND,A.A.

IndianaMichiganPowerCo.(formerly Indiana&MichiganEleRECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER88-003-08:on 880111,repetitive violation ofESFinstrumentation LCOtolerances duetohighlyRAvalues.W/9DISTRIBUTION CODE:IE22TCOPIESRECEIVED:LTR ENCLSIZE:TITLE:50.73/50.9 LicenseeEventReport(LER),IncidentRpt,etc.NOTES:RECIPIENT IDCODE/NAME PD3-1LAGIITTER,J.

INTERNAL:

ACNWAEOD/DSP/TPABDEDRONRR/DET/EMEB9H3 NRR/DLPQ/LPEB10 NRR/DREP/PRPB11 NRR/DST/SICB 7ENRR/DST/SRXB 8ERES/DSIR/EIB EXTERNAL:

EG&GSTUART,V.A LPDRNSICMAYS,GNUDOCSFULLTXTCOPIESLTTRENCL11'122111111112211111144111111RECIPIENT IDCODE/NAME PD3-1PDAEOD/DOAAEOD/ROAB/DS PNRR/DET/ECMB 9HNRR/DLPQ/LHFB11 NRR/DOEA/OEAB11 NRR/DST/SELB 8DLB8D1EGFILE0201LSTLOBBYWARDNRCPDRNSICMURPHY,G.A COPIESLTTRENCL111'2211111111111111111111NOTETOALL"RIDS"RECIPIENTS:

PLEASEHELPUSTOREDUCEWASTE!CONTACTTHEDOCUMENTCONTROLDESK,ROOMPl-37(EXT.20079)TOELIMINATE YOURNAMEFROMDISTRIBUTION LISTSFORDOCUMENTS YOUDON'TNEEDFULLTEXTCONVERSION REQUIREDTOTALNUMBEROFCOPIESREQUIRED:

LTTR34ENCL34 IndianaMichiganPowerCompanyCookNuclearPlantP.O.Box458Bridgman.

Ml491066164655901INDIANANfCHIGiANPOWERJune22,1990UnitedStatesNuclearRegulatory Commission DocumentControlDeskRockville, Maryland20852Operating LicensesDPR-58DocketNo.50-316DocumentControlManager:Inaccordance withthecriteriaestablished by10CFR50.73entitledLicenseeEventReortinSstem,thefollowing reportisbeingsubmitted:

88-003-08 Sincerely,

~~A.A.BlindPlantManagerAAB:clwAttachment CC9OO/O2QQiI-Di~D.H.Williams, Jr.A.B.Davis,RegionIIIM.P.AlexichP.A.BarrettJ.E.BorggrenR.F.KroegerB.Walters-Ft.WayneNRCResidentInspector J.G.Giitter,NRCJ.G.KepplerM.R.PadgettG.Charnoff, Esp.DottieSherman,ANILibraryD.HahnINPOS.J.Brewer/B.P.

Lauzau9t.Cyr'..";<)"i(iC)O>>jqqW(pgII NRCFORM366(569)V.S.NUCLEARREGULATORY COMMISSION LICENSEEEVENTREPORTILER)APPROVEDOMBNO,31500104 EXPIRES:4/30/92ESTIMATED BURDENPERRESPONSETOCOMPLYWTHTHISINFORMATION COLLECTION REQUESTt500HRS.FORWARDCOMMENTSREGARDING BURDENESTIMATETOTHF.RECORDSANOREPORTSMANAGEMENT BRANCH(F630>,U.S.NUCLEARREGULATORY COMMISSION, WASHINGTON.

OC20555,ANDTOTHEPAPERWORK REDUCTION PROJECT(31500104).

OFFICEOFMANAGEMENT ANOBUDGET,WASHINGTON, OC20503.FACILITYNAME(I)D.C.COOKNUCLEARPLANT-UNIT2DOCKETNUMBER(llPA050003]61OF0REPETITIVE VIOLATION OFESFINSTRUMENTATION LIMITINGCONDITIONS FOROPERATION TOLERANCES DUETOHIGHLYRESTRICTIVE ALLOWABLE VALUESEVENTDATE(5)LERNUMBER(6)REPORTDATE(TIOTHERFACILITIES INVOLVED(SlMOIITHOAYYEARYKARSEOUENTIAI NVMBEII:rvor','EVtSK MON'THOAYYEARNUMBEIIFACILITYNAMES.C.COOK-UNIT1DOCKETNUMBER(5) 05000018800006229005000THISREPORTISSUBMITTED PURSUANTT0THERLQUIREMENTS OF10CFR():(CheckOneormoreotthetorrorrino>

(11OPERATING MODK(9)120.405(c) 60.36(c)(Il50.36(c)(2>X5073(~l(2)R)50.73(c>12) lii)64.73(cI(2)(ii(I20.402(tr>

10.405(~l(1III)20.405(el(1)

(ii)20405(~l(1l(iiil20.406(c)

(I1(iv)10.405(~Illl(vlPOWERLEVEL050.73(e)(2)(>v)50.73(c)(2)

(v)50.73(~)(2)(v9)50.73(el(21(viii)(A) 50.73(c)(2>(vi(1)

(6)50.73(~)(2>(c)73.71(II) 73.71(c)OTHER(SoecitytnAOttrectOererr~ndIn7eefhtRCForm366A)LICENSKKCONTACTFORTHISLER(12)*T.P.BEILMANMAINTENANCE DEPARTMENT SUPERINTENDENT TELEPHONE NUMBERAREACODE61665-591COMPLETE.

ONELINEFOREACHCOMPONE)4T PAILVREDESCRIBED IHTHISREPORT(13)CAUSESYSTEMCOMPONENT MANUFAC.TVRERTOHFROSIy",~gg@r'Pk>FWmCp~

CAUSESYSTEMCOMPONENT PereIrrpr,";.-:iPN MAHUItAC.

TVREREPORTABLE TONPRDSa>pWPP~,i~lyP~

SUPPLEMENTAL REPORTEXPEC'TED (14)MONTHDAYYEARYESIityn,COmnretefXPfCyfDSVSMISSIOty OATfINOEXPECTEDSUBMISSI0NDATE(15)ABSTRACTILrmtttote(k>tercet.r,~,,eooroeimetely Afteentinpretoecetyoerrrrtten hnetl(16)Thisrevisionisbeingsubmitted toreflectanupdateontheresultsoftheincreased frequency (monthly) calibration checksperformed todate.OnMarch11,1988anequipment trendinvestigation wasbeingperformed on4KVBusLossofVoltagerelaysandthe4KVBusDegradedVoltagerelays(EIIS/EK-27).

The'asfound'ondition oftheserelays.duringpastcalibration checkshasgenerally beenfoundtobebeyondtheTechnical Specification (T.S.)allowable values.Eachrelaywasadjustedtowithinallowable valuesatthetimeitwasdiscovered outofspecification.

Allrelayswerefunctional andwouldhaveperformed theESFfunction, althoughataslightlydifferent voltagethanspecified inT.S.Anengineering reviewhasdetermined aplusorminus3percenttolerance (asopposedtothecurrent0.5percent)tobeacceptable fortheLossofVoltageapplication.

TheDegradedVoltageapplication willacceptaplusorminus1.5percenttolerance andwillr'equireinstallation ofmoreaccurateundervoltage relays(DesignChangecurrently underway),

AT.S.changerequesthasbeensubmitted.

AsstatedintheoriginalLER,wehaveincreased thecalibration frequency fromeveryeighteenmonthstomonthly.NRCForm366(64)91 NRCFORM366A)669)US.NUCLEARREGULA'TORY COMMISSION LICENSEEEVENTREPORT(LERITEXTCONTINUATION APPROVEOOMBNO.31500104EXPIRESI4/30/62ESTIMATED BURDENPEARESPONSETOCOMPLYWTHTHISINFORMATION COLLECTION REQUEST;500HRS.FORWARDCOMMEN'TS REGARDING BURDENESTIMATETOTHERECORDSANDREPOATSMANAGEMENT BRANCH(P.530).U.S,NUCLEARREGULATORY COMMISSION, WASHINGTON.

DC20555,ANDTO1HEPAPERWORK REDUCTION PROJECT13')500)04),

OFFICEOFMANAGEMFNT ANDBUDGET,WASHINGTON, DC20503.FACILITYNAME11)D.C.COOKNUCLEARPLANT"UNIT2DOCKETNUMBER12)YEARLERNUMBERLS).'<."ISEQUENTIAL NUMSRIll45VISIONNI/M64PAGE13)TEXTl///44/4SPPCeJI/PFVPPd.I/>>Pdd/Pe/M//YRC FP//4366A3/l)Tlosooo31688-030802oFOThisrevisionisbeingsubmitted toreflectanupdateontheresultsoftheincreased frequency (monthly) calibration checksperformed todate.Conditions PriortoOccurrence Unit1andUnit2wereoperating at90percentand80percentreactorthermalpower,respectively, throughout theevent.Therewerenoinoperative struc-tures,components, orsystemsthatcontributed tothisevent.DescritionofEventOnMarchll,1988,anequipment trendinvestigation wasbeingperformed onthe4KVBusLossofVoltagerelays(EIIS/EK-27) andthe4KVBusDegradedVoltagerelays(EIIS/EK-27).

Thesetpoints fortheserelayshavebeenfoundtobeoutsideoftheTechnical Specification (T.S.)allowable values(T.S.3.3.2.1Table3.3-4,items8aand8b).Of144individual calibrations onthelossofvoltagerelaysoverasevenyearperiod,68werefoundtobeoutsideoftheT.S.tolerances.

Ofthe66individual calibrations performed onthedegradedvoltagerelaysoverasevenyearperiod,41'erefoundtobeoutsideoftheT.S.tolerances.

Theamountofdeviation fromtheallowable setpointbandwaslimitedanddistribution amongtherelayswasrandom,indicating noparticular relaytobedefective.

Asurveyofotherutilities whichusethistypeofrelayrevealedthattheperformance ofourrelaysisconsistent withtheirexperience andwithinmanufacturer's specifications.

Eachrelaywasreadjusted towithinallowable valuesatthetimeitwasdiscovered outofspecification.

TheLossofVoltagerelaysareinstalled tosensealossofoffsiteornormalauxiliary powertotheESS4KVbuses.Oncethelossofvoltagehasbeensensedandafteratwo-second timedelay,theserelaysina2/3phaseslogicinitiateloadsheddingandemergency dieselgenerator starting.

TheDegradedBusVoltagerelaysareinstalled tosensedegradedreservepowerfeedtotheESS4KVbusesand,ona2/3phaseslogicwithatwo-minute timedelay,tripopenthereserveSeedbreakersandstarttheemergency dieselgenerators.

Oncetheemergency dieselgenerator hasrestoredbusvoltagetonormal,safetyloadsaresequenced ontothesafetybuses.TheTechnical Specifications forUnits1and2haveexistingsetpoints of80percent(+.5%,-1.0%)fortheLossofVoltageand90percent(+1.0%,-.5%)fortheDegradedGriddetection.

Thetolerance onthesesetpoints aretighterthantherelayscanobtain,andmoreimportantly, tighterthanrequiredforperforming theirintendedfunction, i.e.,sensinglossofnormalvoltage,initiating loadshedding, anddieselstarting.

NRCFon4366A168S)

NRCFORMS66A(689(V.S,NUCI.EARREGULATORY COMMISSION LlCENSEEEVENTREPORT(LER)TEXTCONTINUATION APPROVEDOMB'NO,S(50010<EXPIRES;ol50(99EST(MA'TEO BUROFNPERRESPONSETOCOMPLYWTHTHISINFORMATION COLLECTION REQUEST.'00 HRS.FORWARDCOMMENTSREGARDING BURDEN'ESTIMATE TOTHERECORDSANDREPORTSMANAGEMENT BRANCH(P5501.U.S.NUCLEARREGV(.ATORY COMMISSION.

WASHINGTON.

DC90555,ANDTO1HEPAPERWORK REDUCTION PROJECTIS(500(OOI.

OFFICEOFMANAGEMENT ANDBUDGET,WASHINGTON, DC90509.FACILITYNAIAE(11D.C.COOKNUCLEARPLANT"UNIT2TEXTillmoroAoocolo(ouuwod.uppoddidooollVRCFounJESA'Jl(IT)DOCKETNVMBER(EIYEARosooo3188LERNUMBERL61SEQUENTIAL NUMOER03ggSREVISIONouNVMSSR08PAGE(Sl030F04CauseofEventCalibration historyshowsaperformance recordinlinewithundervoltage relaysusedatotherplants.Wehavereviewedtheapplication ofundervoltage relaysforthisfunctionwithotherutilities andvariousrelaymanufacturers.

Wehaveconcluded thattheundervoltage relaysarebeingproperlyappliedinthismodeasaconventional protective relay.Thisusewouldnotnormallyinvolvehavinganacceptance band.Hanyutilities consulted hadnoTechnical Specification requiredtolerances forthisfunctionandothershadbroaderallowance valueswhichmorecloselyreflectthemanufacturer's expectedperformance tolerances.

AnalsisofEventAmericanElectricPower'sSystemvoltagestudieshavebeenperformed andindicatethattheworstcasevoltageontheESSbusesattheCookNuclearPlantwouldbe87.3percent.WedonotexpecttheESSbusvoltagetodroptoalowervoltagethanthisunlessacompleteplantblackoutcondition occurred.

Underablackoutcondition, theESSbusvoltagewouldquicklydropwellbelowthe80percentundervoltage relaysetpointandinitiateloadsheddinganddieselstart.ESSusvTheonlyfunctionofthe80percentvoltagerelaysistosemeatotallfoss0busvoltage.Therefore, thesetpointdeviations we'eexperienced translate intoadifferent linevoltageandtimethantheTechnical Specification callsfor,butthetimeinvolvedforthisadditional voltagedropisinsignificant.

Thefunctionofthedegradedbusrelaysaretodisconnect theplantfromthegridforasustained degradedcondition, i.e.,lessthan90percent.voltageforatleast.two minutes.Theyarearmedonlywhentheplantisfedfromoffsite.power.Plantnormalconfiguration istobefedfromthegenerator auxiliary transformers exceptforshortperiodsduringstartupandshutdown.

Therefore, theserelaysarenotnormallyactiveduringunitoperation.

Again,relatingtooursystemstudies,wedonotbelievetheshiftoutoftolerance tobeasafetyproblemforthedegradedbusrelays.Ourstudiesindicatethatthelowestpossibleoffsitevoltagetoourbuseswouldbe93.3percentexceptfortheshortperiodduringReactorCoolantPump(RCP)starting, whichislessthanoneminute.DuringRCPstarting, thebusvoltagecandipto87.3percent,however,weareprotected fromanunnecessary tripbythetwo-minute timedelayonthiscircuit.N8CFounS66A(6$91 NRCFORM366A(689IV.S.NUCLEARREGULATORY COMMISSION LICENSEEEVENTREPORT(LER)TEXTCONTINUATION APPROVEDOM8NO,3I500106EXPIRES:A/30/93ESTIMATED 8VRDENPERRESPONSETOCOMPLYWTHTHISINFORMATION COLLECTION REOVEST-,

500HRS.FORWARDCOMMENTSREGARDING 8URDENESTIMATETOTHERECORDSANDREPORTSMANAGEMENT BRANCHIP630).U.S.NUCLEARREGULATORY COMMISSION.

WASHINGTON.

DC30555,ANDTo1HEPAPERWORK REDUCTION PROJECTI31504104I, OFFICEOFMANAGEMENT AND8VDGET,WASHINGTON, DC30503,FACILITYNAMEIIID.C.COOKNUCLEARPLANT-UNIT2DOCKETNUMBERI2/LERNUMBERIEIYEAR':966QUENNAL

'".n<Y'6Ž NUM668r'NUM6nPAGEIS)TEXT/llnuuppnpco/FPuquuud,upppddnenp//YRC%%d366A9/IITI050003188-03080Anengineering reviewhasdetermined aplusorminus3percenttolerance (asopposedtothecurrent0.5percent)tobeacceptable fortheLossofVoltageapplication.

Mostofthecalibration historydataiswithin3percentoftherequiredsetpoint.

Thefewexceptions areconsidered nqrmalrandomfailures.

TheDegradedVoltageapplication willacceptaplusorminus1.5percenttolerance.

Thisvalueissuitablefortheinstallation ofmoreaccurateundervoltage relays.Basedontheabove,ithasbeenconcluded thatthereisnojeopazdytothehealthandsafetyofthepublicasaresultofthisevent.Corrective ActionTherelayswererecalibrated towithintheallowable valuesatthetimeofdiscovery duringthecalibration.

Anengineering reviewhasdetermined aplusorminus3percenttolerance tobeacceptable fortheLossofVoltageapplication andaplusorminus1.5percenttolerance fortheDegradedVoltageapplication.

ATechnical Specification changerequesthasbeensubmitted.

Inaddition, aDesignChangeregarding thereplacement ofthecurrently installed DegradedVoltagerelayswithmoreaccuraterelaysisscheduled tobecompleted atthenextrefueling outagesforbothunits.AsstatedintheoriginalLER,wehaveincreased thecalibration frequency fromeveryeighteenmonthstomonthlyuntilthetrendindicates adifferent frequency isjustified.

Monthlycalibration checkshaveyieldedthefollowing resultstodate:4KVLossofVoltage-528calibrations 65failures12.3percent4KVDegradedVoltage-264calibrations 41failures15.5percentFailedComonentIdentification None.PreviousSimilarEventsLER316/81-015 LER315/81-017 LER315/82-051 LER315/82-059 LER316/82-100 LER316/82-108 LER315/83-069 L'ER315/83-094 NRCForm366AI669)