ML18005A012

Forwards Status Rept on Inadequate Core Cooling Instrumentation Sys,Per 831219 Request.Rept Addresses Reactor Vessel Instrumentation Sys,Core Exit Thermocouples, Subcooling Margin Monitor & NUREG-0737,Item II.F.2

ML18005A012
Person / Time
Site:	Cook
Issue date:	08/20/1984
From:	ALEXICH M P INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG
To:	DENTON H R Office of Nuclear Reactor Regulation
References
RTR-NUREG-0737, RTR-NUREG-737, TASK-2.F.2, TASK-TM AEP:NRC:0761C, AEP:NRC:761C, NUDOCS 8408240188
Download: ML18005A012 (10)

Text

'\I,REGULATOR'rLNFORMATION5ISTRIBUTIONSPFl'EM,(RIDS)ACCESSIONNBR'408240188DOC~DATE84/08/20NOTAR'IZED~'OFACIL;50-315DonaldC~CookNuclearPowerPlantrUnit1~Indiana850-316DonaldC,CookNuclearPowerPlant~Unit2<IndianaAUTH,NAME.AUTHORAFFILIATIONALEXICHgM>>P.Indiana8MichiganElectricCo.~RECIP>>NAMERECIPIENTAFFILIATIONDENTONiH~R>>OfficeofNuclearReactorRegulationiDirector'

SUBJECT:

Forwardsstatusreptoninadequatecorecoolinginstrumentationsysiper831219request.Reptaddressesreactorvesselinstrumentationsysgcoreexittpermocouplesisubcoolingmalginmonitor8NUREG-0737gItemII~F>>2~DISTRIBUTIONCODE!A002DCOPIESRECEIVED:LTRENCSIZE>>,TITLE:ORSubmittal:InadequateCoreCooling(ItemII,F.2)GL8228.NOTES!OL>>10/25/74OL:12/23/72DOCKET05000315050003160500031505000316RECIPIENTIDCODE/NAMENRRORB1BCFRIGGINGTONiDINTERNAL:ADMLFMBNRR/DHFS/HFEB15NRR/DL/ORAB08NRR/DSIDIR09NRR.481404COPIESLTTRENCL11111011111111RECIPIENTIDCODE/NAMENRRORB1LANRRSHEAiJ01NRR/DHFS/PSRB16NRR/DL/ORB5NRR/DSI/CPB10NRR/DSI/RSB13RGN307COPIES'TTRENCL11111111331111'EXTERNAL:ACRSNRCPDRNTIS17020510101111LPDRNSIC03062211TOTALNUMBEROFCOPIESREQUIRED:LTTR32ENCL31 1Ptl~4II!'I'IP!PPtAl1P.P'SntlI INDIANA8MICHIGANELECTRICCONPANYP.O.BOX1663ICOLUMBUS,OHIO432'16August20,1984AEP:NRC:0761CDonaldC.CookNuclearPlantUnitNos.1and2DocketNos.50-315and50-316LicenseNos.DPR-58andDPR-711INADEQUATECORECOOLINGINSTRUMENTATIONSYSTEMSTATUSREPORTMr.HaroldR.Denton,DirectorOfficeofNuclearReactorRegulationU.S.NuclearRegulatoryCommissionWashington,D.C.20555

DearMr.Denton:

ThisletterrespondstoHr.S.A.Varga'sletter'atedDecember19,'983,whichtransmittedtoMr.JohnE.DolanoftheIndiana&HichiganElectricCompany(IMECo)theNRC'spreliminarySafetyEvaluationoftheInadequateCoreCoolingInstrumentation(ICCI)systemfortheDonaldC.CookNuclearPlant.Morespecifically,theAttachmenttothisletterprovidesastatusreportontheDonaldC.CookNuclearPlantICCIsystem,whichconsistsofaReactorVesselLevelInstrumentationSystem(RVLIS),CoreExitThermocouples(CETs),andaSubcoolingMarginMonitor(SMM).ThisstatusreportfulfillsthecommitmentswemadeinourletterAEP:NRC:0761B(datedFebruary3,1984)regardingEnclosure1toHr.Denton'sDecember19,1983letter.InformationregardingEnclosure2oftheDecember19,1983letterwillbetransmittedfollowingcompletionoftheUpgradeEmergencyOperatingProceduresGenerationPackagescheduledforsubmittalinSeptember,1980.ThisdocumenthasbeenpreparedfollowingCorporateprocedureswhichincorporateareasonablesetofcontrolstoensureitsaccuracyandcompletenesspriortosignaturebytheundersigned.Verytrulyyours,H.P.AexichVicePresidentMPA/damcc:JohnE.DolanW;G.Smith,Jr.-BridgmanR.C.CallenG.CharnoffE.R.Swanson-NRCResidentInspector,Bridgman8408240188840820PDRADOCK05000315P..PDR)O6>>I/

~%l~g~,,~a4'~JeIIJ INATTCNU0EITUNNSRTruoThisattachmentprovidesastatusreportontheDonaldC.CookNuclearPlantInadequateCoreCoolingInstrumentation(ICCI)system,whichconsistsofaReactorVesselLevelInstrumentationSystem(RVLIS),CoreExitThermocouples(CETs),andaSubcoolingMarginMonitor(SMM).Thecontentsofthisstatusreportaddressthe4itemsofconcernidentifiedbytheNRCinEnclosure1tothepreliminaryICCIsystemSafetyEvaluation,transmittedvialetterdatedDecember19,1983[S.A.Varga(NRC)toJohnE.Dolan(IMECo)].The4itemsofconcernandtheIMECoresponsesareprovidedbelow:Anunresolvedconcernregardingpost-accidentenvironmentaleffectsonin-containmentwiderangepressuretransmittersandsubsequenteffectsonRVLISaccuracywasidentified.DescribethestatusoftheresolutionofthewiderangepressuretransmitterapplicationincludinganychangestothecurrentinstalledRVLISsystemandprovidethescheduleforcompletionofinstallationandcalibrationoftheRVLISsystem.InIMEColetterNo.AEP:NRC:0761A,datedJune22,1983;itwasnotedthattheWestinghouseElectricCorporation(g)concernwithregardtothetransmitterswasbeingdiscussedwithg.Sincethattine,thegrecommendationthatthewiderangepressuretransmittersinterfacingwithRVLISbelocatedoutsidecontainmenttoachievethedesignRVLISaccuracywasreviewedandfoundtobeacceptable.Subjecttofinalengineeringanddesignreview,itisproposedthatthecurrentlyinstalledRVLISbemodifiedbyrelocatingtheexistingwiderangepressuretransmittersfrominsidecontainmenttooutsidecontainment,wheretheywillbeconnectedtoRVLISthroughleveltransmitteraccessassemblies.Thisinstallation,togetherwiththerequiredcalibration,isscheduledtobecompletedbytheendofthenextrefuelingoutagesforbothunits.TheseoutagesarecurrentlyexpectedtobegininMarch1985forUnitNo.1andinNovember1985forUnitNo.2.TheRVLISinstallationiscompleteinbothUnitswiththeexceptionoftheaforementionedrelocationofthewiderangepressuretransmittersscheduledtobecompletedbytheendof1985.Thesystemsarefunctional.Remainingcalibrationtasksreportedinthepasthavebeencompleted.Shouldthesystemsberequiredinanemergency,thelevelindicatorsandrecordersareavailable.However,operatorsarenotnowpermittedtousethesesystems.

4tm2ProvideanevaluationofthefinalCETsystemwithrespecttoconformancewithItemII.F.2Attachment1andAppendixBofNUREG-0737requirementssincethedataprovidedisinsufficientlyspreadovernumerousreferenceddocumentsandadefinitivedeterminationofconformanceisnotpossible.eoeteTheCETsysteminUnitNo.1isundergoingupgradeworkwhichisexpectedtobecompleteduringthe1985refuelingoutagewiththefollowingexception:Therelocationoftwo(2)thermocouplestomonitortheupperheadregionwillnotbedoneduringthe1985refuelingoutagebecauseoftechnicalproblemsthatstillremaintoberesolved.Thisworkisanticipatedtobecompletedduringthenextrefuelingoutageafterthe1985refuelingoutage.Presently,thirty-two(32)newenvironmentallyandseismicallyqualifiedconnectorsandthirty-two(32)temporarytransitioncableshavebeeninstalled.~Additionally,arecoverymethodfortheinoperableCETsisbeingtestedandappearstobesuccessfulatthistime.WebelievethatthedesignoftheupgradedCETsystemmeets,withtheexceptionofcableseparationcriteriaandcoremapdisplaycapabilities(explainedlater),alltherequirementsofNUREG-0737ItemII.F.2,Attachment1.ThefollowingdescribestheupgradedCETsystemtobeinstalledinUnitNo.1~Uponsuccessfulrecovery'oftheinoperablethermocouples,sixty-three(63)ofthe,sixty-five(65)thermocoupleswillbedividedintotwo(2)electricallyindependentchannels.EachchannelwillbeenergizedfromaClassIEpowersource,andphysicallyseparated,exceptattheReactorVesselHeadarea,usingtheappropriateguidanceofRegulatoryGuide1.75,uptoandincludingtheisolationdevices.Thesethermocoupleswillbedividedasevenlyaspossibletoprovideadequatecoverageofeachcorequadrant.Two(2)thermocouples,one(1)fromeachchannel,areplannedtoberelocatedtomonitortemperaturesintheupperheadregiontoassistinmonitoringlocalvesseltemperatureconditionsduringnaturalcirculationmodesofoperation.ItshouldbenotedthatthesetwothermocouplesarenotrequiredtomeettherequirementsofNUREG-0737.Environmentallyandseismicallyqualifiedconnectorsandmineralinsulatedcablingwillbeinstalledfrom0heCETnozzlesuptoalocationpastthemissileshieldwall,whereatransitiontoqualifiedorganiccablingwilltakeplaceviaqualifiedsplices.Fromthispointthequalifiedorganicthermocouplecablingwillberunthroughpenetrationsandwillterminateatnewsignalprocessingequipment.

Signalprocessingequipmentwillconsistoftwo(2)racksofhardwarecapableofconvertingthelowlevelthermocouplesignalsintohighlevel{4-20or]0-50ma)signals.Thetwo(2)rackswillbeClassIEandqualified'totheappropriateenvironmentalandseismicrequirementsofIEEEStd323-1974.IsolationbetweenIEandnon-IEsignalswillbeprovided.Coldjunctioncompensationwillbedoneautomaticallybytheequipment.Thetwo(2)racksw1llbephysicallyseparatedusingtheguidanceofRegulatoryGuide1.75includingtheIEsignalsandnon-IEsignals.Thirty-three(33)signalswillbeprocessedonone(1)rackandthirty-two(32)ontheother.(ThismayvaryslightlywhenfinaldeterminationsofCETconfigurationismade.)TheserackswilleachbepoweredbyaIEpowersource.TheoutputsoftheserackswillbetransmittedtothenormalplantprocessandTechnicalSupportCentercomputers,two(2)back-updisplays,andtheSHM'sincorethermocoupleinputs(two(2)perquadrantforatotalofeight(8)).IsolationbetweenIEandnon-IEequipmentisprovidedintheelectronicsofthevariouspiecesofequipment.Theprimarydisplaywillbetheplantprocesscomputerwhichhasdirectreadoutan(hardcopycapabilitiesforallthermocouples.Therangewillbe200Fto2300F.Trendingcapabilitiesalsoexistwhichcan'showthetimehistoryofCETtemperaturesondemand.Alarmcapabilities'presentlyexistandwillbemadetobeconsistentwithEmergencyOperatingProcedures.Theoperatord1splaydevicesarepresentlyunderreview,asistheentirecontrolroomforhumanfactors.Resultsofthisreview,whencomplete,.willbetakenintoaccount.Aspatiallyorientedcoremap,availableondemand,showingthetemperatureateachCETlocationwillbeavailablefromtheTechnicalSupportCenterCRTlocatedinthecontrolroom.TheTechnicalSupportCentercomputer1snotdesignatedastheprimaryoperatordisplay.Therefore,thismethodofprovidingacoremapisinvariancewithNUREG-0737.However,itisouropinionthattheTechnicalSupportCentercomputerman-machineinterface,togetherwithoperatortra1ninginuseoftheupgradedEmergencyOperatingProcedures,providesadequatecompensatorymethodsforth1s,deviation.ItisthereforeconcludedthatthisdeviationfromNUREG-0737isnotsignificantandshouldbeanacceptablemethodofprovidingacoremap.AClassIEback-updisplaywillbeprovidedforeachchannelwiththecapabilityfortheselectivereadingofaminimumofsixteen{16)operablethermocouples(four(4)perquadrant).

Thepresentdesignspecifiesmanualswitchingbetweeneachthermocouple.ItisexpectedthattheswitchingcanbecompletedbetweenallCETswithinatimeintervalofsix(6$minutes.Thedisplayedtemperaturerangewillbe200Fto2300F.Approximatelyfifty-seven(57)ofthesixty-five(65)CETsareoperableinUnitNo.2.ProvidedtheUnitNo.1upgradeissuccessful,theanticipatedscheduleforUnitNo.2isasfollows:CompletionofUnitNo.1upgradingin1985,exceptforthethermocouplesintheupperheadarea.One(1)yearoperationalstudy.CompletedetaildesignNovember1987.CompleteinstallationduringfirstrefuelingoutagewhichoccursafterDecember1987.AdefinitescheduleandadetaileddescriptionforreviewofcompliancewithNUREG-0737cannotbeavailableuntiltheUnitNo.2detaileddesigniscomplete.ShouldtheUnitNo.1upgradebesuccessfulitislikelythattheUnitNo.2upgradewillbedesignedinasimilar,ifnotidentical,mannerasUnitNo.1,providingthatthehardwareisstillavailableforpurchase.ProvidejustificationforthescheduleforcompletionoftheICCIsystemandfortheadequacyoftheCETsystemduringtheinterimperioduntilupgradingcanbecompleted.esonsetoteTheICCIsystemcompletionscheduleiscontingentuponthesuccessfulupgradeoftheCETsystem.TheRVLISisinstalledandcalibratedandaftersomemodificationscanbemadeoperablepriortothecompletionoftheCETsystemineitherUnit.TheSHMisinstalledandoperationalandoperatorshavebeentrainedinitsuse.SincetheSMM'sprimaryinputsarewiderangeReactorCoolantSystemtemperatures,theremainingworkonupgradingtheCETsdoesnotimpacttheSMMnormaloperation.TheschedulingforUnitNo.2isbasedontheongoingUnitNo.1CETupgradeprogram.ThedesignandprocurementofmaterialsfortheUnitNo.2CETscannotproceeduntiltheresultsoftheUnitNo.1upgradeprogramareknown.TheadequacyofthepresentUnitNo.2CETsystemcanbeshownbythefactthatafterseven(7)years,fifty-seven(57)ofthethermocouplesarestilloperational.Thesecouldbeusedtoprovidetheoperatorswithadequatesecondaryinformationunderaccidentconditions.

~~I~~DuringtheinterimperioduntilCETupgradingcanbecompleted,theSMMcanbeusedtodetectInadequateCoreCoolingconditions.Widerangepressureandtemperature(i.e.,ResistanceTemperatureDetectors)ClassIEsignalsareusedasinputs,andtheoperatorshavebeentrainedintheSMM'suseandemergencyproceduresareinplace.WebelievethattheRVLIScannowbeusedinanemergency,althoughithasnotbeendeclaredoperational.Additionally,thesurvivabilityofincorethermocoupleswasdemonstratedduringtheTHI-2accident.Fromtheresultsofthataccident,itisbelievedthatasufficientportionofthepresentCETsystemshouldsurviveapostulatedincidentandcouldprovidetheoperatorswithadequateinformationtoestablishqualitativetrendingindications.TheSubcoolingMarginMonitorreceivesinputsignalsfromamixofClass1Eandnon-Class1Einstrumentationsources.Furthermoreitisnotclearthatthesubcoolingmargincomputeranddisplayareseismicallyandenvironmentallyqualified.ClarifythatinallinstancesClass1EequipmentisprotectedbyqualifiedisolationdevicestoprecludethepossibilityofadverseinteractionbetweenClass1Eandnon-Class1Edevicesorsignals.tteInputstothesaturationmeterconsistofClassIEsignals(i.e.,ReactorCoolantSystemwiderangepressuredetectors)andnon-ClassIEsignals(i.e.,CETs).EachoftheseinputsignalsisisolatedbyaqualifiedSignalConverterTransformer.Allcablingandconnectionsfortheseisolationdevicestothesaturationmeterareconfinedtothecontrolroom,eliminatingtheneedforenvironmentalqualification.ThesaturationmarginmeteranddisplaywereinstalledtomeettherequirementsofNUREG-0578.Thesedevicesweredesigned,purchased,andinstalledduringtheperiodofOctober1979toOctober1980inagoodfaithefforttomeetthethenexistingrequirements.Therefore,theywerenotrequiredtobeandassuchhavenotbeenseismicallyandenvironmentallyqualified.

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