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'r LNFORMATION 5ISTRIBUTIONSPFl'EM,(RIDS)ACCESSION NBR'408240188DOC~DATE84/08/20NOTAR'IZED

~'OFACIL;50-315 DonaldC~CookNuclearPowerPlantrUnit1~Indiana850-316DonaldC,CookNuclearPowerPlant~Unit2<IndianaAUTH,NAME.AUTHORAFFILIATION ALEXICHgM>>P.

Indiana8MichiganElectricCo.~RECIP>>NAME RECIPIENT AFFILIATION DENTONiH~R>>OfficeofNuclearReactorRegulationi Director'

SUBJECT:

Forwardsstatusreptoninadequate corecoolinginstrumentation sysiper831219request.Reptaddresses reactorvesselinstrumentation sysgcoreexittpermocouplesi subcoolingmalginmonitor8NUREG-0737gItem II~F>>2~DISTRIBUTION CODE!A002DCOPIESRECEIVED:LTR ENCSIZE>>,TITLE:ORSubmittal:Inadequate CoreCooling(ItemII,F.2)GL8228.NOTES!OL>>10/25/74OL:12/23/72DOCKET05000315050003160500031505000316RECIPIENT IDCODE/NAME NRRORB1BCFRIGGINGTONiDINTERNAL:

ADMLFMBNRR/DHFS/HFEB15 NRR/DL/ORAB 08NRR/DSIDIR09NRR.481404COPIESLTTRENCL11111011111111RECIPIENTIDCODE/NAME NRRORB1LANRRSHEAiJ01NRR/DHFS/PSRB16 NRR/DL/ORB5 NRR/DSI/CPB 10NRR/DSI/RSB13RGN307COPIES'TTR ENCL11111111331111'EXTERNAL:

ACRSNRCPDRNTIS17020510101111LPDRNSIC03062211TOTALNUMBEROFCOPIESREQUIRED:

LTTR32ENCL31 1Ptl~4II!'I'IP!PPtAl1P.P'SntlI INDIANA8MICHIGANELECTRICCONPANYP.O.BOX1663ICOLUMBUS, OHIO432'16August20,1984AEP:NRC:0761C DonaldC.CookNuclearPlantUnitNos.1and2DocketNos.50-315and50-316LicenseNos.DPR-58andDPR-711INADEQUATE CORECOOLINGINSTRUMENTATION SYSTEMSTATUSREPORTMr.HaroldR.Denton,DirectorOfficeofNuclearReactorRegulation U.S.NuclearRegulatory Commission Washington, D.C.20555

DearMr.Denton:

ThisletterrespondstoHr.S.A.Varga'sletter'ated December19,'983,whichtransmitted toMr.JohnE.DolanoftheIndiana&HichiganElectricCompany(IMECo)theNRC'spreliminary SafetyEvaluation oftheInadequate CoreCoolingInstrumentation (ICCI)systemfortheDonaldC.CookNuclearPlant.Morespecifically, theAttachment tothisletterprovidesastatusreportontheDonaldC.CookNuclearPlantICCIsystem,whichconsistsofaReactorVesselLevelInstrumentation System(RVLIS),CoreExitThermocouples (CETs),andaSubcooling MarginMonitor(SMM).Thisstatusreportfulfillsthecommitments wemadeinourletterAEP:NRC:0761B (datedFebruary3,1984)regarding Enclosure 1toHr.Denton'sDecember19,1983letter.Information regarding Enclosure 2oftheDecember19,1983letterwillbetransmitted following completion oftheUpgradeEmergency Operating Procedures Generation Packagescheduled forsubmittal inSeptember, 1980.Thisdocumenthasbeenpreparedfollowing Corporate procedures whichincorporate areasonable setofcontrolstoensureitsaccuracyandcompleteness priortosignature bytheundersigned.

Verytrulyyours,H.P.AexichVicePresident MPA/damcc:JohnE.DolanW;G.Smith,Jr.-BridgmanR.C.CallenG.CharnoffE.R.Swanson-NRCResidentInspector, Bridgman8408240188 840820PDRADOCK05000315P..PDR)O6>>I/

~%l~g~,,~a4'~JeIIJ INATTCNU0EITUNNSRTruoThisattachment providesastatusreportontheDonaldC.CookNuclearPlantInadequate CoreCoolingInstrumentation (ICCI)system,whichconsistsofaReactorVesselLevelInstrumentation System(RVLIS),CoreExitThermocouples (CETs),andaSubcooling MarginMonitor(SMM).Thecontentsofthisstatusreportaddressthe4itemsofconcernidentified bytheNRCinEnclosure 1tothepreliminary ICCIsystemSafetyEvaluation, transmitted vialetterdatedDecember19,1983[S.A.Varga(NRC)toJohnE.Dolan(IMECo)].

The4itemsofconcernandtheIMECoresponses areprovidedbelow:Anunresolved concernregarding post-accident environmental effectsonin-containment widerangepressuretransmitters andsubsequent effectsonRVLISaccuracywasidentified.

Describethestatusoftheresolution ofthewiderangepressuretransmitter application including anychangestothecurrentinstalled RVLISsystemandprovidethescheduleforcompletion ofinstallation andcalibration oftheRVLISsystem.InIMEColetterNo.AEP:NRC:0761A, datedJune22,1983;itwasnotedthattheWestinghouse ElectricCorporation (g)concernwithregardtothetransmitters wasbeingdiscussed withg.Sincethattine,thegrecommendation thatthewiderangepressuretransmitters interfacing withRVLISbelocatedoutsidecontainment toachievethedesignRVLISaccuracywasreviewedandfoundtobeacceptable.

Subjecttofinalengineering anddesignreview,itisproposedthatthecurrently installed RVLISbemodifiedbyrelocating theexistingwiderangepressuretransmitters frominsidecontainment tooutsidecontainment, wheretheywillbeconnected toRVLISthroughleveltransmitter accessassemblies.

Thisinstallation, togetherwiththerequiredcalibration, isscheduled tobecompleted bytheendofthenextrefueling outagesforbothunits.Theseoutagesarecurrently expectedtobegininMarch1985forUnitNo.1andinNovember1985forUnitNo.2.TheRVLISinstallation iscompleteinbothUnitswiththeexception oftheaforementioned relocation ofthewiderangepressuretransmitters scheduled tobecompleted bytheendof1985.Thesystemsarefunctional.

Remaining calibration tasksreportedinthepasthavebeencompleted.

Shouldthesystemsberequiredinanemergency, thelevelindicators andrecorders areavailable.

However,operators arenotnowpermitted tousethesesystems.

4tm2Provideanevaluation ofthefinalCETsystemwithrespecttoconformance withItemII.F.2Attachment 1andAppendixBofNUREG-0737 requirements sincethedataprovidedisinsufficiently spreadovernumerousreferenced documents andadefinitive determination ofconformance isnotpossible.

eoeteTheCETsysteminUnitNo.1isundergoing upgradeworkwhichisexpectedtobecompleteduringthe1985refueling outagewiththefollowing exception:

Therelocation oftwo(2)thermocouples tomonitortheupperheadregionwillnotbedoneduringthe1985refueling outagebecauseoftechnical problemsthatstillremaintoberesolved.

Thisworkisanticipated tobecompleted duringthenextrefueling outageafterthe1985refueling outage.Presently, thirty-two (32)newenvironmentally andseismically qualified connectors andthirty-two (32)temporary transition cableshavebeeninstalled.

~Additionally, arecoverymethodfortheinoperable CETsisbeingtestedandappearstobesuccessful atthistime.WebelievethatthedesignoftheupgradedCETsystemmeets,withtheexception ofcableseparation criteriaandcoremapdisplaycapabilities (explained later),alltherequirements ofNUREG-0737 ItemII.F.2,Attachment 1.Thefollowing describes theupgradedCETsystemtobeinstalled inUnitNo.1~Uponsuccessful recovery'oftheinoperable thermocouples, sixty-thr ee(63)ofthe,sixty-five (65)thermocouples willbedividedintotwo(2)electrically independent channels.

Eachchannelwillbeenergized fromaClassIEpowersource,andphysically separated, exceptattheReactorVesselHeadarea,usingtheappropriate guidanceofRegulatory Guide1.75,uptoandincluding theisolation devices.Thesethermocouples willbedividedasevenlyaspossibletoprovideadequatecoverageofeachcorequadrant.

Two(2)thermocouples, one(1)fromeachchannel,areplannedtoberelocated tomonitortemperatures intheupperheadregiontoassistinmonitoring localvesseltemperature conditions duringnaturalcirculation modesofoperation.

Itshouldbenotedthatthesetwothermocouples arenotrequiredtomeettherequirements ofNUREG-0737.

Environmentally andseismically qualified connectors andmineralinsulated cablingwillbeinstalled from0heCETnozzlesuptoalocationpastthemissileshieldwall,whereatransition toqualified organiccablingwilltakeplaceviaqualified splices.Fromthispointthequalified organicthermocouple cablingwillberunthroughpenetrations andwillterminate atnewsignalprocessing equipment.

Signalprocessing equipment willconsistoftwo(2)racksofhardwarecapableofconverting thelowlevelthermocouple signalsintohighlevel{4-20or]0-50ma)signals.Thetwo(2)rackswillbeClassIEandqualified'to theappropriate environmental andseismicrequirements ofIEEEStd323-1974.

Isolation betweenIEandnon-IEsignalswillbeprovided.

Coldjunctioncompensation willbedoneautomatically bytheequipment.

Thetwo(2)racksw1llbephysically separated usingtheguidanceofRegulatory Guide1.75including theIEsignalsandnon-IEsignals.Thirty-three (33)signalswillbeprocessed onone(1)rackandthirty-two (32)ontheother.(Thismayvaryslightlywhenfinaldeterminations ofCETconfiguration ismade.)TheserackswilleachbepoweredbyaIEpowersource.Theoutputsoftheserackswillbetransmitted tothenormalplantprocessandTechnical SupportCentercomputers, two(2)back-updisplays, andtheSHM'sincorethermocouple inputs(two(2)perquadrantforatotalofeight(8)).Isolation betweenIEandnon-IEequipment isprovidedintheelectronics ofthevariouspiecesofequipment.

Theprimarydisplaywillbetheplantprocesscomputerwhichhasdirectreadoutan(hardcopycapabilities forallthermocouples.

Therangewillbe200Fto2300F.Trendingcapabilities alsoexistwhichcan'showthetimehistoryofCETtemperatures ondemand.Alarmcapabilities

'presently existandwillbemadetobeconsistent withEmergency Operating Procedures.

Theoperatord1splaydevicesarepresently underreview,asistheentirecontrolroomforhumanfactors.Resultsofthisreview,whencomplete,.

willbetakenintoaccount.Aspatially orientedcoremap,available ondemand,showingthetemperature ateachCETlocationwillbeavailable fromtheTechnical SupportCenterCRTlocatedinthecontrolroom.TheTechnical SupportCentercomputer1snotdesignated astheprimaryoperatordisplay.Therefore, thismethodofproviding acoremapisinvariancewithNUREG-0737.

However,itisouropinionthattheTechnical SupportCentercomputerman-machine interface, togetherwithoperatortra1ninginuseoftheupgradedEmergency Operating Procedures, providesadequatecompensatory methodsforth1s,deviation.

Itistherefore concluded thatthisdeviation fromNUREG-0737 isnotsignificant andshouldbeanacceptable methodofproviding acoremap.AClassIEback-updisplaywillbeprovidedforeachchannelwiththecapability fortheselective readingofaminimumofsixteen{16)operablethermocouples (four(4)perquadrant).

Thepresentdesignspecifies manualswitching betweeneachthermocouple.

Itisexpectedthattheswitching canbecompleted betweenallCETswithinatimeintervalofsix(6$minutes.Thedisplayed temperature rangewillbe200Fto2300F.Approximately fifty-seven (57)ofthesixty-five (65)CETsareoperableinUnitNo.2.ProvidedtheUnitNo.1upgradeissuccessful, theanticipated scheduleforUnitNo.2isasfollows:Completion ofUnitNo.1upgrading in1985,exceptforthethermocouples intheupperheadarea.One(1)yearoperational study.CompletedetaildesignNovember1987.Completeinstallation duringfirstrefueling outagewhichoccursafterDecember1987.Adefinitescheduleandadetaileddescription forreviewofcompliance withNUREG-0737 cannotbeavailable untiltheUnitNo.2detaileddesigniscomplete.

ShouldtheUnitNo.1upgradebesuccessful itislikelythattheUnitNo.2upgradewillbedesignedinasimilar,ifnotidentical, mannerasUnitNo.1,providing thatthehardwareisstillavailable forpurchase.

Providejustification forthescheduleforcompletion oftheICCIsystemandfortheadequacyoftheCETsystemduringtheinterimperioduntilupgrading canbecompleted.

esonsetoteTheICCIsystemcompletion scheduleiscontingent uponthesuccessful upgradeoftheCETsystem.TheRVLISisinstalled andcalibrated andaftersomemodifications canbemadeoperablepriortothecompletion oftheCETsystemineitherUnit.TheSHMisinstalled andoperational andoperators havebeentrainedinitsuse.SincetheSMM'sprimaryinputsarewiderangeReactorCoolantSystemtemperatures, theremaining workonupgrading theCETsdoesnotimpacttheSMMnormaloperation.

Thescheduling forUnitNo.2isbasedontheongoingUnitNo.1CETupgradeprogram.Thedesignandprocurement ofmaterials fortheUnitNo.2CETscannotproceeduntiltheresultsoftheUnitNo.1upgradeprogramareknown.TheadequacyofthepresentUnitNo.2CETsystemcanbeshownbythefactthatafterseven(7)years,fifty-seven (57)ofthethermocouples arestilloperational.

Thesecouldbeusedtoprovidetheoperators withadequatesecondary information underaccidentconditions.

~~I~~DuringtheinterimperioduntilCETupgrading canbecompleted, theSMMcanbeusedtodetectInadequate CoreCoolingconditions.

Widerangepressureandtemperature (i.e.,Resistance Temperature Detectors)

ClassIEsignalsareusedasinputs,andtheoperators havebeentrainedintheSMM'suseandemergency procedures areinplace.WebelievethattheRVLIScannowbeusedinanemergency, althoughithasnotbeendeclaredoperational.

Additionally, thesurvivability ofincorethermocouples wasdemonstrated duringtheTHI-2accident.

Fromtheresultsofthataccident, itisbelievedthatasufficient portionofthepresentCETsystemshouldsurviveapostulated incidentandcouldprovidetheoperators withadequateinformation toestablish qualitative trendingindications.

TheSubcooling MarginMonitorreceivesinputsignalsfromamixofClass1Eandnon-Class 1Einstrumentation sources.Furthermore itisnotclearthatthesubcooling margincomputeranddisplayareseismically andenvironmentally qualified.

Clarifythatinallinstances Class1Eequipment isprotected byqualified isolation devicestoprecludethepossibility ofadverseinteraction betweenClass1Eandnon-Class 1Edevicesorsignals.tteInputstothesaturation meterconsistofClassIEsignals(i.e.,ReactorCoolantSystemwiderangepressuredetectors) andnon-Class IEsignals(i.e.,CETs).Eachoftheseinputsignalsisisolatedbyaqualified SignalConverter Transformer.

Allcablingandconnections fortheseisolation devicestothesaturation meterareconfinedtothecontrolroom,eliminating theneedforenvironmental qualification.

Thesaturation marginmeteranddisplaywereinstalled tomeettherequirements ofNUREG-0578.

Thesedevicesweredesigned, purchased, andinstalled duringtheperiodofOctober1979toOctober1980inagoodfaithefforttomeetthethenexistingrequirements.

Therefore, theywerenotrequiredtobeandassuchhavenotbeenseismically andenvironmentally qualified.

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