ML17335A356
| ML17335A356 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 12/03/1998 |
| From: | POWERS R P INDIANA MICHIGAN POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML17335A357 | List: |
| References | |
| AEP:NRC:09000, AEP:NRC:9000, NUDOCS 9812080045 | |
| Download: ML17335A356 (12) | |
Text
.~REGULA'J;ORYINFORMATIONDISTRIBUTIOSYSTEM(RIDS)ACCESSIONNBR:9812080045DOC.DATE:98/12/03NOTARIZED:YESlACIL:50-315DonaldC.CookNuclearPowerPlant,Unit1,IndianaM50-3).6DonaldC.CookNuclearPower.Plant,Unit2;IndianaMAUTHA'fAME"-AUTHORAFFILIATIONPOWERS,R.P.IndianaMichiganPowerCo.RECIP.NAMERECIPIENTAFFILIATIONRecordsManagementBranch(DocumentControlDesk)DOCKET¹0500031505000316
SUBJECT:
ApplicationforamendstolicensesDPR-58EDPR-74,revisingTS4.6.5.1,"IceCondensedr,IceBed"Sassociatedbasestoreflectmaxicecondenserflowchannelblockageassumedinaccidentanalyses.DISTRIBUTIONCODE:AOOIDCOPIESRECEIVED:LTRIENCLISIZE:TITLE:ORSubmittal:GeneralDistributionNOTES:RECIPIENTIDCODE/NAMEPD3-3LASTANG,JCOPIESLTTRENCL1111RECIPIENTIDCODE/NAMEPD3-3PDCOPIESLTTRENCL110INTERN.FILCENRRDE/EMCBNRR/DSSA/SPLBNUDOCS-ABSTRACTEXTERNAL:NOAC1111111111IINRR/DE/ECGB/ANRR/DRCH/HICBNRR/DSSA/SRXBOGC/HDS3NRCPDR111111101.1DNOTETOALL"RZDS"RECIPIENTS:PLEASEHELPUSTOREDUCEWASTE.TOHAVEYOURNAMEORORGANIZATIONREMOVEDFROMDISTR1BUTZONLISTSORREDUCETHENUMBEROFCOPIESRECEIVEDBYYOUORYOURORGANIZATION,CONTACTTHEDOCUMENTCONTROLDESK(DCD)ONEXTENSION415-2083TOTALNUMBEROFCOPIESREQUIRED:LTTR13ENCL12
.3IndianaMichlga~PowerCompany~500CircleDriveBuchanan,Ml491071373ÃIRONMANICHIGAMP8lfMDecember3,1998AEP:NRC:09000DocketNos.:50-31550-316U.S.NuclearRegulatoryCommissionATTN:DocumentControlDeskMailStop0-Pl-17Washington,DC20555-0001Gentlemen:DonaldC.CookNuclearPlantUnits1and2TECHNICALSPECIFICATIONSCHANGEREQUESTICECONDENSERFLOWCHANNELSIndianaMichiganPowerCompany,theLicenseeforDonaldC.CookNuclearPlantunits1and2,proposestoamendAppendixA,technicalspecifications(T/S),'ffacilityoperatinglicensesDPR-58andDPR-74pursuantto10CFR50.90.TheLicenseeproposestoreviseT/S4.6.5.1,"IceCondenser,IceBed,"anditsassociatedbasestoreflectthemaximumicecondenserflowchannelblockageassumedin'theaccidentanalyses.Attachment1providesadetaileddescriptionandsafetyanalysisoftheproposedchanges.Attachments2Aand2BprovidemarkedupT/Spagesforunit1andunit2,respectively,Attachments3Aand3BprovidetheproposedT/Spageswiththechangesincorporatedforunit1andunit2,respectively.Attachment4describestheevaluationperformedinaccordancewith10CFR50.92(c),whichconcludesthatnosignificanthazardsconsiderationisinvolved.Attachment5providestheenvironmentalassessment.Theproposedchangeshavebeenreviewedbytheplantnuclearsafetyreviewcommitteeandbythenuclearsafetyanddesignreviewcommittee.98f208004598f203PDR,ADOCK05000815P'DR U.S.NuclearRegulatoryCommissionPage2AEP:NRC:09000CopiesofthisletteranditsattachmentsarebeingtransmittedtotheMichiganPublicServiceCommissionandMichiganDepartmentofPublicHealth,inaccordancewiththerequirementsof10CFR50.91.Sincerely,R.P.PowersVicePresidentSWORNTOANDSOBSCRIBEDBEFOREMETHIS~iDAYOF)iI/I1998NotaryPublicMyCommissionExpires/jmc~ANiCEM.BiGKERSAttachments~@8FoboBe+onCoNIQ,MMyCommissionExpiresFeb.16,2001c:J.A.Abramson,w/attachmentsJ.L.Caldwell,w/attachmentsMDEQ-DW&RPD,w/attachmentsNRCResidentInspector,w/attachmentsJ.R.Sampson,w/attachments U.S.NuclearRegulatoryCommissionPage3AEP:NRC:09000bc:T.P,Beilman,w/attachmentsJ.J.EutoB.J.HickleG.HomnaFOLIO,w/attachmentsD.F.Kunsemiller/J.BEKingseed/G.P.Arent/M.J.GumnsM.W.Rencheck/E.R.Eckstein/D.F.Powell/D.R.Hafer/K.R.BakerJ.F.Stang,Jr.,-NRCWashington,DC,w/attachments ATTACHMENT1TOAEP:NRC:09000DESCRIPTIONANDSAFETYANALYSISFORPROPOSEDCHANGES Attachment1toAEP:NRC:09000Page1DescritionandSafetAnalsisfortheProosedChanesA.SummaryofProposedChangesTheLicenseeproposestorevisetechnicalspecification(T/S)4.6.5.1.b.3and4.6.5.1.c,"IceCondenser,IceBed,"anditsassociatedbasesforDonaldC.CookNuclearPlantunits1and2.Theproposedchangewouldrevisethesurveillanceforicecondenserflowchannelstoprovideamoreconservativesamplingapproachforinitiallyassessingthepotentialforflowchannelblockageandtoimposespecificcriteriaforassessingtheextentandsignificanceofanyobservedblockagewhencomparedtothemaximumblockageallowedbyanalysis.Thiscriteriaisnotadequatelydefinedinthecurrentsurveillance.Additionally,thesurveillancewillbechangedtoutilizethetermflowchannel(viceflowpassage)tobeconsistentwithcorrespondingT/S3.6.5.1.b.Informationcurrentlylocatedin4.6.5.1.b.3,involvingareasnotconsideredtobeaflow"channel,"isrelocatedtoT/S4.6.5.1.c.Finally,thebasesarerevisedtodefineaflowchannelandthereasonforthemaximumallowableblockage.Thecurrentbasesprovidenoinformationrelatedtoflowchannelblockage.TheproposedchangesaredescribedindetailinsectionEofthisattachment.T/Spagesthataremarkedtoshowtheproposedchangesareprovidedinattachments2Aand2Bforunit1andunit2,respectively.TheproposedT/Spageswiththe'changesincorporatedareprovidedinattachments3Aand3Bforunit1andunit2,respectively.B.DescriptionoftheCurrentRequirementsT/Ssurveillancerequirement4.6.5.1.b.3requiresaninspectionevery18monthstoconfirmthatflowpassages(topdeckfloorgrating,intermediatedeckandflowpassagesbetweenicebasketsandpastlatticeframes)ineachicecondenserbayhavenotaccumulatedfrostoriceexceedinganominalthicknessof3/8ofan'inch.Thisisaccomplishedbyvisualinspectionofatleasttwoflowpassagesperbay.Exceedingthecriteriaforeitherselectedpassagerequiresvisualinspectionofanadditional20representativepassages.Morethanonerestrictedflowpassageperbayisevidenceofabnormaldegradationoftheicecondenser.Surveillancerequirement4.6.5.1.crequiresasimilarassessmentofthelowerinletplenumsupportstructuresandturningvanes.C.BasesfortheCurrentRequirementsNobasesareprovidedforthecurrentsurveillancerequirements.However,itisclearthattheapproachwasbasedontheassumptionthatfrostandicebuildupwouldbefairlyuniformthroughouteachbayoftheicecondenser.Therefore,inspectionofafewflowchannelswouldprovideagoodindicationofoverallconditionsinthatbay,constitutingthebasisforacceptanceor 0I Attachment1toAEP:NRC:09000Page2indicatingtheneedforadditionalinspection/evaluationoficecondenserconditions.Acriteriontoresolve"indicationsofabnormaldegradation"wasnotprovidedinthesurveillanceorthebases.D.NeedforRevisionoftheRequirementTheLicenseeissubmittingthisamendmenttoT/Ssurveillance4.6.5'.b.3and4.6.5.1.c,to:i.addressthepotentialfornon-uniformaccumulationoffrost/icewithintheicecondensersbyincreasingthesamplesizetoselectivelyincludeareaswhereoperatingexperiencehasshownincreasedaccumulation;ii.provideaspecificnumericalacceptancecriteria(basedonanalysis)forassessing"indicationsofabnormaldegradation"inflowchannels;iii.clarifythetermflow"channel"andconsistentlyutilizeitinsurveillance4.6.5.1.b.3.becausethistermisusedinthecorrespondingT/SLCO3.6.5.1b;andiv.removefromT/S4.6.5.1.b.3.thediscussionoficecondenserareasnotcomprisingflowchannels(asutilizedintheanalysisofii.above)andconsolidatetheseareasunderT/S4.6.5.1.cwheresimilarareasareincluded;E.DescriptionoftheProposedChangesTheLicenseeproposestoreviseT/Ssurveillance4.6.5.1.b.3to:i.requireanincreaseinthesurveillancesamplesizefromthecurrent2flowchannelspericecondenserbayto4flowchannelsperbay.Theadditionaltwoflowchannelsinspectedarespecifiedtoincludeoneinradialrows1(adjacenttothecontainmentwall)andoneinradialrow9(adjacenttothecranewall);ii.inthecaseofdiscoveringmorethanonerestrictedflowchannelpericecondenserbay,requirea100%inspectionofthebaytodeterminethatthebayislessthan15%blocked;andiii.(andiv.)consistentlyutilizethetermflow"channel"inlieuofflow"passage"tomaintainconsistencywithcorrespondingT/SLCO3.6.5.1b.Themeaningofthetermflowchannelisclarifiedbyremovingmentionofthetopdeckfloorgratingareaandtheintermediatedeckarea.ThesetwoareasarerelocatedtoT/S4.6.5.1.cwhereotherareasimportanttoicecondenserperformanceareincluded.TheLicenseeproposestoincludeappropriatebasesforT/S4.6.5.1.b.3and4.6.5.1.cconsistentwiththechangesdescribedini,ii,iii,andivabove.Thebasesshouldalsoclarifytheintentof"representative"sampleof20additionalflowchannelsasutilizedintheT/S.
Attachment1toAEP:NRC:09000Page3F.BasesoftheProposedChangesInJanuary1998,adetailedinspectionandmappingoftheaccumulationoffrostandiceintheunit1andunit2icecondenserflowchannelswasperformed.Theinspectionshowedthattheflowchannelsineachicecondenserbayassociatedwithicebasketsinradialrows1(adjacenttothecontainmentwall)andradialrow9(adjacenttothecranewall)hadthemostaccumulationsoffrostandice.Evaluationoftheinspectionresultsattributedtheconditiontoaslighttemperaturegradientintheicecondensersresultingfromthegenerallywarmercranewallandthecoolercontainmentwall.Thisgradienthasbeenattributedtocausingtheincreasedsublimationratesobservedforiceinrow9baskets.Someofthemasslostduetosublimationinrow9isbelievedtomigratetocoolerregionsoftheicecondenserandshowsupinrow1asincreasedfrosting.Duetothehighersublimationratesinrow9,thesebasketshavemostfrequentlybeensubjectedtoiceadditionactivities.Iceadditionstothebasketscanresultinicespillageintotheadjacentflowchannels.Thisicethenbecomesapotentialnucleationsiteforfrostgrowthandaccumulation.Theicecondensermappingshowedthatfrostandiceaccumulationfrequentlyinvolvesrelativelylocalizedareasattributedtothenucleationandgrowthmechanism.Duetothismechanism,theflowchannelsinradialrows1and9aregenerallynotrepresentativeoftheotherflowchannelsinrows2through8.Toprovidereasonableassurancethatrows1and9areproperlyassessedduringicechannelsurveillanceactivities,thespecificationisbeingchangedtorequire1additionalsamplefromeachradialrow1andradialrow9ineachbay.Thishastheeffectofbiasingthesampleinaconservativedirectionthatshouldtendtopromotesampleexpansionandadditionalevaluationutilizingthe15%blockagecriteriawhenwarranted.Thenucleationandgrowthmechanismisalsothereasonthatexpansionofsamplingduetodiscoveryofobstructedchannelsisspecifiedtobeperformedintheareathattheobstructionwasfound.Thisisconsideredmorerepresentativeandconservativethanrandomlyexpandingthesampletoareasnotadjacenttotheareaoftheobservedobstruction.AsdescribedinChapter14.3.4,ContainmentIntegrityAnalysisoftheCookNuclearPlantUpdatedFinalSafetyAnalysisReport(UFSAR),aTransientMassDistribution(TMD)computercodewasutilizedforthesub-compartmentanalysisoftheunit1andunit2containments.Theanalysiswasperformedassumingatotalblockageofupto15%oftheflowareasthroughtheicecondensers.Theanalysiswasapplicabletobothunit1andunit2andassessedtheeffectsofthe15%icecondenserflowblockageonthepeakdifferentialpressureactingacrosstheoperatingdeck,thecranewall,andthecontainmentshell.Theanalysismodelsthelowercompartmentas6elementsandtheicecondenserismodeledwith6sections.Theanalysisdoesnotperformdetailedflowchannelanalysis,buttheTMDanalysislumpstheicecondenserbayswithasfewas2.75baystogether.The15%flowblockageanalysisassumedauniformiceblockagethroughouttheicecondenserflowpaths.ThebasisfortheTMDflowareas Attachment1toAEP:NRC:09000Page4includestheareasbetweentheendsofthelatticeframesandthewallpanelairductsonboththecranewallandthecontainmentwallsides.Theminimumicecondenserflowareathrougheachbayoccursatthelatticeframesupportelevationsandistakentobethenetopenareaatthesesupportelevations.Thisincludesthenetopenarealeftbetweenthecranewallandthecontainmentwallinsidesurfaces,aftersubtractingouttheareasfortheicecondenserequipmentatthatelevation,thatincludes:icebasketsfullofice,latticeframe,latticeframecolumns,wallpanelairducts,wallpanelcradles,andotherappurtenances.Thisisconservative,astheminimumareawouldbeatthelatticeframeelevation,andtheflowareaselsewherewouldbelarger.Theblockagewasassumedtobepermanent,i.e.,nocreditwastakenforthehighenergyflowofairandsteamenteringtheicecondensertoblowoutormeltaccumulationsoffrostorice.Additionally,theonedimensionalflowmodelofthecurrentTMDcodedoesnotconsiderthebeneficialeffectsofcross-flowwithintheicecondenser.G.Impactof0heProposedChangesTheproposedchangesarerequiredtosupportstartupofunit1.Theicecondenserisrequiredtobeoperablepriortoenteringmode4.Ifthechangeisnotapproved,themodechangecannotbemade.ThissubmittalaffectssomeofthesamepagesassubmittalsAEP:NRC:1319andAEP:NRC:1291.AEP:NRC:1319involvesproposedchangestotheicecondensericeweightT/SandAEP:NRC:1291,involvingthedistributedignitionsystem,providesnewbasespagesthataffectthesamepagesasthissubmittal'heT/Spagesinattachments2A,2B,3A,and3Bdonotreflectthechangesproposedintheothersubmittals.Changeswillbeincorporatedbasedonwheneachrequestisapproved.H.ScheduleRequirementsTheLicenseerequestsapprovalofthisrequestbyJanuary20,1999,tomeetthestartupschedule.