ML17335A541
| ML17335A541 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 10/01/1999 |
| From: | POWERS R P INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML17335A542 | List: |
| References | |
| C1099-08, NUDOCS 9910060099 | |
| Download: ML17335A541 (40) | |
Text
carzaoarREGULATORY INFORMATION DISTRIBUTION
'SYSTEM(RIDS)UACCESSION NBR:9910060099 DOC.DATE:
99/10/01NOTARIZED:
YESFACIL:50-315 DonaldC.CookNuclearPowerPlant,'nit 1,IndianaM50-316DonaldC.CookNuclearPowerPlant,Unit2,IndianaMAUTH.NAMEAUTHORAFFILIATION POWERS,R.P.
IndianaMichiganPowerCo.(formerly IndianaSMichiganEleRECIP.NAMERECIPIENT AFFILIATION RecordsManagement Branch(Document ControlDesk)DOCKET¹0500031505000316NOTES:RCIPIENTIDCODE/NAME STANG,JCOPIESLTTRENCL1111RECIPIENT IDCODE/NAME BARNHILL,E SC
SUBJECT:
Appl'ication foramendstolicensesDPR-585:DPR-74,revising
("containment recj.rculation sumpwaterinventory.
Calculation Enon-proprietary WCAP-15302 reptalsoencl.ADISTRIBUTION CODE:ROOIDCOPIESRECEIVED:LTR iENCLISIZE:Itl4TITLE:ORSubmittal:
GeneralDistribution GCOPIESLTTRENCL011INTERNAFIECENTER01NRRDXBOGC/RPEXTERNAL:
NOAC11111011NRR/DSSA/SPLB JDOCS-ABSTRACT NRCPDR111111D.U'ENNOTETOALL"RZDS"RECIPIENTS:
PLEASEHELPUSTOREDUCEWASTE.'TO HAVEYOURNAMEORORGANIZATION REMOVEDFROMDISTRIBUTION LISTSORREDUCETHENUMBEROFCOPIESRECEIVEDBYYOUORYOURORGANIZATION, CONTACTTHEDOCUMENTCONTROLDESK(DCD)ONEXTENSION 415-2083TOTALNUMBEROF.COPIESREQUIRED:
LTTR10ENCL9
~Ml491071373ANMIClhM'LECI/CA7MfERC1099-0810CFR50.90DocketNos.:50-31550-316U.S.NuclearRegulatory Commission ATTN:DocumentControlDeskMailStop0-P1-17'Washington, DC20555-0001 October1,1999DonaldC.CookNuclearPlantUnits1and2TECHNICAL SPECIFICATION CHANGEREQUESTCONTAINMENT RECIRCULATION SUMPWATER.INVFNTORY Pursuantto10CFR50.90, IndianaMichiganPowerCompany(18cM),theLicenseeforDonaldC.CookNuclearPlant(CNP)Units1and2,proposestoamendAppendixA,Technical Specifications (T/S),ofFacilityOperating LicensesDPR-58andDPR-74.18'cMhasdetermined that,forcertainsmallbreakloss-of-coolant accidentscenarios, theremaynotbesufficient containment recirculation sumpwaterinventory tosupportcontinued operation oftheemergency corecoolingsystemandcontainment spraysystempumpsduringandfollowing switchover tocoldlegrecirculation.
Resolution ofthisissueconsistsofacombination ofphysicalplantmodifications, newanalysesofcontainment recirculation sumpinventory, andresultant changestotheaccidentanalysestoensuresufficient waterinventory inthecontainment recirculation sump.Theseplannedmodifications andanalysesresultinthechangestotheT/Sproposedinthissubmittal.
Thephysicalplantmodifications andanalysesresulting intheproposedT/SchangesresolveConfirmatory ActionLetterNo.RIII-97-011, Item1,"Recirculation SumpInventory/Containment DeadEndedCompartments."
ApublicmeetingwasheldonJuly12,1999,involving I&Mrepresentatives andNuclearRegulatory Commission/Nuclear ReactorRegulation staff.ThepurposeofthismeetingwasforI&MtopresenttheanalysesandproposedphysicalPDRADOCK050003AEP:America's EnergyPartner" U.S.NuclearRegulatory Commission Page2C1099-08modifications toresolvethecontainment recirculation sumpminimuminventory issue.Following thismeeting,IAMreceivedcommentsRomamemberofthepublicconcerning thetechnical presentation.
Thesecommentsandtheassociated IAMresponses areprovidedinAttachment 11.I&MrequestsapprovalofthisrequestbyDecember13,1999.Thisrequestisbasedonsupporting thedevelopment andapprovalofapplicable emergency operating procedures, andallowingsufficient timeforlicensedoperatortrainingontheapprovedchangespriortoentryofUnit2intoMode4.Copiesofthisletteranditsattachments arebeingtransmitted totheMichiganPublicServiceCommission andMichiganDepartment ofPublicHealth,inaccordance withtherequirements of10CFR50.91.Shouldyouhaveanyquestions, pleasecontactMr.RobertC.Godley,DirectorofRegulatory Affairs,at(616)466-2698.
Sincerely, R.P.PowersVicePresident
,1999SWORNTOANDSUBSCRIBED BEFOREMETIS-DAYMyCommission Expires)~CQKMIKhgewA.C.Bakken,III,w/attachments J.E.Dyer,w/attachments MDEQ-DWScRPDNRCResidentInspector, w/attachments R.Whale
~lgJIfBIG%I4~~C~
U.S.NuclearRegulatory Commission Page3C1099-08Attachments 1.Description andSafetyAnalysisfortheProposedChanges2A.Technical Specifications PagesMarkedtoShowProposedChanges-RevisedPages-Unit12B.Technical Specifications PagesMarkedtoShowProposedChanges-RevisedPages-Unit23A.ProposedTechnical Specifications Pages-RevisedPages-Unit13B.ProposedTechnical Specifications Pages-RevisedPages-Unit24.NoSignificant HazardsConsideration Evaluation 5.Environmental Assessment 6.Description andResolution ofContainment Recirculation SumpWaterInventory Issue7.FauskeIAssociates, Incorporated
-FAU99-77, "Containment SumpLevelEvaluation fortheD.C.CookPlant"8.MPRAssociates, Incorporated
-"Containment SumpLevelDesignCondition A,FailureEffectsAnalysisforPotential Draindown Scenarios" 9.MPRAssociates, Incorporated
-"Evaluation ofCookRecirculation SumpLevelforReducedPumpFlowRates"10.WCAP-15302, "DonaldC.CookNuclearPlantUnits1and2Modifications totheContainment SystemsWestinghouse SafetyEvaluation (SECL99-076,Revision3)"11.ResponsetoJuly12,1999,PublicMeetingTechnical Comments12.Commitments
~)~g4 ATTACHMENT 11TOC1099-08RESPONSETOJULY12,1999,PUBLICMEETINGTECHNICAL COMMENTSApublicmeetingwasheldonJuly12,1999,involving IndianaMichiganPowerCompany(IEcM)representatives andNuclearRegulatory.
Commission/Nuclear ReactorRegulation staff.ThepurposeofthismeetingwasforI&Mtopresenttheanalysesandproposedphysicalmodifications toresolvethecontainment recirculation sumpminimuminventory issue.Following thisineeting, I&Mreceivedseveralcommentsfromamemberofthepublicconcerning thetechnical presentation.
Thesecomments, andtheassociated IAMresponses, aredescribed below.1.Dotheemergency dieselgenerator loadprofiles(voltagevs.time)indicatesufficient margintoaccommodate theairrecirculation fanloadsat144seconds?Yes.Startingthecontainment airrecirculation/hydrogen skimmer(CEQ)fansat144secondswillhavenoeffectonthetransient studyfortheemergency dieselgenerators.
Thesequencing ofloadsiscompleted wellbeforetheCEQfansstart.Theemergency dieselgenerator steadystateloadingevaluates totalloadthroughout theemergency dieselloading,sequence.
TheCEQfanstarttimechangewillnotresultinanewpeak.load.Therefore, theresultsofthesteadystatecalculation willnotbeaffected.
2.Cantheemergency dieselgenerator fueloiltanksandtransfersystemaccommodate thehigheroutput(i.e.,greaterfuelconsumption)?
Yes.Theemergency dieselgenerator fueloilsystemisdesignedtosupportcontinuous fullloadoperation.
Asnotedabove,thechangeinCEQfanstarttimewillnotchangethemaximumsteadystateoutput.Therefore, theemergency dieselgenerator fueloiltanksandtransfersystemwillnotbeaffected.
Thetotalfuelconsumedinthetransient willchangeslightlyduetothepotential foralongerfanruntime.Thiswillbeevaluated aspartofthedesignchangeprocess,butwillbeinsignificant comparedtothetotalavailable fueloilcapacity.
3.IfECCSrecirculation switchover occursat1900secondsinboththecurrentdesignandinthenewdesign,whyismoreRWSTinventory required?
(ItappearsthattheRWSTflowdurationintocontainment, andtherefore therequiredRWSTinventory, isthesameinbothcases).Theslidethatwasusedinthepresentation detailing thesequenceofeventsfollowing adesignbasisaccidentwastohighlight thechangeineventprogression asaresultofthe'arlieractuation oftheCEQfans,andmistakenly listedthetimefortheinitiation ofswitchover to-coldlegrecirculation as1900secondsintotheevent.Therealimpactofthe Attachment 11toC1099-08Page2refueling waterstoragetank(RWST)modifications (RWSToverflowlinemodification andexistinginstrumentation respan)isthat,allotherconditions beingequal,switchover tocoldlegrecirculation willoccurlaterintheevent.4.Theoverallreduction inicemasscorresponds toslightlyover16,000gallonsofwater.If.AEPelectednottoreducetheminimumicemassperbasket,wouldtheRWSTinventory needtobeincreased by16,000gallons?The16,000gallonapproximate valuesforboththeincreaseinRWSTcontained inventory andthereduction inicemassareonlycoincidentally thesame.Theplannedmodifications totheRWSTresultin"new"waterinjectedintothecontainment priortoinitiation ofemergency corecoolingsystem(ECCS)recirculation.
Theactualamountofadditional deliverable RWSTwaterisapproximately 25,500gallons.Thisadditional waternotonlyincreases waterinventory inthecontainment recirculation sump,butalsoincreases thetimefortheonsetofcoldlegrecirculation.
Thereduction iniceweightfortheicebasketsisunrelated totheshort-term portionofthecalculations fordetermining waterinventory inthecontainment recirculation sump.Themostimportant ice-related parameter intheearlystagesofaneventistherateoficemelt,andthechangeinminimumiceweightdoesnotimpacttheicemeltrate.Theiceweightchangedoesreasonably impacttheultimateamountofwaterinthecontainment recirculation sumpunderlong-term steady-.state conditions following aloss-of-coolant accident.
However,atthatpointintimethereismorethanenoughwaterinthecontainment recirculation sumptosatisfytheminimumrequiredvortexing level.Thus,themagnitude ofthetwochangesisunrelated.
0AI
~'ATTACHMENT 12TOC1099-08COMMITMENTS Thefollowing tableidentifies thoseactionscommitted toby'IndianaMichiganPowerCompany(I&M)inthissubmittal.
Otheractionsdiscussed inthesubmittal represent intendedorplannedactionsbyISLAM.Theyaredescribed totheNuclearRegulatory Commission (NRC)fortheNRC'sinformation andarenotregulatory commitments.
Commitment Alltheidentified modifications inthissubmittal foraparticular unitwillbeinplacefortherestartofthatunit(eitherUnit1orUnit2).DatePriortoMode4entryfortheapplicable unitThesafetyevaluations addressing thestructural andmechanical effectsoftheplannedmodifications willbedocumented intheDesignChangePackagesfortheindividual modifications.
ThefinalimpactoneachaffectedEmergency Operating Procedure (EOP)willbeaddressed aspartofacomprehensive EOPreview,revision, andvalidation program.PriortoMode4entryfortheapplicable unit4PriortoMode4entryfortheapplicable unitNetpositivesuctionhead(NPSH)calculations forthedifferent operating configurations oftheemergency corecoolingsystem(ECCS)pumpsandcontainment spraysystem(CTS)pumpshavebeencompleted.
Theresultsofthesecalculations willbeprovidedinaseparatesubmittal addressing GenericLetter(GL)97-04,"Assurance ofSufficient NetPositiveSuctionHeadforEmergency CoreCoolingandContainment HeatRemovalPumps."PriortoMode4entryfortheapplicable unit E~~
50-315D.C.COOK1IMPCOATTACHHENT 1TOC1099-08DESCRIPTION ANDSAFETYANALYSISFORTHEPROPOSEDCHANGESRECORDM/LTRDTD10/1/999910060099
-NOTICE-THEATTACHEDFILESAREOFFICALRECORDSOFTHEOCIO/INFORMATION MANAGEMENT DIVISION.
THEYHAVEBEENCHARGEDTOYOUFORALIMITEDTIMEPERIODANDMUST.BERETURNEDTOTHERECORDSANDARCHIVESSERVICESSECTION,T-5C3.PLEASEDONOTSENDDOCUMENTS CHARGEDOUTTHROUGHTHEMAIL.RFMOVALOFANYPAGE(S)FROMDOCUMENTS FORREPRODUCTION MUSTBE.REFERREDTOFILEPERSONNEL.
lO<
A~~q ATTACHMENT 1TOC1099-08DESCRIPTION ANDSAFETYANALYSISFORTHEPROPOSEDCHANGES.A.SummaryofProposedChangesIndianaMichiganPowerCompany(IEcM),theLicenseeforDonaldC.CookNjclpar'Plant.
(CNP)Units1and2,proposestoamendAppendixA,Technical Specifications,(T/S);
of:Faciiity Operating LicensesDPR-58andDPR-74.i'I&;Mhasdetermined that,forcertainsmallbreakloss-of-coolant accident(LOCA)scenarios, theremaynotbesufficient containment recirculation sumpwaterinventory to.support continued operation oftheemergency corecoolingsystem(ECCS)andcontainment spraysystem(CTS)pumpsduringandfollowing switchover tocoldlegrecirculation.
Thecauseofthisdeficiency includesdesignfeaturesoftheinternallowercontainment compartments thatcausesignificant amountsofwatertobedivertedfrom,andnottobemadeavailable to,thecontainment recirculation sump.Afurtherdescription ofthetechnical issuesinvolvedwiththisdeficiency, including theoriginaldesignbasisofthecontainment recirculation sumpandthecircumstances leadingtothediscovery andresolution oftheseissues,isprovidedinAttachment 6.ISLAMhasdetermined thatacombination ofphysicalplantmodifications, newanalyses.
ofcontainment recirculation sumpinventory, andresultant changestotheaccidentanalysesarenecessary toensuresufficient waterinventory inthecontainment recirculation sump.Theplannedmodifications resultinincreasing theamountofwaterdelivered tothereactorcoolantsystem(RCS)andcontainment following aLOCA,andincreasing theamountoficemeltfromtheicecondenser duringtheearlystagesofaLOCA.Newcontainment recirculation'ump inventory analyseshavebeenperformed thatreflecttheplannedmodifications andverifysufficient inventory isavailable inthecontainment recirculation sumpfollowing aLOCA.Finally,theaccidentanalyseshavebeenevaluated, andrevisedasnecessary, toreflecttheplannedmodifications andproposedT/S.Theseplannedmodifications andanalysesresultinthefollowing proposedchangestotheT/S:~Therequiredrefueling waterstoragetank(RWST)contained inventory isbeingincreased toaddressthenewminimumdeliverable boratedwatervolumeusedinthecontainment recirculation sumpwaterinventory analysesandaccidentanalyses.
Inaddition, aconservative maximumRWSTsolutiontemperature isbeingaddedtotheexistingT/Stoensurethevalueusedintheaccidentanalysesremainsbounding.
~Theengineered safetyfeaturesactuation system(ESFAS)initiating signalandtimedelaytostartthecontainment airrecirculation/hydrogen skimmer(CEQ)fansandopenassociated valvesarebeingrevisedtomaximizetheresultant icecondenser ice.meltratefollowing aLOCA.Thisensuressufficient containment recirculation sumpwaterinventory following asmallbreakLOCA.
".;.f4l'i"sh'*~)c'>.fAf%tc>e~r,+JiV>cI'Ll~13~t~'4C""Q'.>f.,>~9 ilki.i~<39/I"rplV'-~'ff'>t'<<'1'~,
~3LJ'Qli<"A[~i'lli("sDs.fl'L
'>I'.f"'f~p Attachment 1toC1099-08.
Page2~Theminimumrequirediceweightintheicecondenser isbeingrevisedtoreflecttheamountoficeusedinthecontainment recirculation sumpwaterinventory analysesandaccidentanalyses.
Theassociated T/SBaseswillberevisedtostatethattheminimumiceweightisrequiredasanas-foundcondition withanappropriate margintoaccountforuncertainties inweighingoftheicebaskets.Previousprovisions intheT/SBaseswillalsobedeletedthatdescribed reducingtheminimumrequirediceweightornumberoficebasketstobeweighedbasedonoperating experience data.TheproposedT/Schangesandassociated T/SBaseschangesprovidedtoassistinthereviewoftheT/Schangesaredescribed indetailinSectionsB,C,andDofthisattachment.
T/Spagesandassociated T/SBasespagesthataremarkedtoshowtheproposedchangesareprovidedinAttachments 2Aand2BforUnit1andUnit2,respectively.
Notethatthesechangesmayreflectformatting thatdiffersslightlyfromthecurrentpages.Theseformatchangesareintendedtoimproveappearance andarenotintendedtointroduce otherchanges.TheproposedT/Spagesandassociated T/SBasespages,withthechangesincorporated, areprovidedinAttachments 3Aand3BforUnit1andUnit2,respectively.
IB.ProposedT/SChangeforRWSTContained Inventory andSolutionTemperature ecurree'eT/S3/4.1.2.8, "BoratedWaterSources-Operating,"
andT/S3/4.5.5,"Refueling WaterStorage.Tank,"requireaminimumcontained volumefortheRWSTof350,000gallonsofwater.TheRWSTwaterisrequiredtocontainbetween2400and2600ppmboronataminimumsolutiontemperature of70'F.Thereis'noexistingrequirement forRWSTmaximumsolutiontemperature.
BothT/Sareapplicable inModes1through4.urrRe'tTheminimumRWSTcontained inventory isbaseduponensuringthatsufficient negativereactivity isinjectedintothereactorcoretocounteract anypositiveincreaseinreactivity causedbyRCScooldown, TheminimumRWSTcontained inventory ensuresthatasufficient supplyofboratedwaterisavailable forinjection bytheECCSpumpsandcontainment spraybytheCTSpumpsfollowing aLOCAoramainsteamlinebreak(MSLB).ThelimitsonRWSTminimumvolumeensurethat,whencombinedwithwaterfrommelted'ice, theRCS,andthesafetyinjection accumulators, sufficient waterisavailable within'containment.to permitrecirculation coolingflowtothereactorcore.Inaddition, thelimitsonboronconcentration ensurethatthereactorwillremainsubcritical following aLOCAassumingmixingoftheRWST, t~~
Attachment 1toC1099-08..
Page3RCS,ECCSwater,andothersourcesofwaterthatmayeventually resideinthecontainment recirculation sump.ThelimitsonRWSTminimumvolumeandboronconcentration alsoensurealong-term pHvalueforthesolutionrecirculated withincontainment afteraLOCAthatminimizes theevolution ofiodine.Inaddition, theeffectofchlorideandcausticstresscorrosion onmechanical systemsandcomponents isminimized whenthelong-term pHvaluesarecontrolled following aLOCA.4TheECCSanalysestodetermine F<limitsinT/S3/4.2.2,"HeatFluxHotChannelFactor-F<(Z),"andT/S3/4.2.6,"Allowable PowerLevel-APL,"assumeanRWSTwatertemperature of70'F.TheRWSTwatertemperature determines thetemperature ofthecontainment spraywaterinitially delivered tothecontainment following aLOCAorMSLBinsidecontainment.
TheminimumassumedRWSTwatertemperature isoneofthefactorswhichdetermines thecontainment back-pressure intheECCSanalysesperformed inaccordance withtheprovisions of10CFR50.46and10CFR50,AppendixK.evieeuirePhysicalmodifications totheRWSToverflowlineandarespanoftheRWSTlevelinstrumentation arebeingimplemented toallowincreasing theavailable deliverable volumefromtheRWST.Thisadditional available waterisnecessary toensuresufficient containment recirculation sumpwaterinventory topreventvortexing andpossiblefailureoftheECCSpumpsandCTSpumps.TheproposedT/SchangeinminimumRWSTcontained inventory isneededtobeconsistent withthetotalminimumdeliverable RWSTvolumeassumedinthecontainment recirculation sumpinventory analysesandrevisedaccidentanalyses.
TheexistingT/Sonlyspecifies aminimumRWSTsolutiontemperature.
However,therecentlyconducted ExpandedSystemReadiness Reviewsidentified theneedtoalsoincludethemaximumRWSTsolutiontemperature intheT/S.ThischangeisneededtoensurethatactualRWSTtemperature ismaintained lessthanthemaximumassumedtemperature intheexistingaccidentanalyses.
Thisproposedchangeisalsonecessary tobeconsistent withtheT/SinNUREG-0452, "Westinghouse StandardTechnical Specifications,"
andNUREG-1431, Revision1,"Standard Technical Specifications
-Westinghouse Plants."4riinfteedaeIAMproposestoreviseT/S3/4.1.2.8 andT/S3/4.5.5toincreasetheminimumRWSTcontained inventory to375,500gallons,andtospecifythemaximumallowedRWSTsolutiontemperature of100'F.
0 Attachment 1toC1099-08.
Page4BaeePredaeTheproposedT/SchangeintheminimumRWSTcontained inventory reflectsplannedmodifications totheRWSToverflowlineandanincreaseinspanoftheRWSTlevelinstrumentation toprovideforadditional available waterfromtheRWST.Themodification totheRWSToverflowlineallowstheproposedincreaseintheT/SminimumRWSTcontained inventory of25,500gallons.'iththismodification, theexistingoperating marginbetweentheT/SminimumRWSTcontained inventory levelandactualoverflowofwaterfromthetankismaintained.
Structural evaluations oftheRWSTconfirmthatthereisnoimpacttotheseismiccapability oftheRWSTatthenew,higheroverflowwaterlevel.Inaddition, theindicated RWSTwaterlevels(indicated as0-100%ofspan)atthetimetheoperatorisinstructed tobeginandcompletetheswitchover tocoldlegrecirculation willnotchange.AmaximumRWSTwatertemperature of105'FisusedintheECCSanalysesperformed inaccordance withtheprovisions of10CFR50.46 and10CFR50,AppendixK.AmaximumRWSTwatertemperature of105'Fisalsousedinthecontainment integrity analysesperformed todetermine time-dependent containment pressures andtemperatures following aLOCAorMSLBinsidecontainment.
AdditionofthemaximumRWSTsolutiontemperature totheT/Susing100'Ftoconservatively boundtheanalytical limitof105'F,ensuresthatthecontainment integrity andLOCAanalysesremainbounding.
Thischangeisalsoconsistent withNUREG-0452 andNUTMEG-1431, Revision1.C.ProposedT/SChangeforManualandAutomatic Actuation LogicandTimeDelayforCEQFansandValvesciheenteueeESFASrequirements arelistedinT/STable3.3-3,"Engineered SafetyFeatureActuation SystemInstrumentation,"-
T/STable3.3-4,"Engineered SafetyFeatureActuation SystemInstrumentation TripSetpoints,"
andT/STable4.3-2,"Engineered SafetyFeatureActuation SystemInstrumentation Surveillance Requirements."
TheT/Stablesspecifythatmanualactuation oftheCEQfansisaccomplished aspartofthecontainment spraymanualactuation requirements.
Thesemanualactuation requirements areapplicable inModes1through4.Automatic actuation oftheCEQfansandvalvesisnotspecifically detailedintheT/Stables.However,theexistingdesignincludesactuation oftheCEQfansandhydrogenskimmervalvesatatimedelayof9+1minutesaflerreceiptofacontainment sprayautomatic actuation signal(containment pressure-high-high) inModes1through3.Thecomponent coolingwater(CCW)
Attachment 1toC1099-08Page5supplyandreturnvalvestotheCEQfanmotorsopenwithouttimedelayaAerreceiptofacontainment sprayautomatic actuation signal(containment pressure-high-high).
Thecontainment sprayautomatic actuation logicisrequiredtobeoperableinModes1through3.T/S3/4.6.5.6, "Containment AirRecirculation Systems,"
specifies surveillance requirements toverifythedelayof9+1minutesaAerreceiptoftheautomatic signalforstartingoftheCEQfansandopeningthehydrogenskimmer.valves.
eteeireetThedesignoftheCEQsystemensuresthatfollowing aLOCAthecontainment atmosphere iscirculated forcoolingbythecontainment spraysandtheaccumulation ofhydrogeninlocalized portionsofthecontainment structure isminimized.
Theautomatic actuation signalandtimedelayfortheCEQfansandvalvesaffectsthecontainment back-pressure usedintheECCSanalysesperformed inaccordance withtheprovisions of10CFR50.46and10CFR50,Appendix.K.
IntheECCSanalysesperformed duringtheoriginallicensing ofbothCNPunits(circa1970),thecomputermodelsusedwereoverlysensitive tocontainment back-pressure following aLOCAascomparedtothecurrentECCSanalysesofrecord.Thiswasespecially trueduringtheperiodafterinitialblowdownoftheRCSuntilthereactorvesselisreflooded bytheinitialinjection ofthesafetyinjection accumulators andflowfromtheECCSpumps.Becauseofthelimitations ofthecalculational methodology usedintheoriginalECCSanalyses, theactuation signalandminimumtimedelayfortheCEQfansandvalveswereestablished to~maximizecontainment back-pressure following aLOCA.Maximizing containment back-pressure providedabenefitintheoriginalECCSanalysesbylimitingbreakflow&omtheRCS,therebyreducingthetimeforreactorvesselreflood.TheexistingtimedelayfortheCEQfansandvalvesalsoensuredadequatecoolingofthecontainment atmosphere bytheCTSandprevented localized
-accumulation ofhydrogeninthelowercontainment compartments.
eRvitee'etsTheproposedT/SchangesfortheESFASinitiating signalandtimedelaytostarttheCEQfansandopenassociated valvesreflectmodifications beingperformed toensureearlierfo'reedflowofsteamandairthroughtheicecondenser.
Thismodification hastheeffectofincreasing theicemeltrateintheearlierstagesofaLOCA.Creditforincreased icemeltensuresthat,forthelimitingsizeLOCAandLOCAbreaklocations, sufficient waterinventory willbepresentinthecontainment recirculation sumpduringRCScoldlegrecirculation.
Thecontainment recirculation sumpinventory analysesandaccidentanalysesdescribed inthissubmittal reflecttheseplannedmodifications.
,Attachment 1toC1099-08Page6Theplannedmodifications.
resultinremovingautomatic actuation oftheCEQfansandvalvesfromtheexistingcontainment sprayESFASautomatic actuation logicandmanualactuation fromtheexistingcontainment spraymanualactuation pushbuttons.
AAerthemodification, theCEQfansandvalveswillbeautomatically actuatedfromacontainment pressure-highinitiation signalfromtheESFASautomatic actuation logic.TheCEQfansandvalveswillbemanuallyactuatedbyusingthenormalhandswitches locatedinthecontrolroominsteadofamanualpushbutton thatactuatestheESFASautomatic actuation logic.Manualactuation oftheCEQfansandvalvesisonlyrequiredintheeventtheESFASautomatic actuation fails,orinMode4whentheESFASautomatic actuation logicisnotrequired.
ThisresultsintheneedtorevisetheESFAST/StablesandCEQfanandvalveT/Ssurveillance requirements toreflectthenewdesign.thIAMproposestoreviseT/STable3.3-3,T/STable3.3-4,T/STable4.3-2,andT/S3/4.6.5.6 toreflectplannedmodifications totheESFASactuation logicandtothetimedelayrelayforstartingoftheCEQfansandopeningoftheCCWsupply,return,andhydrogenskimmervalvestotheCEQfans.ThisdesignchangewillmodifytheCEQfansstartinglogictoallowthefanstostartaflera120+12secondstimedelayafterreceiptofacontainment pressure-high(1.1psig)ESFASsignal.Thedesignchangealsoconsiders instrument uncertainties fortheactuation pressuresetpoint.
TheexistingdesignhasthefansstartaAeratimedelayof921minutes aAerreceiptofacontainment pressure-high-high (2.9psig)signal.Earlieractuation oftheCEQfansinresponsetocontainment pressure-highisreflected inthenewanalysesofwaterinventory inthecontainment recirculation sumpandtheassociated analysesdescribed inSectionEbelow.TheproposedchangestoT/STable3.3-3,T/STable3.3-4,andT/STable4.3-2includespecifying manualactuation requirements fortheCEQfansandvalvesseparately fromtheexistingcontainment spraymanualactuation requirements.
Inaddition, thenewcontainment pressure-highautomatic actuation logicrequirements fortheCEQfansandvalvesareproposedtobeaddedtotheappropriate limitingconditions foroperation requirements, tripsetpoints, andsurveillance requirements intheT/Stables.TheproposedchangestoT/S3/4.6.5.6 reflecttheplannedmodifications tothetimedelayforstartingoftheCEQfansandactuation oftheCEQvalves.TheexistingT/SSurveillance Requirement 4.6.5.6.d fortheCEQvalvesisproposedtobedeleted.AnewT/SSurveillance Requirement 4.6.5.6.d isproposedtoaddverification thattheCEQfanswillstartfromtheirrespective handswitches inthecontrolroom,andtheCEQvalveswillopen,every3monthsonastaggered testbasis.Therequirement toverifythattheCEQvalveopenswhentheCEQfanisstartedisproposedtobeaddedtotheexistingT/SSurveillance Requirement 4.6.5.6.a.
In Attachment 1toC1099-08Page7addition, itisproposedthatT/SSurveillance Requirement 4;6.5.6.a bespecified asapplicable inModes1,2,and3only.BaeeProedaeTheproposedT/Schangesspecifying theactuation oftheCEQfansandvalvesonacontainment pressure-highsignal,withatime.delayof120+12seconds,reflectplannedmodifications toincreasetheamountofairandsteamflowthroughtheicecondenser duringtheearlystagesofasmallbreakLOCA.Theearlierinducedflowthroughtheicecondenser hastwonoticeable effects.First,theenergyofthesteamreleasedduringthesmallbreakLOCAinthelowercontainment compartment ispreferentially absorbedbytheicebedratherthaninpassivestructures.
Preferential absorption ofheatbytheicebedresultsinincreased icemelt,lowertemperatures inthelowercontainment compartment, andincreased containment recirculation sumpinventory.
Second,thisabsorption ofenergyreleasedearlierinasmallbreakLOCAwilldelayreachingthecontainment pressure-,high-high actuation
- setpoint, whichinturnwoulddelaytheinitiation ofcontainment sprays.ForalargebreakLOCA,thetimeofCTSinitiation isnotdelayedbecauseoftheresultant rapidcontainment pressurerise.DelayingCTSinitiation alsoincreases icemeltsincethecontainment sprayswouldcompetewiththeicecondenser forheatremoval.Anotherbenefitoftheplannedmodifications isthatshort-term accumulation ofhydrogeninthelowercontainment compartments isminimized forbothlargebreakandsmallbreakLOCAscenarios.
ThecomputermodelsusedinthecurrentECCSanalysesofrecordarenotassensitive tocontainment back-pressure following aLOCAascomparedto'theoriginalECCSanalyses.
Therevisedaccidentanalysesdescribed inAttachment10 considered theimpactoftheplannedmodification totheactuation signalandminimumtimedelayfortheCEQfansandvalves.Theseanalysesdemonstrate thattheplannedmodifications areacceptable.
Theproposedchangesto.T/STable3.3-3,T/STable3.3-4,andT/STable4.3-2areconsistent withotherexistingESFASrequirements.
Theproposedlimitingconditions foroperation inthetablesareidentica) totheexistingrequirements forcontainment pressure-highautomatic actuation logicandCEQfanandvalvemanualactuation requirements.
Thisincludestotalnumberofchannels, channelstotrip,minimumnumberofchannelsrequired, modeapplicability, andactionstatement requirements identical toexistingrequirements formanualactuation andcontainment pressure-highautomatic actuation logic.Thenewmanualactuation functional unitisrequiredtoaddressthefactthatthenewdesignwillrequireuseofthecontrolroomhandswitches tomanuallyactuatetheCEQfansandvalves.Consistent withexistingrequirements, thecapability tomanuallyactuatetheCEQfansandvalveswillberequire'd inModes1through4.Thenewfunctional unit'fortheCEQfansisrequiredtoaddressthenew,separateESFASautomatic actuation logicfortheCEQfansandvalves.Alsoconsistent withexistingrequirements, theautomatic actuation logicwillberequired
Attachment 1toC1099-08Page8tobeoperableinModes1through3.Inaddition, thecontainment pressure-highsetpointisnotchangedbythissubmittal, andthe'roposed surveillance requirements areidentical tootherexistingrequirements formanualactuation andcontainment pressure-highautomatic actuation logic.TheproposedchangetoT/S3/4.6.5.6 reflectsthetimedelayusedintheanalysesofwaterinventory inthecontainment recirculation sumpandtheassociated analysesdescribed inSectionEbelow.Thenewsurveillance requirement forverifying manualstartoftheCEQfansfromthecontrolroomandverification thattheCEQvalvesopenwhentheCEQfansstart,isconsistent withthenewdesignoftheCEQfanandvalveactuation logic.Thisisbecausemanualactuation oftheCEQfansandvalveswillbethroughuseofthenormalhandswitches inthecontrolroominsteadofapushbutton thatinitiates theESFASautomatic actuation logic(liketheexistingcontainment sprayautomatic actuation design).Addingtherequirement toverifythattheCEQvalvesopenwhentherespective CEQfanstartsisconsistent withtheexistingandnewdesignoftheCEQfanandvalvelogic.EachCEQfanhas'asingletimedelayrelaythatwillbesetat120+12seconds.TheCEQvalvesareinterlocked withtherespective CEQfantoopenimmediately whentheCEQfanstarts.Therefore, theexistingT/SSurveillance Requirements 4.6.5.6.a and4.6.5.6.d arebothdescribing thesametimedelayrelayandareredundant.
Specifying T/SSurveillance Requirement 4.6.5.6.a asapplicable onlyforModes1through3reflectsthattheplannedmodification doesnotincludeamanualactuation pushbutton usingESFASautomatic actuation logic.Consistent withtheESFAST/Stablechanges,theT/Ssurveillance requirements thataddressoperability oftheautomatic actuation logicareonlyrequiredinModes1through3.TheotherT/Ssurveillance requirements arenecessary forverifying bothautomatic actuation andmanualactuation functions.
Therefore, itisappropriate torequiretheotherT/Ssurveillance requirements inModes1through4.D.ProposedT/SChangeforMinimumRequiredIceWeightintheIceCondenser c't'eeementT/S3/4.6.5.1, "IceBed,"specifies aminimumrequirediceweightpericebasketof1333pounds,oratotalof2,590,000 pounds.T/SBases3/4.6.5.1 specifies a5%allowance foricelossthroughsublimation overaneighteen-month periodasthebasisfortheminimumrequirediceweight.T/S3/4.6.5.1 Surveillance Requirements state,inpart,thatoperability oftheicecondenser shallbeverifiedatleastonceper18monthsbyweighingarepresentative sampleoficebaskets.Toaccountforuncertainties associated withicebasketweighingandsublimation oficeoveran
Attachment 1toC1099-08Page9eighteen-month period,eachicebasketisverifiedtocontainatleast1333poundsofice.Thisisanas-leftvalueforiceweightthatincludesameasurement uncertainty (1%),andallowance foricesublimation (5%),appliedtotheminimumiceweightusedintheaccidentanalyses.
T/SBases3/4.6.5.1 includesallowance foradjusting iceweightsorthenumberoficebasketstobeweighedduringsurveillance testingbasedonaccumulated dataovermultipleoperating cycles.aeheenReienTherequirements associated withtheicecondenser ensurethatsufficient pressuresuppression capability isprovidedtolimitthecontainment peakpressuretransient tolessthanorequalto12psigduringLOCAandMSLBconditions.
TheicebedT/Sensuresthattheminimumrequirediceweightisproperlydistributed throughthecontainment bays.Inaddition, sufficient heatremovalcapability isavailable tocondensethereactorsystemvolumereleasedduringaLOCA.Theseconditions areconsistent withtheassumptions usedintheLOCAanalyses.
ThelimitsonminimumrequirediceweightalsoensurethatwhencombinedwithwaterfromtheRWST,theRCS,andthesafetyinjection accumulators, sufficient waterisavailable withincontainment topermitrecirculation coolingflowtothereactorcore.Theminimumweightrequirement of1333poundsoficeperbasketcontainsa5%allowance foricelossthroughsublimation overaneighteen-month period.TheT/SBasesstatethat,iftheobservedsublimation isequaltoorlowerthandesignpredictions afterthreeyearsofoperation, theminimumweightoftheicebasketsmaybeadjusteddownward.
Inaddition, therequirednumberoficebasketstobeweighedeveryeighteenmonthsmaybereducedafterthreeyearsofoperation ifsuchareduction issupported byobservedsublimation data.Theseprovisions toadjusttheiceweightornumberoficebasketstobeweighedreflectthattheoriginalrequirements werebasedonpredictions ratherthanoperating data.eviReuieeThenewcontainment recirculation sumpwaterinventory analyseshaveusedalowerminimumweightof1132poundsoficeperbasket.Theminimumiceweightvaluechosenshouldminimizetherequiredamountoficeintheicecondenser tofacilitate effective management oficeinventory fortheicecondenser andtofacilitate icecondenser maintenance.
Inaddition, theproposediceweightmustbesufficient tomeettheacceptance criteriafortherevisedaccidentanaly'ses described inWCAP-15302, "DonaldC.CookNuclearPlantUnits1and2Modifications totheContainment SystemsWestinghouse SafetyEvaluation (SECL99-076, Revision3)"(Attachment 10).TheproposedT/Sminimumiceweightsmeetthesecriteria.
TheexistingT/Srequirement forminimumiceweightincludesallowance forweightmeasurement uncertainty (1%)andforicesublimation (5%)overaneighteen-month period.18cMprefersthattheminimumiceweightbespecified asanas-foundvaluewithonlytheweight
Attachment 1toC1099-08.
Page10measurement'uncertainty includedintheT/Sspecified minimumiceweight.Thisisnotconsistent withNUREG-0452.
However,itisconsistent withthedefinition in10CFR50.36foralimitingcondition foroperation.
Inaddition, NUREG-1431, Revision1,doesnotspecifyanallowance foricesublimation.
Instead,licensees arerequiredtocontrolconsideration oficesublimation inowner-controlled documents suchasapprovedprocedures toensurethattheminimumiceweightatanygiventimeduringanoperating cycleisatorabovetheanalytical value.Therefore, specifying theminimumiceweightasanas-foundvalueisconsistent withthisapproach.
Compliance withtheT/Shadpreviously beendemonstrated byastatistical analysisofsampleicebasketweightswhichwereconsidered representative.
However,someicebasketscannotbephysically weighed,asacknowledged byboththe.T/SandtheCNPUpdatedFinalSafetyAnalysisReport(UFSAR).Visualsurveysoficebasketsindicated thatsomeicebasketsinbothunits,predominantly inradialrow9,butalsoradialrow8andazimuthal row5,showedgreaterthanexpectedicelossduetosublimation.
Sincethedatausedtosupporttheexistingiceweightlimitwasbasedonthesamesamplingmethod,itwasnecessary toreevaluate thecalculations performed todetermine theweightlimitandtheassumptions used.Basedonthisreevaluation, theproposedT/Sreflecttherestoration ofthe10%allowance forsublimation overaneighteen-month period.TheexistingT/SBasesincludesprovisions toallowadjusting iceweightsornumberofbasketstobeweighedbasedonaccumulated dataovermultipleoperating cycles.However,thevalueinT/ScannotbechangedwithoutNRCapproval.
Therefore, theT/SBasesstatement isnotnecessary sinceitwouldresultinimplementing anunapproved T/Schangeifitwerefollowed.
ntheoeISLAMproposestoreviseT/S3/4.6.5.1, "IceBed,"toreflecttheminimumiceweightusedinthenewanalysesofcontainment recirculation sumpinventory andassociated analysesdescribed in"SectionEbelow.Thenewminimumiceweightof1144poundspericebasket,or2,222,000 poundstotal,includesa1%allowance foruncertainties involvedinweighingoftheicebaskets.Therefore, theactualiceweightproposedintheT/Sisbasedonanas-foundweightoficecorrected formeasurement uncertainties todetermine operability oftheicecondenser.
Inaddition, aneditorial changetorevise"eachicebasket"to"icebaskets"isproposedtoclarifythattheas-foundweightappliestoalloftheicebasketsweighed.Concurrent withNRCapprovaloftheproposedT/Schanges,I&MwillreviseT/SBases3/4.6.5.1 toincreasetheallowance foricelossthroughsublimation from5%to10%overaneighteen-month period.Thissublimation willbeconsidered intheactualas-lefticeweighttobespecified intheprocedures governing weighingandfillingoftheicebaskets.Inaddition, theprovision toallowadjusting iceweightsornumberofbasketstobeweighedbasedonaccumulated dataovermultipleoperating cycleswillbedeleted.
0 Attachment 1toC1099-08Page11sefohereaeTheproposedT/Schangetotheminimumrequirediceweightintheicecondenser reflectsthevaluesusedinanalysesofminimumcontainment recirculation sumpinventory andtheaccidentanalysesdescribed inSectionEbelow.Tobeconsidered
- operable, theice.condenser isrequiredtobecapableofremovingenergybycondensing releasedsteam,providing boratedwatertothecontainment recirculation sump,andmaintaining structural integrity.
Inaddition, thewaterfromthemeltedice,whencombinedwithothersourcesofwaterduringtheaccidentincluding theRWST,theRCS,andsafetyinjection accumulators, mustnotresultincontainment waterlevelsabovethemaximumallowedflooduplevel,andmustensuresufficient boronconcentration inthecontainment recirculation sump.Theanalyses, asfurtherdescribed inSectionEbelow,includeaninputassumption ofaminimumiceweightof2,200,000 poundsofice(1132poundspericebasket).Theproposedminimumtotaliceweightrequirement forT/S4.6.5.1.b.2 of2,222,000 poundsisthecalculated minimumweightof2,200,000 pounds,plusa1%weightmeasurement uncertainty allowance.
Theproposedminimumweightrequirement forT/S3.6.5.1of1144poundspericebasketisthecalculated minimumweightof1132poundspericebasket(2,200,000 poundsdividedby1944icebaskets),
plusa1%weightmeasurement allowance.
Atthebeginning ofafuelcycle,individual icebasketswillcontainsufficient additional iceovertherequiredminimumtoaccountforanaverageicebedsublimation of10%overaneighteen-month period.Therefore, theminimumend-of-cycle iceweightwouldbegreaterthanorequaltotheamountneededtoperformtherequiredsafetyfunction.
Statingtherequiredminimumiceweightonanas-foundbasisisachangefromtheexistingT/S.Thecurrently specified T/Sminimumiceweightincludesa5%marginforsublimation overaneighteen-month period.Therefore, thecurrently specified valueis'nas-leftvalueatthebeginning-of-cycle.
Specifying theas-leftvalueintheT/Sisconsistent withtheintentofNUREG-0452.
However,itispreferable fortheT/Storepresent thevalueusedfordetermining operability oftheicecondenser regardless ofthepointintimetheiceisphysically weighed.Sublimation of10%overaneighteen-month periodwasinitially established withoutindustrydata.However,thesubsequent datafromoperating icecondenser plantshaveshownthatoverall.sublimation islessthan10%duringaneighteen-month operating cycle.Therefore, theassumption isconservative andappropriate.
NUREG-0452 andtheCNPT/SBasesincludeaprovision toreducetheallowance foricelossthroughsublimation ifobservedsublimation isequaltoorlowerthandesignpredictions aflerthreeyearsofoperation.
Thisprovision wasoriginally includedintheT/SBasestoallowicecondenser plantstodecreaseas-lefticebasketweightsandtoreducethenumberoficebasketsrequiredtobeweighedaflersufficient operating datawasevaluated.
Thisprovision isnotrequiredbecauseanychangestotheactualT/Srequirements mayonlybemadeinaccordance Attachment 1toC1099-08Page12withanapprovedamendment totheoperating license.ItshouldbenotedthatNUREG-1431, Revision1,doesnotincludeaspecificvalueforsublimation allowance ortheprovision toreducetheallowance.
Theaccidentanalysesfurtherdescribed belowdemonstrate thattheproposedminimumrequirediceweightissufficient toensurecontainment integrity ismaintained bylimitingthemaximumcontainment pressureandtemperature.
Inaddition, theanalysesdescribed inAttachment 7alsodemonstrate thatsufficient iceisavailable tomaintainaminimumwaterinventory inthecontainment recirculation sumpabovetheminimumvortexing level.Thestructural analysisfortheicecondenser demonstrates thatstructural integrity ismaintained uptoanaverageweightof1877poundsfortheicebasketswithineachlatticeframestructure (icebasketsplusice).Themaximumicebasketplusiceweightisadministratively controlled toensurethatthislimitisnotexceededforeachlatticeframestructure withintheicecondenser.
E.Acceptability andImpactoftheProposedT/SChangesAttachments 7through10areanalysesperformed byFauske&Associates, MPRAssociates, andWestinghouse ElectricCompany.Theseanalyseswereperformed todemonstrate theacceptability andimpactoftheproposedT/Schanges.I&Mhasreviewedandapprovedthese"analyses inaccordance withapprovedadministrative procedures forowner-acceptance ofvendor-supplied designandanalysisinformation.
irativet1eAttachment 7describes thecontainment recirculation sumpwaterinventory analyses.
Theanalysesdemonstrate thattheincreased RWSTcontained inventory, theanalyzedamountoficemelt,andRCSandsafetyinjection accumulator waterinventory releasedtocontainment, issuflicient toensurethattheminimumcontainment recirculation sumplevelrequiredtopreventvortexing ismaintained.
Thesecontainment recirculation sumpinventory analysesincludeconsideration oflimitingsinglefailuresofECCSandCTScomponents asdescribed inAttachment 8.iAsdemonstrated bytheseanalyses, aminimumcontainment recirculation sumplevelgreaterthanorequalto602'-10"(theleveldemonstrated bytesttobeacceptable) wouldbeobtainedforMode1LOCAevents.However,certainMode3LOCAeventsresultinminimumcontainment recirculation sumplevelsslightlylessthan602'-10".
ThisisbecauseofthelowermassandenergyreleasefromtheRCSexperienced duringaMode3LOCAandtheresultant decreaseintheicecondenser icemeltrate.However,overallECCSandCTSflowrequiredformitigation ofaMode3LOCAislessthanthemaximumflowsusedintheoriginalcontainment recirculation sumpdemonstration tests.AsshowninAttachment 9,theanalysesdemonstrate thatminimumcontainment recirculation sumplevelsbelow602'-10"areacceptable topreventvortexing inthecontainment recirculation sump,atflows-less thanthemaximumflowsusedintheoriginal 0
Attachment 1toC1099-08Page13containment recirculation sumpdemonstration tests.ForMode3LOCAevents,theanalysesdemonstrate thattheminimumcontainment.
recirculation sumplevelslessthan602'-10"arestillsufficient topreventvortexing atthereducedECCSandCTSflowratesexpected.
Thereportpresented inAttachment 7inclitdes:
~adescription oftheModularAccidentAnalysisProgram(MAAP)computercodemodelandversion(MAAP4.0.4.1) usedforperforming CNPcontainment recirculation sumpinventory
- analyses,
~adescription ofthedynamicbenchmarking performed fortheMAAP4.0.4.1 modelagainstavailable designbasismodelsandicecondenser experiments,
~adescription ofthemostlimitingconditions usedinthecontainment recirculation sumpinventory
- analyses,
~theanalytical resultsforMode1LOCAeventsincluding comparison ofminimumcontainment recirculation sumplevelswiththe602'-10"vortexing level,~theanalytical resultsforMode3LOCAeventsincluding comparison ofminimumrecirculation sumplevelswiththeminimumvortexing levelsdetermined inAttachment 9,~theanalytical resultsforMSLBevents,and~conclusions ofthecontainment recirculation sumpinventory analyses.
Theavailable netpositivesuctionhead(NPSH)fortheECCSpumpsandCTSpumpsisdependent ontheminimumwaterlevelsinthecontainment recirculation sump.Analyseshavebeenperformed thatdemonstrate adequateavailable NPSHfor,theECCSpumpsandCTSpumpsisassuredwhenthepumpsarealignedtotakesuctionfromthecontainment recirculation sump.Theanalysesalsodemonstrate thattheminimumvortexing levelsinthecontainment recirculation sumparemorelimitingthantherequiredNPSHlevelsfortheECCSpumpsandCTSpumps.TheanalysesforensuringadequateNPSHconsidered eachofthepossibleoperating configurations fortheECCSpumpsandCTSpumpsfollowing aLOCA.Theseoperating configurations includeinitialECCSinjection andCTSoperation, RCScoldlegrecirculation, RCShotlegrecirculation, andtheallowable operating configurations whenresidualheatremoval(RHR)containment sprayisplacedintoservicefollowing alargebreakLOCA.Inaddition, IEcMhasevaluated minimumvortexing levelsatreducedECCSpumpandCJSpumpflowratesasfurtherdescribed inAttachments 7and.9,andhasdemonstrated acceptable marginforthescenarios thatinvolvelowerpumpflowrates.Forthelowflowcases,thevortexing levelsarestillboundingandprovidemarginabovetherequiredNPSHfortheECCSpumpsandCTSpumps.
Attachment 1toC1099-08Page14valuatioofenaleIacedteenec'uIueAsfurtherdescribed inWCAP-15302 (Attachment 10),anevaluation wasperformed todetermine theimpactoftheproposedT/SchangesontheexistingCNPaccidentanalyses.
Thisevaluation demonstrates thattheaccidentanalysesarenotadversely affectedbytheproposedT/S'hanges.TheanalysesprovidedinWCAP-15302 reflecttheproposedchangesinletterC0999-11, "LicenseAmendment RequestforCreditofRodClusterControlAssemblies forColdLegLargeBreakLoss-of-Coolant AccidentSubcriticality,"
datedSeptember 17,1999.valtiofDe'rainacmtec'c'imceeThecontainment recirculation sumpisprovidedwithascreenandgratingstructure thatpreventsdebrisfromenteringtheECCSpumpsandCTSpumps.Thisscreenisdesignedtoprovidesufficient flowtopreventvortexing inthecoritainment recirculation sumpwithamaximumblockageof50%.Thisdesigncapability wasdemonstrated inthecontainment recirculation sumptestingperformed byAldenResearchLaboratory.
Aspreviously described, modifications arebeingmadetothecontainment structures toprovidepositivecommunication betweenthepipeannulusregionandtheRCSloop,compartment.
Thesemodifications consistofaddingseveralpenetrations inthecontainment partition wallatlowelevations.
Theflowratethroughthecontainment cranewallandnewcontainment partition wallpenetrations willbesmall.Theresulting lowapproachvelocities willminimizedebristransport.
Inaddition, curbsandtrashgratingswillbeprovidedsomedistancefromthepenetrations tominimizepotential forblockageofthepenetrations, andtherearemultiplepenetrations intwoseparateareastofurtherprotectagainstblockage.
Therefore, theprobability ofblockageofthescreensforthecontainment recirculation sumpisnotincreased.
1F.SummaryofImpactoftheProposedChangesTheproposedT/Schangeswillensurethecapability ofthecontainment recirculation sump,andthecontainment structures, systems,andcomponents, tomeettheoriginaldesignbasisrequirements forthefacility.
Byensuringsufficient waterinventory ismaintained topreventvortexing inthecontainment recirculation sump,theoriginalevaluation oftheconsequences ofpreviously evaluated accidents asdescribed intheCNPUFSARwillnotbeaffected.
Thephysicalmodifications tobeimplemented areintendedtoensuretheoriginaldesignbasisfunctional capabilities ofthecontainment recirculation sump,andothercontainment systems,structures, andcomponents, tosupportECCS,icecondenser, andCTSoperation.
TheproposedT/Schangesensurethatthecontainment structure andsystemsprovideaneffective barriertothereleaseoffissionproducts.
Attachment 1toC1099-08Page15G.ImpactonPreviousSubmittals Noprevioussubmittals affectthetechnical basisforthissubmittal, orrequireapprovaltosupportthissubmittal.
However,severalprevioussubmittals affectT/Spagesandassociated T/SBasespagesthataresubmitted inthisrequest.Theseincludeletters:1)AEP:NRC:0433Q, "Technical Specifications ChangeRequest-Administrative Changes,"
datedDecember3,1998;2)AEP:NRC:09000, "Technical Specifications ChangeRequest-IceCondenser FlowChannels,"
datedDecember3,1998;3)AEP:NRC:1291, "Technical Specification Amendment-Distributed IgnitionSystemTechnical Specification andAssociated Bases,"datedDecember3,1998;and4)C0999-11, "LicenseAmendment RequestforCreditofRodClusterControlAssemblies forColdLegLargeBreakLoss-of-Coolant AccidentSubcriticality,"
datedSeptember 16,1999.TheWestinghouse NuclearSafetyanalysesprovidedinWCAP-15302 (Attachment 10)reflecttheproposedchangesinletterC0999-11, withbothsubmittals reflecting thesamesubcriticality analyses.
TheT/SandT/SBasespagesinAttachments 2A,2B,3A,and3Bdonotreflectthechangesproposedintheotherexistingsubmittals.
Fortheseandanyfuturesubmitt'als thataffecttheT/SandT/SBasespagesprovidedinthissubmittal, IAMwillcoordinate changestothepageswith.theNRCPxojectManagertoensureproperT/SandT/SBasespagecontrolwhentheassociated licenseamendment requestsareapproved.