ML17326A145

From kanterella
Revision as of 09:11, 29 June 2018 by StriderTol (talk | contribs) (Created page by program invented by StriderTol)
Jump to navigation Jump to search
Requests Withholding of WCAP-15246, Control Rod Insertion Following Cold Leg Lbloca.
ML17326A145
Person / Time
Site: Cook  American Electric Power icon.png
Issue date: 08/04/1999
From: SEPP H A
WESTINGHOUSE ELECTRIC COMPANY, DIV OF CBS CORP.
To: COLLINS S J
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML17326A143 List:
References
CAW-99-1348, NUDOCS 9909240200
Download: ML17326A145 (12)
v • d • e


Text

Westinghouse ElectricCompanyDocumeiit ControlDeskU.S.NuclearRegulatory Commission Washington, DC'0555Box355Pittsburgh Pennsylvania 15230-0355 August4.)999CAW-99-I348Attention:

Mr.SamuelJ.CollinsAPPLICATION FORWITHI-IOLDING PROPRIETARY INFORMATION FROivlPUBLICDISCLOSURE Subject"ControlRodInsertion Followin<

aColdLc<LBLOCA.D.C.Cook.UnitsIand.."<VCAP-I5245(Proprietarv).

islay.1999and"ControlRodInsertion Following aColdLegLBLOCA.D.C.Cook.UnitsIand2.."EVCAP-I5246(Non-Proprietary).

<clay,l999

DearMr.Collins:

Theproprietary information forwhichivithholding isbeingrequested intheabove-referenced reportisfurtheridentified inAffidavit CATV-99-l348signedbytheowtteroftheproprietary information.

Westinghouse ElectricCon>panyLLC.'fheaffidavit.

ivhichaccoinpanies thisletter,setsforththebasisonwhichtheinformation maybewithheldfroinptiblicdisclosure bytheCon>mission andaddresses withspecificity theconsiderations listedinparagraph (b)(4)of10CFRSection2.790oftheCoiumission's regulations.

/Accordingly, thisletterautliorizes theutilization oltheacconipanying Affidavit byAinerican ElectricPower.Correspondence withrespecttotheproprietary aspectsoftheapplication forwithholding orthei<Vestinghouse affidavit.

shouldreference thisletter.CATV-99-l348andshouldbeaddressed totheundersigned.

VcrvtrulvvoursII.A.Sepp.<vlana<erRegulatory andLicensing Engineering Enclosures cc:T.Carter/NRC (5E7)~'<~t,<,~<tC.I,.s49'>VV09ÃeOaOO 9909<>(PDR,ADOCK'5000315

.POR

.CAW-99-1348 AFFIDAVIT COMMONWEALTH OFPENNSYLVANIA:

ssCOUNTY=OFALLEGHENY:

Beforeme,theundersigned authority.

personally appearedHenryA.Sepp,who.beingbymedulyswornaccording tolaw,deposesandsaysthatheisauthorized toexecutethisAffidavit onbehalfofWestinghouse ElectricCompanyLLC("westinghouse"),

andthattheaverrnents offactsetforthinthisAffidavit aretrueandcorrectto'thebestofhisknowledge.

information, andbelief:Sworntoandsubscribed beforethis~deyof.I999HenryA.Sepp,ManagerRegulatory andLicensing Engineering NotaryPublictrot:t;sai Bet)tJanettA,bci&an,rt.til.rrrstOt,{onrottvtt'e BoreAtogttonyCot.ntyM~Coritmtsston E>n<rosMay22.2000Mttrttbttr,

~vanhtAssooation otNotanes CAW-99-1348 (I)IamManager,Regulatory andLicensing Engineering, intheNuclearServicesDivision, oftheWestinghouse ElectricCompanyLLC("Westinghouse"

),andassuch,Ihavebeenspecifically delegated thefunctionofreviewing theproprietary information soughttobewithheldfrompublicdisclosure inconnection withnuclearpowerplantlicensing andrulemaking proceedings, andamauthorized toapplyforitswithholding onbehalfofWestinghouse.

(2)IammakingthisAffidavit inconformance withtheprovisions of10CFRSection2.790oftheCommission's regulations andinconjunction withtheWestinghouse application forwithholding accompanying thisAffidavit.

(3)Ihavepersonalknowledge ofthecriteriaandprocedures utilizedbyWestinghouse ElectricCompanyLLCindesignating information asatradesecret.privileged orasconfidential commercial orfinancial information.

(4)Pursuanttotheprovisions ofparagraph (b)(4)ofSection2.790oftheComtnission's regulations, thefollowing isfurnished forconsideration bytheCommission indetermining whethertheinformation soughttobewithheldfrompublicdisclosure shouldbewithheld.

(i)Theinformation soughttobewithheldfrompublicdisclosure isownedandhasbeenheldinconfidence byWestinghouse.

(ii)Theinformation isofatypecustomarily heldinconfidence byWestinghouse andnotcustomarily disclosed tothepublic.Westinghouse hasarationalbasisfordetermining thetypesofinformation customarily heldinconfidence byitand,inthatconnection, utilizesasystemtodetermine whenandwhethertoholdcertaintypesofinformation inconfidence.

Theapplication ofthatsystemandthesubstance ofthatsystemconstitutes Westinghouse policyandprovidestherationalbasisrequired.

Underthatsystem,information isheldinconfidence ifitfallsinoneormoreofseveraltypes,thereleaseofwhichmightresultinthelossofanexistingorpotential competitive advantage, asfollows:(a)Theinfortnation revealsthedistinuishingaspectsofaprocess(orcomponent.

structure.

tool.method.etc.)whereprevention ofitsusebyanyof CAW-99-1348 Westinghouse's competitors withoutlicensefromWestinghouse constitutes acompetitive economicadvantage overothercompanies.

(b)Itconsistsofsupporting data,including test'data,relativetoaprocess(orcomponent, structure, tool,method,etc.),theapplication ofwhichdatasecuresacompetitive economicadvantage, e.g.,byoptimization orimprovedmarketability.

(c)Itsusebyacompetitor wouldreducehisexpenditure ofresources orimprovehiscompetitive positioninthedesign,manufacture,

shipment, installation, assurance ofquality.orlicensing asimilarproduct.(d)Itrevealscostorpriceinformation.

production capacities.

budgetlevels,orcommercial strategies ofWestinghouse, itscustomers orsuppliers.

(e)Itrevealsaspectsofpast,present.orfutureWestinghouse orcustomerfundeddevelopment plansandprogramsofpotential commercial valuetoWestinghouse.

(f)Itcontainspatentable ideas,forwhichpatentprotection maybedesirable.

/TherearesoundpolicyreasonsbehindtheWestinghouse systemwhichincludethefollowing; (a)Theuseofsuchinfortnation byWestinghouse givesWestinghouse acompetitive advantage overitscompetitors.

Itis,therefore, withheldfromdisclosure toprotecttheWestinghouse competitive position.

(b)Itisinformation whichisn>arketable inmanyways.Theextenttowhichsuchinformation isavailable tocompetitors diminishes theWestinghouse abilitytosellproductsandservicesinvolving theuseoftheinformation.

(c)Usebyourcompetitor wouldputWestingttouse atacompetitive disadvantage byreducinghisexpenditure ofresources atourexpense.

4CAW-99-1348 (d)Eachcomponent ofproprietary infortnarinu ymmuetuttoaparticular competitive advantage ispotentially asvaluableasthewtaIcompetitive advantage.

Ifcompetitors acquirecomponents ofproprietary information, anyonecomponent maybethekeytotheentirepuzzle.therebydepriving Westinghouse ofa.competitive advantage.

(e)Unrestricted disclosure wouldjeopardize thepositionofprominence ofWestinghouse intheworldmarket,andtherebygiveamarketadvantage tothecompetition ofthosecountries.

(f)TheWestinghouse capacitytoinvestcorporate assetsinresearchanddevelopment dependsuponthesuccessinobtaining andmaintaining acompetitive advantage.

(iii)Theinformation isbeingtransmitted totheCommission inconfidence and,undertheprovisions of10CFRSection2.790,itistobereceivedinconfidence bytheCommission.

(iv)Q>einformation soughttobeprotected isnotavailable inpublicsourcesoravailable information hasnotbeenpreviously employedinthesameoriginalmannerormethodtothebestofourknowledge andbelief.(v)Theproprietary information soughttobewithheldinthissubmittal isthatwhichisappropriately markedin"ControlRodInsertion Following aColdLegLBLOCA,D.C.Cook,UnitsIand2,."WCAP-15245 (Proprietary),

May,1999fortheD.C.CookUnits1and2NuclearPlant.beingtransn>itted byAmericanElectricPowerleuerandApplication forWithholding Proprietary Information fromPublicDisclosure, totheDocumentControlDesk,Attention lvlr,SamuelJ.Collins.Theproprietary information assubmitted forusebyAmericanElectricPowerfortheD.C.CookNuclearPlantUnits1and2isexpectedtobeapplicable inotherlicenseesubmittals inresponsetocertainNRCrequirements forjustification oftheuseofControlRodInsertion Following aColdLegLBLOCA.' CAW-99-1348 Thisinformation ispartofthatwhichwillenablewestinghouse to:(a)AssistthecustomertoobtainNRCapproval.

Furtherthisinformation hassubstantial commercial valueasfollows:(a)Westinghouse planstoselltheuseofsimilarinformation toitscustomers forpurposesofmeetingNRCrequirements forlicensing documentation.

(b)Westinghouse cansellsupportanddefenseofthetechnology toitscustomers inthelicensing process.Publicdisclosure ofthisproprietary information islikelytocausesubstantial harmtothecompetitive positionofWestinghouse becauseitwouldenhancetheabilityofcompetitors toprovidesimilarservicesandlicensing defenseservicesforcommercial powerreactorswithoutcommensurate expenses.

Also,publicdisclosure oftheinformation wouldenableotherstousetheinformation tomeetNRCrequirements forlicensing documentation withoutpurchasing therighttousetheinformation.

Thedevelopment ofthetechnology described inpartbytheinformation istheresultofapplyingtheresultsofmanyyearsofexperience inanintensive Westinghouse effort,andtheexpenditure ofaconsiderable sumofmoney.Inorderforcompetitors ofWestinghouse toduplicate thisinformation, similartechnical programswouldhavetobeperformed andasignificant manpowereffort.havingtherequisite talentandexperience.

wouldhavetobeexpendedfordeveloping testingandanalytical n>ethodsandperforming tests.Furtherthedeponentsayethnot.

ATTACHMENT 1TOC0999-11DESCRIPTION OFTHEPROPOSEDMETHODOLOGY CHANGEA.SummaryofProposedChangesIndianaMichiganPowerCompany(IAM),thelicenseeforDonaldC.CookNuclearPlant(CNP),Units1and2,proposestoamendFacilityOperating LicensesDPR-58andDPR-74.I&Mproposestoallowcreditintheapplicable subcriticality analysisforthenegativereactivity providedbyinsertion oftherodclustercontrolassemblies (RCCAs)duringrealignment fromacoldlegrecirculation toahotlegrecirculation configuration.

Thisrealignment, whichisreferredtoashotlegswitchover (HLSO),isperformed following aloss-of-coolant accident(LOCA).Thismethodology changerequiresNRCstaffreviewandapprovalpertheprovisions of10CFR50.90.TheproposedchangeaffectstheBasesforTechnical Specification (T/S)3/4.5.5,"Refueling WaterStorageTank,"andseveralsectionsoftheUpdatedFinalSafetyAnalysisReport(UFSAR).Theproposedchangesaredescribed indetailinSectionEofthisattachment.

T/Spagesthataremarkedtoreflecttheproposedmethodology changeareprovidedinAttachments 2Aand2BforUnit1andUnit2,respectively.

TheproposedT/Spages,withthesechangesincorporated, areprovidedinAttachments 3Aand3BforUnit1andUnit2,respectively.

B.Description oftheCurrentRequirements InthecurrentLBLOCAanalysis, asstatedinUFSARSection14.3,"ReactorCoolantSystemPipeRupture(LossofCoolantAccident),"

anaveragereactorcoolantsystem(RCS)/sump mixedboronconcentration iscalculated toensurethecoreremainssubcritical duringlong-term coolingfollowing aLOCA.Theinsertion ofcontrolrodstoprovideanynegativereactivity tothereactorcoreisnotcreditedinthelargebreakloss-of-coolant accident(LBLOCA)analyses.

Theemergency corecoolingsystem(ECCS)hasbeendesignedtomitigatetheeffectsofpostulated LOCAsbyproviding asufficient amountofboratedwatertoprotectthefuelinthereactorcore.Unit1UFSARSection14.3.1andUnit2UFSARSection14.3.1.1.2, "Sequence ofEventsandSystemsOperations,"

states,inpart,thefollowing:

/"Criticality controlisachievedbydetermining theRWSTandaccumulator

/concentrations necessary tomaintainsubcriticality withoutcreditforRCCAinsertion.

Thenecessary RWSTandaccumulator concentrations areafunctionofeachcoredesign/andarecheckedeachcycle.ThecurrentTechnical Specifications valueis2400to2600ppmboron."TheUnit2UFSARcontainsanadditional clarification thattheT/Srangeof2400to2600ppmboronappliestotheRWSTandtheaccumulators.

Theaccumulators areconservatively modeledat2300ppmforthepost-LOCA subcriticality analysis.

Attachment 1toC0999-11Page2Similarly, T/S3/4.5.5Basescurrently states,"Consistent withtheapplicable LOCAanalyses, thelimitsonRWSTminimumvolumeandboronconcentration ensurethat1)whencombinedwithwaterfrommeltedice,theRCS,andtheaccumulators, sufficient waterisavailable withincontainment topermitrecirculation coolingflowtothecore,and2)thereactorwillremainsubcritical inthecoldcondition following aLOCAassumingmixingoftheRWST,RCS,ECCSwater,andsourcesofwaterthatmayeventually resideinthesump,withallcontrolrodsassumedtobeout."C.BasesfortheCurrentRequirements ThecurrentLOCAanalysesrequirements arebaseduponthecoreremaining subcritical after~shutdownfollowing theoccurrence ofsuchanaccident.

Thecycle-specific reloadsafetyevaluations confirmthatpost-LOCA subcriticality requirements aremet.Thecurrentpost-LOCAsubcriticality analysismethodology doesnotcreditthenegativereactivity thatwouldbeprovidedbythecontrolrodsfollowing acoldlegLBLOCA.D.NeedforRevisionoftheRequirements InJune1992,theNRCnotifiedtheWestinghouse OwnersGroup(WOG)ofitsconcernsgenerictopressurized waterreactorsregarding possiblecorere-criticality following aLBLOCA.Inresponsetotheseconcerns, Westinghouse ElectricCompany(WEC)reviewedportionsoftheaccidentwithrespecttotheboronconcentration intheinjectedECCSliquid.WECdetermined thatforcoldlegLBLOCAs,thebuildupofhighboronconcentration inthereactorcorecouldresultinsignificant borondilutioninthesump.Consequently, apotential re-criticality condition coulddevelopwhenswitchover oftheECCStohotlegrecirculation wasbeingperformed.

WhenaLBLOCAoccurs,abuildupofboroninthevesselcausesanassociated borondilutioninthesump.Atthetimeofswitchover tohotlegrecirculation, insufficiently boratedcontainment sumpwaterisintroduced tothetopofthecore.TheHLSOsubcriticality analysisconservatively assumesthatthedilutedboronsumpliquidcompletely displaces themorehighlyboratedliquidduringthetransition fromcoldlegrecirculation tohotlegrecirculation.

Therefore, ifthesumpliquidwerecalculated tobeatorbelowthecriticalboronconcentration, corere-criticality couldbepostulated.

Toaddressthisissue,theWOGcontracted WECtoperformanECCShotlegrecirculation elimination analysis.

Theobjective oftheanalysiswastoevaluateand,ifpossible, justifytheelimination ofECCShotlegrecirculation following aLOCA.Theresulting

analysis, whichwasdocumented inWCAP-14486, "ECCSHotLegRecirculation Elimination forWestinghouse 3and4LoopDesign[NuclearSteamSupplySystem]NSSS,"modeledRCSflowthroughthegapbetweenthecorebarrelandvesselatthehotlegnozzle.Thishotlegnozzlegapflowwasviewedasawaytooffsettheeffectsofboronconcentrating inthereactorvesselandtherebyeliminate theneedforrealignment tohotlegrecirculation.

Attachment 1toC0999-11Page3Inthefallof1997,CNPidentified containment sumpdesignissuesonUnits1and2thatadversely affectedtheHLSOcriticality calculation.

Asaresult,thesumpdilutioneffectassociated withthepartitioning offluidbetweentheactiveandinactivesumpvolumeswastobeoffsetbytakingcreditfortheboratedcoolantflowthroughhotlegnozzlegaps,asdocumented inWCAP-14486.

Thischangeinapproachwaspresented inaletterfromI&MtoNRC,AEP:NRC:1260G4, "Confirmatory ActionLetter(CAL)Supplemental Response,"

datedDecember24,1997.Duringthesummerandearlyfallof1998,WECconcluded thatconcernsraisedduringtheNRCreviewofWCAP-14486 madedefenseofthemethodology impractical.

WECrecommended thattheWCAPbewithdrawn.

Following WOGconcurrence, theWCAPwaswithdrawn inOctober1998.Inlate1998,aflerthewithdrawal ofWCAP-14486, WECassessedwhethersubcriticality atthetimeofswitchover tohotlegrecirculation forCNPcouldbeassuredwithouttakingcreditforthehotlegnozzlegaps.Atthattime,subcriticality couldbeensuredforUnit1(forthecurrentfuelcycle)bytakingcreditforexistingburnupofgreaterthan4000megawattdayspermetrictonneofinitialuraniummetal(MWD/MTU).

However,subcriticality atthetimeofHLSOcouldnotbedemonstrated forUnit2sinceithasafreshreactorcore.I&MmetwiththeNRConMay6,1999,tooutlineastrategyforcrediting theadditionofnegativereactivity throughcontrolrodinsertion afteracoldlegLBLOCA.Duringthemeeting,theWECanalysistechniques andpreliminary conclusions werepresented todemonstrate acceptability ofthecontrolrodinsertion approach.

Theresulting negativereactivity available topreventre-criticality atthetimeofHLSOwouldbeapproximately 400ppmormore(boronrodworth),depending uponplantdesign.Thestrategies outlinedduringtheMay6,1999,meetinghavebeenanalyzedandareaddressed inAttachments 6(WCAP-15245, "ControlRodInsertion Following aColdLegLBLOCA,D.C.Cook,Units1and2,"aproprietary version)and7(WCAP-15246, "ControlRodInsertion Following aColdLegLBLOCA,D.C.Cook,Units1and2,"anon-proprietary version)ofthisamendment request.Inaddition, severalquestions raisedattheMay6,1999,meetingthatwerenotansweredatthetimeareprovidedwithresponses inAttachment 8.E.Description oftheProposedChangesI&MproposestocreditRCCAnegativereactivity, discounting theworthofthemostreactiverod,following apostulated coldlegLBLOCAinthere-criticality analysisforI-ILSO.Theproposedmethodology changetocreditRCCAinsertion issupported bytheWestinghouse analysisprovidedasAttachments 6and7.TheBasesforUnit1andUnit2T/S3/4.5.5wouldberevisedtoallowcreditforRCCAinsertion aspartofthebasisforconcluding thatthereactorwillremainsubcritical inthecoldcondition following acoldlegLBLOCAwhenHLSOisperformed.

Similarly, thepertinent sectionsoftheUFSARwouldberevisedtoreflectthecreditofRCCAsforcriticality controlfollowing acoldlegLBLOCAatthetimeofHLSO.

Attachment 1toC0999-11F.BasesfortheProposedChangesPage4Theproposedchangemodifiesthemethodology usedinthepost-LOCA subcriticality analysisduringtherealignment fromcoldlegrecirculation tohotlegrecirculation.

Theprovisions of10CFR50,AppendixK,allowcontrolrodstobecreditediftheirinsertion iscalculated tooccur.Analysesdemonstrating thattheCNPcontrolrodscanbeinsertedfollowing acoldlegLBLOCAhavebeenpreparedandareprovidedinAttachments 6and7.Theseanalysesaddressreactorvesselcomponent structural distortion inaLOCAenvironment coincident withaseismicevent.Plant-specificseismicresponsespectraandplant-specific designparameters fortheCNPwereused.BasedonAttachments 6and7,I&Mhasreachedthefollowing keyconclusions:

1.ForbothUnits1and2,theRCCAupperinternals guidetubecalculated loadsarewithinallowable limits,asestablished bytestsperformed byWEC,suchthatcontrolrodinsertion willnotbeprecluded foreitherthelimitingleak-before-break (LBB)criteriabreaklocations orthedesignbasiscoldlegbreaks.2.Baseduponcalculated loadsandmeasuredgridloadallowables, fuelassemblygriddistortion willnotinhibitcontrolrodinsertion foreitherLBBcriteriabreaklocations orthedesignbasiscoldlegbreaks.Basedontheaboveconclusions itisacceptable tocreditthenegativereactivity associated withtheinsertion ofthecontrolrodsinthepost-LOCA HLSOsubcriticality analysisforlargecoldlegbreaks.'fhecycle-specific reloadsafetyevaluations documenttheconfirmation ofpost-LOCA subcriticality incompliance withthelong-term coolingrequirements of10CFR50.46.G.Probabilistic RiskAssessment oftheProposedChangeTheHLSOevolution isnotspecifically modeledinthecurrentCNPprobabilistic riskassessment (PRA).However,itisestimated belowthattheprobability ofacoldlegRCSbreaklargeenoughtoresultinsumpdilutionplusafailureoftheRCCAstoinsertisconsiderably lessthan1.0x10-6peryear.Thisresultisbasedoncombining theprobability ofthespectrumoflargeRCSbreaks,fromthelargestdouble-ended coldlegguillotine rupturedowntoasix-inchequivalent diameterholeintheRCS(5.0x10-6peryearfromNUREG/CR-5499),

withengineering judgement thatthefailureofmultipleRCAAstoinsertwouldbeconsiderably lessthat1.0x10-1peryear.Thisissupported bytheWECanalysiscontained inWCAP-15245 (Attachment 6)andWCAP-15246 (Attachment 7)thatshowthatcommonmodefailureoftheRCAAstoinsertduetocoldlegLBLOCAandseismicforcesisnotcredible.

Attachment 1toC0999-11Page5H.ImpactonPreviousSubmittals Noprevioussubmittals areaffectedbytheproposedchange.ImpactonEmergency Operating Procedures TheCNPEmergency Operating Procedures (EOPs)relatedtoLOCAresponsedirecttheoperators toperformtheswitchover tohotlegrecirculation.

ThemaximumHLSOtimeisdetermined based'ononeoftwoissues.Oneistheneedtopreventexceeding aboronconcentration limitof23.5weight-percent inthecoretoprecludeboronprecipitation, andtheotheristheneedtoensurenoreturntocriticality asdilutedsumpliquiddisplaces thecoolantinthereactorvessel.ThecurrentCNPEOPs,aswellastheCNPUFSAR(Sections 6.2.2and14.3.1foreachunit),establish themaximumtimeallowedtotransition toHLSOasbasedonboronprecipitation concernsinthevesselbeingmorelimitingthanre-criticality concerns.

RecentHLSOsubcriticality

analyses, whichdonotcreditRCCAinsertion, demonstrate thatthetimetoperformthehotlegrecirculation alignment must.occurmuchsoonertoprecludere-criticality.

CreditforRCCAinsertion, asrequested inthissubmittal, wouldremovethere-criticality concernfrombeingthebasisforthemaximumHLSOtime.Thus,theallowedmaximumtimethatHLSOmustbeperformed willreturntobeingbasedontheprecipitation limitsandwillprovidealargeroperatortimeresponsewindowtoperformrealignment tohotlegrecirculation.

Retrieved from "https://kanterella.com/w/index.php?title=ML17326A145&oldid=738031"