ML17309A190

Use of Lake Ontario Water in Steam Generators During Hot Shutdown.

ML17309A190
Person / Time
Site:	Ginna
Issue date:	02/28/1981
From:	COPLEY S E, LEIBOVITZ J, PEARL W L NWT CORP.
To:
Shared Package
ML17309A169	List: ML17309A168 ML17309A190
References
NWT-167, NUDOCS 8106300308
Download: ML17309A190 (150)

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I1iliceÃuelzvROCHESTER GAS"h.704KANDELECTRICCORPORATION o89EASTAVENUE,ROCHESTER, N.Y.14649JOHNE.MAIERVICEPRESIDENT June23,1981TEt.EPHONE ARE*COOE7IOi54g27000I<ll~,j=6'>'/4IDirectorofNuclearReactorRegulation Attention:

Mr.DennisM.Crutchfield, ChiefOperating ReactorsBranch55U.S.NuclearRegulatory Commission Washington, D.C.20555

Subject:

SEPTopicsV-10.B,V-11.A,V-11.B,VI-7.C.1, VII-3,andVIII-2,R.E.GinnaNuclearPowerPlantDocketNo.50-244

References:

(1)LetterfromDennisM.Crutchfield, NRC,toJohnE.Maier,RGE,SEPTopics,V-10.B,V-ll.B,andVII-3(SafeShutdownSystemsReport),May13,1981.(2)LetterfromDennisM.Crutchfield, NRC,toJohnE.Maier,RGE,SEPTopicsV-11.A,V-11.B,andVI-7.C.1, datedApril24,1981.(3)LetterfromDennisM.Crutchfield, NRC,toJohnE.Maier,RGE,SEPTopicsVII-3andVIII-2,datedApril2,1981.

DearMr.Crutchfield:

ThisletterisinresponsetotheSEPtopicassessments providedinthethreeabove-referenced letters.Duetotheintimaterelationship ofthe"SafeShutdown" topicsV-10.B,V-ll.A,V-11.BandVII-3addressed inthesethreeletters,allofourcommentsareprovidedconcurrently inthethreeattachedresponses.

Thisshouldaidtheinclusion ofourcommentsintotheNRC's"SEPIntegrated Assessment".

Attachments Verytrulyyours,ohnE.Maier+~aili Attachment 1:RGKEresponses toNRCAssessment ofSEPTopicsV-10.B,RHRSystemReliability, V-ll.B,RHRInterlock Requirements, andVII-3,SystemsRequiredforSafeShutdown(SafeShutdownSystemsreport),May13,1981.InRG6E'sJanuary13,1981responsetotheNRC'sNovember14,1980"SafeShutdownSystems"assessment, anumberofcommentsweremadewhichhavenotbeenincorporated intoRevision2ofthisassessment, transmitted byletterdatedMay13,1981.Wefeelthesecommentswerevalid,andshouldbeincorporated.

Forcontinuity, thesecommentswillbelistedbelow(withtheiroriginalcommentnumbers):

Onpage5,PiinSstemPassiveFailures, theNRCassumespipingsystempassivefailures"...beyond thosenormallypostulated bythestaff,e.g.,thecatastrophic failureofmoderateenergysystems...".

Althoughitisshownthatsafeshutdownfollowing suchaneventcouldbeachieved, itisnotconsidered thatsuchanevaluation shouldevenbemade.Asnotedbythestaff,itisclearlybeyondareasonable designbasis.Itisthusrecommended thatthisparagraph bedeletedfromtheevaluation.

Subsequent evaluations tothis"criterion",

suchasthoserelatedtotheCCWsystemonpage22and23,shouldalsobedeleted.Inparagraph gonpage66,itisnotedthat,whenapplyingthepowerdiversity requirements ofBTPASB10-1ineventofanSSE,nomeanstosupplyfeedtothesteamgenerators exists.Itwasdetermined thatthiswasacceptable, basedonlowlikelihood ofoccurrence.

Thisconclusion iscorrect;however,sinceBPTASB10-1doesnotconsideranSSEinconjunction withthelossofallA.C.power,thereisnoneedtoevenmaketheevaluation.

Thecomparisons intheSEPprogramshouldbetocurrentcriteria, ratherthantoarguableextrapo-lations.Reference tolossofallA.C.powerinconjuncton withanSSEshouldthusbedeletedfromthisparagraph.

12.OnpageA-4,itisnotedthatadditional systemsarerequiredtoachievecoldshutdownforaPWRthanforaBWRbecauseofadifference inthedefinition ofcoldshutdown.

Thisdoesnotappeartobeareasonable basis.Systemrequirements shouldbebasedonspecificsafetyreasons.TheNRCshouldbeconsistent initsrequirements forcoldshutdown, orprovideatechnical basisforanydifferences."

~f7 Staffposition1statesthat"thelicenseemustdevelopplantoperating/emergency procedures forconducting aplantshutdownandcooldownusingonlythesystemsandequipment identified inSection3.1oftheSEPSafeShutdownSystemsReport."RGsEdisagrees withtheneedfortheseprocedures.

Wereiterate thecommentsprovidedinourJanuary13,1981responsethattheoperatorshouldperformacooldownwiththebestequipment available tohimatthetime.Ifapieceofnon-safety equipment isavailable, andwouldbethemostbeneficial forperforming arequiredfunction, itisexpectedthatthispieceofequipment wouldbeused.Ifitisnotavailable, theoperatorcouldfallbackontheuseofsafety-grade equipment.

ButRGGEdoesnotintendtocommitplantpersonnel touseonlysafety-related equipment, ifnon-safety equipment isavailable andmoreeffective.

Wefeelthatitwouldbeimpossible todetermine whena"safety-grade-only" cooldownprocedure wouldeverbeimplemented.

Aslongasthesafety-grade equipment isavailable (andthesafeshutdownassessment concudesthatitis),RGSEconsiders thatthenecessary safetyrequirements aremet.RGSEalsonotesthatnoregulatory basisforthisrequirement isprovided.

ItisadmittedinSection4.5oftheSafeShutdownreportthat"theneedforprocedures fortheseevaluations isnot,identified inRegulatory Guide1.33...".

Section4.5thengoesontosaythatthebasisisfoundinBTPRSB5-1andSEPTopicVII-3.ButBTPRSB5-1merelyreferences RG1.33,andthisistheassessment ofSEPTopicVII-3.Therefore, sincenobasisforthis"requirement" exists,andwedonotfeelthatitwouldevenbebeneficial, andsincetheSafeShutdownreportdidconcludethatthecapability forattaining coldshutdownusingonlysafety-related equipment exists,RG&Econcludes thatthisstaffpositionshouldbedeletedfromconsideration.

Staffposition3doesnotappeartotakeintoaccounttheinformation providedinourMarch27,1981submittal regarding SEPTopicV-11.A.Enclosure 3tothatsubmittal providesthevalveequipment specification, notingthatthe700,701,720and721MOV'saredesignedsuchthattheyphysically areunabletoopenagainstadifferential pressureofgreaterthan500psi.Thisensuresthatanintersystem LOCAcausedbytheopeningoftheoutboardvalves,plusleakageoftheinboardvalves,cannotoccur,sincetheoutboardvalvescannotopen.

Evenwithoutthisprovision, itisdifficult tocomprehend howtheGinnaarrangement couldresultinan"EventV".Byadministrative procedure, theRHRvalvesarekey-locked closed,withpowerremoved.Further,interlocks areprovidedfortheinboardRHRvalves.Thus,foran"EventV"tooccurwouldrequirethe:1)failureoftheadministrative procedure requiring powerlock-out(atthebreaker),

2)failureoftheadministrative procedure governing operation ofthevalveatpower,3)failureoftheinboardisolation valve,4)failureofthereliefvalve(RV203)whichhasacapacityof70,000lb/hratits600psigsetpoint, torelievetheleakagepasttheinboardRHRvalve.Thissetoffailuresisconsidered veryremote.WhencoupledwiththefactthattheRHRvalvedesignpreventsopeningofthevalvesagainstagreaterthan500psidifferential

pressure, itisRGEE'sconclusion thatthepossibility ofanintersystem LOCAshouldnotbeacredibledesignbasis.Noadditional modifications, suchasdiverseinterlocks fortheoutboardvalves,arewarranted.

Staffposition5statesthat"theoperating procedures fortheGinnaplantshouldbemodifiedtodirecttheoperatortocooldownanddepressurize toRHRinitiation

.parameters within36hourswhenevertheServiceWaterSystemisusedforsteamgenerator feedwater..."

Thispositionisbasedonthereference BNL-NUREG-28147, "ImpureWaterinSteamGenerators andIsolation Condensers."

WehavehadthisreportreviewedbyNWTCorporation.

NWT-167,"UseofLakeOntarioWaterinSteamGenerator DuringHotShutdown" (attached) concludes that,"although notrecommended fromthestandpoint ofmaximizing component life,andoperation forperiodsuptoseveraldaysisnotexpectedtoresultinanysignificant crackingorindeterioration ofsteamgenerator integrity."

RG&Etherefore concludes thataspecificdirective tocooldownanddepressurize toRHRinitiation conditions isnotwarranted, andshouldnotbeincludedinaprocedure.

Thecapability todothisdoesexist,however,andcouldbeusedifdetermined tobenecessary atthetime.

l\J"v1v~Jl Attachment 2:RG&Eresponses toNRCletterofApril24,1981regarding SEPTopicsV-11.A,"Isolation ofHighandLowPressureSystems",

V-11.B,"RHRInterlock Requirements",

andVI-7.C.1, "Independence ofRedundant OnsitePowerSystems".

1.TheSafetyEvaluation forSEPTopicV-11.A,"Requirements forIsolation ofHighandLowPressureSystems",

specifies thattheoutboardRHRvalvesshouldhavediverseinterlocks topreventopening.whentheRCSpressureisgreaterthanRHRsystemdesignpressure.

RGGErationale fornotproviding theseadditional interlocks isprovidedincomment3ofAttachment 1ofthistransmittal.

2.Thesafetyevaluation alsorequiredthatinterlocks beinstalled ontheCVCSsuctionvalves(200A,200B,202),topreventapossibleoverpressurization oftheCVCSletdownlineoutsidecontainment.

RGEEhasnotedinourMarch27,1981letteronthisSEPTopicthatareliefvalve(RV203),withacapacitygreaterthanthecombinedcapacityofthethreeorifices, wouldrelievethepressurebuildupcausedbyclosureofthecontain'ment isolation valve'71.

Nooverpressurization oftheCVCSwouldthusbeexpected.

RGGEhasalsoevaluated thepotential consequences ofsuchanoverpressurization event,withasubsequent smallLOCAoutsidecontainment, anddetermined thatnounacceptable consequences wouldresult.ThisbreakwouldbeasmallLOCAoutsidecontainment (maximumflowof140gpm),andwouldbeterminated byclosureofvalves200A,200B,and202eitherbyoperatoractionorautomatically bylowpressurizer level.Radiological consequences wouldbeminimal,sincenofueldamagewouldresult.Thiseventisspecifically evalu-atedbySEPTopicXV-16,"Radiological Consequences ofFailureofSmallLinesCarryingPrimaryCoolantOutsideContainment."

RG&Ehasprovidedinformation concerning thistopicbyletterdatedJune18,1980fromL.D.WhiteJr.toMr.DennisM.Crutchfield.

TheRG&Econclusion isthat,basedontheavailability ofRV203topreventoverpressurization, togetherwiththelackofunacceptable consequences duetoanoverpressurization, nointerlocks orothermodifications arerequiredfortheCVCSsuctionvalves.3.Thesafetyevaluation furtherstatesthatpositionindication isrequiredontheCVCSdischarge checkvalves.AsstatedinourMarch27,1981letteronSEPTopicV-11.A,wedonotbelievethatthislineshouldbeclassified asalowpressure I

systemconnected totheRCS,sincethepipingis2500-1bpipingthroughout itslength(tothepositivedisplacement chargingpump).RG&Ehashadnoexperience with'ailures ofthepositivedisplacement chargingpumppistonstoholdprimarysystempressure, norwouldanyfailuresbeanticipated.

Ourcontention thatthecharginglineisnotalineofconcernisborneoutbyamemofromEdsonG.CasetoRaymondF.Fraley,"Isolation ofLowPressureSystemsfromReactorCoolantSystem",datedJuly11,1977.Thatlettertransmitted anNRCstudyofthissubjecttotheACRS,andevaluated allpotential linesofconcern.Thecharginglinewasnotincluded.

Toverifythatthecharginglinewasnotavalid"EventV"concern,RG&Ecalculated thePWRCheckValveEventTree(Section4.4ofNASH-1400),

usingthecharginglinecon-figuration (twoin-series checkvalvesandachargingpumppiston).Veryconservatively assumingthatbothcheckvalveswereundetected open,andthattheprobability ofthechargingpump~iston failurewasequaltoacheckvalvefailure,theQUMcalculated forthisconfiguration wasdetermined toSe1.4x10/year.Thisisalowenoughvaluetoobviously beofnoconcern.RG&Etherefore considers thatcheckvalvepositionindi-cationisnotneededonthechargingline checkvalves.WithrespecttotheSEPTopicAssessment V-11.B,nocommentsarenecessary, sincetheresolution ofoutstanding issuesisaddressed inthetopicassessment forSEPTopicV-11.A.Theadditional information requested forSEPTopicVI-7.C.1ispresently beingdeveloped.

Itisanticipated thatthisinformation canbefurnished totheNRCbyJuly15,1981.

lLJ Attachment 3:RGEEresponses toNRCletterofApril2,1981,concerning SEPTopicsVII-',"Electrical, Instru-mentation, andControlFeatureofSystemsRequiredforSafeShutdown",

andVIII-2,"DieselGenerators".

ItappearsthatallcommentsprovidedbyRG&EinourJanuary23,1981andJanuary30,1981lettersconcerning thesetopicshavebeenproperlyincorporated.

Basedontheresolution ofallopenitems,andtheremovalofdieselgenerator testingfromSEPTopicVIII-2,RGEEconcludes thatbothofthesetopicsarecomplete, withnooutstanding issuestobecarriedintotheIntegrated Assessment.

0IHitLNIPI NWT167February1981USEOFLAKEONTARIOWATERINSTEAMGENERATORS DURINGHOTSHUTDOWNW.L.PearlS.E.CopleyJ.Leibovitz PreparedforRochester Gas&ElectricCompanyCorporation 7015REALMDRIVE,SANJOSE,CALIFORNIA 95119 0'I ThisdocumentwaspreparedfortheRochester Gas&ElectricCompany.NeithertheNWTCorporation noranypersonactingonitsbehalfassumesanyresponsibility forliability ordamagewhichmayresultfromtheuseofanyinformation disclosed inthisdocument.

I1h'!'~,1zf'))

INTRODUCTION Thepossibility ofusingLakeOntariowaterasanemergency PWRfeedwater supplyformorethan36hoursduringwhichtheplantwouldbebroughttocoldshutdownisbeingconsidered.

Themaximumsteamingrateduringsuchaperiodwouldbe100,000pounds/h(200gpm)atatemperature of350'F.Asa'consequence ofsteaming, impurities oftheuntreated LakeOntariowaterwillconcentrate inthesteamgenerator.

Ofmajorconcernisthepossibleriskofstresscorrosion cracking(SCC)ofsteamgenerator materials incontactwiththeconcentrated solutionthusformed.Toaddressthisconcern,thechemistry variation intheliquidphaseassteamingproceedsat350'Fwasestimated withemphasisonpH.Then,thepossiblepotential forSCCwasassessedonthebasisoftheseestimates andavailable SCCdata.

pHVARIATION AT350'F'UPONSTEAMINGLAKEONTARIOWATERA.ComputerModelingThecomposition ofLakeOntariowaterasdetermined byRGEisgiveninTablel.TABLE1LAKEONTARIOWATERANALYSISppmCalciumMagnesium SodiumPotassium AluminumChlorideSulfate"358133.60.13235NitratePhosphate FluorideSilica(asSi02)Dissolved OxygenAmmonia(asNitrogen) 2.50.30.150.259.50.24Estimates ofthewaterchemistry variation uponsteamingweredeveloped usingthefollowing assumptions:

1.Sincealuminumandsilicaareins'toichiometric proportion inLakeOntariowater(Table1),theyareassumedtoprecipitate asaluminumsilicate(clay)uponconcentrating

'andtherefore areremovedfromsolution.

2.Sincecalciumoccursinthewater(Table1)inlargeexcessoverphosphate, itisassumedtoprecipitate allthephosphate ascalciumhydroxyapatite(Ca5(P04)30H) andremoveitfromthesolution.

Thecalciuminsolutionisdecreased bythecorresponding amount.3.Fluorideandnitriteareassumedtobehaveaschloride.

Potassium isassumedtobehaveassodium.4~Sodiumandchlorideinsolutionareassumedtoremaincompletely dissociated.

5.Calciumcarbonate precipitation isneglected.

Degasification ofCO~bysteamingisassumedtooccur.

r~l~

6.Theconcentration ofsodiumandcalciumchlorides isassumedlimitedbyasolubility of5molal.7.Chemicalequilibrium expressions ofreferences 2and3apply.Onthisbasis,theliquidsolutionpHvariation uponsteamingat350'Fwasestimated asafunctionofconcentration factordefinedasthemassratiooftotalwater(steam+liquid)toliquidwaterresidual.

Theresultsarepresented graphically inFigure1.Itisimportant tonotethatthedefinition ofpHusedhereisthatfollowedbyMesmer4inthedetermination ofthedissociation constantofwaterathightemperatures, viz,thenegativeofthelogarithm ofthehydrogenionconcentration (notofitsactivity).

Similarly, neutralpHisdefinedasthatwherethehydrogenandhydroxylionconcentrations aree'qual.ThisneutralpHisafunctionofionicstrength.

Therefore, thepHvariation oftheconcentrated solutions mustbeconsidered inrelationtothatofneutralpH,alsoplottedinFigure1.Forbasicsolutions asisthecaseconsidered here,itisimportant tobearinmindthatthehydroxylionconcentration isexpressed intermsofpHas'follows:

10pH-2NpH OH(whereNpHistheneutralpHv'alue)andthatwhentheneutralpHvariestogetherwiththeionicstrengthastheliquidsolutionisbeingconcentrated uponsteaming, thebasicityofthesolutionmaynotbeappreciated fromthesolutionpHalone.Theequivalent NaOHconcentration ismoresuitableforthispurposeandisplottedalsoinFigure1.B.Discussion SteamGenerator BulkWaterBasedon-'amaximumfeedrateof200gpmtothesteamgenerator andatotalsteamgenerator liquidvolumeofapproximately 12,000gallons,amaximumofonesteamgenerator volumeissteamedawayeachhour.Therefore, undermaximumsteamingconditions, theconcentration factorachievedinthebulksteamgenerator waterist+1wheretisthenumberofhoursofsteaming.

10SolutionpHEquivalent NaOHConcentration NeutralpH.400O300o2008lot101001000100000Time,hFigurel.Variation ofSteamGenerator pHwithSteamingat350'F(feedingLakeOntariowaterat200gpm) l-!tI, Thevariation withtimeoftheequivalent sodiumhydroxide concentration inthesteamgenerator withsteamingofemergency LakeOntariofeedwater thencanbefollowedonFigurel.Itisseenthatamaximumequivalent NaOHconcentration

'fabout300ppmwillbereachedinthesteamgenerator bulkwaterwhen15to20steamgenerator volumeswillhavebeenconverted to,steam,i.e.,inapproximately twentyhours.Furtherboilingshouldthendecreasetheequivalent NaOHconcen-trationasmagnesium and/orcalciumhydroxides and/orcalciumsulfateprecipitate withincreased concentrating.

Thedecreasereachesalimit(atabout20,000steamgenerator volumesconverted tosteam,i.e.,in20,000hours)whensodiumandcalciumchlorides starttoprecipitate also.Thislimitisestimated atabout100ppmequivalent NaOHforLakeOntariowatercomposition asspecified inTable1andwiththeassumptions alreadystated.Theassumptions seemreasonable and,atanyrate,canbetestedexperimentally withasmallautoclave fromwhichknownamountsofLakeOntariowaterwouldbeboiledawayat350'Fatconstantliquidlevelintheautoclave.

CrevicesTheestimated equivalent NaOHsolutionconcentration insteamgenerator creviceswilldependupontherelativedegreeofcrevicesolutionconcentration abovethebulkwater.Intubetotubesupportplatecrevices, theremaybeadistribution ofrelativeconcentration factorsofunityandhigher.Thechemistry inacrevicewouldleadthatofthebulkinthesensethatthechemistry ofaspecificcrevicewouldtravelthesamecurve(Figure1)asthebulkbutwouldbeatapointonthecurvesomewhataheadofthebulk.Sincethecausticity ofLakeOntariowaterisnotastrongfunctionofconcentration, thisdoesnotposeaproblem.'ndeed itisexpectedinthiscasethatafterashortperiodofsteaming, thecrevicechemistry willbelessbasicthanthatofthebulk.CoolinWaterComositionTheNWTchemistry modelingworkdiscussed hereinisbasedonthechemicalcomposition ofLakeOntariowatersummarized inTable1assuppliedbyRGE.

~~'

Itispossiblethatseasonalchangesin-thecharacteristics'f thelakewatermay,result fromtheinterrelation betweensourceriverflowrates, industrial pollution and/oracidrain.NWThasnorelevantdatatoassesssucheffects.Itmaybedesirable thatanalysesmadeofLakeOntariowaterduringdifferent seasonsandundervariousconditions befedintotheNWTchemistry model.InthismannerthesafetyoffeedingLakeOntariowater,overtherangeoflikelychemicalcompositions, canbeverified.

POTENTIAL FORSCCA.Corrosion Themostaggressive solutionexpectedbasedonthemodelingworkis300ppmNaOH,withsl0ppm02(seebelow)at350'F.Althoughlaboratory dataregarding theseexactconditions arenotavailable, dataareavailable whichcanbeextrapolated toassessthemaximumcorrosion ratesexpectedforagivenrangeofconditions.

vanRooyenandKendig'ite Westinghouse dataindicating thatU-bendsofAlloy600indeaerated lOXNaOHcrackafterseveralmonthsofexposure.

Figures2and3summarize Westinghouse tests'hich showthatatleast100daysofexposuretodeaerated 10%NaOHat600'Fisrequiredtoproduceadetectable crackinstressedAlloy600.Figure4showsdatagatheredbyBergeandDonati.~ThesecurvesareforyieldstressedCringsat660'F.Extrapolating thecurveformillannealedAlloy600to300ppmNaOHyieldsaminimumtimeof3500-4000 hourstoinducea0.5millimeter crack.Thedatapresented abovearefordeaerated systemsandareconsistent withvanRooyen'sconclusion thatAlloy600in105NaOHwouldnotcrackforseveralmonths.Inthepresenceofoxygen,thesusceptibility ofAlloy600toSCCmaybeincreased.

Figure5showsstresscorrosion behaviorin600'Fhighpuritywatercontaining varyingamountsofoxygeninthegasphaseabovethewaterandadjustedtopH10atstartupwithammonia.Astheoxygencontentofthegasphaseincreased, thepercentofthespecimens attackedandextentoftheattackincreased.

AsnotedinFigure5theaveragelifeinthe18-weektestvariedfromnocrackingwith1Xoxygeninthegasphase

(<2ppmoxygeninthewater)to7weekswith100Ãoxygeninthegasphase(<200ppmoxygeninthewater).<<IlreeandHichelsandlaterSedriks,etal.,"reportedlessthan20Kcrackingafter27daysforAlloy600(2commonheattreatments) inaerated,50/.NaOHat570'F.

~~(~Cresswatsg.C00eaStressIsss(s/es0 ZT5/al50//50tla/IOV0/V.4NtttAhneetdThere((alt/

Treats(s~ettass4stt~tstaNXIt(e(ees(re Tle(~IhestFigure2.CrackDepthasaFunctionofTime,StressLevelandMaterialCondition forIDPressurized CapsulesExposedtoDeaerated 10$NaOHat600'F,O.e0.3ss5040.3~J0.2Heat5CM.A.T.T.ROT.0118901.OV~SSM.03t~T3Q.04$105HaOH310'CCwlrs051-U05yte505MIHAntsealtd

.0768'01ea0.1e~~~I&t000Dlssstsre Tits(e1hrslTherthally TreatedFigure3.CrackDepthasaFunctionofExposureTimeforMillAnnealedandThermally TreatedInconelAlloy600ExposedtoDeaerated 10KNaOHat600'F'

,4000CRingsStressedtoa=YsAccording toASTMSTP425~o3000SS0Va)IE~rlAo2000Er0)IIK01000Alloy600HT16h1300FAl1oy600MA01,000,10,000'00,000NaOHConcentration, ppmFigure4.Resistance toStressCorrosion CrackingofAlloy600Mill-Annealed-orHeatTreatedat1300FasaFunctionofDeaerated SodiumHydroxide Concentration at600'F' l

~~t2l2l2XWWI20CIo~IOOOZo80~CPI:60W~cL>40.OÃQWW~~2Oill2NO.OFSPECIMENS, MILLANN.8PERCENTCRACKED0AVUFEIN18WEEKTESTS>8AV,OFMAX.CRACKDEPTHS,MIL 0tIOO7525892l5500ie00I80l72I888812161818I12181818I818181818181818181818 IR18478256ALLOY600HEATN278542478256478256478256100OXYGENINGASATSTART,(%).NILNIL2IBALANCEOFGAS,HYDROGENARGON'ITROGEN NITROGENAIR10Figure5.StressCorrosion BehaviorinCreviceAreasinHillAnnealedInconel600DoubleU-bendSpecimens in600'FHighPurityWaterAdjustedtopH10withAmmoniaatStartup' e1 Laboratory studiesshowthatthereisasignificant temperature dependence ofcausticstresscorrosion crackingasillustrated inFigures6and7.Theseresultsare.forpressurized capsulesexposedto10Kand50%NaOHatvaryingstressesattemperatures rangingfrom650to550'F.Ascanbeseen,reducingthetemperature below,600'F

.significantly extendsthetimeforSCCtooccur.Thistemperature dependence isfurtherillustrated inFigure8wheretemperature isplottedversusrateconstantforboth105and505NaOH.8.OxygenThelakewaterfedtothegenerators probablywouldbeairsaturated (approximately 10ppm02).However,at350'FtheKp(theequilibrium ratiobetweensteamphaseandliquidphase)foroxygenisslightlygreaterthan5000.Eventhoughthedynamicdistribution inpracticemaynotreachtrueequilibrium conditions, theneteffectofthehighKDvalueisthatrecriculated steamgenerator coolantwillcontainoxygenconcentrations lowerthan10ppm.Thisrecirculated coolantwilldilutetheoxygenconcentration ofincomingfeedwater withanetoxygenlevelinthedowncomer of~1to10ppm,depending ontherecirculation ratiounderthecontingency conditions.

C.Conclusion Withthesignificantly lowerconcentrations ofsodiumhydroxide (max300ppm),oxygenconcentration

<10ppmandthelowertemperature (350'F)involved, thecontingency offeedingLakeOntariowatertotheGinnasteamgenerators shouIdresultinnomeasureable damagetosteamgenerator internals.

A'jthough notrecommended fromthestandpoint ofmaximizing component life,suchoperatio~

forperiodsuptoseveraldaysisnotexpectedtoresu1tinanysignificant crackingorinadeterioration ofsteamgenerator integrity.

~~

NaOH50%10%575FII0.5to5mils5030A0)NQlL)flJ>10mils5to10mils100.5to5mils001000200030004000500060007000ExposureTime,hrsFigure6.CausticCrackingofMillAnnealedAlloy600at575'F(Linesdepictzonesofcrackdepthfrom105NaOHat600'F)12 NaOH50%10%550F70<0.5milsCl05to5milsg0.5to5mils50%NaOH650'F5040~~30A~I072010mils5to10mils100.5to5mils00100020003000400050006000ExposureTime,hrsFigure7.CausticCrackingofMi11AnnealedA11oy600at5and650'F)Linesdepictzonesofcrackdepth<<omNaOHat600'F)13 g's"a'll 200MAI-600150IVIJlQCa%40f5IO4JNc5D100500530550570590610630Temperature, FFigUre8.Indicated Variation inRateofSCCwithTemperat14

'a."S~~PP<~p~~"':~

".COMMENTSONVANROOyENANPKE!i01GSREPORT'he referenced repo'resbasica)]y i5abroadsummarycoveringalargevolumeofdataapplicable inparttostainless steelsandinparttoAlloy600.We~'gg"4"~aregenerally inagreement withheirninesummaryconclusions, butfindit"~is@'"8,>>'ifficult toapply'their broad-brush treatment tothespecifics ofaPWRhot~4'~gp-,'--shutdownwithlake'water'dded tothesteamgenerators 5t350'F.Theirdocumentismisleading fors'uchanapplication intworespects:

'wC>"..;~0',$4tfkkcf1.CausticConcentration Theirstatement that..."ForthenurposesofSCCpredictions, ithastobeassumedthatthetimetoformdangerous levelsofNaOH,onceimpurities havebeenintroduced, isshort,i.e.,onedayorless"doesnotfully,(,--s:irecognize thespecificconcentration chemistry ofthecoolingwaterinvolvednorthelowheatfluxavailable andthecutbackinsteamingrate\'uringaperiodofhotshutdown.

!nthecaseoftheLakeOntariowater,forexample,themaximumNaOHconcentration reachedis300ppm(aftersteaming~20steamgenerator vo>umes)withadecreaseinconcentration thereafter.

I,raS',~tl2.Temperature Allofthetestworkreferenced inthereferenced reportswasperformed inthetemperature rangeof550to630'F.Withthesignificant temperature dependence ofcausticSCCasshownabove,theconcernat350Fismanytireslessthanisindicated fromthedataquotedbytheauthors.'ased ontheabovethreeconsiderations.

itisourassessment thatthegeneralized timelimitof36ho~rsin:hereport~isnotdirectlyapplicable totheGinnasteamgenerators steam'ng"350'FwhilefedbyLakeOntariowater.15

~1~V1~v

.REFERENCES 1.Harhay,A.,.1981.2.3.Rochester Gas8Electric, PersonalCommunication, Februaryll,rLeibovitz, J.,andSawochka, S.G.,"Modeling theEffectsofCondenser Inleakage onPWRChemistry",

presented at41stAnnualInternational WaterConference, Pittsburgh, Pennsylvania, October1980.Leibovi;tz, J.andSawochka, S.G.,"Modeling ofCoolingWaterInleakage EffectsinPWRSteamGenerators, TopicalReport,ResearchProject404-1",ElectricPowerResearchInstitute, May1980,tobepublished.

4.Mesmer,R.E.,Baes,C.F.,Jr.,andSweeton,F.M.,"BoricAcidEquilibria andpHinPWRCoolants",

Proceedings

'ofthe32ndInternational WaterCon-ference,Pittsburgh, P'ennsylvania, November1971,pp.55-65.vanRooyen,D.,andKendig,M.W.,"ImpureWaterinSteamGenerators andIsolation Generators",

Brookhaven NationalLaboratory, June1980(Draft-BNL-NUREG-2814?).

6.Airey,G.P.,"EffectofProcessing Variables ontheCausticStressCorrosion Resistance ofInconelAlloy600",presented atNACEMeetingiMarch1979(PaperNumber101).7.8.Berge,Ph.andDonati,J.R.,"Materials Requirements forSteamGenerator Tubing",presented atInternational Conference onMaterials Performance inNuclearSteamGenerators, St.Petersburg, Florida,October1980.Copson,H.R.andEconomy,G.,"EffectofSomeEnvironmental Conditions onStressCorrosion BehaviorofNi-Cr-FeAlloysinPressurized Wate~".Corrosion, 24,No.3,pp.55-65(March1968).9.McIlree,A.R.andMichels,H.T.,"StressCorrosion BehaviorofFe-<<->>andOtherAlloysinHighTemperature CausticSolutions",

Corrosion.

33.No.2,pp.60-67(February 1977).10.Sedriks,A.J.,etal.,"InconelAlloy690-ANewCorrosion Resistant Material",

-Corrosion Engineering (Japan),28,No.2,pp.82-95(1979).Burstein, S.,WEPCO,ltrtoH.R.Denton,NRC,dtdNovember23withattachments.

16

'0st<Vj~f,'JI,r4 HWT167February1981USEOFLAKEONTARIOWATERIHSTEANGENERATORS OURIHGHOTSHUTDOWNW.L.PearlS.E.CopleyJ.Leibovitz PreparedFor'ochester Gas&ElectricCompanyCo%oration 7015REALMORIVE,SANJOSE,CALIFORNIA 95119 ThisdocumentwaspreparedfortheRochester Gas&ElectricCompany.Neitherthe%/TCorporation noranypersonactingonitsbehalfassumesanyresponsibility forliability ordamagewhichmayresultfromtheuseofanyinformation disclosed inthisdocument.

INTRODUCTION Thepossibility ofusingLakeOntariowaterasanemergency PWRfeedwater supplyformorethan36hoursduringwhichtheplantwouldbebroughttocoldshutdownisbeingconsidered.

Themaximumsteamingrateduringsuchaperiodwouldbe100,000pounds/h(200gpm)atatemperature of350'F.Asaconsequence ofsteaming, impurities oftheuntreated LakeOntariowaterwillconcentrate inthesteamgenerator.

Ofmajorconcernisthepossibleriskofstresscorrosion cracking(SCC)ofsteamgenerator materials incontactwiththeconcentrated solutionthusformed.Toaddressthisconcern,thechemistry variation intheliquidphaseassteamingproceedsat350'Fwasestimated withemphasisonpH.Then,thepossiblepotential forSCCwasassessedonthebasisoftheseestimates andavailable SCCdata.

6.Theconcentration ofsodiumandcalciumchlorides isassumedlimitedbyasolubility of5molal.7.Chemicalequilibrium expressions ofreferences 2and3apply.Onthisbasis,theliquidsolutionpHvariation uponsteamingat350'Fwasestimated asafunctionofconcentration factordefinedasthemassratiooftotalwater(steam+liquid)toliquidwaterresidual.

Theresultsarepresented graphically inFigurel.Itisimportant tonotethatthedefinition ofpHusedhereisthatfollowedbyMesmer"inthedetermination ofthedissociation constantofwaterathightemperatures, viz,thenegativeofthelogarithm ofthehydrogenionconcentration (notofitsactivity).

Similarly, neutralpHisdefinedasthatwherethehydrogenandhydroxylionconcentrations areequal.ThisneutralpHisafunctionofionicstrength.

Therefore, thepHvariation oftheconcentrated solutions mustbeconsidered inrelationtothatofneut.alpH,alsoplottedinFigure1.Forbasicsolutions asisthecaseconsidered nere,itisimportant tobearinmindthatthehydroxylionconcentration isexpressed intermsopHasfollows:10pH-2NpH OH(whereNpHistheneutralpHvalue)andthatwhentheneutralpHvariestogetherwiththeionicstrengthastheliquidsolutionisbeingconcentrated uponsteaming, thebasicityofthesolutionmaynotbeappreciated fromthesolutionpHaloneTheequivalent NaOHconcentration is.moresuitableforthispurposeandisplottedalsoinFigure1'.B.Discussion SteamGenerator BulkWaterBased.onamaximumf'eedrateof'00gpmtothesteamgenerator andatotals.earngenerator liquidvolumeof.approximately 12,000gallons,amaximumofonesteamgenerator volumeissteamedawayeachhour.Therefore, undermaximumsteaming<<nditions, theconcentration factorachieved.

inthebulksteam.generator water.,ist+1~he~etisthenumberofhoursofsteaming.

Thevariation withtimeoftheequivalent sodiumhydroxide concentration inthesteamgenerator withsteamingofemergency LakeOntariofeedwater thencanbefollowedonFigure1.Itisseenthatamaximumequivalent NaOHconcentration ofabout300ppmwillbereachedinthesteamgenerator bulkwaterwhen15to20steamgenerator volumeswillhavebeenconverted tosteam,i.e.,inapproximately twentyhours.Furtherboilingshouldthendecreasetheequivalent NaOHconcen-trationasmagnesium and/orcalciumhydroxides and/orcalciumsulfateprecipitate withincreased concentrating.

-Thedecreasereachesalimit(atabout20,000steamgenerator volumesconverted tosteam,i.e.,in20,000hours)whensodiumandcalciumchlorides starttoprecipitate also.Thislimitisestimated atabout100ppmequivalent NaOHforLakeOntariowatercomposition asspecified inTableIandwiththeassumptions alreadystated.Theassumptions seemreasonable and,atanyrate,canbetestedexperimentally withasmallautoclave fromwhichknownamountsofLakeOntariowaterwouldbeboiledawayat350'Fatconstantliquidlevelintheautoclave.

Crev',ces Theesimatedequivalent NaOHsolutionconcentration insteamgenerator creviceswi11dependupontherelativedegreeofcrevicesolutionconcentration abovethebulkwater.Intubetotubesupportplatecrevices, theremaybeadistribution ofrelativeconcentration factorsofunityandhigher.Thechemistry inacrevicewouldleadthatofthebulkinthesensethatthechemistry ofaspecificcrevicewouldtravelthesamecurve(FigureI)asthebulkbutwouIdbe:at.a-pointonthe;curve.somewhataheadof'hebulk.Since'Ethecausticity ofLakeOntariowaterisnota.strongfunctionofconcentration, thisdoesnotposeaproblem.Indeeditisexpectedinthiscasethatafterashortperiodofsteaming, thecrevicechemistry willbelessbasicthanthatofthebulk.CoolinMaterComaosition TheNWTchemistry modelingworkdiscussed hereinisbasedonthechemicalcomposition ofLakeOntariowatersummarized.

inTableIassuppliedbyRGE.

POTENTIAL FORSCCA.Corrosion Themostaggressive solutionexpectedbasedonthemodelingworkis300ppmNaOH,withs'10ppm02(seebelow)at350'F.Althoughlaboratory dataregarding theseexactconditions arenotavailable, dataareavailable whichcanbeextrapolated toassessthemaximumcorrosion ratesexpectedforagivenrangeofconditions.

vanRooyenandKendig'ite Westinghouse dataindicating thatU-bendsofAlloy600indeaerated 10~NaOHcrackafterseveralmonthsofexposure.

Figures2and3summarize Mestinghouse tests'hich showthatatleast100daysofexposuretodeaerated 10~NaOHat600'Fisrequiredtoproduceadetectable crackinstressedAlloy600.;igure4showsdatagatheredby8ergeandDonati.'hese curvesareforyieldstressedCringsat660'F.Extrapolating thecurveformillannealedAlloy600to300ppmNaOHyieldsaminimumtimeof3500-4000 hourstoinducea0.5millimeter crack.Thedatapresented abovearefordeaerated systemsandareconsistent withvanRooyen's'onclusion thatAlloy600in10%NaOHwouldnotcrackforseveralmonths.Inthepresenceofoxygen,thesusceptibility ofAlloy600toSCCmaybeincreased.

Figure5showsstresscorrosion behaviorin600'Fhighpuritywatercontaining varying-amounts of'.oxygen inthe-gasphaseabovethewaterandadjustedtopH10'tstartupwithammonia.'s theoxygencontentofthegasphaseincreased, thepercentofthespecimens attackedandextentoftheattackincreased.

AsnotedinFigure5theaveragelifeinthe18-weektestvariedfromnocrackingwith1~oxygeninthegasphase(<2ppmoxygeninthewater)to7weeks,with100~oxygeninthegasphase(<200ppmoxygeninthewater).~cIlreeandNichelsandlaterSedriks,etal.,'eportedlessthan20~~~~ckingafter27daysforAlloy600(2commonheattreatments) inaerated,50KNaOHat570F.7 40QOCRingsStressedtocr=YsAccording toASTMSTP4253000O4PCJ~~WQ>0001000A11oy600HT16h13QO'FA11oy600MA1,00010.,000100,000NaOHConcentration, ppmFigure4.Resistance toStressCorrosion CrackingofA11oy60QMi11-Annea1ed orHeatTreatedat1300'FasaFunctionofOeaerated SodiumHydroxide Concentration at600'F~9

~~Laboratory studiesshowthatthereisasignificant temperature dependence ofcausticstresscorrosion crackingasillustrated inFigures6and7.Theseresultsareforpressurizedcapsulesexposedto10>>and50Ž~NaOHat,varyingstressesattemperatures rangingfrom650to550'F.Ascanbeseen,reducingthetemperature below600'Fsignificantly extendsthetimeforSCCtooccur.Thistemperature dependence isfurtherillustrated inFigure8wheretemperature isplottedversusrateconstantforboth10%and50~HaOH.B.OxygenThelakewaterfedtothegenerators probablywouldbeairsaturated (approximately

.'0ppm02).However-,

at350'FtheK0(theequilibrium ratiobetweensteamphaseandliquidphase)foroxygenisslightlygreaterthan5000.EventhoughthedynamicdistribUtion inpracticemaynotreachtrueequilibrium conditions, theneteffectofthehighK0valueisthatrecriculated stamgenerator coolant~~illcontainoxygenconcentrations lowerthan10ppm.Thisrecirculated coolan='~>>l'ilute theoxygenconcentration ofincomingfeedwater withanetoxygen:evelinthedowncomer of~lto10ppm,depending ontherecirculation ratiounderthecontingency conditions.

CDConclusion thesignificantly lowerconcentrations ofsodiumhydroxide (max300ppm),oxygenconcentration s10ppmandthelowertemperature (350'F)involved, thecontingency offeedingLakeOntariowater.totheGinnasteamgenerators should.resultinnomeasureable damagetosteam-generator internaTs.

Although:

not'ecommended fromthestandpoint ofmaximizing component life,suchoperation forperiodsuptoseveraldaysisnotexpectedtoresu1tinanysignificant crackingorinadeterioration ofsteamgenerator integrity.

11

50ZNaOH10X550'PQ<0.5mils0.5to5milsg0.5to5mils50XNaOH650'F5040NII3010mils05ro10mils100.5to5mils0010002000300Q40QO5000ExposureTime,hrs550'FFigure7'.CausticCrackingofMillAnnealed-Alloy 600at55and650'F(Linesdepictzonesofcrackdepth<<omNaOHat600'F)13

~,smA~'4%44+AvwCOMMENTSONYAHROUENANPyE!;g..-".'5

."-.EPORT

,;v~p+W<.-:

"'-Thereferenced reportsbas<ca]]v

-...broadsummarycoveringalargevolumeofdataapplicable

')npartto...z::.i.sssteelsandinparttoAlloy600.Mearegenerally inagreement wi:h:".eirninesummaryconclusions, butfindit;~I,&gdifficult toapply'the)r broad-br's~

treatment tothespecifics ofaPMRhotshutdownwithlakewateradded:o'.'.".=searngenerators at350'F.Theirdocument,Ifgm'$ismisleading forsuchanapplicatonintworespects:

tt<<.~~I1.CausticConcentration Theirstatement that..."For..-.-;rposesofSCCpredictions, ithastobeassumedthatthetimetoc;"..:vgerous levelsofNaOH,onceimpurities havebeenintroduced, isshor..:.=.,onedayorless"doesnotfullyrecognize thespecificconce"'.r'=

.:;;chemistry ofthecoolingwaterinvolvednorthelowheat.'!x;:;a;'able andthecutbackins.earning ra.eduringaperiodofhotshu.co<<.'::-.hecaseof.heLakeOntariowater,=orexample,themaxiaam.'4C:":;r':,",-ration reacheds300ppm(afterszeam',ng~20s.earngenera:or

.:..-'.;"'.thadecreaseinconcentra tionthereafter.

2.Temperature Allofthetestworkreferenced

'"";hereferenced reportwasperformed inficanttempeldependence ofcausticSCCasshown.above,theconcernat350'Fismanyti"eslessthanisindicated.

from<~<<'aquoted'ytheauthors.Basedontheabovethreeconside<<-ions.itisourassessment, thatthegeneralized timelimitof36ho""s'"=ereport'snotdirectlyapp>>ctotheGinnasteamgenerators stea"'n"="':350'FwhilefedbyLakeOntariowater.15

~p,RRangy(40Cy/y+w*w~'ocket,'No.

50%44LS05-81-04-035UNITEOSTATESNUCL'EARREGULATORY COMMISSION WASHINGTON, O.C.20555April24,1981/c&~Mr.JohnE,MaierVice,President ElectricandSteamProduction Rochester Gas&ElectricCorporation 89EastAvenueRochester, NewYork14649

DearMr.Maier;SUBJECT:

SEPTOPICSV-ll.A,ISOLATION OFHIGHANDLOWPRESSURESYSTEMS,V-ll,B,RHRINTERLOCK REQUIREMENTS ANDVI-7.C.l, INDEPENDENCE OFREDUNDANT Q5SITEPOWERSYSTEMS-.R,E,GINNANUCLEARPOWERPLANTWehavereviewedyourletterofMarch27,1981andagreewithresolving openitemsduringtopicevaluations ratherthandeferring adecisiontotheIntegrated Assessment, Tothisend,weareenclosing arevisedsafetyevaluation ofTopicV-ll.A.WehavealsoreviewedyourcommentsonthedraftTechnical Evaluation Report(TER)SEPTopicV-ll.BdatedJanuary8,1981,Yourcommentson'EPTopicV-'1.BarecoveredbySections3.1and3.2ofoursafetyevalua-tiononSEPTopicV-ll,A.Weareenclosing arevisedTechnical Evaluation ReportonTopicV-ll.Bwhichincorporates areference toSection3,1and3.2ofoursafetyevaluation reportonTopicV-ll.A.Weareenclosing arequestforadditional information onSEPTopicVI-7,C,lwherewedonothavesufficient information toreachanindependent safetyassessment.

Sincerely,'

Enclosure:

WaSERforSEPTopicV-ll.Aguestjons f'rSEPTopicVI-.7.C,1 ccw/enclosure'ee nextpageDennisM,Crutchfield, iefOperating ReactorsBranchNo,5DivisionofLicensing

SAFETYEVALUATION TOPIC:V-ll.ARequirements forIsolation ofHighandLowPressureSystemsSeveralsystemsthathavearelatively lowdesignpressureareconnected tothereactorcoolantpressureboundary',

Thevalvesthatformtheinterface betweenthehighandlowpressuresystemsmusthavesufficient redundancy andinterlocks toassurethatthelowpressuresystemsarenotsubjected tocoolantpressures thatexceeddesignlimits.Theproblemiscomplicated sinceundercertainoperating modes(e.g,,shutdowncoolingandECCSinjection) thesevalvesmustopentoassureadequatereactorsafety,AsnotedinEG&GReport1285(Appendix A),GinnahasthreesystemswithalowerdesignpressureratingthantheRCS,thataredirectlyconnected totheRCS.TheRHR,SIS,andCVCSsystemdonotmeetcurrentlicensing requirements forisolation ofhighandlowpressuresystemsasspecified below.(1)TheRHRsystemisnotincompliance withthecurrentlicensing require-mentsofBTPRSB5-1sincenoneoftheisolation valveswillautomatically closeifRCSpressureexceedsRHRdesignpressure.

Also,theoutboardisolation valveshavenointerlocks topreventRHRoverpressurization, andtheinboardvalveinterlocks areneitherdiversenorindependent, (2)TheSISisnotincompliance withthecurrentlicensing requirements ofSRP6.3sincetheMOVsinthelowpressureinjection lineshavenointerlocks topreventopeningwheretheRCSpressureandthesinglecheckv'alveineachlineisnottested.(3)TheCVCSisnotincompliance withcurrentlicensing requirements forisolation ofhighandlowpressuresystemscontained inBTPEICSB-3sincethesuctionanddischarge linesolenoid-operated valveshavenointerlocks topreventsystemoverpressurization, andthedischarge linecheckvalveshavenopositionindication available inthecontrolroom.Becauseofthesevereconsequences ofaLOCAoutsideofcontainment andthelackofassurance thattheseisolation valvescouldbeclosedagainstsignifi-cantflowundertheresulting environmental conditions, theRHRisolation valvesandtheCVCSsuctionvalvesshouldbemodifiedtosatisfythefunctional require-mentsofBTPRSB5-1andBTPEICSB-3.Themodifications ofthisequipment shouldmeetcurrentcriteriaforseismicandenvironmental qualification.

Thescheduleforinstalling thesemodifications willbedetermined duringtheintegrated assessment portionofourreview.Thebasisforrequiring diverseinterlocks intheRHRoutboardisolation valvesisthat,ifanoperatoropenstheoutboardvalveandtheinboardvalveleaks,anuncontrolled LOCAoutsideofcontainment (EventV)couldpossiblyoccur. ..Thebasisfornotrequiring interlocks in.thelowpressureinjection systemisthat,sincethecontractor's reportwaspublished, acheckvalvetestprogramhasbeenestablished, andthus,thesystemnowsatisfies thesingle.failurecriterion.

Thebasisforrequiring theinterlocks onthesuctionandpositionindicationonthedischarge checkvalvesintheCVCSsystemisthatafailureofthereliefvalvetofunctionwhenrequired.may'eadtooverpressurization andasubsequent eventV.Thebasisfornotrequiring interlocks ontheCVCSdischarge valvesisthatthecheckvalvesinserieswiththepositivedisplacement pumpssatisfythesinglefailurecriterion aslongascheckvalvepositionisknownandthepumpcapacityisverifiedperiodically.

Aspreviously noted,inoursystemssafetyevaluation ofSEPTopicV-lO.B,itisnotnecessary toclose-the RHRvalvesautomatically onincreasing reactorcoolantsystempressureduringstartupbecauseoftheoverpressurization pro~tectionsystem.(SeealsoTopicV-3.)

.hcGIj(C~CeW+s*e+DocketNo.50-244LS05-81-02-060 UNITEDSTATESNUCLEARREGULATORY COMMISSION WASHINGTON, D.C.20555r~r"G21ala~iMr.JohnE.MaierVicePresident

.ElectricandSteamProduction Rochester Gas8ElectricCorporation 89EastAvenueRochester, NewYork14649

DearMr.Maier:

RE:SEPTOPICSV-II.A,ISOLATION OFHIGHANDLOWPRESSURESYSTEMS,ANDVI-7.C.1, INDEPENDENCE OFREDUNDANT ONSITEPOWERSYSTEMS-R.E.GINNANUCLEARPOWERPLANTEnclosedarefinalevaluations ofSEPTopicsV-II.AandVI-7.C.lforR.E.GinnaNuclearPowerPlant.Theseassessments compareyourfacility, asdescribed inDocketNo.50-244,withthecriteriacurrently usedbytheregulatory staffforlicensing newfacilities.

ThesereportshavebeenrevisedtoreflectthefactualcommentsprovidedbyyourJanuary8,1981letter.Yourobservations withregardtotheacceptability ofalternative designsandtheuseofadministrative controlswillbeconsidered duringourpreparation oftheintegrated safetyassessment foryourplant.However,itmustbepointedoutthatthecurrently approvedversionofRegulatory Guide1.139isRevision0.Revision0requiresdiverseinterlocks.

Theseevaluations willbebasicinputstotheintegrated safetyassess-mentforyourfacility.

Aspreviously stated,theseassessments mayberevisedinthefutureifyourfacilitydesignischangedorifNRCcriteriarelatingtothissubjectaremodifiedbeforetheintegrated assessment iscompleted.

Sincerely,,

Enclosure:

DraftSEPTopicsV-II.AandVI-7.C.1ccw/enclosure:

SeenextpageDennisM.Crutchfield, iefOperating ReactorsBranch85DivisionofLicensing

.iMr.JohnE.Maierccw/enclosure:

HarryH.Voigt,EsquireLeBoeuf,Lamb,LeibyandMacRae1333NewHampshire Avenue,N.M.Suite1100Washington, D.C.20036Mr.MichaelSlade12Trailwood CircleRochester, NewYork14618Rochester Committee for-ScientificInformationRobertE.Lee,Ph.D.P.0.Box5236RiverCampusStationRochester, NewYork14627JeffreyCohenNewYorkStateEnergyOfficeSwanStreetBuildingCore1,SecondFloorEopireStatePlazaAlbany,NewYork'2223Director, Technical Development ProgramsStateofNewYorkEnergyOfficeAgencyBuilding2EsquireStatePlazaAlbany,NewYork12223Rochester PublicLibrary115SouthAvenueRochester, NewYork14604Supervisor oftheTownofOntario107RidgeRoadMestOntario,NewYork14519ResidentInspector R.E.GinnaPlant.c/oU.S.NRC1503LakeRoadOntario,NewYork14519RichardE.Schaffstall, Executive DirectorforSEPOwnersGroup1747Pennsylvania Avenue,NWWashington, D.C.20006R.E.GINNANUCLEARPOWERPLANTDOCKETNO.50-244Director, Technical Assessment DivisionOfficeofRadiation Programs(AW-459)U.S.Environmental Protection AgencyCrystalHalIf2Arlington, Virginia20460U.S-Environmental Protection AgencyRegionIIOfficeATTN:EISCOORDINATOR 26FederalPlazaNewYork,NewYork10007HerbertGrossman, Esq.,ChairmanAtomicSafetyandLicensing BoardU.S.NuclearRegulatory Comnission Washington, D.C.20555Dr.RichardF.ColeAtomicSafetyandLicensing BoardU.S.NuclearRegulatory Comission Mashington, D.C.20555Dr.EmnethA.LuebkeAtomicSafetyandLicensing BoardU-S.NuclearRegulatory Comnission Mashington, D.C.20555Hr.ThomasB.Cochran~NaturalResources DefenseCouncil,Inc.1725IStreet,N.M.Suite600Washington,

.D.C.20006EzraI.BialikAssistant AttorneyGeneralEnvironmental Protection BureauNewYorkStateDepartment ofLaw2WorldTradeCenterNewYork,NewYork10047 0130JSEPTECHNICAL EVALUATION TOPICV-11.AELECTRICAl, INSTRUMENTATION, ANDCONTROLFEATURESFORISOLATION OFHIGHAi%)LOWPRESSURESYSTEMSFINALDRAFTR.E.GINNANUCLEARSTATIONDocketNo.50-244January1981S.E.Mays1-26-81 CONTENTS

1.0INTRODUCTION

2~0CRITERIA~~~~o~~~~~~~~~~~2.1ResidualHeatRemoval(RHR)System.2.2Emergency CoreCoolingSystem2.3OtherSystems1~2~23.0DISCUSSION ANDEVALUATION

~~~~~~~~~~33.1ResidualHeatRemoval(RHR)System.3.2SafetyInjection System3.3ChemicalandVolumeControlSystem.~~~~~"~~~~~~3344o0SUMMARY~~~~~~~~~~~~~~~~~~~~~~~~5>F0REFERENCES

~~~~~~~~~~o~~~~~~~~~~~~~~~6 SEPTECHNICAL EVALUATION TOPICV-ll.AELECTRICAL, INSTRUMENTATION, ANDCONTROLFEATURESFORISOLATION OFHIGHANDLOWPRESSURESYSTEMSFINALDRAFTR.E.GINNANUCLEARSTATION

1.0INTRODUCTION

Thepurposeofthisreviewistodetermine iftheelectrical, instrumentation, andcontrol(EI&C)featuresusedtoisolatesystemswithalowerpressureratingthanthereactorcoolantprimarysystemareincompliance withcurrentlicensing requirements asoutlinedinSEPTopicV-llA.Cuzrentguidanceforisolation ofhighandlowpres-suresystemsiscontained inBxanchTechnical Position(BTP)EICSB-3,BTPRSB-5-1,andtheStandardReviewPlant(SRP),Section6.3.2.0CRITERIA2.1ResidualHeatRemoval(RHR)Sstems.'solation requirements forRHRsystemscontained inBTPRSB"5-1axe:1.Thesuctionsidemustbeprovidedwiththefollowing isolation features:

a.Twopower-operated valvesinserieswithposi-tionindicated inthecontrolroom.b.Thevalvesmusthaveindependent anddiverseinterlocks topreventopeningif'hereactorcoolantsystem-(RCS) pressuxeisabovethedesignpressureoftheRHRsystem.C~Thevalvesmusthaveindependent anddiverseinterlocks toensureatleastonevalveclosesuponanincreaseinRCSpressureabovethedesignpressureoftheRHRsystem.2.Thedischarge sidemustbeprovidedwithoneofthefollowing features:

a.Thevalves,positionindicators, andinterlocks desczioed in(1)(a)'hxough (1)(c)above.

boOneormorecheckvalvesinserieswithanormally-closed power-operated valvewhicnhasitspositionindicated inthecontrolroom.IfthisvalveisusedforanEmergency CoreCoolingSystem(ECCS)function, thevalvemustopenuponreceiptofasafetyinjection signal(SIS)whenRCSpressurehasdecreased belowRHRsystemdesignpressure.

c.Threecheckvalvesinseries.d.Twocheckvalvesinseries,providedthatbothmaybeperiodically checkedforleaktightness----

andarecheckedatleastannually.

2.2EmerencCoreCoolinSstem.Isolation requirements forECCSarecontained inSRP6.3.Isola'tion ofECCStopreventoverpres-surization mustmeetoneofthefollowing features:

l.Oneormorecheckvalvesinserieswithanormally<<

closedmotor>>operated valve(MOV)whichistobeopeneduponreceiptofaSISwhenRCSpressureislessthantheECCSdesignpressure2.Threecheckvalvesinseries3..Twocheckvalvesinseries,providedthatbothmaybeperiodically checkedforleaktightness andarecheckedatleastannually.

J*withtheRCSmustmeettnefollowing isolation requirements fromBTPEICSB-3:AtleasttwovalvesinseriesmustbeprovidedtoisolatethesystemwhenRCSpressureisabovethesystemdesignpressureandvalvepositionshouldbeprovidedinthecontrolroom2.ForsystemswithtwoNOVs,eachNOVshouldhaveindependent anddiverseinterlocks topreventopeninguntilRCSpressureisbelowthesystemdesignpressureandshouldautomatically closewhenRCSpressureincreases abovesystemdesignpressure3.ForsystemswitnonecheckvalveandaMOV,theMOVshouldoeinterlocked topreventopeningifRCS pressureisabovesystemdesignpressureandshouldautomatically closewheneverRCSpressureexceedssystemdesignpressure.

3.0 DISCUSSION

ANDEVALUATION TherearethreesystemsatR.E.GinnaNuclearStationwhichhaveadirectinterface withtheRCSpressureboundaryandhaveadesignpressureratingofallorpartofthesystemwhichislessthanthatoftheRCS.ThesesystemsaretheChemicalandVolumeControlSystem(CVCS),theSafetyInjection System(SIS),andtheResidualHeatRemoval(RHR)systern.3.1ResidualHeatRemovalSstem.TheRHRsystemtakesasuctionontheRCSloopAhotleg,circulates thewaterthroughtheRHRsystemheatexchanger, anddischarges totheRCSloopBcoldleg.Twomotor-operatedvalvesinseriesprovideisolation capabilities inboththesuctionanddiscnarge lines.EachoftheseNOVshaspositionindica-tioninthecontrolroom.Theinboard(closesttotheRCS)valvesareinterlocked topreventopeningifRCSpressureisaboveRHRsystemdesignpressure.

However,bothvalvesusethesamepressureswitchandrelaytoprovidethisinterlock.

Theoutboardvalveshavenopressureinterlocks.

Noneofthevalveswillautomatically closeifRCSpres-suzeincreases aboveRHRsystemdesignpressureduringRHRsystemoperation.

TheRHRsystemisnotincompliance withthecurrentlicensing requirements ofBTPRSB-5"1sincenoneoftheisolation valveswillautomatically closeifRCSpressureexceedsRHRdesignpressure.

Also,theoutboardisolation valvesnavenointerlocks topreventRHRoverpressurization, andtheinboardvalveinterlocks areneitherdiversenorindependent.

3.2SazetIn'ection Sstem.OneSISsubsystem consistsoftwoaccumulators pressurized withnitrogenwitheachaccumulator isolatedrzomtheRCSbyapairofcheckvalves.Thereareconnections upstreamozeacncneckvalvethatcanallowthemtobetested.Anormally-open motor-operated isolation valveupstreamofthecheckvalvesforeachaccumulator haspositionindication inthecontrolroom.EachMOVisopenedautomatically, i.fclosed,uponreceiptofasafetyinjection signal.ThesecondSISsubsystem consistsoftwoloops,eachsuppliedbyasafetyinjection pump.Eachpumpdischarges tothehotandcoldlegsofoneRCSloop.Isolation isprovidedbytwocheckvalvesinseriesforeachbranchofthesafetyinjection loop.Thecoldlegcheckvalvesaretestable.

Thecheckvalvesinthelinessupplying theRCShotlegforeachSISlooparenottestable.

However,theMOVineachhotlegislockedshutwithpowerremovedandisnotrequiredforaccidentmitigation.

Amotor-operated isolation valvewithpositionindication inthecontrolroomisprovidedineachbranchofthecoldleg.discharge lines.Thesevalvesopenuponreceiptofasafetyinjection signal,buthavenointerlocks preventing openingwhenRCSpressureisaboveSISdesignpressure.

ThethirdSISsubsystem usestheRHRsystemtoprovidelowpres-surewaterfromtherefueling waterstoragetanktothereactorvesselhead(coredeluge).Isolation isprovidedbyaMOVcheckvalveineachoftwobranches.

TheMOVsopeninserieswithauponreceiptofasafetyinjection signalbuthavenointerlocks topreventopeningwhenRCSpressureisaboveSISdesignpressure.

TheSISisnotincompliance withthecurrentlicensing require-mentsofSRP6.3sincetheMOVsforthelowpressureinjection lineshavenointerlocks topreventopeningwhenRCSpressureexceedsSISdesignpressure.

3.3ChemicalandVolumeControlSstem.TheCVCStakeswaterfromtheRCSandpassesitthrougharegenerative heatexchanger, anorificetoreduceitspressure, andanonregenerative heatexchanger beforereducingitspressure'furtherbytheuseofapressurecontrolvalve.Afterfilteri.ng andcleanup,thewatermaybereturnedtotheRCSbytheuseofthecnargingpumps,whichincrease.thewaterpressure

andpassitthrougntheregenerative heatexchanger toeitnerthehotorcoldlegsoftheRCSortothepressurizer auxiliary sprayline.TheCVCSsuctionlineisolation isprovidedbyamanually-operated solenoidvalveinserieswiththreeparallelsolenoid-operated valves.Eachofthesevalvesisoperatedfromthecontrolroomandhasvalvepositionindicated.

Noneofthevalveshaveinterlocks topreventopeningortoautomatically closeifthepressureexceedsthedesignratingofthelowpressureportionsofthesystem.TheCVCSdischarge lineisolation isprovidedbyacommondis-chargelinecheckvalveandabranchcheckvalveineachofthethreebranchesdownstream, ofthecommoncheckvalve.Drainfittingsonthedischarge lineupstreamofeachcheckvalvecanallowthevalvestobetested.Thereisnopositionindication available inthecontrolroomforthecheckvalves.Therearesolenoidisolation valvesineachdiscnarge linebranchwhichhavepositionindication inthecontrolroom,butthesevalveshavenointerlocks topreventsystemoverpressurization.

TheCVCSisnotincompliance withcurrentlicensing requirements forisolation ofhighandlowpressuresystemscontained inBTPEZCSB-3sincethesuctionlinesolenoid-operated valveshavenointerlocks topreventsystemoverpressurization, andthedischarge linecheckvalveshavenopositionindication available inthecontrolroom.4.0SUaiRYTheR.'.GinnaNuclearStationhasthreesystemswithalowerdesignpressureratin'gthantheRCS,whicharedirectlyconnected totheRCS.TheCVCS,SIS,andRHRsystemdonotmeetcurrentlicensing requirements forisolation ofhighandlowpressuresystemsasspeci-fiedbelow.

~I~~1.TheCVCSsolenoid-operated valveshavenopressure-relatedinterlocks, andthedischarge linecheckvalveshavenopositionindication available inthecontrolroomasrequiredbyBTPEICSB-32.TheMOVsinthelowpressureSISlineshavenopressure-related interlocks requiredbySRP6.33.NoneoftheRHRsystemisolation valvesautomati-callycloseifRCSpressureincreases aboveRHRsystemdesignpressureduringRHRsystemoperation, andtheoutboardisolation valveshavenopressure-relatedinterlocks asrequiredbyBTPRSB-5-1.Theinterlocks fortheinboardisolation valvesareneitherdiversenorindependent.

50REFERENCES 1.NUREG-075/087, BranchTechnical Positions EICSB-3,RSB-5-1;StandardReviewPlano.3.2.UpdatedFinalFacilityDescription andSafetyAnalysisReport,GinnaNuclearPowerPlant,UnitNo.1.3.RG&Edrawings33013-422,

-424'257426'27'28'32'33'434,

-435,and-436.4.RGGEdrawings10905-280,

-285,-287,-295,-296,-300,and-301.

TOPICY-11,8(SYSTH'8)

SEETOPICV-'lO.A gy,RRfgyc<~oCy'A+~~O+**++Docket'No.

50-244LS05-81-04-035UNITEDSTATESNUCL'EARREGULATORY COMMISSION WASHINGTON, D.C.20555April24,1981gj/Mr.John.E.MaterVicePresident ElectricandSteamProduction Rochester Gas8ElectricCorporation 89EastAvenueRochester, NewYork14649

DearMr.Maier;SUBJECT:

SEPTOPICSV-ll.A,ISOLATION OFHIGHANDLOWPRESSURESYSTEMS,V-ll,B,RHRINTERLOCK REQUIREMENTS ANDVI-7.C.l, INDEPENDENCE OFREDUNDANT VISITEPOWERSYSTEMS-R.E.GINNANUCLEARPOWERPLANTWehavereviewedyourletterofMarch27,1981andagreewithresolving openitemsduringtopicevaluations ratherthandeferring adecisiontotheIntegrated Assessment, Tothisend,weareenclosing arevisedsafetyevaluation ofTopicV-ll.A.Wehavealsoreviewedyourcomments-onthedraftTechnical Evaluation Report(TER)SEPTopicV-ll.BdatedJanuary8,1981,YourcommentsonSEPTopicV-ll.BarecoveredbySections3.1and3.2ofoursafetyevalua-tiononSEPTopicV-ll,A.Weareenclosing arevisedTechnical Evaluation ReportonTopicV-ll.Bwhichincorporates areference toSection3,1and3.2ofoursafetyevaluation reportonTopicV-ll.A.Weareenclosing arequestforadditional information onSEPTopicVI-7,C,1wherewedonothavesufficient information toreachanindependent safetyassessment.

Sincerely,'nclosure:

SERforSEPTopicV-ll.AQuestions forSEPTopicVI-.7.C.l ccw/enclosure:

SeenextpageDennisM,Crutchfield, iefOperating ReactorsBranchNo,5DivisionofLicensing

Hr.JohnE.MaierCCHariyH.Voigt,EsquireLeBoeuf,Lamb,LeibyandNacRae1333Ne~(Hampshire Avenue,N.W.Suite1100Washington, D.C.20036t<r.MichaelSlade12Trailwood CircleRochester, NewYork14618EzraBialikAssistant AttorneyGeneralEnvironmental Protection BureauNewYorkStateDepartment ofLaw2WorldTradeCenterNewYork,NewYork10047JeffreyCohenNewYorkStateEnergyOfficeSwanStreetBuilding, Core1,SecondFloorEmpireStatePlazaAlbany,NewYork12223Director, Technical Development ProgramsStateofNewYorkEnergyOfficeAgencyBuilding2EmpireStatePlazaAlbany,NewYork12223Rochester PublicLibrary115SouthAvenueRochester, NewYork14604Supervisor oftheTownofOntario107RidgeRoadWestOntario,NewYork14519ResidentInspector R.E.GinnaPlantc/oU.S.NRC1503LakeRoadOntario,NewYork14519Director, CriteriaandStandards DivisionOfficeofRadiation Programs(ANR-460}

U.S.Environmental Protection AgencyWashington, D.C.20460U.S.Environmenta1

.ProtectionAgencyRegionIIOfficeATTN'ISCOORDINATOR 26Federal,PlazaNewYork,NewYork10007HerbertGrossman, Esq.,ChairmanAtomicSafetyandLicensing BoardU.S.NuclearRegulatory Commission Washington, D.C.20555Dr.RichardF.ColeAtomicSafetyandLicensing BoardU.S.NuclearRegulatory Comnission Mashington, D.C.20555Dr.EmethA.LuebkeAtomicSafetyandLicensingBoardU.S.NuclearRegulatory Cowrission Mashington, D.C.20555Hr.ThomasB.CochranNaturalResources DefenseCouncil,Inc.1725IStreet,N.M.Suite600Washington, D.C.20006EzraI.BialikAssistant AttorneyGeneralEnvironmental ProtectionBureauNewYorkStateDepartment ofLaw2WorldTradeCenterNewYork,NewYork10047 4~<~w-'~-.~mEnergyMeasurements Group,EGG1183-4154 21April1981SYSTFMAT/C EVALUATION PROGRAMRFVIEVfQFNRCSAFETYTOPICV-II.BASSOCIATED WITHTHEELECTRICAL, IHSii-UiYiKNTATIQN, Ai~'DCONTROLPQRTIOF~S QFTHERESIDUALHEATRED"<OVAL.SYSTEM FORTHEGINNANUCLEARPQVZERPIARTSANRAMONOPERATIONS 29C".GLG<<rCWC~NYC4PC9cN84MCQ,CAglsGANIA 9(<99 EGG1183-4]S4 SYSTEMATIC EVALUATION PROGRAMREYIDVQFNRCSAFETYTOPICV-31.BASSOCIATED VflTHTHEELECTRICAL, INSTRUMENTATION'ND CONTROLPORTIONSOFTHERESIDUALHEATREMOVALSYSTEMFORTHEGINNANUCLEARPOWERPLANT ABSTRACTThisreportdocuments thetechnical evaluation'nd reviewofNRCsafetytopicY-,li.B,associated withtheelec.rical, instrumentation, andcontrolpor.ionsoftheresidualheatremoval(RHR)systemfortheGinnanuclearpowerplant.Currentlicensing criteriaareusedtoevaluate.

theoverpressure protection andincependence oftheRHRsys.em.

FQREMCROThisrepor.issupp1iedaspartoftheSystematic EvaluationProgrambeingconducted fortheU.S.NuclearRegulatoryCommissionbyLawrenceLivermore NationalLaboratory.

Theworkwasperformed by.EGEG,EnergyMeasurements Group,SanRamonOperationsforLawrenceLivermore NationalLaboratory underU.S.Oepartment ofEnergycontractnumberOE-AC08-75NV01183.

TABLEOFCONTENTSPage1.INTRODUCTION............

12.C'URREHTLICEHSIHGCRITERIA~~oe~~~'o~33~REYIFhGUIDE'NES

-~-..'~....~54.SYST"-t1DESCRIPTiON...........

75.EVALUATION ANDCONCLUSIONS.......

~.96.SUM~VRY~~~~llR=".=ERENCES

~~~o13'PPENDIX AHRCSAFETYTOPICSRELATEDTOTHiSREPORT...

A-1

SYSTEMATIC EVALUATION PROGRAMREVIEMOFNRCSAFETYTOPICV-11.BASSOCIATED WITHTHEELECTRICAL, INSTRUMENTATION, ANDCONTROLPORTIONS.OFTHERES'IDUAL HEATREMOVALSYSTEMFORTHEGINNANUCLEARPOMERPLANT1.INTROOUCTIQN Anumberofplantshaveresidualheatremoval(RHR)sysemsin0whichthedesignpressureratingislowerthanthereactorcoolantsystem(RCS)pressure, boundarytowhichthesystemisconnected.

TheRHRsystemnormallyislocatedoutsideofprimarycontainment andhasmotor-opera edvalves(MOVs),which isolateitfromtheRCS.Thereis,therefore, apo-tentialthatthesesystemswouldbesub'ctedtopressurestressesinexcessoftheirdesignratingiftheisolation MOVswereopenedinadvert-entlywhiletheRCSwasabovetheRHRsystemdesignpressurerating.ThiscouldresultinaLOCAou-sidecontairment andalossofrefloodcapability since'hecoolantinventory could.belost.Generally, interlocks areprovidedtopreventisolation MOVsfrcmopeningunderhighRCSpressureconditions.

Itisimportantoincorporate featuresintothesystemdesign.whichwillpreventoverpressuri zingthelowpressure-rated RHRsystemswhichinterface withthereactorcoolantpressureboundary.

Thecurrentlicensing criteriarequiresredundant, diverseinterlocks topreventopeningoftheisolation MOVswhenRCSpressureexceedsRHRpressuredesign

limits.Thecurrentlicensing criteriaalsorequiresautomatic closureoftheisolation NOYswhenRCSexceedsRHRpressuredesignlimits.Theobjective ofthisreviewistoensurethattheplanthasadequatemeasurestoprotectalowpressure-rated RHRsystemthatinter-faceswith.heRCSfromfailuresduetoexcessive pressureandthatsuchprotection issuitablyredundant anddiverse.Thisreviewappliestotheinterlocks associa.ed withtheisola-tionNOYsoftheRHRsystem.Otherprotection schemessuchasdouble-testablechekvalvesarediscussed'n reportsonotherNRCSafetyTopics.'

2.CURRENTL'ICENSINGCRiTERIABranchTechnical PositionICSB-3[Ref.13,entitled"Isolation ofLowPressureSystemsfromtheHighPressureRCS,"statesthat:Theisolation MOYsshouldhaveindependent anddiverseinterlocks topreventopeningunlesstheprimarysystempressureisbelowthesubsystem designpressure.

Also,theisola.ion NOYoperators shouldreceiveasignaltoclosethevalvesautomatically whentheprimarysysempressureex-ceedsthesubsystem designpressure.

BranchTechnical PositionRSBS-IiRef.2j,entitled"OesignRe-qu'.rements fortheResidual'~eatRemovalSystem,"statesthat:Isolationshal1beprovidedbyat1esttwopower-operated valves.inseries,andthevalvessnailhaveindependent diverseinterlocks topreventthevalvesfrombeingopenedunlesstheRCSpressureisbelowtheRHRsystemdesignpres-sure.Thevalvesshallhaveindependent, diverseinterlocks toprotectagainstoneorbothvalvesbeingopenduringanincreaseaboveRHRsystemdesign'pressure.

IftheRHRsystemdischarge lineisusedforanemergency corecoolingsysem(ECCS)function, thepower-operated valveistobeopeneduponreceiptofasafetyinjecionsignaloncethereactorcoolantpressurehasdecreased belowtheECCSdesignpressure.

3.REVIEWGUIDELINES TheNRCguidelines usedinthisreviewareasfollows:t(1)IdentifythevalveswhichisolatetheRHRsystemfranthereactorcoolantpressureboundry:(RefertoNRCmemorandum fromB.L.Siegel,RSB,toP.A.OiBenedetto, SEP;whichisenclosure 3ofaletterfromCrutchfield NRC,SEPB,toDittmore, LLNL,dated6'-10-80[Ref.3]).(2)(3)Evaluate(hedesignfeatureswhichprovideprotec-tion=-gainsttheoverpressurization cftneRHRsystem.Identifytherelatedtopicreviewsinanappendixuthisreport.(4)CompilealistofthemajorEISCsystemsthatarenecessary forOBEandforsafeshutdownoftheplant.Submitthecompilation ofnecessary itemsforsafeshutdownasanappendixtoNRCSafetyTopicYII-3,entitled"SystemsRequiredforSafeShutdown."

(5)Ifpowerislocked-out totheRHRisolation MOYs,revie~todetermine ifanyfunctions oftheinter-locksorperm..'ssives areadversely affec.ed.(ThereportonNRCSafetyTopicYi-7.C,amongothers,sta.eswhichvalueshavepowerlockedout).

4.SYSTEMDESCRIPTION TheRHRloopconsis.softwopumps,twoheatexchanoers, andthenecessary valves,piping,andinstrumen;ation.

Duringplantcooldown, coolantflowsfrcmtheRCStotheRHRpumps,throughthetubesideoftheRHRheaexchangers andbacktotheRCS.ThesingleinletlinetotheRHRloopcommences athehotlegofractorcoolantloopA,throughtwore-dundan.pumps.'ndthei,rassociated heatexchangers, andbacktothecoldlegofreactorcoolantloop8viaasingleheader.rTheRHRpumpsandhea.exchangers servedualfunct',cns.

Al:houghthenormaldu".yof.heRHRpumpsandheatexchangers isperformed duringperiodsofreac.orshutdown, thisequipment isalignedduringtheinjection phaseafteraloss-of-coolant-accident (LOCA)toperformthelow-headsafetyinjection

'(LPSI)function.

Inaddition, duringtherecirculetonphaseofaLOCAthecapability maybedividedbetweenthe.core-cooling functionandthecortainment-cooling functionasapartofthecontainment spraysystem.

5.EVALUATION ANDCONC'SIONS ThesuctionlineoftheRHRsystemisisolatedfromtheloopAhotlegoftheRCSbyMOV-700andMOV-701inseries.Thedischarge lineoftheRHRsystemisisolatedfrcmtheloopBcoldlegoftheRCSbyMOV-720andMOV-721inseries.I:Ref.4,drawing33013-436-A].

Allpermissive interlocks associated wi.htheRHRsysemisola-tionMOYsaredesignedtoopenthevalves;therearenopermissive intr-locksassociated withisola.ionMOYclosure.Sec.ion4.1of..theSEPreviewoSafeShudownSyste.,s[Ref;5jstatesthatthepermissive interlocks requiredtoopenthefourRHRsys.emisola.ion valvesareaslistedbelow:MOV-700....RCS pressuremustbelessthan410psig.RHRsuctionvalvesMOV-850AandMOY-850Bfranthecontainment sumpmustbeclosed.MOY-701...

.Thevalve.isoperatedbyakeyswitch.RHRsue.ionvalvesMOV-850AandMOY-8508from.hecontainment sumpmustbeclosed.MOV-720....No in;erlocks exist;valveoperatedbykeyswltch~1MOV-721....RCS pressuremustbelessthan410psig.TheRHRsystemdischarge lineisnotusedforanECCSfunctionthatwouldrequireMOY-720orMOY-721.oopen;however,abranchof.heRHRdischarge lineprovideslowpressuresaetyinjecton(LPSI)tothereac.orvesselviaparal1ellines.isolation betweenheRHRsystemandLPSinjecioninto.hereactorve'sselisprovidedbytwoseparatepathsfromtheRHRdischarge line,~ith eachpathcontaining anMOYandcheckvalve,MOY-852Aandcheckvalve853Aprovideisolation inonepath,whileMOY-852Bandcheckvalve8538provideisolaionintheotherpathI:Ref.4,drawing 33013-436-A; Ref.6,drawing33013-432-A].

TheLPSIisolation MOYsopenonaSIsignalregardless ofRCSpressure;

.herearenointerlocks associated

~ithclosureofthe'LPS'Iisolation MOYs,althoughkeyswi.chclosurecap-abilityisprovided.

Section-".1oftheSEPreviewofSafeShutdownSystem[Ref.53statesinpartthat:AbranchoftheRHRdischarge lineprovideslowpressuresafetyinjection (LPSI)tothereactorvesselviaparallellineswithonenormallyclosedmoor-operated valve(NOV)andonecheckvalveineachline.TheMOYpositionindi-cationisprovidedinthecortrolroomancthesevalves.eceiveanopensignalcoincident, withthesafetyinjection (S;)signal.TheMOVsintheLPSIlinesopen,onanSIsignalbeforeRCSpressuredropsbe'owRHRdesignpressure.

TheRequirements"thefol1owiag:(2)(3)plantccmpliestoallEIECaspec.softhe"RHRInterlock reviewcriterialistedinSection2ofthisreportexceptforTheplantRHRsystemdoesnotsatisfyBTPICSB3[Ref.13andBTPRSB5-1[Ref.23becausetheRHRdischarge andsuctionisolationMOYsdonothaveindependent diverseinterlocks topreventopeningthevalvesuntilRCSpressureisbelow4'0psig.OnlytheinboardvalvesMGY-7GOandMGY-721havethisirterlock.

TheoutboardvalvesMOY-701andMOY-720aremanuallycontrolled withkey-locked swit"hes.

Byprocedure, MOV-701andMOY-720arenotopenedun.ilRCSpressureislessthan410psig.TheplanRHRsystemdoesnotsatisfyBTPICSB3[Ref.1jandBTPRSB5-1[Ref.23becauseallRHRisolation MOYslackanin.erlock featuretoclosethemwhenRCSpressureincreases abovetheRHRdesignpressure.

TheplantRHRsys.emdoesnotsatisyBTPICSB3[Ref.ljandBTPRSB5-1I.Ref.2]becausetheisolation MOVsintheLPSIlines(MOY-852A andMOY-852B) ooen.onanSIsignalbeforeRCSpressuredropsbelowRHRdesignpressure.

6.SUMMARYTheplantRHRinterlock systemfailstosatisfycurrent.licensing criteriaforthefollowing reasons:TheRHRsuctionanddischarge isolation MOVsdonothaveindependent diverseinterlocks topreventopeningtheisolation MOYsuntilRCSpressureisbelow410pslgo(2)AllRHRisolation MOYslackaninterlock featuretoclosethemwhenRCSpressureincreases aboveRHRdesignpressure.

(3)Theisolation MOYsintheLPSIlinesopenonanSIsignalregardless ofRCSpressure.

Theresolution ofitems1,2and3arepresented inSections3.1and3.2ofSEPTopicV-ll.A.

REFERENCES 1.U.S.NuclearRegulatory Commission, BranchTechnical PositionICSB3,"Isolation ofLowPressureSystemsfromtheHighPressureReactorCoolantSystem."2.3.6.U.S.NuclearRegulatory Commission, BrancnTechnical.

PositionRSB5-1,"DesignRequirements oftheResidualHeatRemovalSystem."NRC(0.M.Crutchfield) lettertoLLNL(M.H.Ditmore),datedJune10,1980.'Ginnadrawing,33013-436-A, "Auxiliarv CoolantSystem".~~SEPReviewofSafeShu.downSystemsfortheR.E.GinnaNuclearPowerPlant,Revision1,qnda~ed.Ginnadrawing,33013-432-A, "Safetyinjection System."

APPENDIXANRCSAFETYTOPICSRELATEDTOTHISRPORT1III-1,"Classifica.ion ofStructures, SystemsandComponents."

2.III-10.A"ThermalOverloadofMOVs."3.Y-10-.B,"RHRSystemReliability."V-11.A,"Requirements forIsolation ofHighandLowPressureSystems."'.

6.Y1-?.C"ECCSSingleFailureCriterion andRequiremen.s forLockingOutPowertoValvesIncluding Independence ofInterlocks onECCSValves.."

YIV.-3,"SvstemsRequiredforSa,eShutdown"?.XVI,"Technical Specifications".

TOPICV-12,ASEETOPICII-4.E

TOPICV-0SEETOPICII-2.8

'~,A.HNENT=,~fg+je~~P'/ggROCHESTER CPSPHDELECTRICCORPORPTIOH

X~S9EASTAVEHUE,ROCHESTER, N.Y.I46<9~lollV<~'RiSI"EN7June23,1981DirectorofNuclearReactorRegulation Attention:

Mr.DennisM.Crutchfield, ChiefOperating ReactorsBranch55U.S.NuclearRegulatory Commission washington, D.C.20555c'~+oiciiciooc-io6'62OO~~l)1'ubject:

SEPTopicsV-10.B,V-ll.A,V-11.B,VZ-7.C.1, VZZ-3,andVIIZ-2,R.E.pGinnaNuclearPowerPlantDocketNo.50-244

References:

(1)LetterfromDennisM.Crutchfield, NRC,toJohnE.Maier,RGE,SEPTopics,V-10.B,V-ll.B,andVZZ-3(SafeShutdownSystemsReport),May13,1981.(2)LetterfromDennisM.Crutchfield, NRC,toJohnE.Maier,RGE,SEPoicsV-11.A,V-11.B,andVZ-7.C.1, datedApril24,1981.(3)LetterfromDennisM.Crutchfield, NRC,toJohnE.Maier,RGE,SEPTopicsVIZ-3andVIII-2,datedApril2,1981.

DearMr.Crutchfield:

ThisletterisinresponsetotheSEPtopicassessments providedinthethreeabove-referenced letters.Duetotheintimaterelationship ofthe"SafeShutdown" topicsV-10.B,V-11.A,V-11.BandVZI-3addressed inthesethreeletters,allofourcommentsareprovidedconcurrently inthethreeattached'esponses.

Thisshouldaidtheinclusion ofourcommentsintotheNRC's"SEPIntegrated Assessment".

rVerytrulyyours,ohnE.MaierAttachments r

Attachment 1:RG&Eresponses toNRCAssessment, ofSEPTopicsV-10.B,RHRSystemReliability, V-ll.B,RHRInterlock Requirements, andVII-3,SystemsRequiredforSafeShutdown(SafeShutdownSystemsreport),May13,1981.1.InRG&E'sJanuary13,1981responsetotheNRC'sNovember14,1980"SafeShutdownSystems"assessment, anumberofcommentsweremadewhichhavenotbeenincorporated.

intoRevision2ofthisassessment, transmitted byletterdatedMay13,1981.Wefeelthesecommentswerevalid,andshouldbeincorporated.

Forcontinuity, thesecommentswillbelistedbelow(withtheiroriginalcommentnumbezs):

assumespipingsystempassivefailures"...beyond thosenormallypostulated bythestaff,e.g.,thecatastrophic failureofmoderateenergysystems...".

Althoughitisshownthatsafeshutdownfollowing suchaneventcouldbeachieved, itisnotconsidered thatsuchanevaluation shouldevenbemade.Asnotedbythestaff,.it isclearlybeyondareasonable designbasis.Itisthusrecommended thatthisparagraph bedeletedfromtheevaluation.

Subsequent evaluations tothis"criterion",

suchasthoserelatedtotheCCWsystemonpage22and23,shouldalsobedeleted.ll.Inparagraph gonpage66,itisnotedthat,wnena.plyingthepowerdiversity requirements ofBT?ASB10-1'evento=anSSE,nomeanstosup}yfeedtothesteamgenerators exists.Itwascetezmined thatthiswasacceptable, basedonlowlikelihood ofoccurrence.

Thisconclusion iscorrect;however,sinceBPTASB10-1doesnotconsideranSSEinconjunction withthelossofallA.C.power,thereisnoneedtoevenmaketheevaluation.

Thecomparisons intheSEPprogramshouldbetocurrentcriteria, ratherthantoarguableextrapo-lations.Reference tolossofallA.C.powerinconjuncton withanSSEshouldthusbedeletedfromthisparagraph.

12.OnpageA-4,itisnotedthatadditional systemsarerequiredtoachievecoldshutdownforaPWRthanforaBWRbecauseofadifference inthedefinition ofcoldshutdown.

Thisdoesnotappeartobeareasonable basis.Systemrequirements shouldbebasedonspecificsafetyreasons.TheNRCshouldbeconsistent in.itsrequirements forcoldshutdown, ozprovideatechnical basisforanydifferences."

Staffposition1statesthat"thelicenseemustdevelopplantoperating/emergency procedures forconducting aplantshutdownandcooldownusingonlythesystemsandequipment identified inSection3.1oftheSEPSafeShutdownSystemsReport."RG&Edisagrees withtheneedfortheseprocedures.

Wereiterate thecommentsprovidedinourJanuary13,1981responsethattheoperatorshouldperformacooldownwiththebestequipment available tohimatthetime.Ifapieceofnon-safety equipment isavailable, andwouldbethemostbeneficial forperforming arequiredfunction, itisexpectedthatthispieceofequipment wouldbeused.Ifitisnotavailable, theoperatorcouldfallbackontheuseofsafety-grade equipment.

ButRG&Edoesnotintendtocommitplantpersonnel touseonlysafety-related equipment, ifnon-safety equipment isavailable andmoreeffective.

Wefeelthatitwouldbeimpossible todetermine whena"safety-grade-only" cooldownprocedure wouldeverbeimplemented.

Aslongasthesafety-grade equipment isavailable (andthesafeshutdownassessment concudesthatitis),RG&Econsiders thatthenecessary safetyrequirements aremet.RG&Ealsonotesthatnoregulatory basisforthisrequirement isprovided.

ItisadmittedinSection4.5oftheSafeShutdownreportthat"theneedforprocedures fortheseevaluations isnotidentified inRegulatory Guide1.33..."~Section4.5thengoesontosaythatthebasisisfoundinBTPRSB5-1andSEPTopicVII-3.ButBTPRSB5-1merelyreferences RG1.33,andthisistheassessment ofSEPTop'cVII-3.Therefore, sincenobasisforthis"requirement" exists,andwedonotfeelthatitwouldevenbebeneficial, andsincetheSafeShutdownreportdidconcludethatthecapability forattaining coldshutdownusingonlysafety-related equipment exists,RG&Econcludes thatthisstaffpositionshouldbedeletedfromconsideration.

Staffposition3doesnotappeartotakeintoaccounttheinformation providedinourMarch27,1981submittal regarding SEPTopicV-ll.A.Enclosure 3tothatsubmittal provides'hevalveequipment specification, notingthatthe700,701,720and721NOV'saredesignedsuchthatthey'physically areunabletoopenagainstadifferential pressureofgreaterthan500psi.Thisensuresthatanintersystem LOCAcausedbytheopeningoftheoutboardvalves,plusleakageoftheinboardvalves,cannotoccur,sincetheoutboardvalvescannotopen.

3Evenwithoutthisprovision, itisdifficult tocomprehend howtheGinnaarrangement couldresultinan"EventV".Byadministrative procedure, theRHRvalvesarekey-locked closed,withpowerremoved.Further,interlocks areprovidedfortheinboardRHRvalves.Thus,foran"EventV"tooccurwouldrequirethe:1)failureoftheadministrative procedure requiring powerlock-out(atthebreaker),

2)failureoftheadministrative procedure governing operation ofthevalveatpower,3)failureoftheinboardisolation valve,4)failureofthereliefvalve(RV203)whichhasacapacityof70,000lb/hratits600psigsetpoint, torelievetheleakagepasttheinboardRHRvalve.Thissetoffailuresisconsidered veryremote.WhencoupledwiththefactthattheRHRvalvedesignpreventsopeningofthevalvesagainstagreaterthan500psidifferential

pressure, itisRG6E'sconclusion thatthepossibility ofanintersystem LOCAshouldnotbeacredibledesignbasis.Noadditional modifications, suchasdiverseinterlocks

'fortheoutboardvalves,arewarranted.

Staffposition5statesthat"theoperating procedures fortheGinnaplantshoulabemodifiedtodirecttheoperatortocooldownanddepressurize toRHRinitiation parameters within36.hourswhenevertheServiceWaterSystemisusedforsteamgenerator feedwater..."

Thispositionisbasedonthereference BNL-NUREG-28147, "ImpureWaterinSteamGenerators andIsolation Condensers."

WehavehadthisreportreviewedbyNWTCorporation.

NWT-167,"UseofLakeOntarioWaterinSteamGenerator DuringHotShutdown" (attached) concludes that,"although notrecommended fromthe-standpoint ofmaximizing component life,andoperation forperiodsuptoseveraldaysisnotexpectedtoresultinanysignificant crackingorindeterioration ofsteamgenerator, integrity."

tRG&Etherefore concludes thataspecificdirective tocooldownanddepressurize toRHRinitiation conditions isnot,.warranted, andshouldnotbeincludedinaprocedure.

Thecapability todothisdoesexist,however,andcouldbeusedifdetermined tobenecessary atthetime.

Attachment 2:RG&Eresponses toNRCletterofApril24,1981regarding SEPTopicsV-11.A,"Isolation ofHighandLowPressureSystems",

V-11.B,"RHRInterlock Requirements",

andVI-7.C.1, "Independence ofRedundant OnsitePowerSystems".

TheSafetyEvaluation forSEPTopicV-11.A,"Requirements

,forIsolation ofHighandLowPressureSystems",

specifies thattheoutboardRHRvalvesshouldhavediverseinterlocks topreventopeningwhentheRCSpressureisgreaterthanRHRsystemdesignpressure.

2..RG&Erationale fornotproviding theseadditional interlocks isprovidedincomment3ofAttachment 1ofthistransmittal.

Thesafetyevaluation alsorequiredthatinterlocks beinstalled ontheCVCSsuctionvalves(200A,200B,202),topreventapossibleoverpressurization oftheCVCSletdownlineoutsidecontainment.

RG&EhasnotedinourMarch27,1981letteronthisSEPTopicthatareliefvalve(RV203),withacapacitygreaterthanthecombinedcapacityofthethreeorifices, wouldrelievethepressurebuildupcausedbyclosureofthecontainment isolation valve371.Nooverpressurization oftheCVCSwouldthusbeexpected.

RG&Ehasalsoevaluated thepotential consequences ofsuchanoverpressurization event,withasubsequent smallLOCAoutsidecontainment, anddetermined tha"nounacceptable consequences wouldresult.Thisbreak.wouldbeasmallLCCAoutsidecontainment (maximumflowof,140gpm),andwouldbeterminated byclosureofvalves200A,20GB,and202eitherbyoperatoractionorautomatically bylowpressurizer level.Radiological consequences wouldbeminimal,sincenofueldamagewouldresult.Thiseventisspecifically evalu-atedbySEPTopicXV-16,"Radiological Consequences ofFailureofSmallLinesCarryingPrimaryCoolantOutsideContainment."

RG&Ehasprovidedinformation concerning thistopicbyletterdatedJune18,1980fromL.D.WhiteJr.toMr.DennisM.Crutchfield.

TheRG&Econclusion isthat,basedonthe..availability ofRV203topreventoverpressurization, togetherwiththelackofunacceptable consequences duetoanoverpressurization, nointerlocks orothermodifications arerequiredfortheCVCSsuctionvalves.3.Thesafetyevaluation furtherstatesthatpositionindication isrequiredontheCVCSdischarge checkvalves.AsstatedinourMarch27,,1981letteronSEPTopicV-ll.A,wedonotbelievethatthislineshouldbeclassified asalowpressure systemconnected totheRCS,sincethepipingis2500-1bpipingthroughout itslength(tothepositivedisplacement chargingpump).RG&Ehashadnoexperience withfailuresofthepositivedisplacement chargingpumppistonstoholdprimarysystempressure, norwouldanyfailuresbeanticipated.

Ourcontention thatthecharginglineisnotalineofconcernisborneoutbyamemofromEdsonG.CasetoRaymond.F.Fraley,"Isolation ofLowPressureSystemsfromReactorCoolantSystem",datedJuly11,1977.Thatlettertransmitted anNRCstudyofthissubjecttotheACRS,andevaluated allpotential linesofconcern.Thecharginglinewasnotincluded.

Toverifythatthecharginglinewasnotavalid"EventV"concern,RG&Ecalculated thePNRCneckValveEventTree(Section4.4ofWASH-1400),

usingthecharginglinecon-figuration (twoin-series checkvalvesandachargingpumppiston).Veryconservatively assumingthatbothcheckvalveswereundet'ected open,andthattheprobability ofthechargingpump~iston failurewasequaltoacheckvalvefailure,theQU>calculated forthisconfiguration wasdetermined to5e1.4x10/year.Thisisalowenoughvaluetoobviously beofnoconcern.RG&Etherefore considers thatcheckvalvepositionindi-cationisnotneededonthecharginglinecheckvalves.iithrespecttotheS=P.opicAssessment V-11.3,nocommentsarenecessary, sincetheresolution ofoutstandi..g issuesisaddressed inthetopicassessmen" "orSEPŽpicV-3.3..A.

Theadditional information requested forSEPTopicVI-7.C.1ispresently beingdeveloped.

Itisanticipated thatthisinformation canbefurnished totheNRCbyJuly15,1981.

Attachment 3:RG&Eresponses toNRCletterofApril2,1981,concerning SEPTopicsVZI-3,"Electrical, Instru-mentation, andControlFeatureofSystemsRequiredforSafeShutdown",

andVIII-2,"DieselGenerators".

ZtappearsthatallcommentsprovidedbyRG&EinourJanuary23,1981andJanuary30,1981lettersconcerning thesetopicshavebeenproperlyincorporated.

Basedontheresolution ofallopenitems,andtheremovalofdieselgenerator testingfromSEPTopicVIII-2,RG&Econcludes thatbothofthesetopicsarecomplete, withnooutstanding issuestobecarriedintotheIntegrated Assessment.

NWT167February1981USEOFLAKEONTARIOWATERINSTEANGENERATORS DURINGHOTSHUTDOWNW.L.PearlS.E.CopieyJ~LelboVlKZPreparedfor'ochester Gas&E1ectricCompanyCorporation 7015REALMDRIVE,SANJOSE,CALIFORNIA 951198106800~

ThisdocumentwaspreparedfortheRochester Gas6ElectricCompany.NeithertheNWTCorporation noranypersonactingonitsbehalfassumesanyresponsibility forliability ordamagewhichmayre'suitfromtheuseofanyinformation disclosed inthisdocument.

INTRODUCTION Thepossibility ofusingLakeOntariowaterasanemergency PWRfeedwater supplyformorethan36hoursduringwhichtheplantwouldbebroughttocoldshutdownisbeingconsidered.

Themaximumsteamingrateduringsuchaperiodwouldbe100,000pounds/h(200gpm)atatemperature of350'F.Asaconsequence ofsteaming, impurities oftheuntreated LakeOntariowaterwillconcentrate inthesteamgenerator.

Ofmajorconcernisthepossibleriskofstresscorrosion cracking(SCC)ofsteamgenerator materials incontactwiththeconcentrated solutionthusformed.Toaddressthisconcern,thechemistry variation intheliquidphaseassteamingproceedsat350'Fwasestimated withemphasisonpH.Then,thepossiblepotential forSCCwasassessedonthebasisoftheseestimates andavailable SCCdata.

pHVARIATION AT350'F'UPONSTEAMINGLAKEONTARIOWATERA.ComputerModelingThecomposition ofLakeOntariowaterasdetermined byRGEisgiveninTable1.'ABLE1LAKEONTARIOWATERANALYSISppmCalciumtlagnesium SodiumPotassium AluminumChlorideSulfate358133.60~13235NitratePhosphate FluorideSi1ica(asSi02)Dissolved OxygenAmmonia(asNitrogen) 2.50.30.150.259.50.24Estimates ofthewaterchemistry variation uponsteamingweredeveloped usingthefollowing assumptions:

1.Sincealuminumandsilicaareinstoichiometric proportion inLakeOntariowater(Table1),theyareassumedtoprecipitate asaluminumsilicate(clay)uponconcentrating

'andtherefore areremovedfromsolution.

2.Sincecalciumoccursinthewater(Table1)inlargeexcessoverphosphate, itisassumedtoprecipitate allthephosphate ascalciumhydroxyapatite(Ca5(P04)30H) andremoveitfromthesolution.

Thecalciuminsolutionisdecreased bythecorresponding amount.3.Fluorideandnitriteareassumedtobehaveaschloride.

Potassium isassumedtobehaveassodium.4.Sodiumandchlorideinsolutionareassumedtoremaincompletely

.dissociated.

5=Calciumcarbonate precipitation isneglected.

Degasification ofCO~bysteamingisassumedtooccur.

6.Theconcentration ofsodiumandcalciumchlorides isassumedlimitedbyasolubility of5molal.7.Chemicalequilibrium expressions ofreferences 2and3apply.Onthisbasis,theliquidsolutionpHvariation uponsteamingat350'Fwasestimated asafunctionofconcentration factordefinedasthemassratiooftotalwater(steam+liquid)toliquidwaterresidual.

Theresultsarepresented graphically inFigure1.Itisimportant tonote'that thedefinition ofpHusedhereisthatfollowedbyMesmer"inthedetermination ofthedissociation constantofwaterathightemperatures, viz,thenegativeofthelogarithm ofthehydrogenionconcentration (notofitsactivity).

Similarly, neutralpHisdefinedasthatwherethehydrogenandhydroxylionconcentrations areequal.ThisneutralpHisafunctionofionicstrength.

Therefore, thepHvariation oftheconcentrated solutions mustbeconsidered inrelationtothatofneutralpH,alsoplottedinFigure1.Forbasicsolutions asisthecaseconsidered here,itisimportant tobearinmindthat.hehydroxylionconcentration isexpressed intermsopHasfollows:=10pH2NpHOH(whereNpHistheneutralpHvalue)andthatwhentheneutralpHvariestogetherwiththeionicstrengthastheliquidsolutionisbeingconcentrated uponsteaming, thebasicityofthesolutionmaynotbeappreciated fromthesolutionpHalone.Theequivalent NaOHconcentration ismoresuitableforthispurposeandisplottedalsoinFigurel.B.Discussion SteamGenerator BulkWaterBased.onamaximumfeedrateof200gpmtothesteamgenerator andatotalsteamgenerator liquid'nlumeofapproximately 12,000gallons,amaximumofonesteamgenerator volumeissteamedawayeachhour.Therefore, undermaximumsteaming-

~onditions, theconcentration factorachievedinthebulksteamgenerator waterist+1wheretisthenumberofhoursofsteaming.

SolutionpH00IIEquivalent NaOHConcentration NeutralpH~400o)Ozoo05Ptft0200810010100100010000Time~ll3Figure1.Variation ofSteamGenerator pHwitHSteamingat350'F(feedingLakeOntariowaterat200gpm)

Thevariation withtimeoftheequivalent sodiumhydroxide concentration inthesteamgenerator withsteamingofemergency LakeOntariofeedwater thencanbefollowedonFigure1.Itisseenthatamaximumequivalent NaOHconcentration ofabout300ppmwillbereachedinthesteamgenerator bulkwaterwhen15to20steamgenerator volumeswillhavebeenconverted tosteam,i.e.,inapproximately twentyhours.Furtherboilingshouldthendecreasetheequivalent NaOHconcen-trationasmagnesium and/orcalciumhydroxides and/orcalciumsulfateprecipitate withincreased concentrating.

Thedecreasereachesalimit(atabout20,000steamgenerator volumesconverted tosteam,i.e.,in20,000hours)whensodiumandcalciumchlorides starttoprecipitate also.Thislimitisestimated atabout100ppmequivalent NaOHforLake)Ontario watercomposition asspecified inTable1andwiththeassumptions alreadystated.Theassumptions seemreasonable and,atanyrate,canbetestedexperimentally withasmallautoclave fromwhichknownamountsofLakeOntariowaterwouldbeboiledawayat350'Fatconstantliquidlevelinthyautoclave.

CrevicesTheestimated equivalent NaOHsolutionconcentration insteamgenerator creviceswilldependupontherelativedegreeofcrevicesolutionconcentration abovethebulkwater.Intubetotubesupportplatecrevices, theremaybeadistribution ofrelativeconcentration factorsofunityandhigher.Thechemistry inacrevicewouldleadthatofthebulkinthesensethatthechemistry ofaspecificcrevicewouldtravelthesamecurve(Figure1)asthebulkbutwouldbeatapointonthe.curvesomewhataheadofthebulk.Since1thecausticity ofLakeOntariowaterisnotastrongfunctionofconcentration, thisdoesnotposeaproblem.Indeeditisexpectedinthiscasethatafterashortperiodofsteaming, thecrevicechemistry willbe'essbasicthanthatofthebulk.CoolinWaterComositionTheNWTchemistry modelingworkdiscussed hereinisbasedonthechemicalcomposition ofLakeOntariowatersummarized inTable1assuppliedbyRGE.

Itispossiblethatseasonalchangesinthecharacteristics'f thelakewatermayresultfromtheinterrelation betweensourceriverflowrates, industrial pollution and/oracidrain.NWThasnorelevantdatatoassesssucheffects.Itmaybedesirable thatanalysesmadeofLakeOntariowaterduringdifferent seasonsandundervariousconditions befedintotheNWTchemistry model.InthismannerthesafetyoffeedingLakeOntariowater,overtherangeoflikelychemicalcompositions, canbeverified.

6 POTENTIAL FORSCCA.Corrosion Themostaggressive solutionexpectedbasedonthemodelingworkis300ppmNaOH,withslOppm02(seebelow)at350'F.Althoughlaboratory dataregarding theseexactconditions arenotavailable, dataareavailable whichcanbeextrapolated toassessthemaximumcorrosion ratesexpectedforagivenrangeofconditions.

vanRooyenandKendig~citeWestinghouse dataindicating thatU-bendsofAlloy600indeaerated 10~NaOHcrackafterseveralmonthsofexposure.

Figures2and'3summarize Westinghouse tests'hich showthatatleast100daysofexposuretodeaerated 10%NaOHat600'Fisrequiredtoproduceadetectable crackinstressedAlloy600.Figure4showsdatagatheredbvBerceandOonat',.'hese curvesareforyieldstressedCringsat660'F.extrapolating the.curveformillannealedAlloy600to300ppmNaOHyieldsaminimumtimeof3500-4000 hourstoinduce5millimeter crack.Thedatapresented abovearefordeaerated systemsandareconsistent withvanRooyen's'onclusion thatAlloy600in10%NaOHwouldnotcrackforseveralmonths.Inthepresenceofoxygen,thesusceptibility ofAlloy600toSCCmaybeincreased.

Figure5showsstresscorrosion behaviorin600'Fhighpuritywatercontaining varyingamountsofoxygeninthegas'phase abovethewaterandadjustedtopH10atstartupwithammonia.As'theoxygencontentofthegasphaseincreased, thepercentofthespecimens attackedandextentof'heattackincreased.

AsnotedinFigure5theaveragelifeinthe18-weektestvariedfromnocrackingwith15oxygeninthegasphase(<2ppmoxygeninthewater)to7weekswith100~oxygeninthegasphase(<200ppmoxygeninthewater).McIlreeandMichelsandlaterSedriks,etal.,'eportedlessthan.20Kcrackingafter27daysforAlloy600(2commonheattreatments) inaerated,50<NaOHat570'F.7~

Cg.aa.I00Wrslasnm<aTgrlXIUIIIIIXIIV.AJaalTheeeenranneeieglraaaea~~0itg'Rnse01XCO41SIcKnKCOCsoesureTleeIhrssFigure2.CrackDepthasaFunctionofTime,StressLevelandMaterialCondition forIDPressurized, CapsulesExposedtoDeaerated 10~NaOHat600'FL56LAea0.3LTHeat'%CMATT9COT.0111901.OTT150.03l7343.OQ310CC&nTs11500yleMIMIIIAnnealed.01ae0'eg.01aaO.ITTIarinally tCOTTsponsreTlaie1nrsl~eeesTreetssl'Figure3.CrackOepthasaFunctionofgxlIosure TimeforMillAnnealedandThermally TreatedInconelAlloy600ExposedtoDeaerated 10KNaOHat600'F' 4000CRingsStressedtoa=YsAccording toASTMSTP42530002000Al1oy600HT16h1300'F1000Al1oy600MA01,00010,000100,000NaOHConcentration, ppmFigure4.Resistance to-Stress Corrosion CrackingofAlloy600Mi11-Annealed orHeatTreatedat1300'FasaFunctionofDeaerated SodiumHydroxide Concentration at600'F~

II'20NO.OFSPECIMENS, MILLANN.8PERCENTCRACKEO0AVLIFEINIBWEEKTESTSIBAVOFMAX.CRACKDEPTHS,MIL 00IB'0'201801258172ll29?I550l2IOO,752oo~IOOO'Z80I-i:60Zgro+)40.CI'"20j80ieieisisieieieieisieisisIlOlOlAIIPIAIAIRtIAAieI18isi8IRi88Ii2'l2OXYGENINGASATSTART,(%)NILALLOY600HEATN27B542NIL47B25647B256478256476256IOO21BALANCEOFGAS,HYOROGENARGOhkNITROGENNITROGENAIRFigure5.StressCorrosion BehaviorinCreviceAreasinMillAnnealedEnconel600OoubleU-bendSpecimens in600'FHighPurityWaterAdjustedtopH10withAmmoniaatStartup'0 Laboratory studiesshowthatthereisasignificant temperature dependence ofcausticstresscorrosion crackingasillustrated inFigures6and7.Theseresultsareforpressurized capsulesexposedto105and50%NaOHatvaryingstressesattemperatures rangingfrom650to550'F.Ascanbeseen,reducingthetemperature below600'Fsignificantly extendsthetimeforSCCtooccur.Thistemperature dependence isfurtherillustrated inFigure8wheretemperature isplottedversusrateconstantforboth10Kand505NaOH.8.OxygenThelakewaterfedtothegenerators probablywouldbeairsaturated (approximateiy

'.0opm0>).However-,

at350'FtheKO(theequilibrium ratiobetweensteamphaseandliquidphase)foroxygenisslightlygreaterthan5000.Eventhoughthedynamicdistribution inpracticemaynotreachtrueequilibrium conditions, theneteffectofthehighKOvalueisthatrecriculated steamgenerator coolant~Iillcontainoxygenconcentrations lowerthan10ppm.Thisrecirculated coolantwil':dilutetheoxygenconcentration ofincomingfeedwatrwithanetoxygenlevelinthedowncomer of~1to10ppm,depending ontlerecirculation ratiounderthecontingency conditions.

C.Conclusion

~Withthesignificantly lowerconcentrations ofsodiumhydroxide (max30oppm),oxygenconcentration

<10ppmandthelowertemperature (350'F)involved, tIie~o~tingency offeedingLakeOntariowatertotheGinnasteamgenerators shouldresultinnomeasureable damagetosteamgenerator internals.

Although'ot recommended fromthestandpoint ofmaximizing component life,suchoperat~o~

forperiodsuptoseveraldaysisnotexpectedtoresu1tinanysignificant.

crackingorinadeterioration ofsteamgenerator integrity.

11 NaOH50X10X575'Fg0.5to5mils504030>10mils')05to10mils100.5to5mils01000200030004000500060007000ExposureTime,hrsFigure6-.CausticCrackingofHillAnnealedAlloy600at575'F(LinesdepictzonesofcrackdepthfromlOXNaOHat600F)12 NaOH50Z10X550'70<0.5mils0.5to5milsg0.5to5mils50XNaOH650p504030nm20>10mils5to10mils00100.5to5mils0100020003000400050006000ExposureTime,hrsFigure7.CausticCrackingofMillAnnealedAlloy600at55and650'F]Linesdepictzonesofcrackdepth<<omNaOHat600'F)13 200~IMAI-600150CKIV4JtC)Ct0ZsIU0)CI100500530550570590610630Temperature, FFigure8.Indicated Variation inRateofSCCwithTemperature 14

~~~i'r.:.L.IEEICOMMENTSONYANROQ'fENANOyE!;0:O'5 REPORT'Thereferenced reportsbasica11v:-.

ibroadsummarycoveringalargevolumeofdataapplicable, inpartto..~:rl.ss steelsandinparttoAlloy600.get>$Earegene~ally inagreement with.'.e'rninesummaryconclusions, butfinditdifficult toapplytheirbroad-br>qn treatment tothespecifics ofapMRhotshutdownwithlakewateraddedto..hesteamgenerators at350'F.TheirdocumentEEE~~fismisleading forsuchanapplication intworespects:

LE~~\E1.CausticConcentration Theirstatement that..."For.".,-;rposes ofSCCpredictions, ithastobeassumedthatthetimeto.'c."..:ngerous levelsofNaOH,onceimpurities havebeenintroduced, isshor:.:.=.,onedayorless"doesnotfullyrecognize thespecificconcen.r'.:.nchemistry ofthecoolingwaterinvolvednorthelowheat'.lux::;'.i'able andthecutbackinsteamingrateduringaperiodofhotshutcown.'"

thecaseoftheLakeOntariowaterforexample,themaximumNaCH...""-=.".-raw'.on reachedis300ppm(aftersteaming~20steamgenerator

-"-';withadecreaseinconcentration thereafter.

2.TemperatureEAllofthetestworkreferenced in-hereferenced report~wasperformed ir.thetemperature rangeof550to=-:G=F.Withthesignificant temperature dependence ofcausticSCCasshownabove,theconcernat350Fismanyti~slessthanisindicated fnmthe,dataquotedbytheauthors.Basedontheabovethreeconsiderations.

itisourassessment thatthegeneralized timelimitof36hoursi,=.'"ereport~isnotdirectlyapplicable totheGinnasteamgenerators steamin.at350'FwhilefedbyLakeOntariowater.15~rtE

.REFERENCES Harhay,A.,Rochester Gas8Electric, personalCommunication, Februaryll,.1981.2.3.5.Leibovitz, J.,andSawochka, S.G.,"Modeling theEffectsofCondenser Inleakage onPWRChemistry",

presented at41stAnnualInternational MaterConference, Pittsburgh, Pennsylvania, October1980.Leibovi;tz, J.andSawochka, S.G.,"Modeling ofCoolingWaterInleakage EffectsinPWRSteamGenerators, TopicalReport,ResearchProject404-1",Elec'tric PowerResearchInstitute, May1980,tobepublished.

Mesmer,R.E.,Baes,C.F.,Jr.,andSweeton,F.M.,"BoricAcidEquilibria andpHinPWRCoolants',

Proceedings ofthe32ndInternational MaterCon-ference,Pittsburgh, P~nnsylvania, November1971,pp.55-65.vanRooyen,D.,andKesdig,M.W.,"ImpureWaterinSteamGenerators andIsolation Generators",

Brookhaven NationalLaboratory, June1980(Draft-BNL-NUREG-28147).

7.8.9.10.Airey,G.P.,"EffectofProcessing Variables ontheCausticStressCorrosion Resistance ofInconelAlloy600",presented atNACEMeeting~March1979(PaperNumber101).Berge,Ph.andDonati,J.R.,"Materials Requirements forSteamGenerator Tubing",presented atInternational Conference onMaterials performance inNuclearSteamGenerators, St.Petersburg,Florida,October1980.Copson,H.R.andEconomy,G.,"EffectofSomeEnvironmental Conditions onStressCorrosion BehaviorofNi-Cr-FeAlloysinPressurized Water'Corrosion, 24,No.3,pp.55-65(March1968).McIlree,A.R.andMichels,H.T.,"StressCorrosion BehaviorofFe"<<->>andOtherAlloysinHighTemperature CausticSolutions",

.Corr'osion.

33.No;2,pp.60-67(February 1977).Sedriks,A.J.,etal.,"InconelAlloy690-ANewCorrosion Resistant Material",

'Corrosion Engineering (Japan),28,No.2,pp.82-95(1979).4Burstein,.

S.,WEPCO,ltrtoH.R.Denton,NRC,dtdNovembe~23~withattachments.

.,ACHMENT

'P%rtROCHESTER GASANDELECTRICCORPORATION

'.Z~89EASTAVENUE,ROCHESTER, N.Y.14649June23,1981DirectorofNuclearReactorRegulation Attention:

Mr.Dennis.M.

Crutchfield, ChiefOperating ReactorsBranch55U.S.NuclearRegulatory Commission Nashington, D.C.20555C!>>O'ICi~NiOaC-io,5-'9-2

~OO-1(p

Subject:

SEPTopicsV-10.B,V-ll.A,V-ll.B,VI-7.C.lg VZX-3,andVIII-2,R.E.GinnaNuclearPowerPlantDocketNo.50-244

References:

(1)LetterfromDennishi.Crutchfield, NRC,toJohnE.Maier,RGE,SEPTopics,V-10.B,V-ll.B,andVII-3(SafeShutdownSystemsReport),May13,1981.(2)Lette"fromDennisM.Crutchfield, NRC,toJohnE.Maier,RG"gSEPopicsV-ll.A,V-ll.B,ancVX-7.C.lf datedApril24,1981.(3)LetterfromDennisM.Crutchfield, NRC,toJohnE.Maier,RGE,SEPTopicsVII-3andVIII-2,datedApril2,1981.

DearMr.Crutchfield:

ThisletterisinresponsetotheSEPtopicassessments providedinthethreeabove-referenced letters.Duetotheintimaterelationship ofthe"SafeShutdown" topicsV-10.B,V-ll.A,V-ll.BandVII-3addressed inthesethreeletters,allofourcommentsareprovidedconcurrently inthethreeattached'espon'ses.

Thisshouldaidtheinclusion ofourcommentsintotheNRC's"SEPXntegrated Assessment".

Attachments Verytrulyyours,ohnE.Maier+~sI/i8106300'3M Attachment 1:RGSEresponses toNRCAssessment ofSEPTopicsV-10.B,RHRSystemReliability, V-11.B,RHRInterlock Requirements, andVII-3,SystemsRequiredforSafeShutdown(SafeShutdownSystemsreport),May13,1981.1.InRG&E'sJanuary13,1981responsetotheNRC'sNovember14,1980"SafeShutdownSystems"assessment, anumberofcommentsweremadewhichhavenotbeenincorporated intoRevision2ofthisassessment, transmitted byletterdatedMay13,1981.Wefeelthesecommentswerevalid,andshouldbeincorporated.

Forcontinuity, thesecommentswillbelistedbelow(withtheiroriginalcommentnumbers):

Onpage5,PiinSstemPassiveFailures, theNRCassumespipingsystempassivefailures"...beyond thosenormallypostulated bythestaff,e.g.,thecatastrophic failureofmoderateenergysystems...".

Althoughitisshownthatsafeshutdownfollowing suchaneventcouldbeachieved, itisnotconsidered thatsuchanevaluation shouldevenbemade.Asnotedbythestaff,itisclearlybeyondareasonable designbasis.Itisthusrecommended thatthisparagraph bedeletedfromtheevaluation.

Subsequent evaluations tothis"criterion",

suchasthoserelatedtotheCCWsystemonpage22and23,shouldalsobedeleted.1nparagraph gonpage66,itisnotedthat,wnenaplvingthepowerdiversity requirements ofBT?ASB10-1ineventofanSSE,nomeanstosuplyfeedtothesteamgenerators exists.Itwasdetermined thatthiswasacceptable, basedonlowlikelihood ofoccurrence.

12'.Thisconclusion iscorrect;however,sinceBPTASB10-1doesnotconsideranSSEinconjunction withthelossofallA.C.power,thereisnoneedtoevenmaketheevaluation.

Thecomparisons intheSEPprogramshouldbetocurrentcriteria, ratherthantoarguableextrapo-lations.Reference tolossofallA.C.powerinconjuncton withanSSEshouldthusbedeletedfromthisparagraph.

OnpageA-4,itisnotedthatadditional systemsarerequiredtoachievecoldshutdownforaPWRthanforaBWRbecauseofadifference inthedefinition ofcoldshutdown.

Thisdoesnotappeartobeareasonable basis.Systemrequirements shouldbebasedonspecificsafetyreasons.TheNRCshouldbeconsistent in.itsrequirements forcoldshutdown, orprovideatechnical basisforanydifferences."

Staffposition1statesthat"thelicenseemustdevelopplantoperating/emergency procedures forconducting aplantshutdownandcooldownusingonlythesystemsandequipment identified inSection3.1oftheSEPSafeShutdownSystemsReport."RG&Edisagrees withtheneedfortheseprocedures.

Wereiterate thecommentsprovidedinourJanuary13,1981responsethattheoperatorshouldperformacooldownwiththebestequipment available tohimatthetime.Ifapieceofnon-safety equipment isavailable, andwouldbethemostbeneficial forperforming arequiredfunction, itisexpectedthatthispieceofequipment wouldbeused.Ifitisnotavailable, theoperatorcouldfallbackontheuseofsafety-grade equipment.

ButRG&Edoesnotintendtocommitplantpersonnel touseonlysafety-related equipment, ifnon-safety equipment isavailable andmoreeffective.

Wefeelthatitwouldbeimpossible todetermine whena"safety-grade-only" cooldownprocedure wouldeverbeimplemented.

Aslongasthesafety-grade equipment isavailable (andthesafeshutdownassessment concudesthatitis),RG&Econsiders thatthenecessary safetyrequirements aremet.RG&Ealsonotesthatnoregulatory basisforthisrequirement isprovided.

ItisadmittedinSection4.5oftheSafeShutdownreportthat"theneedforprocedures fortheseevaluations isnotidentified inRegulatory Guide1.33...".

Section4.5thengoesontosaythatthebasisisfoundinBTPRSB5-1andSEPTopicVII-3.ButBTPRSB5-1merelyreferences RG1.33,andthisistheassessment ofSEPop'cVII-3.Therefore, sincenobasisforthis"requirement" exists,andwedonotfeelthatitwouldevenbebeneficial, andsincetheSafeShutdownreportdidconcludethatthecapability forattaining coldshutdownusingonlysafety-related equipment exists,RG&Econcludes thatthisstaffpositionshouldbedeletedfromconsideration.

Staffposition3doesnotappeartotakeintoaccounttheinformation providedinourMarch27,1981submittal regarding SEPTopicV-11.A.Enclosure 3tothatsubmittal provides'hevalveequipment specification, notingthatthe700,701,720and721MOV'saredesignedsuchthatthey:physically areunabletoopenagainstadifferential pressureofgreaterthan500psi.Thisensuresthatanintersystem LOCAcausedbytheopeningoftheoutboardvalves,plusleakageoftheinboardvalves,cannotoccur,sincetheoutboardvalvescannot,open.

~~Evenwithoutthisprovision, itisdifficult tocomprehend howtheGinnaarrangement couldresultinan"EventV".Byadministrative procedure, theRHRvalvesarekey-locked closed,withpowerremoved.Further,interlocks areprovidedfortheinboardRHRvalves.Thus,foran"EventV"tooccurwouldrequirethe:1)failureoftheadministrative procedure requiring powerlock-out(atthebreaker),

2)failureoftheadministrative procedure governing operation ofthevalveatpower,3)failureoftheinboardisolation valve,4)failureofthereliefvalve(RV203)whichhasacapacityof70,000lb/hratits600psigsetpoint, torelievetheleakagepasttheinboardRHRvalve.Thissetoffailuresisconsidered veryremote.WhencoupledwiththefactthattheRHRvalvedesignpreventsopeningofthevalvesagainstagreaterthan500psidifferential

pressure, itisRG&E'sconclusion thatthepossibility ofanintersystem LOCAshouldnotbeacredibledesignbasis.Noadditional modifications, suchasdiverseinterlocks fortheoutboardvalves,arewarranted.

Staffposition5statesthat"theoperating procedures fortneGinnaplantshouldbemodifiedtodirecttheoperatortocooldownanddepressurize toRHRinitiation parameters within36hourswhenevertheServiceWaterSystemisusedforsteamgenerator feedwater..."

Thispositionisbasedonthereference BNL-NUREG-28147, "ImpureWaterinSteamGenerators andIsolation Condensers."

WehavehadthisreportreviewedbyNWTCorporation.

NWT-167,"UseofLakeOntarioWaterinSteamGenerator DuringHotShutdown" (attached) concludes that,"although notrecommended fromthestandpoint ofmaximizing component life,andoperation forperiodsuptoseveraldaysisnotexpectedtoresultinanysignificant crackingorindeterioration ofsteamgenerator.

integrity."

RG&Etherefore concludes thataspecificdirective tocooldownanddepressurize toRHRinitiation conditions isnot,.warranted, andshouldnotbeincludedinaprocedure.

Thecapability todothisdoesexist,however,andcouldbeusedifdetermined tobenecessary atthetime.

Attachment 2:RG&Eresponses toNRCletterofApril24,1981regarding SEPTopicsV-ll.A,"Isolation ofHighandLowPressureSystems",

V-11.B,"RHRInterlock Requirements",

andVI-7.C.1, "Independence ofRedundant OnsitePowerSystems".

TheSafetyEvaluation forSEPTopicV-11.A,"Requirements forIsolation ofHighandLowPressureSystems",

specifies thattheoutboardRHRvalvesshouldhavediverseinterlocks topreventopeningwhentheRCSpressureisgreaterthanRHRsystemdesignpressure.

RG&Erationale fornotproviding theseadditional interlocks isprovidedincomment3ofAttachment 1ofthistransmittal.

2.Thesafetyevaluation alsorequiredthatinterlocks beinstalled ontheCVCSsuctionvalves(200A,200B,202),topreventapossibleoverpressurization oftheCVCSletdownlineoutsidecontainment.

RG&EhasnotedinourMarch27,1981letteronthisSEPTopicthatareliefvalve(RV203),withacapacitygreaterthanthecombinedcapacityofthethreeorifices, wouldrelievethepressurebuildupcausedbyclosureofthecontainment isolation valve371.Nooverpressurization oftheCVCSwouldthusbeexpected.

RG&Ehasalsoevaluated thepotential consequences ofsuchanoverpressurization event,withasubsequent smallLOCAoutsidecpntainment, anddetermined tha"nounacceptable consequences wouldresult.ThisbreakwouldbeasmallLCCAousideconta'ment (maximumlowof,140gpm),andwouldbeterminated byclosureofvalves200A,20GB,and202eitherbyoperatoractionorautomatically bylowpressurizer level.Radiological consequences wouldbeminimal,sincenofueldamagewouldresult.Thiseventisspecifically evalu-atedbySEPTopicXV-16,"Radiological Consequences ofFailureofSmallLinesCarryingPrimaryCoolantOutsideContainment."

RG&Ehasprovidedinformation concerning thistopicbyletterdatedJune18,1980fromL.D.whiteJr.toMr.DennisM.Crutchfield.

TheRG&Econclusion isthat,basedonthe..availability ofRV203topreventoverpressurization, togetherwiththelackofunacceptable consequences duetoanoverpressurization, nointerlocks orothermodifications arerequiredfortheCVCSsuctionvalves.3.Thesafetyevaluation furtherstatesthatpositionindication isrequiredontheCVCSdischarge checkvalves.AsstatedinourMarch27,1981letteronSEPTopicV-11.A,wedonotbelievethatthislineshouldbeclassified asalowpressure systemconnected totheRCS,sincethepipingis2500-1bpipingthroughout itslength(tothepositivedisplacement chargingpump).RG&Ehashadnoexperience withfailuresofthepositivedisplacement chargingpumppistonstoholdprimarysystempressure, norwouldanyfailuresbeanticipated.

Ourcontention thatthecharginglineisnotalineofconcernisborneoutbyamemofromEdsonG.CasetoRaymondF.Fraley,"Isolation ofLowPressureSystemsfromReactorCoolantSystem",datedJuly11,1977.Thatlettertransmitted anNRCstudyofthissubjectto'heACRS,andevaluated"all potential linesofconcern.Thecharginglinewasnotincluded.

Toverifythatthecharginglinewasnotavalid"EventV"concern,RG&Ecalculated thePWRCheckValveEventTree(Section4.4ofWASH-1400),

usingthecharginglinecon-figuration (twoin-series checkvalvesandachargingpumppiston).Veryconservatively assumingthatbothcheckvalveswereundetected open,andthattheprobability ofthechargingpump~iston failurewasequaltoacheckvalvefailure,theQU>calculated forthisconfiguration wasdetermined to5e1.4x10/year.Thisisalowenough,valuetoobviously beoznoconcern.RG&Etherefore considers thatcheckvalvepositionindi-cationisnotneededonthecharginglinecheckvalves.~;ithrespecttotne="=P.opicAssessment V-11.3,nccommen"sarenecessary, sincetheresolution ofoutstanci..g issuesisaddressed intietopicassessr..en" orSEPepicV-ll.A.Theadditional information requested forSEPTopicVI-7.C.1ispresently beingdeveloped.

Itisanticipated thatthisinformation canbefurnished totheNRCbyJuly15,1981.

Attachment 3:RG&Eresponses toNRCletterofApril2,1981,concerning SEPTopicsVII-3,"Electrical, Instru-mentation, andControlFeatureofSystemsRequiredforSafeShutdown",

andVIII-2,"DieselGenerators".

ItappearsthatallcommentsprovidedbyRGSEinourJanuary23,1981andJanuary30,1981lettersconcerning thesetopicshavebeenproperlyincorporated.

Basedontheresolution ofallopenitems,andtheremovalofdieselgenerator testingfromSEPTopicVIII-2,RG6Econcludes thatbothofthesetopicsarecomplete, withnooutstanding issuestobecarriedintotheIntegrated Assessment.

NWT167February1981tUSEOFLAKEONTARIOWATERINSTEAMGENERATORS DURINGHOTSHUTDOWNW.L.PearlS.E.CopleyJ.Leibovitz PreparedfoiRochester Gas&ElectricCompanyCorporation 7015REALMORIVE.SANJOSE,CALIFORNIA 95119 ThisdocumentwaspreparedfortheRochester Gas&ElectricCompany.Neitherthe%/TCorporation noranypersonactingonitsbehalfassumesanyresponsibility forliability ordamagewhichmayresultfromtheuseofanyinformation disclosed inthisdocument.

INTRODUCTION Thepossibility ofusingLakeOntariowaterasanemergency PWRfeedwater supplyformorethan36hoursduringwhichtheplantwouldbebroughttocoldshutdownisbeingconsidered.

Themaximumsteamingrateduringsuchaperiodwouldbe100,000pounds/h(200gpm)atatemperature of350'F.Asaconsequence ofsteaming, impurities oftheuntreated LakeOntariowaterwillconcentrate inthesteamgenerator.

Ofmajorconcernisthepossibleriskofstresscorrosion cracking(SCC)ofsteamgenerator materials incontactwiththeconcentrated solutionthusformed.Toaddressthisconcern,thechemistry variation i'ntheliquidphaseassteamingproceedsat3k'Fwasestimated withemphasisonpH.Then,thepossiblepotential forSCCwasassessedonthebasisoftheseestimates andavailable SCCdata.

.pHVARIATION AT350'FUPONSTEAMINGLAKEONTARIOWATER,A.ComputerModelingThecomposition ofLakeOntariowaterasdetermined byRGEisgiveninTablel.'ABLE1LAKEONTARIOWATERANALYSISppm~IIII'alciumMagnesiumSodiumPotassium AluminumChlorideSulfate35133.60.13235NitratePhosphate FluorideSilica(asSi02)Dissolved OxygenAmmonia(asNitrogen) 2.50.30.150.259.50.24Estimates ofthewaterchemistry variation uponsteamingweredeveloped usingthefollowing assumptions:

1.Sincealuminumandsilicaareinstoichiometric proportion inLakeOntariowater(Table1),theyareassumedtoprecipitate asaluminumsilicate(clay)uponconcentrating

'andtherefore areremovedfromsolution.

2.Sincecalciumoccursinthewater(Table1)inlargeexcessoverphosphate, itisassumedtoprecipitate allthephosphate ascalciumhydroxyapatite(Ca5(P04)30H) andremoveitfromthesolution.

Thecalciuminsolutionisdecreased bythecorresponding amount.3.Fluorideandnitriteareassumedtobehaveaschloride.

Potassium isassumedtobehaveassodium.4'.Sodiumandchlorideinsolutionareassumedtoremaincompletely

.dissociated.

5=Calciumcarbonate precipitation isneglected.

Degasification ofCO~bysteamingisassumedtooccur.

6.Theconcentration ofsodiumandcalciumchlorides isassumedlimitedbyasolubility of5molal.7.Chemicalequilibrium expressions ofreferences 2and3apply.Onthisbasis,theliquidsolutionpHvariation uponsteamingat350'Fwasestimated asafunctionofconcentration factordefinedasthemassratiooftotalwater(steam+liquid)toliquidwaterresidual.

Theresultsarepresented graphically inFigurel.Itisimportant tonotethatthedefinition ofpHusedhereisthatfollowedbyMesmer"inthedetermination ofthedissociation constantofwaterathightemperatures, viz,thenegativeofthelogarithm ofthehydrogenionconcentration (notofitsactivity).

Similarly, neutralpHisdefinedasthatwherethehydrogenandhydroxylionconcentrations areequal.ThisneutralpHisafunctionofionicstrength.

Therefore, thepHvariation oftheconcentrated solutions mustbeconsidered inrelationtothatofneutralpH,alsoplottedinFigure1.Forbasicsolutions asisthecaseconsidered here,itisimportant tcbearinmindthat.hehydroxylionconcentration isexpressed intermsopHasfollows:10pH-2NpH OH(whereNpHistheneutralpHvalue)andthatwhentheneutralpHvariestogetherwiththeionicstrengthastheliquidsolutionisbeingconcentrated uponsteaming, thebasicityofthesolutionmaynotbeappreciated fromthesolutionpHalone.Theequivalent NaOHconcentration ismoresuitableforthispurposeandisplottedalsoinFigurel.B.Discussion SteamGenerator BulkWaterBasedonamaximumfeedrateof200gpmtothesteamgenerator andatotalsteamgenerator liquidMlumeofapproximately 12,000gallons,amaximumofonesteamgenerator volumeissteamedawayeachhour.Therefore, undermaximumsteamingconditions, theconcentration factorachievedinthebulksteamgenerator waterist+1wheretisthenumberofhoursofsteaming.

SolutionpH30OPl63IIEquivalent NaOHConcentration NeutralpH~400p)rt300n200100101001000100000'l'9me,hFigure1.Variation ofSteamGenerator pHwltliSteamingat350'F(feedingLakeOntariowaterat200gpm)

Thevariation withtimeoftheequivalent sodiumhydroxide concentration inthesteamgenerator withsteamingofemergency LakeOntariofeedwater thencanbefollowedonFigure1.Itisseenthatamaximumequivalent NaOHconcentration ofabout300ppmwillbereachedinthesteamgenerator bulkwaterwhen15to20steamgenerator volumeswillhavebeenconverted tosteam,i.e.,inapproximately twentyhours.Furtherboilingshouldthendecreasetheequivalent NaOHconcen-trationasmagnesium and/orcalciumhydroxides and/orcalciumsulfateprecipitate withincreased concentrating.

Thedecreasereachesalimit(atabout20,000steamgenerator volumesconverted tosteam,i.e.,in20,000hours)whensodiumandcalciumchlorides starttoprecipitatealso.Thislimitisestimated atabout100ppmequivalent NaOHforLakeOntariowatercomposition asspecified inTable1andwiththeassumptions alreadystated.Theassumptions seemreasonable and;atanyrate,canbetestedexperimentally withasmallautoclave fromwhichknownamountsofLakeOntariowaterwouldbeboiledawayat350'Fatconstantliquidlevelintheautoclave.

CrevicesTheestimated equivalent NaOHsolutionconcentration insteamgenerator creviceswilldependupontherelativedegreeofcrevicesolutionconcentration abovethebulkwater.Intubetotubesupportplatecrevices, theremaybeadistribution ofrelativeconcentration factorsofunityandhigher.Thechemistry inacrevicewouldleadthatofthebulkinthesensethatthechemistry ofaspecificcrevicewouldtravelthesamecurve(Figure1)asthebulkbutwouldbeatapointonthecurvesomewhataheadof'hebulk.Sincesthecausticity, ofLakeOntariowaterisnotastrongfunctionofconcentration, thisdoesnotposeaproblem.Indeeditisexpectedinthiscasethatafterashortperiodofsteaming, thecrevicechemistry willbe'essbasicthanthatofthebulk.CoolinWaterComositionTheNWTchemistry modelingworkdiscussed hereinisbasedonthechemicalcomposition ofLakeOntariowatersuamarized inTable1assuppliedbyRGE.

Itispossiblethatseasonalchangesinthecharacteristics'f thelakewatermayresultfromtheinterrelation betweensourceriverflowrates, industrial pollution and/oracidrain.NMThasnorelevantdatatoassesssucheffects-Itmaybedesirable thatanalysesmadeofLakeOntariowaterduringdifferent seasonsandundervariousconditions befedintotheNMTchemistry model.InthismannerthesafetyoffeedingLakeOntariowater,overtherangeoflikelychemicalcompositions, canbeverified.

POTENTIAL FORSCC~A.Corrosion Themostaggressive solutionexpectedbasedonthemodelingworkis300ppmNaOH,withslOppm02(see.below)at350'F.Althoughlaboratory dataregarding theseexactconditions arenotavailable, dataareavailable whichcanbeextrapolated toassessthemaximumcorrosion ratesexpectedforagivenrangeofconditions.

vanRooyenandKendig~citeWestinghouse dataindicating thatU-bendsofAlloy600indeaerated 10NaOHcrackafterseveralmonthsofexposure.

Figures,2 and'3summarize Westinghouse tests'hich showthatatleast100daysofexposuretodeaerated 10%NaOHat600'Fisrequiredtoproduceadetectable crackinstressedAlloy600.Figure4showsdatagatheredbvSergeandOonati.'hese curvesareforyieldstressedCringsat660'F.Extrapolating thecurveformillannealedAlloy600to300ppmNaOHyieldsaminimumtimeof3500-4000 hourstoinducea0.5millimeter crack.Thedatapresented abovearefordeaerated systemsandareconsistent withvanRooyen'sconclusion thatAlloy600in10%NaOHwouldnotcrackforseveralmonths.Inthepresenceofoxygen,thesusceptibility ofAlloy600toSCCmaybeincreased.

Figure5showsstresscorrosion behaviorin600'Fhighpuritywatercontaining varying.amountsofoxygeninthegas'haseabovethewaterandadjustedtopH10atstartupwithammonia.Astheoxygencontentofthegasphaseincreased, thepercentof thespecimens attackedandextentof'theattackincreased.

AsnotedinFigure5theaveragelifeinthe18-weektestvariedfromnocrackingwith1%oxygeninthegasphase(<2ppmoxygeninthewater)to7weekswith1005oxygen-inthegasphase(<200ppmoxygeninthewater).<<IlreeandMichelsandlaterSedriks,etal.,'eportedlessthan.20Ãcrackingafter27daysforAlloy600(2commonheattreatments) inaerated,50KNaOHat570'F.7 Inseuus<<sn9.OOT.OIOQressIhtpsISsOTI$14l%11ÃIUllggUOITI.OSsiilTheresIIIAnneaiegTrasseg4404saXCO41OlOXIOXOTspasuselieslhrsiFigure2.CrackDepthasaFunctionofTime,StressLevelandMaterialCondition forIDPressurized CapsulesExposedtoDeaerated 10<NaOHat600'FL5BLOeaL3LZHeel%CM.A.T.T.gC03.OllSTOT.OZT35$.03lT34Z.04OleRsOTI31VCC&isggT-UOSylel41~emOI~~e~HeMillAnnealedThefinslly Treated.OZBCIM.01saOCOOfspossifo TTsie1hfgl'Figure3.CrackOepthasaFunctionofExposureTimeforMillAnnealedandThermally TreatedInconelAlloy600ExposedtoDeaerated lOXNaOHat600F' 4000CRingsStressedtoa=YsAccording toASTMSTP4253000S-S-O47'r4i2000'r<J1000Alloy600HT16h1300FAlloy600MA01,00010,000100,000NaOHConcentration, ppmFigure4.Resistance toStressCorrosion CrackingofAlloy600Mill-Annealed orHeatTreatedat1300'FasaFunctionofDeaerated SodiumHydroxide Concentration at600'F~9 (VlV,IIIIIIJ'.ZI20NO.OFSPECIMENS, MII.LANN.BPERCENTCRACKED0AVI.IFEINIBWEEKTESTSIBAV.OFMAX.CRACKDEPTHS,MII 00IB"0'20IB0I25BIT2ll292I550f2IOOT52~1OoIOOZ80I-I:604IZg4-')40.~,OX'<<'1~ZO1I50.IALLOY600HEATNqOXYGENINGASATSTART.('/4)8IIe4IeIe1I8l28418I8ISISI14'4I4ISISISISISIeI8IS14I4141414~14te141414278542NILNIL478256I4782564782564782562IIOOBALANCEOFGAS,HYDROGENARGON;NITROGENNITROGENAIRFigure5.StressCorrosion BehaviorinCreviceAreasinMillAnnealedlnconel600DoubleU-bendSpecimens in600'FHighPurityWaterAdjustedtopM10withAmmoniaatStartup'0 Laboratory studiesshowthatthereisasignificant temperature dependence ofcausticstresscorrosion crackingasillustrated inFigures6and7.Theseresultsareforpressurized capsulesexposedto105and50KNaOHatvaryingstressesattemperatures rangingfrom650to550'F.Ascanbeseen,reducingthetemperature below600'Fsignificantly extendsthetimeforSCCtooccur.Thistemperature dependence isfurtherillustrated inFigure8wheretemperature isplottedversusrateconstantforboth10$and50>NaOH.B.OxygenThelakewaterfedtothegenerators probablywouldbeairsaturated (approximately

'0ppm02).However-,

at350'FtheKO(theequilibrium ratiobetweensteamphaseandliquidphase)foroxygenisslightlygreaterthan5000.Eventhoughthedynamicdistribution inpracticemaynotreachtrueequilibrium conditions, theneteffectofthehighKOvalueisthatrecriculated steamgenerator coolant'iillcontainoxygenconcentrations lowerthan10ppm.Thisrecirculated coolantwilldilutetheoxygenconcentration ofincomingfeedwater withanetoxygen'evelinthedowncomer of~lto10ppm,depending ontherecirculation ratiounderthecontingency conditions.

C.Conclusion Withthesignificantly lowerconcentrations ofsodiumhydroxide (max30oppm),oxygenconcentration

<10ppmandthelowertemperature (350'F)involved, thecontingency offeedingLakeOntariowatertotheGinnasteamgenerators shouldresultinnomeasureable damagetosteamgenerator internals.

Althoughn<<recommended fromthestandpoint ofmaximizing component life,suchoperatio~

forperiodsuptoseveraldaysisnotexpectedtoresu1tinanysignificant crackingorinadeterioration ofsteamgenerator integrity.

NaOH50X10X575FgQ.5to5mils504030>10mils105tolpmils100.5to5mils00100020003000400pExposureTime,hrs500060007000Figure6-.CausticCrackingofNi11Annea1edA1loy600at575F(LinesdepictzonesofcrackdepthfromlOXNaOHat600'F)12

~~~V50XNaOH10X550'F1't':0<0.5mils0.5to5milsg0.5to5mils50XNaOH650F504030A'hljLa(Q20>10mils5to10mils100.5to5mils00100020003000400050006000ExposureTime,hrsFigure7.CausticCrackingofMillAnnealedA1]oy600at550Fand650F(Linesdepictzonesofcrackdepthfrom10'aOHat600F)13 200MAI-600150XIUN)Cc5ZIU100500530550570590610630Temperature,

'F"igure8.Indicated Variation inRateofSCCwithTemperature 14 iI~~~~~~~~~I~~~~~~i',.rif'p~<!i.c.%I'i'4$P.COMMENTSONYANRpp>ENNDKE!iD!O'5 "EppRTThereferenced reportsbas<callv

-broadsummarycoveringalargevolumeit>N4ofdataapplicablein partto.ta

:l;sssteelsandinparttoAlloy6pp.Meic>b:aregenerally inagreement with:hrrninesummaryconclusions, butfinditdif<<culttoapplytheirbroad-bri~n treatment tothespecifics ofapMRhot444cH~,~shutdownwithlakewateraddedtohesteamgenerators at350'F.Theirdocumentg~<<f1a~'Cismisleading forsuchanapplication intworespects:

~~~*rra'I1.CausticConcentration v.<+eTheirstatement that..."For.-;;";rposes ofSCCpredictions, ithastobeassumedthatthetimeto.'c.:ngerouslevelsofNapH,onceimpurities havebeenintroduced, isshor-..:.=.,onedayorless"doesnotfullyrecognize thespecificconcen.'.:nchemistry ofthecoolingwaterinvo1vednorthelowheatE':.ibleandthecutbackinsteamingrateduringaperiodofhotshutco'~>

n:.hecaseoftheLakeOntariowater,forexample,themaximum.laCH=,"=.ntration reachedis300ppm(aftersteaming~20steamgeneraoru..'s;".<ithadecreaseinconcentration thereafter.

2-Temperature Allofthetestworkreferenced in-;hereferenced report'as performed inthetemperature rangeof550to=.G=F-Withthesignificant temperature dependence ofcaustic-SCCasshownabove,theconcernat350'Fismanytimeslessthanisindicated lcmthedataquotedbytheauthors.rHasedontheabovethreeconsiderations, itisourassessment thatthegeneralized timelimitof36hoursin=hereport'snotdirectlyapplicable totheGinnasteamgenerators steami"qt 350'FwhilefedbyLakepntariowater.15

.REFERENCES 1.Harhay,A.,Rochester GasInElectric, PersonalCommunication, Februaryll,.1981.2.3.4.5.6.7.9.10.Leibovitz, J.,andSawochka, S.G.,"Modeling theEffectsofCondenser Inleakage onPWRChemistry",

presented at41stAnnualInternational MaterConference, Pittsburgh, Pennsylvania, October1980.Leibovitz, J.andSawochka, S.G.,"Modeling ofCoolingWaterInleakage EffectsinPWRSteamGenerators, TopicalReport,ResearchProject404-1",ElectricPowerResearchInstitute, May1980,tobepublished.

Mesmer,R.E.,Baes,C.F.,Jr.,andSwekton,F.M.,"BoricAcidEquilibria andpHinPWRCoolarrts',

Proceedings of'the32ndInternational WaterCon-ference,Pittsburgh, Pt.nnsylvania, November1971,pp.55-65.vanRooyen,D.,andKeadig,M.W.,"ImpureWaterinSteamGenerators andIsolation Generators",

Brookhaven NationalLaboratory, June1980(Draft-BNL-NUREG-28147).

Airey,G.P.,"EffectofProcessing

'lariables ontheCausticStressCorrosion Resistance ofInconelAlloy600",presented atNACEMeeting%March1979(PaperNumber101).Berge,Ph.andDonati,J.R.,"Materials Requirements forSteamGenerator Tubing",=presented atInternational Conference onMaterials Performance inNuclearSteamGenerators, St.Petersburg, Florida,October1980.Copson,H.R.andEconomy,G.,"EffectofSomeEnvironmental Conditions onStressCorrosion BehaviorofNi-Cr-FeAlloysinPressurized Water'Corrosion, 24,No.3,pp.55-65(March1968).McIlree,A.R.andMichels,H.T.,"StressCorrosion Behaviorof'Fe-Cr>>

andOtherAlloysinHighTemperature CausticSolutions",

.Corrosion.

33No.2,pp.60-67(February 1977).Sedriks,A.J.,etal.,"InconelAlloy690-ANewCorrosion Resistant Material",

"Corrosion Engineering (Japan),28,No.2,pp.82-95(1979}.4Bursteln, S,WEPCO,ltrtoH.R.Denton,NRC,dtdNovember23,1979,withattachments.

16 If"'AgeI~Ig