ML17331B139
| ML17331B139 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 12/15/1993 |
| From: | INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG |
| To: | |
| Shared Package | |
| ML17331B140 | List: |
| References | |
| NUDOCS 9312270240 | |
| Download: ML17331B139 (7) | |
Text
ATTACHMENT 3TOAEP:NRC:1166H MARKED-UP COPIESOFTHEEXISTINGT/SPAGES9312270240 931215PDRADOCK05000315PPDB CTOCOOSYSTEMSURVEILLANCE SContinued Co2.Tubesinthoseareas~hereexperience hasindicated potential problems.
3.h.tubeinspection (pursuant toSpecification 4.4.5.4.a.8) shallbeperformed oneachselectedtube..Ifanyselectedtubedoesnotpermitthepassageoftheeddycurrentprobeforatube~inspection, thisshallberecordedandanadjacenttubeshallbeselectedandsubjected toatubeinspection.
Thetubesselectedasthesecondandthirdsamples(ifrequiredbyTable4.4>>2)duringeachinsezvice inspection maybesubjecte'd toapartialtubeinspection provided:
l.Thetubesselectedforthesamplesincludethetubesfromthoseareasofthetubesheetarraywheretubeswithimperfections werepreviously found.d.2.Theinspections includethos'epor'tions ofthetubeswhereimperfections werepreviously found..l9"Implementation ofthesteamgenerator tube/tube suppplateinterimpluggingcriteriaforonefuelcycle(Cyclerequiresa100%bobbincoilinspection forhot.legtubesupportplateintersections andcoldlegintersections downtothelowestcoldlegtubesupportplatewithknownouterdiameterstress'corrosion cracking{ODSCC)indications.
Theresultsofeachsampleinspection shallbeclassified intooneofthefollowing threecategories:
CategoOIusectionResultsC-lLessthan5tofthetotaltubesinspected aredegradedtubesandnoneoftheinspected tubesaredefective.
C-2Oneormoretubes,butnotmorethan1%ofthetotaltubesinspected aredefective, orbetween5%and10%ofthetotaltubesinspected aredegradedtubes.C-3Korethan10%ofthetotal.tubesinspected aredegradedtubesormorethan1'toftheinspected tubesaredefective.
COOKNUCLEARPLANT-UNIT13/44-8AMENDMENT NO.M,454166 REACTORCOOSSTEMSSURVEILLANC USCotuedaroundtheU-bendtothetopsupportofthecoldleg.Poratubeinwhichthetubesupportplateelevation interim,plugginglimithasbeenapplied,theinspection willincludeallthehotlegintersections andall'oldlegintersections downto,atleast,thelevelofthelastcrackindication.
9.~aleevinataheispernitaed onlyinareasvherethesleevespansthetubesheet areaandwhoselowerjointisattheprimaryfluidtubesheet face.10.eTubeuortlatenterimPluinCriteriaisusedfordisposition ofasteamgenerator tubeforcontinued servicethatisexperiencing outerdiameterinitiated stresscorrosion crackingconfinedwithinthethickness ofthetubesupportplates.Porapplication ofthetubesupportplateinterimplugginglimit,thetube'sdisposition forcontinued servicewillbebaseduponstandardbobbinprobesignalamplitude.
Theplant-specific guidelines usedforallinspections shall'eamendedasappropriate toaccommodate theadditional information neededtoevaluatetubesupportplatesignalswithrespecttotheabovevoltage/depth parameters.
Pendingincorporation ofthevoltageverification requirement inASMEstandardverifications, anASMEstandardcalibrated againstthelaboratory standardwillbeutili.red intheDonaldC.CookNuclearPlantUnit1steamgenerator inspections forconsistent voltagenormalization.
1.Atubecanremaininserviceifthesignalamplitude ofacrackindication islessthanorequalto1.0volt,regardless ofthedepthoftubewallpenetration, if,asaresult,theprojected end-of-cycle distribution of"'rack.indications isverifiedtoresultin'rimary-to-secondary leakagelessthan1gpminthefaultedloopduringapostulated steamlinebreakevent.Themethodology forcalculating expectedleakratesfromtheprojected crackdistribution mustbeconsistent withVCAP-13187, Rev.0)(~85PgSi"AheQ 1llJfgjjjPg/Q/gP/2.htubeshouldbepluggedorrepairedif,thesignalamplitude ofthecrackindication isgreaterthan1.0voltexceptasnotedin4.4.5.4.a.10.3 below.AMENDMENT NO.084541663/44-113.Atube.canremaininservicewithabobbincoilsignalamplitude greaterthan1.0voltbutlessthanorequalZdlvoltsifarotatingpancakeprobeinspection doesnotdetectdegradation.
"Indications ofdegiadation withabobbincoilsignalamplitude greaterthan.voltswillbepluggedorrepaired.
~,lCOOKNUCLEARPLANT-UNIT1 0CGCNDRp3.4.6.2ReactorCoolantSystemleakageshallbelimitedto:a.NoPRESSUREBOUNDARYLEAKAGE,b.1GPHUNIDENTIFIED LEAKAGE,c600gallonspezdaytotalpz-to-secondazy leakagethroughallsteamgenerators and150'nsperdaythroughanyonesteamgeneraeor forcruelCycled.10GPHIDENTIFIED LE/QQLGEfromtheReactorCoolaneSystem,e.Seallineresistance greaterthanorequalto2.27E-1ft/gpmiand,1GPHleakagefromanyreactorcoolantsystempressureisolation valvespecified inTable3.4-0.AOTZON'ith anyPRESSUREBOUNDARYLEDGE;beinaeleaseHOTSTANDBYwithin6hoursandinCOLDSHUTDOWNwithinthefollowing 30hours.b.WithanyReactorCoolantSystemleakagegreaterthananyoneoftheabovelimits,excluding PRESSUREBOUNDARYLEAKAGE,reducetheleakageratetowithinlimitswithin4hoursorbeinaeleastHOTSTANDBYwithinthenext6hoursandinCOLDSHUTDOQHwithinthefollowing 30hours.CeKithanyreactorcoolanesystempressureisolation valve(s)leakagegreaterthantheabovelimit,exceptwhen:I1.Theleakageislessthanorequalto5.0gpm,and2.Themostrecenemeasuredleakagedoesnoeexceedthepreviousmeasuredleakage*byanamountthatreducestheAHENDHENT NO.kent16joOrderdatedApril20,1981*TosatisfyhD8hraquiremenes, measuredleakagemaybemeasuredindirectly (asfromtheperformance ofpressureindicators) ifaccomplished inaccordance withapproved'rocedures and"supported bycomputations showingthatthemethodiscapableofdemonstrating valvecompliance withtheleakagecriteria.
Specifi.cation 3.4.6.2.e.
is-applicable withaveragepressurewithin20.psiofthenominalfullpressurevalue.COOKNUCLEARPLANT-UNIT13/44-16 0C4.4,TheSurveillance Requirements forinspection ofthesteamgenerator tubasensurethaethastructural integrity ofthisportionofeheRCSvillbemaintained.
Theprogramforinsaxvice inspection ofsteamgenezator tubesisbasedonamodification ofRegulatory Guide1.83,Revision1.Xnservice inspe'ction ofsteamgenerator tubingisessential QLordextomaintainsurveillance oftheconditions ofthetubesinthaeventthatthereisevidenceofmechanical disagaorprogressive degradation duetodesign,manufacturing errors,orinservice conditions thatleadtocorrosion.
Inservica inspection ofsteamgenerator tubingalsoprovidesa,means'ofcharacterizing thenaturaandcauseofanytubedegradation sothatcorrective measux'es canbetaken.tqTheplaneisexpectedtobeoperatedinamannersuchthathesecond-arycoolantvillbemaintained vithinthosechemistry limitsoundtoresultinnegligible corrosion ofthesteamgenerator tubes.Ifesecondary coolanechemistry isnotmaintained vithintheseparametecozrosion maylikelyresultinstresscorrosion crackingcrackingduringplantoperation vouldbelimitedbythegenerator tubeleakagebetveentheprimarycoolanesystcoolantsystem.Theallovable primary-to-secondary lelimits,localized Theextentofimitation ofsteamandthesecondary rateis150gallonsperdayperseeamgenerator foronefuelcycle(Cycle.Axialorcizcumferentially orientedcrackshavingaprimary-to-secondary leakagelessthanthislimitduringoperation villhaveanadequatemarginofsafetytovithstand eheloadsimposedduringnormaloperation andbypostulated accidents.
Leakageinexcessofthislimitvillrequireplaneshutdovnandaninspection, duringvhichtheleakingtubesvillbelocatedandpluggedorrepaired.
Asteamgenerator vhileundergoing creviceflushinginNode4isavailable fordecayheatremovalandisoperable/opexaeing uponreinstatement ofaux'.iazy ormainfeedflovcontrolandsteamcontrol.wastage-type defectsaraunlikelyviththeallvolatQ.etreatment (AVT)ofsecondary coolant.Hovevex',
evenifadefectofsimilartypeshoulddevelopinservice,itvillbefoundduringscheduled insenrica steamgenerator tubeexanixmtions.
Pluggingorsleevtngvillberequiredforalltubesvithimperfections exceeding therepairlimitvhich,isdefinedinSpecification 4.4.5.4.a.
Steamgenerator tubeinspections ofoperating plantshavedemonsezatad thecapability toreliablydetectdegzadaeion thathaspenetrated 20%oftheoriginaltubevalithickness.
Tubesexperiencing outerdiameterstresscorrosion czackingvithinehethickness ofthetubesupportplatesarapluggedorrepairedbythecriteriaof4.4.5.4.a.lO.
COOKNUCLEARPLANT-UNIT1B3/44<<2ahHEH".":~
NO.~444166 C0C0HaSntaining anoperating 1gelimitof150gpdpersteamgenerator (600gpdtotal)forPuelCyclevillminimi=ethepotential fox'largeleakageeventduzingsteamlinereaRunderLOCAconditions.
BasedontheNDEuncertainties, bobbincoilvoltagedistribution andcrackgrovthratefromthepreviousinspection, theexpectedleakratefolloving asteamlineruptureislimitedtobelov120gpminthefaultedloopand150gpdpersteamgenerator Intheintactloops,vhichvilllimitoffsitedosestovithin10percentofthe10CPR100guidelines.
Ifthepro)ected endofcycledistzibution ofczackindications resultsInprimary-to-secondary leakagegreaterthan120gpminthefaultedloopduringapostulated steamlinebreakevent,additional tubesmustbaremovedfromserviceinordertoreducethepostulated primary-to-secondazy steamlinebreakleakagetobelov120gpm.PRESSUREBOUNDARYLEAKAGEofanymagnitude isunacceptable sinceitmaybeindicative ofanImpending grossfailureofthepressureboundary.
ShouldPRESSUREBOUNDARYUMQLGEoccuzthroughacomponent vhichcanbeisolatedfromthebalanceoftheReactorCoolantSystem,plantoperation maycontinueprovidedtheleakingcomponent ispromptlyisolatedfromtheReactorCoolantSystemsinceisolation removesthesouxcaofpotential failure.TheSurveillance RequIrements forRCSPressureXsolation Valvesprovideaddedassurance ofvalveintegrity therebyreducingtheprobability ofgrossvalvefailureandconsequent intersystem LOCA.LeakagefromtheRCSPressureIsolation ValvesisZDENTXPXED LEAKAGEandvillbeconsidered asaportionofthealloved11mit.34.4.7CKBfISTRY Thelimitations onReactorCoolantSyst~chemistry ensurethatcorrosion oftheReactorCoolantSystemisminimized andreducesthepotential forReactorCoolantSystemleakageorfailureduetostresscorrosion.
maintaining thechemistry vithintheSteadyStateLimitsprovidesadequatecorrosion protection toensuzethestructural integrity oftheReactorCoolantSystemoveithelifeoftheplant.Theassociated effectsofexceeding theoxygen,chloride, andfluoridelimitsare'timeandtemperature dependent.
Corrosion studiesshovthatoperation may'econtinued vithcontaminant concentration levelsinexcessoftheSteadyStateLimits,uptotheTransient Limits,foxthespecified limitedtimeintervals vithouthavingasignIficant effectonthestructural integrity oftheReactorCoolantSystem.ThetimeIntervalpermitting continued operation vithintherestrictions oftheTransient Limitsprovidestimefortakingcorrective actIonstorestorethecontaminant concentrations tovithintheSteadyStateLimits.COOKNUCLEARPLANT-UHXT1B3/44-4hHEHDHZNT NOM166.
ATTACHMENT 4TOAEP:NRC:1166H PROPOSEDREVISEDT/SPAGES