ML17262A832
ML17262A832 | |
Person / Time | |
---|---|
Site: | Ginna |
Issue date: | 04/23/1992 |
From: | ROCHESTER GAS & ELECTRIC CORP. |
To: | |
Shared Package | |
ML17262A830 | List: |
References | |
NUDOCS 9205060110 | |
Download: ML17262A832 (18) | |
Text
ATTACHMENT ARevisetheTechnical Specification pagesasfollows:Remove3~1314.14-14.14-24..14-34.14-44.14-54..14-64.14-74.14-8Insert3%1314.14-14.14-24.14-34.14-44.14-54.14-64.14-74.14-84-.14-94.14-10'9205060110 920423PDRADOCK05000244PPDR 3.13SnubbersLimitinCondition for0eration3..13.1WithRCSconditions abovecoldshutdown, allsafety-related 3.13.2snubbersshallbeoperable.
Thisspecification doesnotapplytothosesnubbersinstalled onnonsafety-related systemsifthesnubberfailure,and,aresulting failureofthesupported.
nonsafety-related.
systemshowntobecausedbythatsnubberfailure,wouldhavenoadverseeffectonanysafety-related system.ActionWithoneormoresnubbersinoperable, within72hoursreplaceorrestoretheinoperable snubber(s) tooperablestatusand,performanengineering evaluation perSpecification 4.14.1fonthesupported.
component ordeclarethesupported systeminoperable and.followtheappropriate actionstatement forthatsystem.BasisSnubbersarerequiredtobeoperabletoensurethatthestructural integrity ofthereactorcoolantsystemandallothersafety-related systemsismaintained duringand.following aseismicorothereventinitiating dynamicloads.Snubbersmaybereplacedbyrigidstructural supports(bumpers) providedananalysisisperformed todemonstrate thatappropriate acceptance criteriaaresatisfied fordesignbasisseismicand.pipebreakeventsandprovidedthatthebumpersareinspected.
periodically inamannerappropriate forrigidstructural supports.
Amendment No.3~131Proposed 4.144.14.1SnubberSurveillance ReirementsEachsnubberrequiredbySpecification 3.13tobeOPERABLEshallbedemonstrated.
OPERABLEbytheperformance ofthefollowing inservice inspection programinadditiontotherequirements ofSpecification 4.2.a~Insection.esAsusedinthisspecification, "typeofsnubber"shallmeansnubbersofthesamedesignandmanufacturer.,
irrespective ofcapacity.
b.VisualInsectionscSnubbersarecategorized asinaccessible oraccessible duringreactoroperation.
Eachofthesecategories (inaccessible andaccessible) maybeinspected independently according tothescheduledetermine byTable4.14-1.Thevisualinspection intervalforeachtypeofsnubbershallbedetermined baseduponthecriteriaprovided.
inTable4.14-1.VisualXnsectionAccetanceCriteriaVisualinspections shallverifythat(1)thesnubberhasnovisibleindications ofdamageorimpairedOPERABILITY, (2)attachments tothefoundation orAmendment No.4.14-1Proposed supporting structure arefunctional, and(3)fasteners fortheattachment ofthesnubbertothecomponent andtothesnubberanchorage arefunctional.
Snubberswhichappearinoperable asaresultofvisualinspections shallbeclassified asunacceptable andmaybereclassified acceptable forthepurposeofestablishing thenextvisualinspection
- interval, providedthat:(1)thecauseoftherejection isclearlyestablished andremediedforthatparticular snubberandforothersnubbers, irrespective oftypethatmaybegenerically susceptible; or(2)theaffectedsnubberisfunctionally tested.intheas-foundcondition anddetermined OPERABLEperSpecification 4.14.1e.Allsnubbersfoundconnected toaninoper-able commonhydraulic fluidreservoir shallbecountedasunacceptable fordetermining thenextinspection interval.
Areviewandevaluation shallbeperformed anddocumented tojustifycontinued operation withanunacceptable snubber.Ifcontinued operation cannotbejustified, thesnubbershallbedeclaredinoperable and.theACTIONrequirement shallbemet.Amendment No.374.14-2Proposed TABLE4.14-1SNUBBERVISUALINSPECTION INTERVALPopulation orCategoryNUMBEROFUNACCEPTABLE SNUBBERS(Ref.Note7)ColumnAColumnBColumnCExtendIntervalRepeatIntervalReduceInterval(Notes1and2)(Notes3and6)(Notes4and6)(Notes5and6)801001502003004005007501000orgreater122.029244056364878109Note1:Thenextvisualinspection intervalforasnubberpopulation orcategorysizeshallbedetermined baseduponthepreviousinspection intervalandthenumberofunacceptable snubbersfoundduringthatinterval.
Snubbersmaybecategorized, basedupontheiraccessibility'uring poweroperation, asaccessible orinaccessible.
Thesecategories maybeexaminedseparately orjointly.However,thisdecisionmustbeAmendment No.4.14-3Proposed f
Note2:Note3:Note4:Note5:Note6:Note7:documented beforeanyinspection andshallbeusedasthebasisuponwhichtodetermine thenextinspection intervalforthatcategory.
Interpolation betweenpopulation orcategorysizesandthenumberofunacceptable snubbersispermissible.
UsenextlowerintegerforthevalueofthelimitforColumnsA,B,orCifthatintegerincludesafractional valueofunacceptable snubbersasdetermined byinterpolation.
Ifthenumberofunacceptable snubbersisequaltoorlessthanthenumberinColumnA,thenextinspection intervalmaybetwicethepreviousintervalbutnotgreaterthan48months.Ifthenumberofacceptable snubbersisequaltoorlessthanthenumberinColumnBbutgreaterthanthenumberinColumnA,thenextinspection intervalshallbethesameasthepreviousinterval.
Ifthenumberofunacceptable snubbersisequaltoorgreaterthanthenumberinColumnC,thenextinspection intervalshallbetwo-thirds ofthepreviousinterval.
However,ifthenumberofunacceptable snubbersislessthanthenumberinColumnCbutgreaterthanthenumberinColumnB,thenextintervalshallbereducedproportionally byinterpolation, thatis,thepreviousintervalshallbereducedbyafactorthatisone-third oftheratioofthedifference betweenthenumberofunacceptable snubbersfoundduringthepreviousintervalandthenumberinColumnBtothedifference inthenumbersinColumnBandC.Theprovisions ofSpecification Section4.0areapplicable forallinspection intervals uptoandincluding 48months.Todetermine thenextsurveillance
- interval, anunacceptable snubbermaybereclassified asacceptable ifitcanbedemonstrated thatthesnubberisoperableinitsas-foundcondition byperformance ifafunctional testandifitsatisfies theacceptance criteriaforfunctional testing.Amendment No.4.14-4Proposed 04 4.14.1.dFunctional TestsAtleastonceper18monthsduringshutdown, arepresentative sample(atleast10-oofthesnubbersrequiredbySpecification 3.13)shallbefunctionally tested.eitherinplaceorinabenchtest.Foreachsnubberthatdoesnotmeetthefunctional testacceptance criteriaof.Specification 4.14.1e,anadditional 10%ofthesnubbersshallbefunctionally testeduntilnomorefailuresarefoundoruntilallsnubbershavebeenfunctionally tested.Therepresentative sampleselectedforfunctional testingshall,asfaraspractical, includethevariousconfigurations, operating environments, rangeofsizesandcapacities ofsnubbers.
Inadditiontotheregularsample,snubbersplacedinthesamelocations assnubberswhichfailedthepreviousfunctional testshallberetestedatthetimeofthenextfunctional test.Additionally, ifafailedsnubberhasbeenrepairedandreinstalled inanotherlocation, thatfailedsnubbershallalsoberetested.
Thesesnubbersshallnotbeincludedintheregularsample.Ifduringthefunctional testing,additional samplingisrequireddueto,failureofonlyonetypeofsnubber,thefunctional testingresultsshallbereviewedatthattimetodetermine ifadditional samplesshouldbelimitedtothetypeofsnubberwhichhasfailedthefunctional testing.Amendment No.4.14-5Proposed 4.14.1.e.
Functional TestAccetanceCriteriaThesnubberfunctional testshallverifythat:1)Activation (restraining action)isachievedwithinthespecified rangeinbothtensionandcompression; 2)Snubberbleed,orreleaseratewhererequired.,
ispresentinbothtensionand,compression, withinthespecified range;3)Whererequired, theforcerequiredtoinitiateormaintainmotionofthesnubberiswithinthespecified rangeinbothdirections oftravel;and4)Forsnubbersspecifically requirednottodisplaceundercontinuous load,theabilityofthesnubbertowithstand loadwithoutdisplacement isverified.
Testingmethodsmaybeusedtomeasureparameters indirectly orparameters otherthanthosespecified ifthoseresultscanbecorrelated tothespecified parameters throughestablished methods.Functional TestFailureAnalsisAnanalysisshallbemadeofeachfailuretomeetthefunctional testacceptance criteriatodetermine thecauseofthefailure.TheresultsofthisanalysisAmendment No.34.14-6Proposed shallbeused,ifapplicable, inselecting snubberstobetestedinanefforttodetermine theoperability ofothersnubbers, irrespective oftype,whichmaybesubjecttothesamefailuremode.Forthespecificcaseofasnubberselectedforfunctional testingwhicheitherfailstoactivateorfailstomove,i.e.,frozen-in-place,the.causewillbeevaluated and,ifcausedbymanufacturer ordesigndeficiency, allsnubbersofthesametypesubjecttothesamedefectshallbefunctionally testedorevaluated inamannertoensuretheiroperability.
Anytestingperformed aspartofthisrequirement shallbeindependent oftherequirements statedinSpecification 4.14.1dforsnubbersnotmeetingthefunctional testacceptance criteria.
Foranysnubbersfoundinoperable, anengineering evaluation shallbeperformed onthecomponents towhichtheinoperable snubbersareattached.
Thepurposeofthisengineering evaluation shallbetodetermine ifthecomponents towhichtheinoperable snubbersareattachedwereadversely affectedbytheinoperability ofthesnubbersinordertoensurethatthecomponent remainscapableofmeetingthedesignedservice.Amendment No.4.14-7Proposed 4.14.1.gSnubberSealServiceLifeMonitorin Thesealservicelifeofhydraulic snubbersshallbemonitored.
andsealsreplacedasrequiredtoensurethattheservicelifeisnotexceededbetweensurveillance inspections duringaperiodwhenthesnubberisrequiredtobeoperable.
Thesealreplacements shallbedocumented andthedocumentation shallberetainedinaccordance withTechnical Specification 6.10.2.BasisSnubbersareprovidedtoensurethatthestructural integrity ofthereactorcoolantsystemandallothersafetyrelatedsystemsismaintained duringandfollowing aseismicorothereventinitiating dynamicloads.Thevisualinspection frequency isbasedonthenumberofunacceptable snubbersfoundduringtheprevious'nspection inproportion tothesizesofthevarioussnubberpopulations orcategories.
Asnubberis-considered unacceptable ifitfailstheacceptance criteriadelineated bySpecification 4.14.1.c.
Thevisualinspection intervalisbaseduponthepreviousinspection intervalandmaybeaslongastwofuelcycles,nottoexceed48months,depending onthenumberofunacceptable snubbersfoundduringthepreviousvisualinspection.
Amendment No.4.14-8Proposed
ttUnacceptable snubbersshallbeevaluated todetermine iftheyareinoperable.
Forinoperable snubberstheapplicable actionrequirements shallbemet.Whenasnubberisfoundinoperable, anengineering evaluation ofthesupported component isperformed inordertodetermine ifanysafety-related component orsystemhasbeenadversely affected.
bytheinoperability ofthesnubber.Thisevaluation isinadditiontothedetermination ofthesnubbermodeoffailure.Theengineering evaluation shalldetermine whetherornotthesnubberfailurehasimpartedasignificant effectonorcauseddegradation ofthesupported component orsystem,toensuretheyremaincapableofmeetingthedesigned, service.Whenthecauseoftherejection ofasnubberisclearlyestablished..
and,remediedforthatsnubberandforanyothersnubbersthatmaybegenerically susceptible, andverifiedbyinservice functional testing,thatsnubbermaybeexemptedfrombeingcountedasinoperable.
Generically susceptible snubbersarethosewhichareofaspecificmakeormodelandhavethesamedesignfeaturesdirectlyrelatedtothesnubberrejectedorarethosewhicharesimilarly locatedorexposedtothesameenvironmental conditions suchastemperature, radiation, and.vibration.
Todetermine thenextsurveillance
- interval, anunacceptable snubbermaybereclassified asacceptable ifitcanbedemonstrated thatthesnubberisoperableinitsas-foundcondition byperformance ofafunctional testandifitsatisfies theacceptance criteriaforfunctional testing.Amendment No.4.14-9Proposed Toprovideassurance ofsnubberfunctional reliability, arepresentative sampleoftheinstalled snubberswillbefunctionally testedduringplantshutdowns atlessthanorequalto18monthintervals.
Observedfailuresofthesesamplesnubbersshallrequirefunctional testingofadditional units.Hydraulic snubbersandmechanical snubbersmayeachbetreatedasadifferent entityfortheabovesurveillance programs.
Theservicelifeofasnubberisevaluated viamanufacturer inputandengineering information throughconsideration ofthesnubberserviceconditions andfunctional designrequirements.
Theonly'snubbercomponents withservicelivesnotexpectedtoexceedplantlifearesealsand,o-ringsfabricated fromcertainsealmaterials.
Therefore, asealreplacement programisrequiredtomonitorsnubbersealando-ringservicelifetoassuresnubberoperability isnotdegradedduetoexceeding component servicelife.Amendment No.4.14-10Proposed ATTACHMENT BDESCRIPTION Theproposedamendment redefines thesnubbervisualinspection schedulepursuanttoguidancecontained inGenericLetter90-09.ThecurrentformatofSpecification 4.14.1willalsobemodifiedtoparalleltheformatdelineated inthemodelcontained.
inGenericLetter90-09.Therefore, someeditorial changes,inadditiontochangestothebasis,weremadetoensureconsistency.
Thecurrentschedule, described inTechnical Specification 4.14.1a,isbasedonlyonthenumberofinoperable snubbersfoundduringthepreviousinspection, irrespective ofthesizeofthesnubberpopulation.
Thecurrentinspection intervalisbasedonafuelcycleofupto18months,withamaximumallowable extension nottoexceed25percentofthespecified surveillance interval.
Theinspection intervaldependsonthenumberofunacceptable snubbersfoundduringthepreviousvisualinspection.
Thealternative inspection
- schedule, described inGenericLetter90-09,isbasedonthenumberofunacceptable snubbersfoundduringthepreviousinspection inproportion tothesizesofvarioussnubberpopulations orcategories.
Asnubberisconsidered unacceptable, inbothcases,ifitfailstheacceptance criteriaofthevisualinspection.
Thealternative inspection intervalisbasedonafuelcycleofupto24monthsand.maybeaslongastwofuelcycles,or48monthsforplantswithotherfuelcyclesdepending onthenumberofunacceptable snubbersfoundduringtheprevious.
visualinspection.
SYSTEMSANDCOMPONENTS AFFECTEDSafety-Related Hydraulic andMechanical SnubbersSAFETYFUNCTIONOFAFFECTEDSYSTEMSANDCOMPONENTS ThesafetyfunctionofSurveillance Requirement 4.14.1a(visualinspection reguirement),
istoensurethatnoobservable deficiencies existwithanysnubberinstallation thatwouldrenderasnubberinoperable.
Snubbersarerequiredtoensurethatthestructural integrity ofthereactorcoolantsystemandallothersafetyrelatedsystemsismaintained duringandfollowing aseismicevent.Snubbers, ordynamicrestraints, areusedtorestrainpipingorequipment duringseismiceventsortransient loads,yettheyallowrelatively unrestrained.
movementofthepiping/component duringnormalheatuporcooldownoperations.
EFFECTSONSAFETYSnubberinservice inspection requirements consistofvisualinspection andfunctional testing.Visualinspection isintendedtodetectpotential impairedoperability causedbyleakage,corrosion ordegradation duetoenvironmental exposure.
Functional testingtypically involvesremovingthesnubberandtestingonaspecifically-designed teststandtoverifyitsabilitytooperatewithinspecified performance limits.Ingeneral,functional testingisintendedtoprovidea95-oconfidence level,that90to100percentofthesnubbersareoperablewithinacceptable limits.Theperformance ofthevisualinspection isaseparateprocesswhichiscomplimentary tothefunctional testingprogramandprovidesadditional confidence insnubberoperability.
Rochester GasandElectricCorporation hascompareddatagathered.
onGinnaStation's hydraulic andmechanical snubberstothatreportedbyBrookhaven NationalLaboratory (BNL).TheBNLreportwaspreparedfortheCommission, "Development ofAlternative SnubberSurveillance Requirements:
Recommended InterimSnubberSurveillance Plan,"datedJune12,1989insupportofGenericLetter90-09.Themethodology presented intheBNLreportisthebasisforGenericLetter90-09.TheresultsofthedatagatheredonGinnaNuclearPowerStationcomparedfavorably tothedataevaluated byBNL.Theresults,forbothGinnaandBNL,showedthatthepercentfailureratesfoundforvisuallyexaminedandfunctionally testedsnubbersarelow.ThefailureratesforGinna'svisualexaminations alsocomparedfavorably tofunctionally testedsnubbers.
Thevisualinspections hadfailureratesof6.0%and4.0%forthehydraulic andmechanical snubbersrespectively.
Thecorresponding failureratewhensnubbersweresubjected toanactualtestwas2.2%.Theresultsdescribed abovearedocumented inGinnaSafetyEvaluation numberNSL-0000-SE004.
Thissafetyevaluation wasreviewedandapprovedbyGinna'sPlantOperations ReviewCommittee (PORC).Itisapparent, fromtheresultsforGinna,thatextending thevisualinspection intervalpursuanttotheguidancecontained inGenericLetter90-09isreasonable.
Itisemphasized that,basedonthereliability analysisforextension ofthevisualinspection intervalpresented intheBNLstudy,themaximumpermissible numberofinoperable snubberssatisfying thereliability criterion dependsonthegroupsizeandthefutureinspection period.Thus,thereduction inmarginofsafetyisconsidered tobeinsignificant.
Thisproposed.
amendment complieswiththesnubberreliability criterion thataminimumof90%ofthesnubbers(inthegroup)beoperableinthenextinspection period.Further,theproposedchangecomplieswiththeguidancecontained.
inGenericLetter90-09.
10CFR50.92 EVALUATION TheproposedchangeintheGinnaTechnical Specifications doesnotinvolveasignificant hazardconsideration.
Thebasisforthisdetermination isdocumented inGinnaSafetyEvaluation numberNSL-0000-SE004.Thissafetyevaluation wasreviewedandapprovedbyGinna'sPlantOperations ReviewCommittee (PORC).Thisevaluation confirmed.
thathistorical maintenance andsurveillance dataforsnubbersatGinnadoesnotinvalidate anextension totheexistinginspection
- interval, i.e.RGGE'sexperience isconsistent withindustryexperience.
Furthersupportforthebasisfortheabovedetermination isasfollows:Thereisnosignificant increaseintheprobability orconsequences ofanaccidentpreviously evaluated becauseaccidentconditions andassumptions arenotaffectedbytheproposedTechnical Specification change.Theeffectontheavailability ofthesnubbersduetoanincreaseinthevisualinspection intervalhasbeenshowntobenegligible.
Further,functional testingaloneassures,witha95-oconfidence level,thatatleast90-oofthesnubbersareoperablewithoutanyvisualinspection, asassuredbyTechnical Specification 4.14.1c(changedto4.14.1dpertheproposed.
amendment).
Thiswillensurethatsystemreliability remainsessentially unchanged.
Furthermore,.
theproposedchangewillreducefutureoccupational radiation exposure.
Thepossibility ofanewordifferent kindofaccidentfromanyaccidentpreviously evaluated isnotcreated,.
Inmattersrelated.tonuclearsafety,allaccidents areboundedbypreviousanalysis.
Theproposedchangedoesnotadd.toormodifyanyequipment orsystemdesignnordoesitinvolveanychangesintheoperation of-anyplantsystem.Theabsenceofahardwarechangemeansthattheaccidentinitiators remainunaffected, sonouniqueaccidentprobability iscreated.Theproposedamendment doesnotinvolveasignificant reduction inthemarginofsafetyasdefined.inthebasisforanyTechnical Specification becausetheproposed:
amendment willcontinuetoensure,with95-oconfidence, thatatleast90percentofthesnubbersareoperable, asassuredbythecalculations reportedintheBNLreportwhichisthebasisforGenericLetter90-09.Therefore, thefunctionofthetotalpopulation ofsnubbersisreasonably assured.Equipment reliability willbemaintained.
andnoLimitingCondition forOperation (LCO)orLimitingSafetySystemSetpoint(LSSS)wouldbeaffected.
Thus,thereduction inmarginofsafetyisconsidered tobeinsignificant.
CONCLUSION Onthebasisoftheabove,RG&Ehasdetermined thattheamendment requestdoesnotinvolveasignificant hazardsconsideration.