ML17265A536

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Forwards Response to NRC 981203 RAI Re Resolution of Unresolved Safety Issue USI A-46.Util Does Not Agree with NRCs Interpretation.Detailed Bases,Encl
ML17265A536
Person / Time
Site: Ginna Constellation icon.png
Issue date: 02/02/1999
From: MECREDY R C
ROCHESTER GAS & ELECTRIC CORP.
To: VISSING G
NRC, NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
REF-GTECI-A-46, REF-GTECI-SC, TASK-A-46, TASK-OR NUDOCS 9902100108
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CATEGORY1REGULATORYINFORMATIONDISTRIBUTIONSYSTEM(RIDS)ACCESSXONNBR:9902100108DOC.DATE:99/02/02NOTARIZED:NOFACXL:50-244RobertEmmetGinnaNuclearPlant,Unit1,RochesterG,,AUTH.NAME,AUTHORAFFILIATIONMECREDY,R.C.RochesterGasSElectricCorp.RECIP.NAMERECIPIENTAFFILIATIONVISSING,G.DOCKET05000244

SUBJECT:

ForwardsresponsetoNRC981203RAIreresolutionofunresolvedsafetyi'@sueUSXA-46.DISTRIBUTIONCODE:A025DCOPIESRECEIVED:LTRENCLSIZE:TITLE:SeismicQualificationofEquipmentinOperatingPlantsNOTES:LicenseExpdateinaccordancewith10CFR2,2.109(9/19/72)A-46-GL-87'05000244ERECIPIENTIDCODE/NAMEOGC/HDS3VISSING,G.XNTERNAILECENTER01NREGBNRR/DRCH/HICBNRR/DRPE/PD1-3EXTERNAL:NRCPDRCOPIESRECIPIENTLTTRENCQIDCODE/NAME11XPD1-1PD11MPR/DE11NRR/DE/EMEB11NRR/DRCH/HOHB11NRR/DISA/SRXB11COPIESLTTRENCL111121111NNOTETOALL"RIDS"RECIPIENTS:PLEASEHELPUSTOREDUCEWASTE.TOHAVEYOURNAMEORORGANIZATIONREMOVEDFROMDISTRIBUTIONLISTSORREDUCETHENUMBEROFCOPIESRECEIVEDBYYOUORYOURORGANIZATION,CONTACTTHEDOCUMENTCONTROLDESK(DCD)ONEXTENSION415-2083TOTALNUMBEROFCOPIESREQUXRED:LTTR13ENCL13 VC4 Ar)rnROCHESTERGASANDElECTRICCORPORATION~89FASTAVENUE,ROCHESTERN.Y.Id6d9.0001ROBERTC.MECREDYVicePresidentNuclearOperatingGroupAREACODE716546-2700February2,1999U.S.NuclearRegulatoryCommissionDocumentControlDeskATTN:GuyVissingProjectDirectorateI-1Washington,D.C.20555-0001

Subject:

ResponsetoNRC"SecondRequestforAdditionalInformation"(RAI)ontheresolutionofUnresolvedSafetyIssue(USI)A-46.R.E.GinnaNuclearPowerPlantDocketNo.50/244

Reference:

A.LetterfromRobertC.Mecredy(RGEE)toDocumentControlDesk(NRC),datedJanuary31,1997,"ResolutionofGenericLetter87-02,Supplement1andGenericLetter88-20,Supplements4and5(SeismicEventsOnly)."B.C.LetterfromGuyS.Vissing(NRC)toDr.RobertC.Mecredy(RGRE),datedApril6,1998,"RequestforAdditionalInformationontheresolutionofUnresolvedSafetyIssue(USI)A-46."LetterfromRobertC.Mecredy(RG&E)toDocumentControlDesk(NRC),datedMay27,1998,"ResponsetoRAIonUSIA-46."D.

DearMr.Vissing:

LetterfromGuyS.Vissing(NRC)toDr.RobertC.Mecredy,datedDecember3,1998,"SecondRequestforAdditionalInformation".1(/QOThisletterprovidesresponsestotheNRC's"RequestforAdditionalInformation"(RAI),datedDecember3,1998(Ref.D).Enclosures1and2alongwiththeparagraphsbelowrespondtoQuestion1partsaandbregardingtheuseofGIP"MethodA"atGinnaStation.Responsestoquestions2,3and4regardingspecificSQUGscreeningmethodsandtestingdataareprovidedinEnclosure3.9902i00108990202PDRADQCK05000244PPDR Theuseof"GIPMethodA"isdescribedintheGenericImplementationProcedure,Revision2(GIP-2),theSupplementalSafetyEvaluationReportNo.2(SSERNo.2),andthedocumentsreferencedinGIP-2uponwhichGIP-2isbased.RG&EusedMethodAtoestimateseismicdemandforcertainequipmentwithin40feetofeffectivegradeatGinna.TheNRChasquestionedRG&E'suseofMethodAonthebasisthatMethodAmaybeusedonlyiftheamplificationfactorbetweenthefree-fieldgroundresponsespectrum(GRS)andthecalculatedin-structureresponsespectra(ISRS)beingusedbytheplantisnotmorethanabout1.5.TheNRCpositionisbasedontheirinterpretationofthelanguageonpage4-16oftheGIPwhichsaysthat"theamplificationfactorbetweenthefree-fieldresponsespectraandthein-structureresponsespectrawillnotbemorethanabout1.5...".RochesterGasandElectricdoesnotagreewiththeNRC'sinterpretation.ItisRG&E'spositionthattheapproachusedforapplyingandimplementingGIPMethodAforestimationoftheseismicdemandonequipmentatGinnaforresolutionoftheUSIA-46programisappropriateandtechnicallyjustified.DetailedbasesareprovidedinEnclosure1.WithrespecttotheNRC'squestionregardingdifferencesbetweenthein-structureresponsespectraandthe1.5xgroundresponsespectra,RG&Enotesthatthesespectraweregeneratedusingconservativemethodsandassumptions(typicalofmostnuclearplantresponseanalyses)whichartificiallyincreasedtheamplificationsoverthosewhichwouldbeexpectedinanactualearthquake.AdetailedqualitativeassessmentoftheseconservatismsareprovidedinEnclosure2.Basedontheabove,andtheinformationinEnclosures1and2,webelievethatRG&EhasproperlyinterpretedtheconditionsonuseofMethodA,andthattheseconditionsappeartohavebeenunderstoodandacceptedbytheNRCstaffuntilrecently,afterRG&Ecompleted'theUSIA-46reviewsatGinna.TochangethisinterpretationatthisstageintheprogramforresolutionofA-46wouldbeinconsistentwiththespiritandintentofA-46andwouldalsorequirereworkofequipmentoradditionalanalysesandevaluationswithoutacommensuratesafetybenefit.PleasecontactGeorgeWrobelat(716)771-3535ifyouhaveanyadditionalquestions.Verytrulyyours,RobertC.Mecredy Enclosures(3)xc:Mr.GuyS.Vissing(MailStop14B2)ProjectDirectorateI-1DivisionofReactorProjects-I/IIOfficeofNuclearReactorRegulationU.S.NuclearRegulatoryCommissionWashington,D.C.20555RegionalAdministrator,RegionIU.S.NuclearRegulatoryCommission475AllendaleRoadKingofPrussia,PA19406Mr.P.DrysdaleU.S.NRCGinnaSeniorResidentInspector Enclosure1BasesforInterpretationandImplementationofGXP-2RulesforMethodAItisRochesterGasandElectric'spositionthatRochester'sGinnaStationhasproperlyinterpretedandimplementedtherulesforuseofGIPMethodAaspreviouslyreviewedandacceptedbytheNRC.Thebasesforthispositionareasfollows:SQUGandRochesterGasandElectric'sInterpretationoftheGIPThecautiongivenonpage4-16ofGIP-2liststwolimitationsonuseofMethodA:Equipmentshouldbemountedinthenuclearplantbelowabout40feetabovetheeffectivegrade,andEquipmentshouldhaveafundamentalnaturalfrequencygreaterthanabout8Hz.TheintroductorywordinginGIP-2forthesetwolimitationsprovidesthebasesorpurposesforimposingthem,namely(1)tolimitamplificationtonomorethanabout1.5and(2)toavoidthehigh-energyfrequencyrangeofearthquakes.ThespecificlimitationswhichareintendedbytheSQUG/NRCexpertpanel(SSRAP)andSQUGtosatisfythesebasesareincludedinthetwobulleteditemslistedabove.Thestatementonpage4-16that"theamplificationwillnotexceedabout1.5"istheexpectedresultofmeetingtheabovelimitations,notathirdcondition.AtnotimewasacomparisonofMethodAamplificationwiththatofcalculatedISRSeverintended.Infact,theentirecontextofthecautiononpage4-16ofGIP-2makesclearthattheadvantageofMethodAisthatequipmentmeetingthetwobulletedlimitationsabove"canbeevaluatedwithouttheneedforusingin-structureresponsespectra..."2.TheIntentoftheGIPisClearandSSRAPAgreesTheGIP(page4-11)citestheSSRAPreportasthebasisfortheBoundingSpectrumwhichisusedinMethodA,andrequiresuserstoreadandunderstandit.TheSSRAPreportclearlyexplainsthelimitationsandconditionswhichappearonpage4-16oftheGIP.SSRAP'sreportstates:

"Thus,itisSSRAP'sjudgmentthatamplificationsgreaterthanafactorof1.5areunlikelyinstiffstructuresatelevationslessthan40feetabovegradeexceptpossiblyatthefundamentalfrequencyofthebuildingwherehigheramplificationsoccurwhensuchafrequencyislessthanabout6Hz.Thus,forequipmentwithfundamentalfrequenciesgreaterthanabout8Hzintheas-anchoredconditionitwasjudgedthatfloorspectralamplificationswithin40feetofgradewouldbelessthan1.5whenreasonablycomputedusingmoremediancenteredapproaches."[SSRAPReport,page102]TheSSRAPChairmananddeveloperofMethodA,Dr.RobertKennedy,wascontactedbySQUGandconcurswiththeinterpretationgiveninitem1above.TheNRCWasAwareofSQUG'sInterpretationWhenItWasDevelopedTheNRCbackfitanalysisinNUREG-1211,whichjustifiesimplementationoftheUSIA-46programbyaffectedlicensees,reliesontheconclusionsreachedbySSRAPintheirreviewofseismicexperiencedata.NUREG-1211statesthefollowing:"TheNRCstaffhascloselyfollowedtheSSRAPworkandisinbroadagreementwithitsconclusions.ThestaffhasconcludedthatiftheSSRAPspectralconditionsaremet,itisgenerallyunnecessarytoperformexplicitseismicqualificationontheeight(1)classesofequipmentstudied."[NUREG-1211,page17](1)TheeightclassesofequipmentcitedinNUREG-1211werelaterexpandedto20equipmentclasses.NotethatthisquotationspecificallymakesreferencetotheSSRAP"spectralconditions."ThespectralconditionsaredescribedinSQUG'spositiongivenaboveandwereincludedinGIP-2.TheuseofMethodAwaspreviouslyreviewedandacceptedbytheNRCandSSRAPrepresentativesduringtwopilotplantreviewsconductedin1987and1988.ThesereviewsaredocumentedinGIP-2References16and25.ThespecificmaterialpresentedtotheNRCrepresentativesonuseofMethodAisdescribedinthereportoftheBWRpilotreviewasshowninFigure1.Notethattheseismicdemandcriteriadescribedduringthistrialplantreviewarethesameasdescribedinitem1above.NRCandSSRAPrepresentativesraisednoobjectionstotheapproachusedbySQUGinconductingthesetrialplantreviews.ThetopicsdiscussedwithandcommentsmadebyNRCandSSRAPrepresentativesduringtheBWRpilot'eviewareincludedinFigure2;notethatseismicdemandinformationwasdiscussedinsomedetail.

TheRochesterGas&Electric/SQUGinterpretationoftherulesforapplyingMethodAisalsoconsistentwiththeSQUGtrainingcourseonuseoftheGIPmethods'igure3isanexcerptfromtheclassnotesusedduringthiscourse.Itshows,inSlide26,severalscreeningmethodsforcomparingequipmentcapacitytodemand.Screen52illustratesusesofGIPMethodAasdescribedinItem1above'hatis,ifequipmentisbelow40feetandabove8Hz,andtheBoundingSpectrumenvelopesthegroundresponsespectrum,theequipmentisacceptable.ThistrainingmaterialwasusedduringthefirstsessionoftheSQUGtrainingcourseheldduringtheweekofJune22,1993.TwoNRCstaffmembers(P.Y.Chen,MichaelMcBrearty)andaNRCcontractor(KamalBandyopodhyay)attendedthisinitialsessionandlaterprovidedcommentsonthetrainingcourseinaletterdatedAugust28,1992.TheNRCdidnotraiseanyobjectionstotheapproachtaughtbySQUGinthiscourseforapplyingMethodA.Subsequenttothisinitialsessionofthecourse,11additionalNRCstaffmembersandcontractorsattendedothersessionsofthiscourse;similarly,noneofthemraisedobjectionstohowSQUGwasteachinguseofGIPMethodA.NRCInterpretationRendersMethodANotUsefulThe..NRCinterpretationisthatMethodAcanbeusedonlywhencalculatedISRSarelessthan1.5xGRS.ThisinterpretationnegatesthevalueofusingMethodAbecauseitcouldonlybeusedwhenitproduceshigherseismicdemandthanMethodBwherecalculatedISRSareused.Underthisinterpretation,MethodAwouldneverbeused.ThisisinconsistentwithMethodA'developmentanduse,andwasnevertheintent.

FIGUREj.(Figure1containsanexcerptfromGIP-2,Reference25,whichshowstheseismicdemandcriteriausedduringtheBWRTrialPlantReview.)SEISMICDEMANDCRITERIAAPPLICATIONDEMANDCRITERIAEquipmentinexperiencedatabaseandlessthan40'bove243',andfundamentalfrequencygreaterthan8Hz.1.ComparegroundSpectrawithboundingspectrum(Figure3.1inSSRAPreport).Equipmentinexperiencedatabaseover40'bove243'over281'levation)orfundamentalfrequencylessthan8Hz.EquipmentcoveredbyGERS(anyelevation,frequency).Compareamplifiedfloorresponsespectrawith1.5xboundingspectrum(FigureR1....,Rn,TI,...,Tn).Compareamplifiedfloorspectra(median-centered)with2/3xSERSforspecificequipmentclass.4~Anchorageevaluationandequipment-specificstresschecks(excludingvalves):Equipmentwithin40'f"grade"(elevation281'ndbelow)andfundamentalfrequencylessthan8Hz.Equipmentatanyelevation.Utilizeaccelerationsfrom(1.5xgroundspectra)x1.25.Utilizeaccelerationsfrommedian-centeredamplifiedfloorresponsespectrax1.25.Equivalentstaticloadfactorforallequipment(exceptvalves).Staticloadcheckforvalveoperator/yokechecks.Usingappropriatespectrawithmultiplier,use:Peakaccelerationforflexibleequipment.ZPAforrigidequipment.Accelerationatcalculatedfundamentalfrequency.3G,Weakdirection.Note:Ingeneral,forequipment.withfundamentalfrequencygreaterthan8Hzandwithin40'fgrade.1.5xgroundspectramaybeusedasanestimateofmedian-centeredamplifiedfloorspectra.

FIGURE2(Figure2containsanexcerptfromGZP-2,Reference25,whichsummarizestheSSRAPandNRCcommentsontheBWRTrialPlantReview)Section8SENIORSEISMICREVIEWANDADVISORYPANEL(SSRAP)ANDNUCLEARREGULATORYCOMMISSION(NRC)REVIEWSRepresentativesofSSRAPandtheNRCattendedtheNMP-1walkdownonFebruary1stthrough3rd(Days8through10).OnFebruary1st,followingradiationprotectiontraininganddosimetryissuance,theSSRAPandNRCrepresentativeswerebriefedontheorganizationandconductoftheNMP-1walkdown.Theindoctrinationandpre-walkdownmaterialscoveredbySQUGforthewalkdownparticipantswerealsoreviewedwithSSRAPandtheNRC.Theindoctrination/trainingmaterialsaregiveninAppendixCandincludeinformationontheorganizationandscheduleofthewalkdown,therulesofconductintheplant,plant-specificdataontheseismicdemandlevelsforthewalkdown,andsummaryinformationonGIPrequirementsforreviewofseismicdemandversuscapacity,equipmentcaveats,anchorageevaluationandevaluationofinteractions.TheNMP-1seismicdemandinformationusedforthiswalkdownwasdiscussedinsomedetail.SQUGrepresentativesexplainedthattheseismicgroundmotionusedasabasisforthewalkdownisaplant-specific,uniformhazard,ground-motionspectradevelopedbyA.CornellandR.McGuixeandisanchoredat0.13G.Thisground-motionspectraenvelopestheNMP-1FSARlicensingbasisSSEspectrawhichisanchoredat0.11G.TheNMP-1uniformhazardground-motionspectraisshowninAppendixC.AlsointhisAppendixareamplifiedfloorresponsespectradevelopedforNMP-1usingmodernreactorandturbinebuildingmodelsandthe0.13Guniformhazardground-motionspectra.Mr.Djordjevic(StevensonsAssociates)reviewedthebasesfortheamplifiedfloorresponsespectraandindicatedthattheyarebeingusedasmean-centered,realisticspectra.Dr.Kennedy(SSRAP)expressedtheviewthathebelievesthefloorresponsespectraareconservativeandgenerallyinaccordancewithcurrentStandardReviewPlancriteria.Asaresult,SSRAPconsidersthatitisnotnecessarytoutilizetheadditionalfactorsofsafetyrecommendedbySSRAPforusewithmean-centeredspectra(1.5foruseofGERSand1.25foranchorageevaluation)inusingtheNMP-1floorresponsespectraduringthiswalkdown.AsecondareadiscussedregardingtheseismicdemandwastheeffectivegradelevelatNMP-1.Atthissite,thetuxbinebuildingisfoundedonrockatelevation243feetabovesealevel.Thereactorbuildingisfoundedonrockat198feet.Gradeelevationis261feet.Intheconstructionofthebuildings,thesiteswereexcavatedtothefoundationlevel,thebuildingsconstructed,andtheannularspacebetweenthebuildingandtherockexcavationwasbackfilledwithcrushedstoneuptothe251footgradeelevation.AnelevationviewoftheplantisincludedinAppendixC.SQUGandNMPCrepresentativesexplainedthatwhiletheybelievelateralsupportisprovidedbythecrushedstonebackfill,ithasbeenconservativelyassumedforthepurposeofthiswalkdownthattheeffectivegradeelevationisatabout240-243feet.Thiselevationcorrespondstothefoundationoftheturbinebuildingandtheelevationinthereactorbuildingwherethestructurechangesfromanessentiallymonolithicconcreteblockstructure(includingthereactorbasemat)tothatofreinforcedconcretewallsandfloors.Essentiallynoamplificationisexpectedinthereactorbuildinguptoabout243feet.Onthisbasis,theelevationswhichareconsideredtobewithin40feetofeffectivegrade,arethoseelevationsinthereactorandturbinebuildingsuptoandincludingthe281footelevation.SSRAPwasingeneralagreementwiththisapproach.

PriortowalkdownoftheplantbySSRAPandNRCreviewers,thethreeSRTsdescribedtheirprogresstodate,highlightingareastheyparticularlywantedthereviewerstoevaluate.SSRAPandNRCrepresentativesspentmostofFebruary2ndperformingindependentwalkdownsofNMP-l.Essentiallyallsafeshutdownequipmentwasseenbythemwiththeexceptionoftheemergencycondensersandrelatedequipment,severalreactorcoolantsysteminstruments,severalreactorcoolantsystemisolationvalves,coresprayandcontainmentspraypumpsinthebasementcornerroomsandtheequipmentinthedrywell,allofwhichwereinaccessibleduetotheneedforradiationworkpermits(RWPs).Followingthiswalkdown,Dr.KennedyprovidedasummaryofSSRAP'sobservationsandconclusions:TheSSRAPwalkdownwasperformedtodeterminehowtheseismicreviewteams(SRTs)wereoperating,toassesshowtheSRTswereevaluatinganddispositioningthesafeshutdownequipment,andtoobtainageneralsenseoftheseismicruggednessofNMP-1.SSRAPdidnotobservemanyseismicconcernsandnoseriousseismicissues.TheexpectedoutliersidentifiedbytheSRTswereconsideredbySSRAPtobetypical.Dr.Kennedyremarkedthat,infact,therewerefeweroutliersthanwouldbeexpectedforaplantofthisvintage.HebelievesthatthisisresultofthenumerousseismicupgradesperformedbyNMPCovertheyearswhichwereapparenttoSSRAPduringtheirwalkdown.ItisSSRAP'sjudgment,basedontheirwalkdown,thattheSRTmembersreceivedadequatetrainingtoperformthewalkdownandthattheyweredoinganadequateandqualifiedjobofevaluatingtheseismicadequacyofthesafeshutdownequipment.SSRAPgenerallyexpressedtheopinionthatwhentheSRTsreacheddifferentconclusionsthanSSRAP,theSRTs'onclusionsweremoreconservative(i.e.,theSRTsmayhaveidentifiedmoreoutliersthanwouldSSRAP).SSRAPisuncertainiftheutilitySRTsusedduringthetrialplantwalkdownarerepresentativeoftheSRTsotherutilitiesmightusefortheirwalkdowns,sinceSSRAPbelievesthattheutilitySRTmembersatthetrialplantwalkdownhaveconsiderableseismicexperience.Asaresult,SSRAPcontinuestobelievethatitisessentialthattheSRTmembershaveadequatequalificationsandexperienceinseismicengineering.FollowingDr.Kennedy'ssummaryreport,NRCrepresentativespresentedtheirobservationsandconclusions.Dr.T.Y.Chang,USIA-46,ProgramManager,reportedthefollowing:TheNRCgenerallyagreeswiththeSSRAPreviewfindings.TheNRCbelievesthatthewalkdownhasshownthattheuseofutilityengineersisaviableapproachprovidedtheSRTmembershavetheproperlevelofexperience.TheNRCstillstronglybelievesthatthequalificationsoftheSRTmembersareveryimportant,irrespectiveofwhetherthemembersareutilityemployeesorcontractors.Further,theNRCbelievesthatthetrainingprogramisnotenoughtomakeanengineeraseismicexpert.TheSRTmembersshouldhavetherequisiteseismicexperiencepriortotheirselectionfortrainingandthewalkdowns.TheconductoftheNMP-1walkdownwasverysmooth.TheNRCcommentedthatitisclearthatthelessonslearnedfromtheTrialPlant1walkdownwerefactoredintothiswalkdowninthattherewasaconsiderableamountofpre-walkdownplanningwhichcontributedtothesmoothnessofthewalkdown.TheNRCwasimpressedwiththelayoutofNMP-1.Theplantisopenandhasconsiderablespacewhichcontributestobothgoodmaintenanceandalackofseismicinteractionhazards.TheNRCobservedduringtheirwalkdown(asdidtheSRTsandSSRAP)thatthequalityoftheanchorweldsinsomeelectricalcabinetswasmarginal.TheNRCnotedthattherelayreviewforNMP-1wasperformedforasampleoftypicalsafeshutdowncircuitsanddidnotcovereverysafeshutdowncircuitandrelayinthisplant.TheynotedthattheremainingcircuitsandrelaysneedtobereviewedbeforetheseismicreviewforNMP-1iscomplete.

Therewassomediscussionoftheuniformhazardground-motionspectrausedforthiswalkdown.Sincethisspectraboundsthelicensingbasisground-motionSSEspectraforNMP-1,theNRCconcludedthatthisground-motionspectraisacceptableandmeetstherequirementsofUSIA-46.TheNRCalsonotedthattheyconcurthattheamplifiedfloorspectrausedforthiswalkdownareconservativespectral (Figure3containsanexcerptfromtheSQUGWalkdownTrainingCourseclassnoteswhichshowsthescreeningprocessforcomparingequipmentcapacitytodemand.)EquipmentCapacityvs.DemandScreeningProcessReferenceSpectrum>IRSScreen1Screen2Below40'AboveSHz88oundingSpectrum>GRSGERS>IRSScreen3Screen4QualiTicationDocumentation>IRSOu5iersCapacity>DerrtandResolve-Slide26 ENCLOSURE2PositionPaerontheUseofMethodAatGinna~PuroseThepurposeofthispositionpaperistoprovidesupportinginformationforapplicationofMethodAatGinnaasrequestedbytheNRCinquestion1ofasecondRAIontheUSIA-46program.Thisenclosuredescribesmanyoftheconservatismsthatexistincomputedin-structureresponsespectraandthesafetysignificanceofthedifferencebetweencomputedandactualbuildingresponse.1.ConservatisminCalculatedISRSTheprocessofcalculatingin-structureresponsespectra(ISRS)isacomplicatedanalyticalexerciserequiringasignificantnumberofapproximations,modelingassumptionsandengineeringjudgments.Asaresult,thehistoricaldevelopmentoftheseISRShasincludedatremendousamountofconservatismwhichhastypicallyservedtwopurposes:IthasreducedthetechnicaldebateastothecorrectmodelingofthemanyparameterswhichareintrinsictotheISRScalculationalmethodology,and;2.Ithasreducedthecostsassociatedwithaverydetailedstate-of-the-artanalysis,(whichwouldattempttotrimoutalltheunnecessaryconservatisms).AsapartoftheA-46programresolutionmethodology,theSSRAPdevelopedandSQUGsubsequentlyendorsedanalternateISRSestimationtechnique(referredtoasMethodAwithintheGIP)whichwasmuchmoremediancenteredandrealisticthanthetypicaldesignpractice.RG&E's'positionisthattheapplicationofMethodAatGinnawasappropriateandtechnicallyjustified.ThefactthatdesignISRSmayshowamplificationsgreaterthan1.5isnotsurprising,nordoesitnegatethevalidityofMethodA.Infact,asnotedintheSSRAPreportitwasevenexpected."Secondly,mostunbroadenedcomputedin-structurespectrahaveverynarrow,highlyamplifiedpeaksattheresonantfrequencyofthestructure.Inmostcasesthesenarrow,highlyamplifiedpeaksareartificiallybroadenedtoaccountforuncertaintyinthestructure'snaturalfrequency.Thisprocesssimplyincreasestheemphasisonthesehighlyamplifiedpeaks.SSRAPisalsooftheopinionthatthesenarrowpeakswillnotbeashighlyamplifiedinrealstructuresathighgroundmotionlevelsasifpredictedbylinearelasticmathematicalmodels,noraresuchnarrowpeakedin-structurespectralikelytobeasdamagingtoequipmentasisabroadfrequencyinputwhichisrepresentedby1.5timestheBoundingSpectrum."

Asdescribedbelow,threeareasarepresentedtosupporttheapplicationofMethodAatU.S.nuclearplantsingeneral,andatGinnainspecific:A.MeasurementsofISRSinActualEarthquakesB.CalculationsofOverallConservatismsinTypicalISRSC.DescriptionoftheConservatismsinISRSinGeneralandGinnaISRSinParticularA.MeasurementsofISRSinActualEarthquakesSSRAPdevelopedtheMethodAresponseestimationtechniquebasedontheirresearchofbothactualearthquakemeasurementsandonrecent"mediancentered"analysis.Theyreference(SSRAPreportpage102)themeasuredfloorresponsespectraatelevationslessthan40feetabovethegradeformoderatelystiffstructuresatthePleasantValleyPumpStation,theHumboltBayNuclearPowerPlant,andtheFukushimaNuclearPowerPlantwhereamplificationsoverthegroundresponsespectradonotexceed1.5forfrequenciesaboveabout6Hz.Other,morerecentearthquakedatafromtheManzanilloPowerPlantandSicartsaSteelMillinMexico,aswellasseveralfacilitiesinCaliforniaandJapan,hasbeenrecentlyreviewedbySQUG.Thisdataalsoshowsthatstiffbuildings(similartotypicalnuclearstructures)amplifyverylittleatelevationslessthan40feetabovegradeandfrequenciesover8Hz.SQUGknowsofnonewmeasureddatathatchallengesGIPMethodA.B.CalculationsofOverallConservatisminTypicalISRSCalculatedISRShaveneverbeenportrayedasrepresentingtherealisticexpectedresponseduringanactualearthquake.Aspreviouslystated,ISRStypicallycontainmanyconservatismswhichmakethemunrealisticallyhigh.TheprimaryreasonforthedevelopmentofMethodAwastoestablishamoremediancenteredmethodofdefiningthestructuralresponsewithouthavingtoembarkoncostlynewanalysesofallthesitebuildings(Itshouldbenotedthateventhemostmodern,state-of-the-artISRScontainsignificantconservatisms;eventhoseclassifiedas"median-centered",areoftenveryconservative).ANRCcontractor(LLNL)concludedinastudyfortheNRC(NUREG/CR-1489)thattypicalcalculatedISRScontainfactorsof1.Sto1.8.RecentsurveysbySQUGshowsimilarlevelsofconservatismincalculatedISRS.

ItwasthecontentionofSSRAPthattheISRSfornuclearstructures(consideringthe40'nd8Hzconditions)wouldbewithinabout1.5timesthegroundresponsespectrum(GRS)iftheplantweresubjectedtoanactualearthquake.InderivingtheMethodAcriteriatheyrecognizedthatduetothevarietyofgroundmotions,soilcharacteristicsandstructurecharacteristicstherecouldbesomepossibilityofexceedancestothe1.5amplification,butstillstronglyjustifiedMethodA'applicability:"ItisSSRAP'sfirmopinionthattheissueofpotentialamplificationsgreaterthan1.5aboveabout8Hzforhighfrequencyinput"isofnoconsequencefortheclassesofequipmentconsideredinthisdocumentexceptpossiblyforrelaychatter'."[SSRAPReport,Page106]ThebasisSSRAPgavefordrawingthisconclusionwasthathighfrequencygroundmotionsdonothavemuchdamagepotentialdueto~lowspectraldisplacement,lowenergycontent,andshortduration.Theyfurthernotedthattheequipmentcovereddoesnotappeartohaveasignificantsensitivitytohighfrequencies(exceptpossiblyforrelaychatter,whichisaddressedseparatelyintheGIP).C.DescriptionofConservatismsinISRSinGeneralandGinnaZSRSinParticularThemostsignificantsourcesofconservatisminvolvedinthedevelopmentoftheISRSforGinnaincludethefollowing:000000000LocationofInputMotion(variationfromthefreefieldinputlocation)GroundResponseSpectrumShapeSoil-StructureInteraction(SoilDamping,WaveScatteringEffects)GroundMotionIncoherenceFrequency(StructureModeling)StructuralDampingTimeHistorySimulationNon-LinearBehavior(e.g.,soilpropertyprofilevariation,concretecracking)PeakBroadeningandEnvelopingClippingofNarrowPeaks'BecauseoftheSSRAPconcernrelatedtopossiblyrelaychatteratfrequenciesabove8Hz,theSQUGmethodologyspecificallyaddressesrelaywhicharesensitivetohighfrequencyvibration.SuchrelaysareincludedontheLowRuggednessRelayslistinAppendixEofEPRIReport,NP-7148.

~~Thedegreeofconservatisminvolvedineachoftheseparametersisspecifictothebuildingbeinganalyzed,tothefloorlevelbeingconsidered,andoften,totheequipmentlocationwithinthespecifiedfloorlevel.Theseconservatismstypicallycannotbeaccuratelyquantifiedusingsimplisticcalculationaltechniquessinceeachparametercontributestoanoverallsetofhighlynon-linearresponses.Thus,itwouldtakeaconsiderableefforttoquantifytheexactexcessconservatismsinherentinthecalculatedISRSatGinna.However,onthequalitativelevelpresentedbelow,itiseasytoseetheoriginsandlevelsofthisconservatism.Thefollowingparametersarethesourceofthemajorportionsoftheexcessconservatism:LocationofInutMotion-ThedefinedlocationoftheplantSSEistypicallypartofthedesignbasisdocumentation.TheSSEshouldtypicallybedefinedatthegroundsurfaceinthefreefieldasdefinedinthecurrentStandardReviewPlancriteria.ThedefinedlocationoftheGinnaSSEisconsideredthegroundsurfaceinthefreefield.ButforpurposedofgeneratingISRS,someplantsconservativelydefinedtheinput(currentlyidentifiedasthe"controlpoint"location)atanotherlocation,suchastheembeddeddepthofabuildingbasemat.Thisconservatismcanbesignificantdependingonthespecificplant/buildingconfiguration.TheGinnaplantsitegeologyconsistsofathinlayerofnaturalorcompactedgranularsoil(30to40feetindepth)immediatelyabovebedrock.Thebedrockisamixtureofsandstoneandfissileshalewithshearwavevelocitiescalculatedtobe7000feetpersecondorgreater.Priortoconstructionoftheplant,thesoiloverburden(30to40feetofglacialdrift)wasremoved.AllGinnaStationCategory1buildings,exceptforthecontrolbuildinganddieselgeneratorbuilding,arefoundedonsolidbedrock.Thefoundationsofthecontrolanddieselgeneratorbuildingswereexcavatedtothesurfaceofbedrock.Leanconcreteorcompactedbackfillwasplacedontherocksurfacetoadepthwherebytheelevationofthetopofthefillmaterialwascoincidentwiththeelevationofthebottomoftheconcretefoundationofthatparticularbuilding.Sections2.5.2.1(Seismicity)and2.5.2.2(MaximumEarthquakePotential)oftheGinnaFSARdescribetheoriginalinvestigationwhichwasperformedtodevelopestimatesofthemaximumexpected(OBE)andmaximumcredible(SSE)earthquakesforthesite.ItwasjudgedthatthemaximumcredibleearthquakewouldbeoneofRichtermagnitude6.0withanepicenter30milesfromthesiteoroneofmagnitude7.0ata90-mileepicentraldistance.AproceduredevelopedbyDames&Moore,usingtheresultsofresearchattheEarthquakeInstituteofTokyo,wasusedtoestimategroundmotionatagivenlocationiftheearthquakemagnitude,epicentraldistance,andelasticpropertiesoffoundationsoilsandrockareknown.TheFSARcontainsthefollowingdescriptionofthelocationofgroundmotion:

"Usingthismethodandtheassumedmaximumcredibleearthquakesdiscussedabove,maximumaccelerationonthesitewascalculatedtobe8'.ofgravityforsoilsurfaceand7%forbedrocksurface.Plantstructures,systems,andcomponentsdesignatedasSeismicCategory1aredesignedtoremainwithinapplicablestresslimitsfortheoperating-basisearthquake(0.08g)andthesafeshutdownearthquake(0.20g)."Basedontheabovelicensingbasisdescriptions,thedesignearthquakes(OBEESSE)wereclearlydefinedatthesoilsurface.SincetheISRSforGinnaweregeneratedusingaconservativemodeldefiningtheinputmotionatthefoundationlevel,significantconservatismexistsduetothelocationofinputmotion.Thelevelofconservatisminvolvedinthisassumptionisdifficulttoestimatewithoutperformingadditionalanalyses,butpaststudieshaveproveditcanbeconsiderable.GroundResonseSectrumShae-TheSSEdefinedwithintheplant-licensingbasisistheappropriatereviewlevelfortheA-46program.Someutilitiesutilizedalternative(conservative)spectralshapesfortheearthquakelevelsutilizedfortheirA-46resolution(i.e.,submittedaspartoftheir120-dayresponseletters).Theamountofconservatismisdirectlyrelatedtothedifferencebetweenthesetwospectralshapesatthefrequenciesofinterestforthestructuresbeingreviewed.Thisfactorcanrangefrom1.0toaround2.0dependingonthedifferencesbetweenthespectra.ThelicensingbasissafeshutdownearthquakeforGinnaischaracterizedbyasite-specifichorizontalgroundresponsespectrumanchoredtoaPGAof0.17g.However,ISRSwerenevergeneratedintheoriginalseismicdesignofGinnaandthisearthquakewasnotusedfortheUSIA-46program.AmoreconservativeearthquakeanchoredtoaPGAof0.2gandwithaRegGuide1.60shape(broaderband)wasusedforthegenerationofISRSintheA-46program.Theuseofthisalternateearthquakeinputisconservativefor3reasons:The4:dampedspectrawereusedinsteadoftheS:dampedspecificfortheA-46program.Theconservatismistypicallyquantifiedbytakingthesquarerootofthedampinglevels,whichwouldresultina1.12(12%)factorofconservatism.2)TheZPAlevelof02.gis18:higherthanthe0.17gsitespe'cificSSElevelforGinna.3)TheRegGuideShapeandthesitespecificshapearebothbroadbanded,buttheirlevelsofamplificationaredifferentandtheirdifferencesvaryasafunctionoffrequency.Dependingonthebuildinginquestionandthefrequencyrangeofinterest,therecanbeadditionalconservatismsduetothedifferencesinshape.

SoilStructureInteractionSSI-TypicaldesignanalysesdonotaccountproperlyforthephenomenaofSSI,includingthedeamplificationwithdepththatreallyoccursforembeddedstructuresandfortheradiationdampingeffectsinherentatsoilsites.Fixed-baseanalyseshavebeenperformedintypicaldesignanalyses,bothforstructuresfoundedonrockandforstructuresfoundedonsoilcolumns.Forrockfoundations,thefixed-basemodelhasbeenshowntobeslightlyconservativedependingontherock/structurecharacteristics.Forsoilfoundedstructuresthisassumptioncanvarybetweenconservativeandveryconservative,dependingonthelevelofsophisticationofthemodelingofthesoil-structuresystem.Thesimplifiedanalysesthatusedthefrequency-independentsoilspringsweretypicallyveryconservativeinthatradiationand/ormaterialdampingwereeitherconservativelyeliminatedorartificiallylimitedduringtheanalysis.Soilpropertieswerealsotypicallynotadjustedtoreflectanticipatedsoilstrainlevels.Significantreductionshavebeendemonstratedoverdesigntypeanalysesusingmoremoderntechniques.Thesereductionfactorsarehighlydependentonthespecificsoilconditionsandstructureconfigurations,butvaluesofaround2to4havebeenseeninpaststudies.TheGinnaanalyseshaveignoredanyreductioninfoundationmotionduetoembedmenteffects,wavescatteringeffectsandradiationofenergyfromthestructureintothesurroundingmedia.Theseeffectsarelessforrockfoundedstructures(StandbyAuxiliaryFeedwaterBuildingsandIntermediateBuilding)thantheyareforthesoillayerfoundedstructures(ControlBuildingandDieselBuilding),buttheyarenotnegligible.Thisassumptioniscommonlymadeforrocksitesbecauseitgreatlysimplifiestheanalysiseventhoughitintroducesconservatism.TheGinnaanalysesalsoignoredanyconstraintthatsurroundingrockorsoilplacedagainstexteriorsidewallsofembeddedstructures.Withoutconsideringlateralsupportfromtherockorsoilagainstembeddedstructures,onecomputesstructuralresponsesatgradethataregreaterthanthefreefieldmotion.However,thestructureatgradecouldnotrespondsignificantlygreaterthanthefree-fieldmotioniftheembeddedportionofthestructureislaterallysupportedbythestiffsoilorrock.Aswasthecasefortheveryfirstconservatismdescribed(locationofinputmotion),itwouldrequiresomereanalysistoestimatethedegreeofconservatisminvolvedintheSSImodelingofGinnastructures.Itisobvious,however,thatsomenon-trivialdegreeofconservatismexits.GroundMotionIncoherence-AshasbeendocumentedintheEPRIseismicmarginreport(EPRINP6041)therecanbeadeamplificationeffectonnucleartypestructuresduetotheincoherenceofgroundmotionovertherelativelylargedimensionsoftypicalnuclearstructures.ConservativereductionfactorsasafunctionoffrequencyandbuildingfootprinthavebeendocumentedwithinNP6041toaccountforthestatisticalincoherenceoftheinputwavemotion.These conservativevaluesrangefromafactorof1.1toaround1.5.Morerecentstudieshavedocumentedevengreaterreductionfactors.ThisgroundmotionincoherenceisapplicabletorocksiteslikeGinna.TimeHistoSimulation-ISRSatGinnahavebeengeneratedusingatimehistorywhichisintendedtoapproximatethedesiredearthquakespectrum(0.20g,Reg.Guide1.60shape).ThisprocessinvolvesthegenerationofanartificialtimehistorywhoseresponsespectraenvelopstheSSE.TheamountofconservatisminvolvedintheenvelopingprocesshasnotbeenspecificallycalculatedforGinnabutcanrangeuptoafactorof2ormoreunlesssignificantresourcesareappliedtominimizethedegreeofenveloping.CliinofNarro~Peaks-TheSSRAPreportandtheGenericImplementationProcedure(GIP)recommendproceduresforadjustingnarrowpeakstoreflecttwoareasofconservatism:Narrowpeaksarenotashighlyamplifiedinrealstructuresasarepredictedbylinearelasticmathematicalmodels,and2.NarrowpeaksinISRSarenotasdamagingtoequipmentasarebroadfrequencyinputsuchastheReferenceSpectrum.TheGIPprocedurerecommendsanaveragingtechniqueoverafrequencyrangeof10%ofthepeakfrequency(e.g.,1Hzrangefora10Hzpeakfrequency)usingtheunbroadenedISRS.TheGinnaISRShavenarrowpeaksanddidnotutilizethepeakreductionmethodsfromtheGIP.Theconservatisminvolvedhasbeenshowntobeintherangeof5%to20%fortypicalnarrowpeaksatseveralplants.WeexpecttheconservatismforthepeaksoftheGinnaISRStofallwithinthisrangebasedonasamplingforacoupleofpeaksshowinga10%effect.Thereareseveraladditionalsourcesofconservatism(e.g.,structuraldamping,structuralmodeling,structural/soilnon-'inearities,peakbroadeningandenveloping,etc.)whichaddtotheoverallconservatisminthecalculationofISRS.Theseadditionalconservatisms,coupledwiththosedescribedabove,certainlyreinforcetheoveralllevelsofconservatisminISRSofbetween1.5and8whichwerereferencedbySSRAP(LLNLReportNUREG/CR-1489),andexplainwhytheconservativeGinnaISRSproduceexceedancebeyondthe1.5factor.2.NotaSiificantSafetIssueTheexpecteddifferencesbetweencalculatedISRSandactualbuildingresponsedonotrepresentasignificantsafetyquestion.ThelessonslearnedfromreviewofhundredsofitemsofequipmentatvarioussitesthathaveexperiencedearthquakeswhichweresignificantlylargerthanthoseforEasternU.S.nuclearplantsarethatmissinganchorage,seismicinteractionhazards,andcertainequipment-specificweaknesses(incorporatedintotheGIPcaveats)weretheseismicvulnerabilitieswhichcauseequipmentdamage.TheseareasareconservativelyaddressedintheGIP.

I~TheNRCstaffacknowledgedtheseismicruggednessofnuclearpowerplantequipmentinthebackfitanalysisforUSIA-46inwhichtheystatedthefollowing:"...subjecttocertainexceptionsandcaveats,thestaffhasconcludedthatequipmentinstalledinnuclearpowerplantsisinherentlyruggedandnotsusceptibletoseismicdamage."[NUREG-1211,page16]MethodAisonlyapplicabletostiffequipmentwithfundamentalfrequenciesoverabout8Hz.AsnotedearlierinSection1ofthispaper,SSRAPandSQUGhaveagreedthatexcitationsover8Hzhavelittledamagepotentialduetolowspectraldisplacements,lowenergycontentandshortduration.ThisjudgmentissupportedbyindustryandNRCguidancefordeterminingwhetheranoperatingbasisearthquake(OBE)isexceededfollowingaseismiceventatanuclearpowerplant.EPRIReportNP-5930andNRCRegulatoryGuide1.166recognizethatdamagepotentialissignificantlyreducedforearthquakegroundmotionsabove10Hz.Inotherwords,thequestionofwhatistheprecisevalueofbuildingamplificationover8Hzhasverylittlesafetysignificance.3.GinnaBuildinsareicalNuclearStructuresAsrequested,RGEEisalsoprovidingdetaileddescriptionofthepowerblock.buildingconstruction.TheGinnapowerblockstructuresaretypicalnuclearpowerplantstructureswhichweredesignedtoresistlateralloadswithreinforcedconcreteshearwallsorbracedstructuralsteelframesystems.AsummarydescriptionofthebuildingsandtheirfoundationsarecontainedintheattachedTable1.4.Determinationof"GradeElevation""GradeElevation"determinationsforGinnaStationpowerblockbuildingweredescribedinSection2.3oftheJanuary1997submittal:"GradeElevationThepowerblockstructuresatGinnaarebuiltonthesideofahi'll.Gradeelevationonthenorth(lakeside)ofthepowerblockis253'.Gradeonthesouthsideofthepowerblockis271'.FortheA-46project,agradeelevationof253'asusedforthestructuresonthenorthsideofthepowerblock(DG,IB,SHTB),andagradeelevationof271'asusedforthestructuresonthesouthsideofthepowerblock(AB,AF,CB).Thecontainment(RC)isfoundedonrockatelevation235';235'asusedasthegradeelevationforA-46.ItshouldbenotedthatCB289'sthehighestelevationatwhichseismicSSELequipmentarelocated,andthatthegreatmajorityofseismicSSELequipmentareatelevation271'rlower.Therefore,forequipmentoutsidecontainment,whether253'r271'susedasgradewouldnotimpactthe"withinabout40'fgrade"criterioncommonlyusedintheGIP."

ItshouldbenotedthatCB289'sthehighestelevationatwhichseismicSSELequipmentarelocated,andthatthegreatmajorityofseismicSSELequipmentareatelevation271'rlower.Therefore,forequipmentoutsidecontainment,whether253'r271'susedasgradewouldnotimpactthe"withinabout40'fgrade"criterioncommonlyusedintheGIP."InadditiontopreviousdiscussionsinEnclosure2describingthepowerblockstructuresandcorresponding"gradeelevations",ageneralNorth-Southsitecrosssectionisprovided.ConclusionsThediscussionaboveleadstoseveralconclusions:ClAlloftheGinnastructuresarelargereinforcedconcreteshearwallorbracedsteelframestructures.Theyaretypicalofthestructuresdesignedfornuclearplantsof.theGinnavintageandare"typicalnuclearstructures".CITheresultsfromactualmeasuredISRSon"nucleartype"structuressupportthe1.5responselevelsadvocatedwithinMethodA.0QualitativeassessmentsoftheconservatisminherentwithinthemethodsutilizedtocalculateISRShavebeenprovidedabove.Theseconservatismsaretypicallyquitesignificant(ashasbeenindependentlyverifiedbymedian/modernassessmentsuchastheLLNLstudy)andcan/willresultinISRSwhichshowamplificationswellbeyondthe1.5factorfromMethodA.RGEEfeelsstronglythatthespecificexceedancesnotedbytheNRC(beyondthe1.5factor)onGinnaareduetothesehighconservatismsinherentintheISRSmethodsandnotdueto"unusual,plant-specificsituations".Therefore,theapplication=ofMethod"AtothestructuresatGinnaisappropriateandvalid.CIThereislittlesafetysignificanceintheexpecteddifferencesbetweencalculatedISRSandactualbuildingresponse.Thelargestsafetyimprovementsareprovidedbyappropriatelyreviewingequipmentanchorage,seismicinteractionhazards,andcertainequipment-specificweaknesseswhereseismicvulnerabilitieshavecausedequipmentdamageinrealearthquakes.ReviewsoftheseareaswereaprimaryfocusoftheSQUGGIPprocess;thereforeRG&E'simplementationoftheGIPatGinnaresultedinsignificantseismicsafetyenhancements.

Table1BuildingDGZBDetailedDescriptionofBuildingConstructionThedieseleneratorbuildin(DG)isaone-storyreinforced-concrete(Rc)structurethathastwocablevaultsunderneaththefloor.ThebuildingroofconsistsofaRCslabsupportedbyfourshearwallsthatsitonconcretespreadfootings.Ztisarelativelystiffstructuretypicalofmostdieselbuildingsatnuclearplants.Theintermediatebuildin(ZB)islocatedonthenorthandwestsidesofthecontainmentbuilding,andisfoundedonrock.Thewestendhasaretainingwallwheretheflooratelevation253ft6in.issupported.Thebottomoftheretainingwallfootingisatelevation233ft6in.Rockelevationinthisareaisatapproximateelevation239ft0in.Foundationsforinteriorcolumnsareonindividualcolumnfootingsandembeddedaminimumof2ftinsolidrock.SHTBCBThescreenhouse-servicewater(SH)buildingiscomprisedoftwosuperstructures,onefortheservicewater(SW)systemandoneforthecirculatingwatersystem(thescreenhouseportion).Theservicewater(SW)portionofthebuilding(bothbelowandabovegrade)isaSeismicCategoryIstructure.Theservicewater(SW)portionhousesfourSeismicCategoryIservicewater(SW)pumpsandSeismicCategoryZelectricswitchgear.Thescreenhouseportionhousesthetravelingwaterscreensandcirculatingwaterpumps.Theentirescreenhouse-servicewater(SH)buildingisfoundedinoronbedrockwiththeexceptionofthebasementoftheelectricswitchgearportionwhichisfoundedapproximately4ftabovebedrock.Sincethebuildingisfoundedinbedrockthebasementwillnotrealizeanyspectralaccelerationandtheseismicloadingisequivalenttothegroundmotionof0.08gand0.20g.ThebuildingisconstructedofRCbelowgradeandhasastructuralsteelsuperstructure.Theturbinebuildin(TB)isa257.5-ftby124.5-ftrectangularbuildingonthenorthsideofthepowerblock.Zthasaconcretebasementatelevation253.5ft,twoconcretefloors(amezzanineflooratelevation271ftandanoperatingflooratelevation289.5ft).Thebuildingisaheavilybracedsteelstructure.Theauxiliabuildin(M))isathree-storyrectangularstructure,70ft9in.by214ft5in.Itislocatedsouthofthecontainmentandintermediatebuildingsandadjacenttotheservicebuilding.Thestructurehasaconcretebasementfloorthatrestsonasandstonefoundationatelevation235ft8in.,andtwoconcretefloors--anintermediateflooratelevation253ftandanoperatingflooratelevation271ft.Constructionbelowgradeis(RC)withastructuralsteelsuerstructure.Thestandbauxiliafeedwaterbuildin(AF)isareinforced-concreteseismiccategoryIstructurewithreinforced-concretewalls,roof,andbasemat.Thebuildingissupportedby12caissonswhicharesocketedintocompetentrock.Thecontrolbuildin(CB)islocatedad)acenttothesouthsideoftheturbinebuildingandisa41-ft11-3/4in.by54-ft1-3/4inthree-storystructurewithconcretefoundationmatatelevation253ft.Thefoundationofthecontrolbuildingissupportedonleanconcreteorcompactedbackfill.Therockelevationinthisareaisatapproximateelevation240ft.0in.Thefoundationofthecontrolbuildingwasexcavatedtothesurfaceofthebedrock.Thefillmaterialwasplacedontherocksurfacetoadepthcoincidentwiththecontrolbuildingfoundation.Thebottomelevationofthedeepestportionofthefoundationmatisatelevation245ft4in.,withastructuralslabsupportedatelevation250ft6in.withathickenedslabforcolumnfootings.ThebuildingconsistsofbothRCandstructuralsteel.RCThecontainmentbuildin(RC)isaverticalrightcylinderwithaflatbaseandahemisphericaldome.Thebuildingis99ft.hightothespringlineofthedomeandhasaninsidediameterof105ft.Thecylindricalconcretewall,whichisprestressedverticallyandreinforcedcircumferentiallywithmildsteeldeformedbars,is3.5-ft.thick.Theconcretedomeisareinforcedconcreteshell2.5-ft.thick.Theconcretebaseslabis2ftthickwithanadditionalthicknessofconcretefillof2ftoverthebottomlinerplate.Thecontainmentcylinderisfoundedonrock(sandstone)bymeansofpost-tensionedrockanchorswhichensurethattherockthenactsasanintegralpartofthecontainmentstructure.*BuildingdescriptionsarefromFSARandUFSAR.

4ScreenhouseDieselgeneratorannexTurbinebldg.Intermediatebldg.ServicebuildingReactorcontainmentbuildingI1I~FacadeControluildin11~SlAuxiliarybuildingAux.bldg,additionROCHESTERGASANDELECTRICCORPORATIONR.E.GINNANUCLEARPOWERPLANTUPDATEDFINALSAFETYANALYSISREPORTFigure3.7-6ContainmentBuildingandComplexofInterconnectedSeismicCategoryIandNonseismicStructures,FlanView LOWWATERDATUNIEL.243.0'IGHWATEROATUNIEL.247.0'REAKWALLEL.261'ISCHARGECANALEL.231.5'RADEEL.253'LANTGRADEEL.270'RADEEL.270'NVERTOFDEERCREEKEL.250'CREENHOUSEGUARDHOUSEAlD(II0AItQOICCfl0IIIconnIII0I0CAe00CQIllIllOAZZZrZcnc0Z.g~mrIlltlCI8UnO0Z ENCLOSURE3SECONDREUESTFORADDITIONALINFORMATIONR.E.GINNANUCLEARPOWERPLANTuestion¹2Inyourresponsetothestaff'sRAIQuestions¹3and¹4,foranumberofequipmentitems,theequipmentfrequencieswerestatedtohavebeen-judgedbySRTtobegreaterthan8Hzbyinspection.ProvidethebasisfortheSRTjudgementregardingequipmentnaturaIfrequency,especiallywhentheestimatedmagnitudefornaturalfrequencyisreliedupontodeterminetheapplicabilityfortheuseofGIP-2MethodA.l.Youarerequestedtoprovidefurtherjustificationforthefrequencyestimation,orprovideanalyticalcalculationstojustifysuchestimation,fortheequipmentitemsidentifiedasFT-4084,FT-4085,PSF01AaB,SAFVPCIP,SAFVPDIP,BVSZ4,DCPDPAB01A&BandDCPDPAB02AaB.Resonsestouestion¹2ThebasesfortheSRTjudgementwas:IIa.TheguidanceprovidedintheEPRIreport,"GuidelinesforEstimationorVerificationofEquipmentNaturalFrequency",ResearchProject2925-2,FinalReport,August1992.b.TheexperienceoftheSRT.TheSRTwascomposedofRGEEstaffandstafffromanoutsideconsultant,Stevenson6Associates,(S&A).TheSaAstaffmembersonthewalkdownswereDr.JohnStevenson,Mr.WalterDjordjevic,andMr.StephenAnagnostis.Dr.Stevensonhas35yearsofexperienceinthenuclearpowerindustry;Mr.DjordjevicandMr.Anagnostiseachhave15to20yearsofexperienceintheindustry.Inaddition,Mr.DjordjevicandMr.Anagnostiseachhaveextensiveexperienceperformingin-situmodal(frequencyresponse)testsofnuclearpowerplantequipment.Thistestinginvolvesdozenofpiecesofequipmentatmorethantennuclearpowerstations.Theequipmenttestedincludescontrolcabinets,motorcontrolcenters,switchgearandinstrumentracks.ThistestdataisthebasisofEPRIReportNP-7146,"GuidelinesforDevelopmentofIn-CabinetAmplifiedResponseSpectraforElectricalBenchboardsandPanels",andtheproceduresforcalculatingin-cabinetspectradescribedinGIP-2Section6.4.2(ScreeningLevel3).FT-4084andFT-4085StandbAFWPumFlowTransmittersTheseflowtransmittersareindividuallymountedtoasteelbaseplateandanchoredtoareinforcedconcretewallwithfour(4)3/8"concreteexpansionanchors,asshowninpicturebelow.TheSRTjudgedthisequipmenttohaveafundamentalfrequencygreaterthan8Hzbasedonthesmallsize,smallweight,andstiffsupport.4j~~.\4Wl'rQ".rjfo1 TheEPRIguidelinesdonotdiscussindividuallymountedpressureswitches,butdodiscusssteelframeinstrumentrackshousinganumberofpressureswitchesandrelatedequipment.Section3.3oftheguidelinesstatethat"Often,bracedrackswillhavefrequenciesgreaterthan8Hz.Thewalkdownteamneedonlybecautiousofverylarge,heavilyweighted,veryweakly-bracedracks,orverylowbracedracks".Basedonthisguidance,itisreasonabletoconcludethatanindividualtransmitter,securelymountedtoareinforcedconcretewall,willhaveafundamentalfrequencygreaterthan8Hz.PSF01APSF01BStandbAFWPumsCandDTheseare300HPelectric-motorhorizontalpumps.Eachpumpismountedonanapproximately3'-6"wideby10'-6"longsteelskid.Theskidisanchoredtoa27"highcontinuousconcretepedestalwithtwelve(12)3/4"cast-in-placebolts.Thepedestaliswellreinforcedanddoweledintothefloorslab.Therearenovibrationisolators.Section2.2oftheEPRIguidelinesstates:"Further,thefollowingclassesofmechanicalequipmentareconsideredtobesufficientlyruggedthatthewalkdownteammayassume,withoutfurtherjustification,thattheirnaturalfrequenciesareabove8Hz:PumpsEngineandMotorGeneratorsAirCompressorsFansandAirHandlersChil,lersTestingonshaketablesandinthefieldhasshownthatequipmentintheseclasseshavenaturalfrequenciesgreaterthan8Hzgiventhattheyhavedirectanchoragetothefloorandthatappendagessuchasveryflexiblecontrolpanelsarenotpresent.Onepossibleexceptionisthatdeepwellpumpsmayhaveunsupportedcantilevercolumnsandsuctionbowlswithnaturalfrequencybelow8Hz(NotethatthisaddressedbyaseparateSQUGcaveat).SAFWPCIPSAFWPDIPStandbAFWPumInstrumentPanelsThesearewallmountedinstrumentpanels.Eachpanelis30"widex54"highx32"deepandisweldedtocontinuousanglesrunningalongthetopandbottomofthepanel.Theanglesaresecuredtoareinforcedconcretewallwith5/8"concreteexpansionanchors(Bothtopanglesandoneofthebottomanglesaresecuredwiththreeanchors;theotherbottomangleissecuredwithtwoanchors.)TheEPRIguidelinesindicatethatthepresenceofwell-engineeredtopbracingonelectricalequipmentissufficienttosupportthejudgementthattheequipmenthasafundamentalfrequencyabove8Hz.TheSRTexperienceisthattypical(30"widex30"deepx90"tall),properlyanchored,floormountedinstrumentcabinetshaveafundamentalfrequencyintherangeof10Hz-15Hz.Smaller,wallmountedcabinetsofsimilarconstruction(suchasthesubjectpanel)haveatleastashighafundamentalfrequency.BUS14480VSwitchearThisisaWestinghouseTypeDBlowvoltageswitchgear,160"widex58"deepx76"high.Theswitchgearisanchoredwithten(10)3/4"HiltiKwikbolts.Section3.7oftheEPRIguidelinesstates:"Aslongasalineuphassixsectionsormore,thenaturalfrequencyofswitchgearunitsmaybeassumedtobeabove8Hz".S&AhastestedasimilarWestinghouselowvoltageswitchgearattheConnecticutYankeenuclearstation.Thatunit(designatedBUS4atCY)is408"widex54"deepx90"high.Afundamentalfrequencyof9.0Hzwasmeasured.

DCPDPAB01AandBDCPDPAB02AandBAuxBuildinDCPowerDistributionPanelsThesearewallmountedpanelboards(powerdistributionpanels).Eachpanelboardis30"widex40"widex12"deep,andwellanchored,nearthetopandbottom,toareinforcedconcretewallorareinforcedconcretecolumn.Section2.3oftheEPRIguidelinesstatesthatpanelboards(wall-mounteddistributionpanels),ifanchoredtoasubstantialfloororwall,willhaveafundamentalfrequencyofatleast12Hz.uestion3Inyourresponsetothestaff'sRAI,Question¹4,youindicatedthattheseismiccapacityvs.demandevaluationfortheUndervoltageRelayCabinetBus24QRAZRC24)wasbasedonshake-tabletesting.Youarerequestedtoprovideadetaileddiscussionofthetestingandtojustifytheadequacyofsuchtesting.Resonsetouestion¹3

References:

AmericanEnvironmentsCompany,Inc.,ReportNo.STR-142280-1,11/4/80(RG&EProjectEWR-1444)AmericanEnvironmentsCompany,Inc.,ReportNo.STR-142280-2,12/31/80(RG&EProjectEWR-1444)AmericanEnvironmentsCompany,Inc.,ReportNo.STR-142280-3,1/5/81(RG&EProjectEWR-1444)Thereareeight(8)relay/controlcabinetsofthismakeontheSSEL.Theirequipmentdesignationsandlocationsarelistedbelow:ARA1CC14ARA1RC14ARA2CC18ARA2RC18ARB1CC16ARB1RC16ARB2CC17ARB2RC17ControlBuilding271.00AuxBuilding271.00Screenhouse253.00Screenhouse253.00ControlBuilding271.00AuxBuilding253.00Screenhouse253.00Screenhouse253.00Thefourcabinetsoutsidethescreenhouseareeachstand-aloneand24"widex24"deepx70"high.Thefourcabinetsinthescreenhouseconsistoftwopairsofattachedcabinets;eachpairis48"widex24"deepx70"high.Each24"x24"x72"cabinetisanchoredtoareinforcedconcretefloorwithfour(4)HiltiKwik-Bolts.Thecabinetswereshake-tabletestedasdocumentedinReferences1through3.Theshake-tabletestswererandom,multi-frequency,andbiaxial(onehorizontalandtheverticaldirection);thetestswererepeatedwiththespecimenrotated90degreesabouttheverticalaxis.The"RRSvs.FRS"plotbelowshowsthetests'RS(RequiredResponseSpectra)comparedtotheenvelopeoftheFRS(FloorResponseSpectra)foralllocationslistedabove.TheRRSenvelopestheFRS,'utnotethattheRRSis3%damped,whiletheFRSis4%damped.However,theRRSiswellabovetheFRSinthepeakrange,andtheactualtestresponsespectraexceededtheRRSbyasubstantialamount,particularlyforfrequenciesabovethepeakrange.Section5.0ofthetestreportsstate:

"Thetestspecimencontinuedtofunctionbefore,duringandafterexposuretotheSeismicQualificationTestProgram.Therewasnoevidenceofphysicaldamage,orreportedelectricalmalfunctionobserved.asaresultofthestressesofthistestprogram."10-RequiredResponseSpectrum,3o/odampingEnvelopeofFloorResponseSpectra,4'4dampingp'L~lprrIrJrrr~l'0.110100Frequency(Hz)uestion44Forthe48DVACMotorControlCenter(MCC)-,youindicatedthattheMCCcanwithstandasinglefrequencytestconsistingofa1.35g,5beat,5cycle/beatinput,performedatthesignficantstructuralfrequencies.Itisknownthatsingle-axis,singlefrequencysinebeattests'ostlyperformedpriortotheissuanceofIEEEStandard344-1975,areconsideredinadequateforequipmentseismicqualificationduetotheirinabilitytoexcitemulti-axis,multi-frequencyresponsesofequipment(theveryreasonthatplantsareincludedintheUSIA-46program).Youarerequestedtojustifytheseismicadequacyofthismotorcontrolcenter.Resonsetouestion4

Reference:

LetterfromG.R.Geertman(Gilbert/Commonwealth)toC.J.Mambretti(RG&E)datedAu<fust11,1976.ThesubjectMCC(equipmentdesignationMCCL)isa4sectionWestinghouseMCC,66"widex19"deepx90"high.Itisanchoredwitheight(8)1/2"concreteexpansionanchors.TheMCCislocatedonelevation271'ftheAuxiliaryBuilding.

10Thefollowingplotcontainsseveralresponsespectratoillustratethediscussionthatfollows.I~I~---r---r--r-1-IJ~I~~II~JI~IIIIJQtI~QI-AB271A46FloorResponseSpectrum(EW/NSEnvelope,Adamping)-Rersponsespectrumtor5cycrbeatwylaeLabTest{4%damping)---ResponsespectrumusedbywestinghousetorAnalysis(assdamping)SIIIS~IIII~IcIII~IIIIIIIr1I1r'II1III,I~IIIIIT1TI,III~~IIIIIII~~IIIII0.11~~I~IIIIJJJIIIIII~IIII1~IIII~I~IIIIIrI~IIIIIII10II1TT~IIITIIII~III~~I~II~II~I~IIIISIIISIIIIIIIII~IIIII~I~Frequency(Hs)ThereferencecontainsasummaryreportfromWestinghousedocumentingtheMCC'sseismi'cqualification.TheMCCwasoriginallytestedin1972atWyleLabsfollowingtherequirementsofTEEE344-1971.Thetest.usedasinglefrequency,5cycle/beatsinebeatinputdwelledatthesignificantstructuralfrequenciesoftheMCC(bytest,thefundamentalfrequencywasfoundtobe8.5Hz).Themotionwassimultaneouslyappliedinthe-horizontaldirectionat1.35gandintheverticaldirectionat0.95g.Thecorrespondingresponsespectrumisshownintheabovefigureasthethinnersolidline.Subsequently,Westinghouseperformedamulti-frequency,multi-directionaldynamicanalysisusingtheresponsespectrumshownintheabovefigureasadashedline.WestinghousetermedthisresponsespectrumthenGinnaStationSSERequiredResponseSpectrum".Theanalysisshowedthatthein-structureaccelerationsinducedbythisresponsespectrumwereabout.1/2thoseinducedbythetest.Basedonthis,WestinghouseconcludedthattheMCCwasseismicallyqualified.ThebasisofWestinghouse'sanalysisspectrum(thedashedline)isnotknown.Forcomparison,theA-46floorresponsespectrumforAuxBuilding271'thelocationoftheMCC)isshownintheabovefigureasthethickersolidline.TheA-46spectrumissubstantiallybelowboththeWestinghouseanalysisspectrumandtheWyletestspectrqm).particularlyinthefundamentalfrequencyrangeat8.5Hz.TheZPAoftheA-46spectrumis0.3g,orlessthan1/4ofthetestinputlevel.Whiletheoriginalsinebeattestwasnotassophisticatedascurrent-daymulti-frequency,multi-axistests,theSRTconcludedthatthehighaccelerationlevelsusedinthetestweremorethanadequatecompensation.Notethatthetestdatadocumentedafundamentalfrequencygreaterthan8HzandthatAuxBuilding271'swithin40'feffectivegrade,thereforetheMCCmeetsthescreeningrequirementsforGIPMethodA.TheSRTchosetobaseitsacceptanceonthetestreport,ratherthanMethodA,becauseitfoundthatthetestreporttobeamorecompellingargument.

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