ML17164A690

Site Audit Rept for Step 2 Review of IPEEE at Susquehanna Steam Electric Station Units 1 & 2. Site Audit Plan, Jul 1998

ML17164A690
Person / Time
Site:	Susquehanna
Issue date:	07/31/1998
From:	KAZARIANS M, KHATIBRAHBAR, SEWELL R T AFFILIATION NOT ASSIGNED, ENERGY RESEARCH, INC., EQE, INC.
To:	NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES)
Shared Package
ML17164A689	List: ML17164A690 ML18026A293
References
ERI-NRC-98-501, NUDOCS 9807240268
Download: ML17164A690 (14)

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ERI/NRC98-501SITEAUDITREPORTFORTHESTEP-2REVIEWOFTHEINDIVIDUALPLANTEXAMINATIONOFEXTERNALEVENTSATSUSQUEHANNASTEAMELECTRICSTATION,UNITS1AND2SITEAUDITPLANJuly1998M.Khatib-RahbarPrincipalInvestigatorAuthors:R.T.Sewell'ndM.KazariansEnergyResearch,Inc.P.O.Box2034Rockville,Maryland20847WorkPerformedUnderthcAuspicesofthcUnitedStatesNuclearRegulatoryCommissionOfliceofNuclearRegulatoryResearchWashington,D.C.20555ContractNo.04-94-050.EQEInternational,Inc.,2942EvergreenParkway,Suite302,Evergreen,CO80439Kazarians&Associates,425EastColoradoStrcct,Suite545,Glendale,CA91205'it807240268'it8072iPDR'ADOCK05000387PPDREnclosure1

TABLEOFCONTENTSIINTRODUCTION2SEISMICIPEEESITEAUDITPLAN2.1PrincipalIssuestobeInvestigated2.2PlantAreastobeWalkedDown.2.3LicenseePersonneltobeInterviewed.2.4Licensee/SiteDocumentationtobeAudited2.5AdditionalSiteAuditConsiderations(Optional).3FIREIPEEESITEAUDITPLAN~3.1PrincipalIssuestobeInvestigated3.2PlantAreastobeWalked-Down3.3LicenseePersonneltobeInterviewed~3.4Licensee/SiteDocumentationtobeAudited3.5AdditionalSiteAuditConsiderations(Optional)4REFERENCES33~~~~~~~~3444.6.6.7.7.7~~~8EnergyResearch,Inc.ERI/NRC98-501 1INTRODUCTIONThe"submittalonly"reviewfl]oftheIndividualPlantExaminationofExternalEvents(IPEEE)fortheSusquehannaSteamElectricStation,Units1and2[2,3],hasraisedsomeimportantconcernswhichmaybesubstantiallyaddressedinaplantsiteaudit.TheplantsiteauditisexpectedtoassisttheNuclearRegulatoryCommission(NRC)indeterminingwhetherthelicensee'sIPEEEprocessmeetstheobjectivesofSupplement4toGenericLetter88-20.TheobjectiveofthesitevisitistoaccessandreviewinformationnotcontainedintheIPEEEsubmittal,butnon'ethelessrequiredtoevaluatethelicensee'sIPEEEprocess.Thesitevisitwillprimarilyincludethefollowingactivities:Anentrance/orientationmeetingtodiscussthesiteauditobjectivesandapproach,andtosatisfyrequirementspertainingtoradiologicalandsecuritycontrolsforplantwalkdown.Anonsiteauditof"Tier2"IPEEEinformation,asdescribedinSection8andAppendixCofNUREG-1407,relatedtotheseismicandfireanalyses.Forinstance,suchinformationmayincludesystemnotebooksandanalyticalmodels,walkdownreports,supportingcalculationsanddata,plantproceduressupportinganycredittakenforoperatoractions,plantconfigurationdata,etc.However,thesiteauditwillfocusonareviewofinformationpertainingtothoseissues(i.e.,unresolvedrequestsforadditionalinformation[RAIs],identifiedpotentialweaknessesoftheIPEEEanalyses,andpotentialplantimprovements)whichhavebeendocumentedasaresultofthesubmittal-onlyreviewprocess.BInterviewswithlicenseepersonneland/orlicenseecontractorswhoarecapableofexplainingthefacetsoftheIPEEEanalysesunderreviewconsiderationandfamiliarwiththeaspectsofplantoperations,configurationanddesignthatarerelevanttotheissuesunderreviewconsideration(asidentifiedinSections2and3ofthisreport).PlantwalkdownswhichconsistofareviewevaluationoftheappropriatenessofIPEEEscreeningdecisions,modelingassumptions,andidentificationofpotentialplantimprovements.Again,thesewalkdownswillfocusonissueswhichhavebeendocumentedfromthesubmittal-onlyreviewandwhichcanbebetterassessedbymeansofphysicalinspection.Foranysuchissuesthatmayhavebroadrelevance(i.e.,areapplicabletoallcomponents,toanentiresafetysystem,ortoageneralclassofcomponents),asopposedtospecificrelevancetoaparticularareaorcomponentattheplant,thenthewalkdownwillbelimitedtoaphysicalinspectionthatsamplesonlyrepresentativeitems.Identificationandcollectionofinformationthatmayrequiresubsequentevaluationtoresolvearemainingreviewissueoraspecificissuerevealedasaresultofthesiteaudit.Anexitmeetingtosummarizetheapproachandresultsofthesiteaudit(includinganyproblemsencountered),andtoclarifyfurtheractionitems,ifany.Thefirstandlastactivitiesidentifiedaboveshouldinvolveallrelevantreviewandlicenseepersonnel.TheremainingactivitiesshouldbecoordinatedviaseparategroupsofrelevantreviewandlicenseepersonnelfortheseismicandfireportionsoftheIPEEEsiteaudit.Hence,forthemostpart,theauditandwalkdownactivitiesfortheseismicandfireanalyseswillbeperformedindependentlyandconcurrently.EnergyResearch,Inc.ERI/NRC98-501 SpecificdetailsregardingthesiteauditplanforseismicandfireeventsareprovidedbelowinSections2and3,respectively.Sections2.1and3.1listtheprincipalissuestobeinvestigatedduringthesiteaudit.Sections2.2and3.2identifytheplantareastobewalkeddown.Sections2.3and3.3identifythelicenseeandplantpersonneltobeinterviewedduringthesiteaudit.Sections2.4and3.4providealistofadditionaldocumentationtobereviewedeitheratthesite,orusedforsubsequentpost-sitevisitevaluations.Lastly,Sections2.5and3.5identifysomeadditionalweakpointshighlightedinthe"submittalonly"review[I],whichmaybeaddressedduringthesiteaudit,atthediscretionofthelicensee.EnergyResearch,Inc.ERI/NRC98-501 2SEISMICIPEEESITEAUDITPLAN2.1PrincipalIssuestobeInvestigatedTheprincipalissuestobeinvestigatedduringtheseismicIPEEEsiteaudithavebeendocumentedinRAlstothelicensee[4]andinatechnicalevaluationreport(TER)[1]resultingfromthesubmittal-onlyreview.Theseissuespertaintounresolvedquestions,potentialweaknessesidentifiedintheseismicIPEEEanalyses,andthepotentialneedforplantimprovements.Thespecificissuesareasfollows:~TheapproachdescribedintheSusquehannalPEEEsubmittalforassessmentofhighconfidenceoflowprobabilityoffailure(HCLPF)capacitieswasapparentlyneithertheconservativedeterministicfailuremargin(CDFM)method,fragilityanalysismethod,orotherconventionalapproach.ThesubmittalindicatesthatHCLPFassessmentswerebasedontheoriginalseismicdesignoronqualificationreports,butthedetailsofthemethodologywerenotprovided.Duringthesiteaudit,theauditteamwillreviewtheHCLPFcalculationsandsupportingdata(includingseismicdesigndocuments,drawings,seismicqualificationreport[SQRT]binders,etc.).ThepurposeofthisreviewwillbetocheckwhetherornottheHCLPFcalculationshavebeenbasedonestablishedpractice,toascertainwhetherornottheapproachandfindingsarereasonable,andtoconfirmwhetherornotthecalculationsareconsistentwithscreeningdecisionsandcriteria,aswellaswiththeinstalledconditionandconfiguration.Toachievethelastoftheseobjectives,itisexpectedthatsomecomponentswillbewalkeddown,asjudgednecessaryduringthesiteaudit.TheseismicIPEEEidentifiedcertainconcernswithrespecttolowseismiccapabilitiesfor(a)adjacentpanelsandcabinetsincloseproximitythatarenotfastenedtogether,(b)unanchoredcolorvideoCRTs,and(c)HCLPFcapacitiesoffourcomponents(twovalves,anautomatictransferswitch,andamotorcontrolcenter);however,nohardwarechanges,orotherenhancements,havebeendocumentedtorectifytheseconcerns.Also,anomalousconditionswereencounteredduringthewalkdownevaluationofseismic-fireinteractions,butagain,norelevantcorrectionswereproposed.Duringthesiteaudit,theauditteamwillreviewthelicensee'sresolutionapproachfortheseitems,includingexaminationofrelevantdrawingsandseismiccapacitycalculations,and/orbyphysicalinspection.Forthetwoidentifiedlow-capacityvalves(whichnlaypotentiallybedamagedthroughadverseseismic-spatialinteractions)thesubmittalstatedthatthesevalveswillbemanuallyoperatedfollowingaseismicmarginearthquake(SME).Duringthesiteaudit,theauditteamwillevaluatethelicensee'sbasisforthisrecoveryaction,includinganyrelevantproceduralenhancementsorsevereaccidentmanagementguidelinesthatmayhavebeenproposedbythelicensee.2.2PlantAreastobeWalkedDownTheseismicwalkdownwillincludeexaminationofthefollowingitemsdiscussedintheIPEEEsubmittal:EnergyResearch,Inc.ERI/NRC9S-501 MotorControlCenter(MCC)2B237(InteractionConcern)ValvesHV-155-F006andHV-251-F024B(InteractionConcerns)ControlandInstrumentationPanelsandCabinets(UnanchoredCRTs)ControlandRelayRooms(CabinetsNotBoltedTogether)AutomaticTransferSwitchOATS556(InteractionConcern)FirePumpsHousedintheNon-SeismicallyDesignedCirculatingWaterPumphouseSeismicallyUnsupportedCO>SupplyTankLocatedinthePlantYardBatteries/RacksfortheDiesel-DrivenFirePump(NoSpacersorStops)UnsupportedMetalCabinetsContainingCombustiblesLicenseePersonneltobeInterviewedLicenseepersonneland/orlicenseecontractorpersonnelwhoparticipatedin,andcanexplainindetail,theseismicscreeningwalkdownanditsfindings,theseismicHCLPFcalculations,andthedispositionapproachandstatusforidentifiedseismicoutliers/anomaliesshouldbeavailableduringtheseismicsiteaudit.Atleastoneoftheseparticipantsshouldbecloselyfamiliarwithdesigndocumentsandproceduresfortheirreadyretrievalduringthesiteaudit.Alicenseeparticipantfamiliarwiththeseismicsuccesspaths,plantsystems,andoperatingproceduresshouldalsobeavailabletodiscusstheseismicsystemsanalysisandtreatmentofoperatoractions.Additionally,aplantoperatorwhoisfamiliarwithplantsystems,andwhohasreviewedthesafeshutdownequipmentlist(SSEL),shouldbeonhandduringtheseismicreviewwalkdown.2.4Licensee/SiteDocumentationtobeAuditedThelicenseeshouldprovidethefollowingdocumentationinsupportofthesiteauditoftheSusquehannaseismicIPEEE:Systemsanalysisreportsupportingthedevelopmentofseismicsuccesspathsandtheidentificationofrandomfailuresandoperatoractionsthataffecttheintegrityofthesuccesspaths.HCLPFcalculationnotesandsupportingSQRTbinder',engineeringcalculations,resultsof'ynamicresponsecalculations(i.e.,in-structurespectra),anddrawings.SeismicIPEEEwalkdownreport,includingscreeningevaluationworksheets(SEWS),walkdownnotes,checklists,andsummaryofwalkdownfindings.Documentation(internalmemorandumsorother)onresolutionoftheopenitemsidentifiedinSection3.10.6oftheSusquehannaseismicIPEEEsubmittal,andsummarizedinTable4.1ofReference[1].2.5AdditionalSiteAuditConsiderations(Optional)AsidefromtheitemslistedinSection2.1,Reference[I]hasidentifiedsomeadditionalweakpointsofthe~IPEEEsubmittal.Theseadditionalpointsarenotconsideredtobesufficientlyserioustoaltertheacceptabilityofthesubmittal;however,thelicenseemay,atitsdiscretion,provideadditionalclarificationorinformationthatmayresultinresolutionoftheassociatedissues,sothatreferencetosomeweaknessescanbeeliminatedinthecontractortechnicalevaluationreport.Theoptionalissuestobeinvestigatedmayincludethefollowing:EnergyResearch,Inc.ERI/NRC98-501

~Thesubmittal'streatmentofseismiccontainmentperformancewaslimited.AlicenseeresponsetoarelatedRAIreliedontheargumentthatcoredamagewouldnotoccur,anddidnotprovidesufficientinformationonplantseismiccapacityrelatedtoaccidentmitigation.Duringthesiteaudit,thelicenseemayprovideadditionalinformationregardingseismiccontainmentperformance.Thisinformationshouldincludeanequipmentlistforsuccessfulearlyaccidentmitigation,descriptionofsuccesscriteriaforearlyaccidentmitigation,comparisonofthecontainmentequipmentlistwiththeSSELforaccidentprevention,andassessmentoftheplantseismiccapacitytoresistearlycontainmentfailureandradiologicalreleases,givencoredamage.\~Thesubmittaldidnotapplyscreeningcriteriatonon-seismicfailuresandhumanactions,asrecommendedinNUREG-1407foranElectricPowerResearchInstitute(EPRI)seismicmarginassessment(SMA).Duringthesiteaudit,thelicenseemayclarifyitstreatmentofnon-seismicfailuresandhumanactions,andtodemonstratethatratesofrandomfailuresandoperatorerrorsaresufficientlylowsoastonotcompromiseseismicsuccesspaths.Walkdownsofspecificareasoftheplantmaybeneededtosupportthelicensee'spresentationofadditionalinformationregardingtheseadditionalissues.Thelicenseepersonneltobeinterviewed,andthelevelofdetailofinformationtobeaudited,willbesimilartowhathasalreadybeenidentifiedinSections2.3and2.4.InSection3.106oftheSusquehannaseismicIPEEEsubmittal,thelicenseehasidentifiedanumberofissuesandhasdescribedapproachesfortheirresolution.TheseissueshavebeensummarizedinTable4.1ofReference[1].Duringsite-auditwalkdowns,thelicenseemaychoosetodemonstratethattheseissueshave.beensatisfactorilyaddressed.ExamplesofsomespecificitemsfromTable4.1ofReference[1]thatmaybeincludedinthesite-auditwalkdownsincludethefollowing:LowVoltageSwitchgear1/2B210,1/2B220,1/2B230,1/2B240(BreakerHoistRemoval)FansOV-116AandOV-116B(Anchorage)Heating,ventilationandairconditioning(HVAC)ComponentsinControlStructure(InteractionConcerns)LoadCenters(BreakerHoistRemoval)BatteriesandRacks(BlockWallInteractions)TanksOT528A-EandOT529A-E(UnscreenedAtmosphericStorageTanks)ContainmentInstrumentGasBottles(LateralSupport)EnergyResearch,Inc.ERI/NRC98-501 3FIREIPEEESITEAUDITPLAN3.1PrincipalIssuestobeInvestigatedTheprincipalissuestobeinvestigatedduringthefireIPEEEsiteaudithavebeendocumentedinRAIstothelicensee[4]andinaTER[1]resultingfromthesubmittal-onlyreview.TheseissuespertaintounresolvedconcernsidentifiedinthefireIPEEEanalyses.Thespecificissuesareasfollows:~Thereareatleasttwocablespreadingrooms,0-25Eand0-27C,thatmayhavebeenscreenedoutprematurely.Thelicenseehasscreenedthesecablespreadingroomsoutonthebasisoftheirlowcombustibleloading.GiventhattheseroomsmaycontainalargenumberofredundantanddiversecircuitsandcontaincablesprotectedwithThermo-lag'firebarriers,thescreeningmethodisnotvalid.Indeed,thereismuchuncertaintyinthelikelihoodofafirethatcoulddamagecablesinsuchcompartments.However,giventhepotentialsevereimpactonsafeshutdownequipment,suchcompartmentsshouldnotbescreenedoutwithoutgaininganunderstandingofthepossibleaccidentsequencesassociatedwithcablefailures(i.e.,sequencesofequipment/systemlossesorothersuchfailuresasvitalinstrumentationcircuits).Apotentialvulnerabilitymayhavebeenoverlooked.Togainanunderstandingofhowthelicenseehasdealtwiththisissue,aswellastheotherissuesmentionedbelow,theauditteamwillneedtogainanoverallunderstandingofhowthelicenseehasconductedtheIPEEE,andwhattypesofdocumentationweregenerated.Theauditteamwillneedtogainanunderstandingoftheoverallplantlayoutandinternalconfigurationwithrespecttothecablespreadingrooms,remoteshutdownpanel(RSP)andthecontrolroom.Thedocumentationsupportingthestatementsmadeinthesubmittalinconjunctionwithscreeningofthecablespreadingroomsandpresenceofredundantanddiversesafeshutdowncircuitswillbereviewedforeachcompartment.Licenseedocumentationwillbereviewedforthetypesofaccidentscenariosthatmayresultfromcablefailureswithinacablespreadingroom.~ThepossibilityofusingtheRSPisnotmodeledintheanalysis.Itisassumedthatevacuationofthecontrolroomwillnotbeneeded.Thisoverlooksthepossibilityofun-inhabitableconditionsinthemaincontrolroom,orthedecisionoftheshiAsupervisortoabandontheroom.LackofanalysisoftheRSP,whichisinstalledformitigatingacontrolroomorcablespreadingroomfire,isasignificantomissioninthefireanalysis.Thedocumentationthatsupporttheassumptionregardingthelackofneedtoevacuatethecontrolroom,andpossiblesourcesthatcanleadtocontrolroominhabitability,willbereviewedduringthe~sitevisit.ThereviewmayalsoincludetheproceduralandtrainingdocumentationthatdiscusscontrolroomevacuationanduseoftheRSP.TheauditteammayneedtogainanunderstandingofpossiblepathsbetweenthecontrolroomandtheRSP,andthepossibilityofblockagefromafirethatmayrequirecontrolroomabandonment.Aspartofthiseffort,theauditteammayneedtoreviewtheRSPcircuits(controlandinstrumentation),andassociatedisolationswitches.~Theoverallcoredamagefrequencyattributedtofireeventsisestimatedtobe10perrefuelingcycle(12to18months),whichismuchsmallerthanfrequenciestypicallyreportedinotherIPEEEsubmittals.ThereasonforthesmallfrequencyisthattheconditionalcoredamageprobabilityadoptedfromtheIndividualPlantExamination(IPE)modelisverysmall,whichinturnisEnergyResearch,Inc.ERI/NRC98-501 dominatedbyhumanactionsandrecoveryactivities.ThehumanactionsandrecoveryanalysesoftheIPEcannotbeusedforfire-inducedcoredamagefrequencyevaluationwithoutanadjustmentfortheinfluencesoffireontheoperatorsandrecoveryactions(e.g.,theeffectonman-power,controlroomhabitability,controlpanelalarmsandinstrumentationreading,useofequipmentfromtheoppositeunit,potentialshutdownofbothunitsfollowingasinglefire,etc.).Thecoredamage.frequenciesforvariousfirescenarios,asreportedintheIPEEEsubmittal,maybeoverlyoptimisticbecauseofthisomission.Toinvestigatethisissue,thesupportingdocumentationforthedominantfire-inducedcoredamagescenarios,andassociatedhumanerrorprobability(HEP)evaluation,willbereviewed.Selectedplantareasmayneedtobevisited,andcontrolroomsequencesmayneedtobereviewed.32PlantAreastobeWalked-DownThefollowingareashavebeenselectedaspriorityareasforthewalk-down:ThecablespreadingroomsandadjacentcompartmentsThecontrolroomAreaswheretheRSPandassociatedisolationswitchesarelocatedPathwaysconnectingthecontrolroomtotheRSPandisolationswitchesTheturbinebuilding3.3LicenseePersonneltobeInterviewedItwillbe,beneficialtointerviewthelicenseepersonnelwhohavebeeninvolvedinthepreparationandsubmittalofthefireportionoftheIPEEE.ThesepersonnelwillbeaskedtodisplaythedocumentationandcomputerfilesthatweregeneratedinthecourseofpreparingtheIPEEE,andprovideawalk-throughofthedocumentsandthefilesthatsupportthesubmittal,anddescribehowtheysupportthesubmittal.Theteamofexpertswhoconductedthehumanerroranalysis,andestimatedtheHEPsforthedominantfire-inducedcoredamagescenarios,willbeneededtoprovideanexplanationofhowtheHEPswerearrivedat.3.4Licensee/SiteDocumentationtobeAuditedThedocumentationandcomputerfilesthatweregeneratedinthecourseofpreparingtheIPEEEwillbeaudited.Thesemayincludesuchitemsasthefollowing:Calculationsheetsandothersupportingdocumentsforfirefrequencyevaluation.Documentssupportingthescreeningoffirezones,ingeneral,andsupportingthescreeningofthecontrolroomandcablespreadingrooms,inparticular.Documentssupportingtheassumptionthatthereisnoneedtoevacuatethecontrolroom,andproceduresthatdiscusscontrolroomevacuationanduseoftheRSP.COMPBRNinputsandoutputsforcasesinvolvingthecontrolroomorcablespreadingrooms.EnergyResearch,Inc."ERI/NRC98-501 Adescriptionofthefire-inducedinitiatingeventanalysis(e.g.,reactortrip,transientsandlossofcoolantaccidents[LOCAs]).CableroutinginformationforthecablespreadingroomsandfortheRSP.Information"onthemodelusedforfire-inducedcoredamageanalysisleadingtotheoverallcoredamagefrequencyreportedinthesubmittal~DocumentationsupportingtheassignmentoftheHEPsusedincalculatingcoredamagefrequenciesforthedominantfirescenarios.3.5AdditionalSiteAuditConsiderations(Optional)eAsidefromtheitemslistedinSection3.1,Reference[1]hasidentifiedsomeadditionalpotentialweakpointsoftheIPEEEsubmittal.Theseadditionalpointsarenotconsideredtobesufficientlyserioustoaltertheacceptabilityofthesubmittal;however,thelicenseemay,atitsdiscretion,choosetoprovideadditionalclarificationorinformationthatmayresultinresolutionoftheassociatedissues,sothatreferencetosomeweaknessescanbeeliminatedinthecontractortechnicalevaluationreport.Theoptionalissuestobeinvestigatedincludethefollowing:Thelicenseehasassumedthatfiresoriginatinginacabinetwillnotaffectcablesandequipmentoutsidethecabinet.Thisassumptionmaybevalidonlyiftherearenoopeningsontopofthecabinets,cabinetdoorsandstructuralelements(i.e.,doors,frame,bodyetc.)ofthecabinetsdonothavetemperaturesensitiveweakpoints,andcombustibleloadinginsidethecabinetscannotcreateanexcessivelystrongfire.Duringthesiteaudit,thelicenseemayprovideadditionalinformationregardingelectricalcabinetcharacteristics.Thosecabinetsthatareinthevicinityofcablesfromothercircuitsorotherelectricalcabinetswillbeinspected.Thelicenseehasassumedthatsmallmotors(<50hp)donotposeafirethreatorfireignitionsourcetoothermaterials.Thisassumptionisvalidonlyiftherearenocablesfromothercircuitsaboveornearthesemotors.Duringthesiteaudit,thelicenseemayprovideadditionalinformationregardingthecharacteristicsoftheareaswheresmallmotorsarelocated.Thoseareaswheresuchmotorsarelocatedmaybevisitedtoverifytherelativelocationofcablesandotherequipment.Asmentionedabove,walkdownsofspecificareasoftheplantmaybeneededtosupportthelicensee'spresentationofadditionalinformationregardingtheseadditionalissues.Thelicenseepersonneltobeinterviewed,andthelevelofdetailofinformationtobeaudited,willbesimilartowhathasalreadybeenidentifiedinSections3.3and3.4.EnergyResearch,Inc.ERI/NRC98-501

4REFERENCESR.T.Sewell,etal.,"TechnicalEvaluationReportontheSubmittal-OnlyReviewoftheIndividualPlantExaminationofExternalEventsatSusquehannaSteamElectricStation,Units1and2,"ERI/NRC95-512,FinalReport,February1998.2."SusquehannaSteamElectricStationIndividualPlantExaminationofExternalEvents(IPEEE),"PennsylvaniaPower&LightCompany,June27,1994.3."SusquehannaSteamElectricStationResponsetoRequestforAdditionalInformationonIndividualPlantExaminationofExternalEvents(IPEEE)Submittal,Units1and2(TACNos.M74478andM744790,"lettertoNRCDocumentControlDesk,fromR.G.Byram,PennsylvaniaPower&LightCompany,August9,1996.4,M.Cunningham(NRC),memorandumtoJ.Stolz(NRC),

Subject:

RequestforAdditionalInformationonSusquehannaIPEEESubmittal,March11,1998.EnergyResearch,Inc.ERINRC98-501