ML18024A073

Susquehanna Units 1 and 2 - Letter Regarding an Interim Report of Reportable Deficiency Regarding Potential Transformers on 4.16KV Switchgear and Advising the Commission That the Definitive Report Will Be Submitted by July 31, 1978

ML18024A073
Person / Time
Site:	Susquehanna
Issue date:	04/17/1978
From:	Curtis N W Pennsylvania Power & Light Co
To:	Grier B H NRC Region 1
References
Download: ML18024A073 (5)

Text

REGULATORYINFORMATIONDISTRIBUTIONSYSTEM(RIDDISTRIBUTIONFQRINCOMINGMATERIAL50-3eSREC:GRIERBH'RCORG:CURTISNWPAPNR8.LIGHTDOCDATE:04j'17/78DATERCVD:05J04f78DOCTYPE:LETTERNOTARIZED:NOCOPIESRECEIVED

SUBJECT:

LTR1ENCL0FURNISHINGINFQRECONSTRUCTIONDEFICIENCYREPTCONCERNINGWESTINGHOUSESUPPLIEDMEDIUMVOLTAGESMETALCLADSWITCHGEARWHICHMAYNOTBEFULLYCAPABLEOFWITHSTANDINGTHEPOSTULATEDSEISMICEVENTFORSUBJECTFACILITY...ADVISINGREQUIREDDEFINITIVEREPTWIPLANTNAME:SUSQUEHANNA-UNITSUSQUEHANNA'UNIT2REVIEWERINITIAL:XJMDISTRIBUTERINITIAL:~~DISTRIBUTIONOFTHISMATERIALISASFOLLOWS++++<%%%+<+<<<+<<+CONSTRUCTIONDEFICIENCYREPORT<10CFR50.55(E).(DISTRIBUTIONCODE3004>FQRACTION:INTERNAL:EXTERNAL:ASSTDIRVASSALLO+~LTRONLY(i>PROG~MINER4NLTRONLY<1)REGFIL~~gNLY<1).E+~LTRONLY(2)GOSSICK5STAFF+4LTRONLY<i)BOYD++LTRONLY(1)HELTEMES+<LTRONLY(i)KNIGHT~+LTRONLY(1>TEDESCO+~LTRONLY<i)STANDARDSDEV.++LTRONLY(1>LPDRSWILKESBARRE>PA~+LTRONLY(TIC4I~LTRONLY(1>NSIC++LTRONLY(1)FERDDREHERfIE4~>LTRONLY(i)ACRSCATB++LTRONLY<16)BRCHIEFPARR++LTRONLY(i>LICASSTRUSHBRQQK<~LTRONLY(i)NRCPDR++LTRONLY<i)QELD++LTRONLY(i>MIPC4+LTRONLY<1)DEYOUNG+>LTRONLY(i>R.MATTSON++LTRONLY<i)ROSS+~LTRONLY(1>EISENHUT++LTRONLY<1)KSEYFRITJIE++LTRONLY(i>DISTRIBUTION:LTR41ENCL0SIZE:2PTHEEND.CONTROLNBR:781240-1I

~iIt~V iw~\~fsrI-AP>>r'\LIPTWONORTHNINTHSTREET,ALLENTOWN,PA.'I8101PHONE:(215)821-5151NORMANW.CURTISVicePresidentEngineering8Construction821.5381April17,1978Mr.BoyceH.GrierDirector,RegionIU.S.NuclearRegulatoryComhtission631ParkAvenuec<<1.1<<Ir%I(/7>a~JCÃ~@errMff$CAC~CIl,'frQ~rrrKc3Rc3Cll~CAlXKingofPrussia,Pennsylvania19406SUSQUEHANNASTEAMELECTRICSTATION~@yy.,INTERIMREPORTOFREPORTABLEDEFICIENCYREGARDINGPOTENTIALTRANSFORMERSON4.16KVSWITCHGEAR~ig'/ggDOCKETNOS50387g'0388LICENSENOSICPPR-101,CPPR-102ERs100450/100508FILE840-4PLA-246

DearM.GriersThisrelatestoareportabledeficiency,

undertheprovisionof10CFR50.55(e),whichwas.identifiedtoMx'ATothNRCgRegionIbyMr.A.R.Sabol,PPGLduringa'elephoneconversationon3/31/78.ThedeficiencyinvolvesWesting-housesuppliedmediumvoltage,metalcladswitchgearwhichmaynotbefullycapableofwithstandingthepostulatedseismiceventfortheSusquehannaplant.ZCSpecifically,Westinghousehasadvisedthat,thepotentialtransformersecondarydisconnectingcontactassembliesonequipmentsimilartothatsuppliedforSusquehannahavefailedtowithstandrecentseismictests.Westinghousefurtherstatedthat,underseismicconditions,itispossiblethatthesecondarycontactscouldbedislodgedfromtheirnormalpositionscausingopencircuitingorshortingofthesecondarycircuits.Ithasbeenestablishedthateightofthesixteenunits,purchasedforuseinsafetyrelatedapplications,havebeenshippedtotheSSESplantsite.Toprecludeinstallationofthisequipment,Bechtelhasidentified(3/16/78)theseeightunitsinaQAStopWorkReport(No.78-06)asbeingnonconforming.Asaresult,BechtelQChaswrittenaNonconformanceReport(NCRNo.2514)andeachswitchgearunithashada"HoldTag"attached.BechtelEngineeringhasreviewedthesystemdesignandtheyhaveconcludedthattheworstconditionexistswiththeloss,oneachswitchgearbus,ofthepotentialtransformersonbothincomingfeederscoupledwiththelossofone,orboth,ofthebusvoltagemonitoringtransformers.78124003kerrrPENNSYLVANIAPOWER8LIGHTCOMPANY 4\,'KrJ Mr.Boycepi.Grier2April17'978Underthiscondition,theincomingbusfeedersfromthesafeguardtransformerswouldbeautomaticallydisconnectedandthedieselgeneratorpowersourceconnectedrestoringpowertothebus.Thefeederbreakerssupplyingpowertotheshutdownloadsarenormallyopen.ALOCAoccurringduringorafterthepostulatedseismiceventwouldinitiateaclosingsignaltothemotorfeederbreakersoftheshutdownloads,i.e.RHRandCoreSprayPumps.Thesefeederbreakerswouldcloseandimmediatelytripduetothefalseundervoltageindicationassensedbytheundervoltagerelay.Thecircuitbreakerswouldbeunabletocloseagainbecauseof'thepermanentundervoltagetripsignalimposedonthem.Theaboveanalysisassumesthatthefailuresconcurrentlyoccuronall'redundantswitchgearbuses.BechtelEngineeringhasfurtherconcludedthatthislossofcapabilitytosupplypowertoshutdownequipmentunderaLOCAconstitutesasafetyhazardtotheoperationoftheplantandrepresentsadeficiencyinfinaldesign.Asproposedremedialaction,Westinghousehasadvisedthatmodificationkitsareavailablewhich,wheninstalled,wouldeliminatethefaultysecondarydis-connectingassembliesfromthecircuit.Thisisaccomplishedbyhardwiring'thesecondarytotheloadcircuits.BechtelEngineeringisconsideringtheuseofthesemodificationkitspendingassurancefromWestinghousethatthismodi-ficationwillmeetalltherequirementsofthetechnicalspecification.Weanticipatesubmittaloftherequireddefinitivereportofthedeficiencyby7/31/78.Verytrulyyours,N.W.CurtisVicePresident-Engineering6Construction$6iG/ARS:cc:Ms.Mr.Mr.Mr.Mr.Mr.Mr.mcbM.C.N.W.R.L.J.W.J.D.H.L.JoToBartoCurtisEmeryGeilingGreenHarrisKauffmanN4N4N4N5SSESSSES-TW16Mr.H.F.LillighMr.E.M.MeadMr.M.R.MuirMr.J.R.SchmiedelMr.R.J.ShovlinSpsECorrespondenceFileSusquehannaLetterFile-BechtelSSES-N5-BechtelSFHO-BechtelSFHON4N3N3