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

REGULATORY INFORMATION DISTRIBUTION SYSTEM(RIDDISTRIBUTION FQRINCOMINGMATERIAL50-3eSREC:GRIERBH'RCORG:CURTISNWPAPNR8.LIGHTDOCDATE:04j'17/78 DATERCVD:05J04f78DOCTYPE:LETTERNOTARIZED:

NOCOPIESRECEIVED

SUBJECT:

LTR1ENCL0FURNISHING INFQRECONSTRUCTION DEFICIENCY REPTCONCERNING WESTINGHOUSE SUPPLIEDMEDIUMVOLTAGESMETALCLADSWITCHGEAR WHICHMAYNOTBEFULLYCAPABLEOFWITHSTANDING THEPOSTULATED SEISMICEVENTFORSUBJECTFACILITY...

ADVISINGREQUIREDDEFINITIVE REPTWIPLANTNAME:SUSQUEHANNA

-UNITSUSQUEHANNA' UNIT2REVIEWERINITIAL:XJMDISTRIBUTER INITIAL:~~

DISTRIBUTION OFTHISMATERIALISASFOLLOWS++++<%%%+<+<<<+<<+

CONSTRUCTION DEFICIENCY REPORT<10CFR50.55(E).(DISTRIBUTION CODE3004>FQRACTION:INTERNAL:

EXTERNAL:

ASSTDIRVASSALLO+~LTR ONLY(i>PROG~MINER4NLTR ONLY<1)REGFIL~~gNLY<1).E+~LTRONLY(2)GOSSICK5STAFF+4LTR ONLY<i)BOYD++LTR ONLY(1)HELTEMES+<LTR ONLY(i)KNIGHT~+LTR ONLY(1>TEDESCO+~LTR ONLY<i)STANDARDS DEV.++LTRONLY(1>LPDRSWILKESBARRE>PA~+LTRONLY(TIC4I~LTR ONLY(1>NSIC++LTR ONLY(1)FERDDREHERfIE4~>LTR ONLY(i)ACRSCATB++LTRONLY<16)BRCHIEFPARR++LTR ONLY(i>LICASSTRUSHBRQQK<~LTR ONLY(i)NRCPDR++LTRONLY<i)QELD++LTR ONLY(i>MIPC4+LTR ONLY<1)DEYOUNG+>LTR ONLY(i>R.MATTSON++LTR ONLY<i)ROSS+~LTR ONLY(1>EISENHUT++LTR ONLY<1)KSEYFRITJIE++LTR ONLY(i>DISTRIBUTION:

LTR41ENCL0SIZE:2PTHEEND.CONTROLNBR:781240-1I

~iIt~V iw~\~fsrI-AP>>r'\LIPTWONORTHNINTHSTREET,ALLENTOWN, PA.'I8101PHONE:(215)821-5151NORMANW.CURTISVicePresident Engineering 8Construction 821.5381April17,1978Mr.BoyceH.GrierDirector, RegionIU.S.NuclearRegulatory Comhtission 631ParkAvenuec<<1.1<<Ir%I(/7>a~JCÃ~@errMff$CAC~CIl,'frQ~rrrKc3Rc3Cll~CAlXKingofPrussia,Pennsylvania 19406SUSQUEHANNA STEAMELECTRICSTATION~@yy.,INTERIMREPORTOFREPORTABLE DEFICIENCY REGARDING POTENTIAL TRANSFORMERS ON4.16KVSWITCHGEAR

~ig'/ggDOCKETNOS50387g'0388LICENSENOSICPPR-101, CPPR-102ERs100450/100508 FILE840-4PLA-246DearM.GriersThisrelatestoareportable deficiency, undertheprovision of10CFR50.55(e),

whichwas.identified toMx'ATothNRCgRegionIbyMr.A.R.Sabol,PPGLduringa'elephone conversation on3/31/78.Thedeficiency involvesWesting-housesuppliedmediumvoltage,metalcladswitchgear whichmaynotbefullycapableofwithstanding thepostulated seismiceventfortheSusquehanna plant.ZCSpecifically, Westinghouse hasadvisedthat,thepotential transformer secondary disconnecting contactassemblies onequipment similartothatsuppliedforSusquehanna havefailedtowithstand recentseismictests.Westinghouse furtherstatedthat,underseismicconditions, itispossiblethatthesecondary contactscouldbedislodged fromtheirnormalpositions causingopencircuiting orshortingofthesecondary circuits.

Ithasbeenestablished thateightofthesixteenunits,purchased foruseinsafetyrelatedapplications, havebeenshippedtotheSSESplantsite.Toprecludeinstallation ofthisequipment, Bechtelhasidentified (3/16/78) theseeightunitsinaQAStopWorkReport(No.78-06)asbeingnonconforming.

Asaresult,BechtelQChaswrittenaNonconformance Report(NCRNo.2514)andeachswitchgear unithashada"HoldTag"attached.

BechtelEngineering hasreviewedthesystemdesignandtheyhaveconcluded thattheworstcondition existswiththeloss,oneachswitchgear bus,ofthepotential transformers onbothincomingfeederscoupledwiththelossofone,orboth,ofthebusvoltagemonitoring transformers.

78124003k errrPENNSYLVANIA POWER8LIGHTCOMPANY 4\,'KrJ Mr.Boycepi.Grier2April17'978Underthiscondition, theincomingbusfeedersfromthesafeguard transformers wouldbeautomatically disconnected andthedieselgenerator powersourceconnected restoring powertothebus.Thefeederbreakerssupplying powertotheshutdownloadsarenormallyopen.ALOCAoccurring duringorafterthepostulated seismiceventwouldinitiateaclosingsignaltothemotorfeederbreakersoftheshutdownloads,i.e.RHRandCoreSprayPumps.Thesefeederbreakerswouldcloseandimmediately tripduetothefalseundervoltage indication assensedbytheundervoltage relay.Thecircuitbreakerswouldbeunabletocloseagainbecauseof'thepermanent undervoltage tripsignalimposedonthem.Theaboveanalysisassumesthatthefailuresconcurrently occuronall'redundant switchgear buses.BechtelEngineering hasfurtherconcluded thatthislossofcapability tosupplypowertoshutdownequipment underaLOCAconstitutes asafetyhazardtotheoperation oftheplantandrepresents adeficiency infinaldesign.Asproposedremedialaction,Westinghouse hasadvisedthatmodification kitsareavailable which,wheninstalled, wouldeliminate thefaultysecondary dis-connecting assemblies fromthecircuit.Thisisaccomplished byhardwiring'thesecondary totheloadcircuits.

BechtelEngineering isconsidering theuseofthesemodification kitspendingassurance fromWestinghouse thatthismodi-ficationwillmeetalltherequirements ofthetechnical specification.

Weanticipate submittal oftherequireddefinitive reportofthedeficiency by7/31/78.Verytrulyyours,N.W.CurtisVicePresident-Engineering 6Construction

$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.Schmiedel Mr.R.J.ShovlinSpsECorrespondence FileSusquehanna LetterFile-BechtelSSES-N5-BechtelSFHO-BechtelSFHON4N3N3