ML18030A192

Interim Deficiency Rept Re Use of Improperly Grounded Flexible Conduit on safety-related Circuits,Initially Reported on 801210.Caused by Manufacturer Failure to Remove Paint from Termination Module.Next Rept by Apr 1981

ML18030A192
Person / Time
Site:	Susquehanna
Issue date:	01/14/1981
From:	CURTIS N W PENNSYLVANIA POWER & LIGHT CO.
To:	GRIER B H NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
10CFR-050.55E, 10CFR-50.55E, ER-100450, ER-100508, PLA-613, NUDOCS 8101210362
Download: ML18030A192 (5)

Text

REGULAT~INFORMATIONDISTRIBUTIONTEr>>(RIDS)ACCESSIONNBR:8101210362DOC~DATE:81/Oi/14NOTARI7ED:NOFACIL:g-8SusquehannaSteamElectricStation<Unit'1RPennsylva0-.388SusquehannaSteamElectricStation~Unit2<PennsylvaA~AUTHORAFFILIATIONCURTISRN~<sPennsy'IvaniaPower8,LightCo.RECIP~NAMERECIPIENTAFFILIATIONGRIERR8,H~RegionlsPhiladelphiaiOfficeoftheDirector

SUBJECT:

Interimdefic>encyreptreuseofimproperlygroundedflexibleconduitonsafety-relatedcir'cuitsEinitiallvreportedon801210~CausedbymanufacturerfailuretoremovepaintfromterminationmodulesNextreptbyApril1981'ISTRISUTIONCODE:SOILSCOPIESRECEIVED:LTR/ENCLSIZE:TITLE:ConstructionDeficiencyReport(10CFR50,55E)NOTES:SendIEE3copiesFSARltallamends.SendILE3copiesFSARRallamends.00CKET05000387050003880500038705000388RECIPIENTIoCODE/Nar>>EACTION;A/0LICENSNG04RUSHBROOKsr>>~06INTERNAL:AD/RCt/IE17ASL'BP/J~HARDOIRMDIVOFLICEQUIPQUALRR11IS,E09iMPA20OELO21QABR14RUTHERFORDEAsI(.OPIESLTTREhlCL11111111'111111111111RECIPIENTIDCODE/IYAYiEYOUf<GBLOODEB05STARKERS07AEOD18D/DIRHUMFAC15EDO8STAFF19HYD/GEOBR22lICQUALBR12NRCPDR02.P--STREV13REGFII01STADS,DEV21COPIESLTTRENCL1111111l1111111111111EXTERNAL:ACRSNSIC160816161LPDR03gp]9SlggTOTALNUMBEROFCOPIESREQUIRED:LTTR~ENCL TWONORTHNINTHSTREET,ALLENTOWN,PA.18101PHONErt215)770-5151NORMANW.CURTISVicePresident'-EngineeringILConstruction-Nuclear77D5381January14,1981Mr.BoyceH.GrierDirector,RegionIU.S.NuclearRegulatoryCommission631PakAvenueKingofPrussia,PA19406SUSQUEHANNASTEAMELECTRICSTATIONINTERIMREPORTOFADEFICIENCYRELATINGTOIMPROPERLYGROUNDEDFLEXIBLECONDUITER's100450/100508FILE840-4PLA-613

DearMr.Grier:

ThisletterservestoconfirminformationprovidedbytelephonetoNRCInspector,Mr.J.Mattia,byMr.A.R.SabolofPP&LonDecember10,1980.DuringthatconversationsMr.Mattiawasadvisedthatthesubjectconditionwasunderevaluationforreportabilityundertheprovisionsof10CFR50.55(e).ThedeficiencyinvolvestheuseofimproperlygroundedflexibleconduitinvarioussafetyrelatedcircuitsasreportedtotheNRCbyGeneralElectricundertheprovisionsof10CFR21onDecember8,1980(LetterNo.MFN212-80).PPaLhasevaluatedtheconditionanddeterminedthatitisreportableunder10CFR50.55(e).Acompletedescriptionoftheconditionalong-withitssafetyimplicationsandcorrectiveactionplannedisattachedtothisletter.Sincethedetailsofthisreportprovideinformationrelevanttothereportingrequirementsof10CFR21,this.correspondenceisconsideredtoalsodischargeanyformalresponsibilityPPaLmayhaveforreportingincompliancethereto.WeexpecttoprovideafinalreportpriortoApril,1981.8102220'3llt7tPENNSYLVANIAPOWERILLIGHTCOMPANY Mr.BoyceH-.GriexJanuary14,1981Verytrulyyours,N.W.'CurtisVicePresident-Engineering6Construction-Nucleax'LW:sabAttachmentcc:Mr.VictorStello(15)Director-OfficeofEnspectionaEnforcementU.S.NuclearRegulatoryCommissionWashington,D.C.20555mcsghgmeOfficeofManagementInformationaProgramControlU.S.NuclearRegulatoryCommissionWashington,D.C.20555Mr.RobertM.GalloU.S.NuclearRegulatoryCommissionP.'O.Box52Shickshinny,PA18655 INTERIMREPORT~sub'ec0:ImproperlyGroundedFlexibleConduitonSafety-RelatedFailSafeCirciMetallicflexibleconduitisutilizedtoencloseelectricalconductorsinvariousfail-safe(deenergizetoperformthe'safetyfunction)safetyrelatedcircuits.Thesefail-safeci.rcuits,arepartoftheReactor.ProtectionSystem(RPS),NuclearSteamSupplyShut-Off'System(NSSS)andNeutronMonitoringSystem(NMS)logics.The'ail-safedesignrequiresthat.theflexibleconduitprovidealowresistancepathtoground.topreventexternalvoltagesources,thatcouldoccurfromcertainshortcircuits,fromdefeating(deenergizingtooperate)fail-safemodeofthesesafetyrelatedcircuits.Thepositivegroundpathassuresthattheupstreamprotectivedeviceswillsenseandinterruptashortcircuit,therebyeliminatingthepossibilityofanexternalvoltagesourcedefeatingthesafetyfunction.Flexibleconduiti:sutilizedforfail-safecircuitswithintheGE-suppliedPowerGenerationControlComplex(PGCC).TypicallytheflexibleconduitisroutedthroughthePGCCfloorsectionsfromtheterminationcabinetstopanelsorfrompaneltopanel.Thedefectbeingreportedisthelackofpositivemetallicgroundingfortheflexibleconduiteitherattheterminati.oncabinetoratthepanel.Inatypicalterm@nationcabinetinstallation;theconduitisattachedwithalockingringtoaterminationmodule.Thisisanacceptablegroundconnecti.on;however,theterminationmoduleisultimatelymountedonapainted(highelectricalresistance)surface.Duringmanufacturing,therewasnoproceduretoassurepaintwasremovedpriortomountingtheterminationmodule.Hence,apositivegroundpathwasnotprovided.GEhasreportedthisdefecttotheNRCunder10CFR,Part21.AnalsisofSafetImlicationsThedesignbasis,forsafety-relatedfail-safecircuitsoftheRPS,NSSSandNMSsystemsrequiresprotectionagainstthepossibilityoflossofprotectivefunctionsfromexternalvoltagesources.Installationofthesecircuitsin'positivelygroundedmetallicconduitisrequiredtomeetthisdesignbasis.'.EngineeringconsiderstheomissionofapositivegroundontheGEsuppliedflexiblemetal'licconduittobeasignificantdeficien'cyindesignandconstructionofthePGCCsuchthatifitweretohaveremaineduncorrected,couldhaveadverselyaffectedthesafetyofoperationoftheplant.Therefore,thelackofgroundingonflexiblemetallicconduitcontainingsafety-relatedfail-safecircuitswithinthePGCCisconsideredreportableunder10CFR5e.55(e).Page1of2 CorrectiveAction:GEwi;11issueinstructions.tofieldinvestigateinstallationsoffail-safecircuitsinflexibleconduit~foradequategrounding.Where'hegroundingis.foundtobeunacceptable,positivegroundingwillbeinstalled.IBechtelhasbeeninstructedtoreview'nstallationsofsafety-relatedfail-safecircuitswithin.theirdesignscopetoassurethatpositiveracewaygroundinghasbeenapplied.AfinalreportidentifyingthetotalscopeoftheproblemandcorrectiveactionswillbeprovidedbyMarch31,1981.SBK/kesPage2of2