ML003715564

Letter to Mr. Ralph Beedle, NEI, Regarding Okonite Cables/Loca Tests

ML003715564
Person / Time
Issue date:	05/18/2000
From:	Collins S J Office of Nuclear Reactor Regulation
To:	Beedle R E Nuclear Energy Institute
Shemanski PC
References
Download: ML003715564 (4)

Text

May18,2000Mr.RalphBeedleSeniorVicePresidentandChiefNuclearOfficer NuclearEnergyInstitute 1776IStreet,N.W.,Suite400 Washington,D.C.20006-3708

DearMr.Beedle:

BrookhavenNationalLaboratories(BNL),undercontracttotheNRC,hasbeenconductingresearchonlow-voltageinstrumentationandcontrolcables(I&C)tosupporttheresolutionof GenericSafetyIssue168,"EnvironmentQualificationofElectricEquipment."Aspartofthis research,inlate1999,aloss-of-coolantaccident(LOCA)testwasconductedonI&Ccables withethylenepropylenerubber(EPR)insulationandbondedchlorosulfonatedpolyethylene (CSPE)outerjackets(Test#5).Thepurposeofthetestwastodetermineifcableswithbonded jacketshaveauniquefailuremechanismthatisnotpresentinunbondedjacketedcablesunder postulatedLOCAconditions.ThetestingwasperformedatWyleLaboratoriesinHuntsville, Alabama,oncablesamplesfromseveralmanufacturersincludingOkonite.ThetestsubjectedthefollowingOkonitecabletoacceleratedthermalandradiationagingandthenexposedthecablesamplestoLOCAconditions:*EPRinsulationwithbondedCSPEjacket;single-conductor;#12Americanwiregage(AWG)ThefollowingacceleratedagingparameterswereselectedonthebasisofOkonite'soriginaltestreportfor40-yearqualification:*504hrs.@302 oFfollowedby50Mrads@0.65Mrad/hr.TheLOCAtestconsistedofexposureto150Mradsofgammaradiationatadoserateof0.75Mrad/hr.followedbyexposuretoadouble-peaksteamprofile,asdescribedinIEEE Std.323-1974.Thepeakconditionsofthesteamprofilewere346 oFand113psig.Aboricacid-basedchemicalspraywasinitiatedwhenthetestchamberpressurehadreached32psig andwascontinuedfor24hours.Thedurationofthesteamexposurewas10days.Following theLOCAexposure,submergedvoltagewithstandtestswereperformedonthespecimensata testvoltageof2400voltsac(equivalentto80v/milac)asdescribedinIEEEStd.383-1974.All threeoftheOkonitespecimensagedtoanequivalentof40years,andoneofthetwoOkonite specimens,agedtoanequivalentof20years,failedinstantaneously.Theartificialaging apparentlycontributedtothefailuremechanismsincecircumferentialcrackswereobserved followingpre-aging.LongitudinalsplitswereobservedonthecablejacketfollowingLOCA exposure.TheenclosedBNLReportcontainsasummaryoftheresultsofLOCATest#5.DiscussionsandmeetingswithrepresentativesfromOkoniteandindustryonFebruary8,and16,2000,respectively,determinedthatthecompositeEPRwithCSPEjacketinOkonitetest reportNQRN-1Aisabondedjacketsystem,similartotheBNLspecimens.ItisNRC's Mr.RalphBeedle2understandingthatOkoniteEPRinsulationwithbondedCSPEjacket,single-conductor,#12AWGcablescanbeusedinelectricequipmentimportanttosafetylocatedinharsh environmentareasofnuclearpowerplants.OkonitetestreportNQRN-1isthebasisfor environmentalqualificationofthiscableunder10CFR50.49"EnvironmentalQualificationof ElectricEquipmentImportanttoSafetyforNuclearPowerPlants."ThesetestresultscallintoquestionthequalificationofrecordforOkonitesingleconductorcablewithEPRinsulationandbondedCSPEjacketingasrequiredby10CFR50.49.Inthis regard,NRChasforwardedalettertoTheOkoniteCompanyprovidingacopyoftheattached testreportfortheirreviewpursuantto10CFRPart21(copyenclosed).Asindicatedabove, thisinformationwasalsosharedpubliclyinmeetingsonFebruary8and16,2000.ItisNRC's understandingthatbecausethesubjectcablingissingleconductor,itsapplicationinsafety-relatedapplicationswhereitmaybesubjecttoharshenvironmentsmaybelimited.Itisalso recognizedthatthepre-agingparametersandaccidentprofilesusedinthequalificationtests areprobablyconservativerelativetoactualconditionswherethiscablingmaybeinstalled.

However,informationontheexactapplicationsofthesubjectcablingisnotreadilyavailableto theNRC.Thusitisdifficultforustocompletelyassesstheplantriskassociatedwithuseofthis typeofcable.Also,wedon'tknowtowhatextentlicenseeshavealreadyassessedthissubject orplantoassessitfortheirfacilities.Therefore,wewouldliketoscheduleameetingtodiscuss possibleoptionsforaddressingthisissue.Accordingly,Iamrequestingthatyourstaffcontact JosephBirmingham,ofmystaff,at(301)415-2829toscheduleapublicmeetinginthenear futuretodiscussthissubject.Iappreciateyourcooperationonthissubject.Sincerely,SamuelJ.Collins,Director/RAbyB.Sheronfor//OfficeofNuclearReactorRegulation

Attachment:

ResultsofTest#5onBondedJacketElectricCables,datedMarch6,2000 cc:Mr.ArthurPack,Jr.,OkoniteCompany Mr.RalphBeedle2May18,2000understandingthatOkoniteEPRinsulationwithbondedCSPEjacket,single-conductor,#12AWGcablescanbeusedinelectricequipmentimportanttosafetylocatedinharsh environmentareasofnuclearpowerplants.OkonitetestreportNQRN-1isthebasisfor environmentalqualificationofthiscableunder10CFR50.49"EnvironmentalQualificationof ElectricEquipmentImportanttoSafetyforNuclearPowerPlants."ThesetestresultscallintoquestionthequalificationofrecordforOkonitesingleconductorcablewithEPRinsulationandbondedCSPEjacketingasrequiredby10CFR50.49.Inthis regard,NRChasforwardedalettertoTheOkoniteCompanyprovidingacopyoftheattached testreportfortheirreviewpursuantto10CFRPart21(copyenclosed).Asindicatedabove, thisinformationwasalsosharedpubliclyinmeetingsonFebruary8and16,2000.ItisNRC's understandingthatbecausethesubjectcablingissingleconductor,itsapplicationinsafety-relatedapplicationswhereitmaybesubjecttoharshenvironmentsmaybelimited.Itisalso recognizedthatthepre-agingparametersandaccidentprofilesusedinthequalificationtests areprobablyconservativerelativetoactualconditionswherethiscablingmaybeinstalled.

However,informationontheexactapplicationsofthesubjectcablingisnotreadilyavailableto theNRC.Thusitisdifficultforustocompletelyassesstheplantriskassociatedwithuseofthis typeofcable.Also,wedon'tknowtowhatextentlicenseeshavealreadyassessedthissubject orplantoassessitfortheirfacilities.Therefore,wewouldliketoscheduleameetingtodiscuss possibleoptionsforaddressingthisissue.Accordingly,Iamrequestingthatyourstaffcontact JosephBirmingham,ofmystaff,at(301)415-2829toscheduleapublicmeetinginthenear futuretodiscussthissubject.Iappreciateyourcooperationonthissubject.Sincerely,SamuelJ.Collins,DirectorOfficeofNuclearReactorRegulation

Attachment:

ResultsofTest#5onBondedJacketElectricCables,datedMarch6,2000 cc:Mr.ArthurPack,Jr.,OkoniteCompanyADAMSAccessionNumber:ML003715564Template:NRR-056DISTRIBUTION:Seefollowingpage*SeepreviousconcurrenceLog.No.35DOCUMENTNAME:G:\EEIB\SHEMANSKI\NEILETTER.WPDToreceiveacopyofthisdocument,indicateintheboxC=Copyw/oattachment/enclosureE=Copywithattachment/enclosureN=NocopyOFFICEEEIBESC/EEIBEC/EEIBDD/DED/DEDIPM/NRRNAMEPCShemanski:rmc*DFThatcher*JACalvo*RHWessman*JRStrosnider*TRQuay*

DATE05/02/0005/02/0005/10/0005/10/0005/12/0005/16/00 ADPT/NRRD/NRRBWSheron*SJCollins05/15/0005/18/00OFFICIALRECORDCOPY Mr.RalphBeedle3DISTRIBUTION

FileCenter/ADAMSEEIB/RF AThadani FMiraglia BSheron JStrosnider RWessman MMayfield EHackett TMarsh CGrimes JCalvo DThatcher SAggarwal DSkeen CCarpenter PShemanski JBirmingham