ML18025A479

Interim Report of Reportable Deficiency Defect in RPV Susquehanna Unit 2 Bottom Head Side Plate

ML18025A479
Person / Time
Site:	Susquehanna
Issue date:	11/05/1976
From:	Curtis N W Pennsylvania Power & Light Co
To:	O'Reilly J P NRC Region 1
References
PLA-142
Download: ML18025A479 (4)

Text

TWONORTHNINTHSTREET,ALLENTOWN,PA.181011PHQN~,(215)52151IPBIOBrlrQnrll'llPenna%"ania,'976.Y'ovanber5,1976gnIPHPrrhiLrr2225552rrrlrINHrrtHrdrcrr.Mr.J.P.O'ReillyDirector-RegionIU.S.NuclearRegulatoryQammission931ParkAvenueKingofPrussia,Pennsylvania19406SUSQUEHANNASTiRMEU!CZRICSTATICN(SSES)INTERIMREPORTOF.REPORTABLEDEFIC~CvDEFECTINRPVUNITI2POTCHHEM'IDEPLATEDOCKETNO:50-388LICENSENO:CPPR-102ERs100450/100508FILE840-4PLA-142

DearMr.O'Reilly:

ThisrelatestoadeficiencyresultingframadefectintheRPVUnitI2bottomheadsideplate.ThecontractorhasreportedthatthedefectwascausedduringtherEmovalofaten~rarysupportstrut.ThedeficiencywasevaluatedandreportedtoMr.MattiaonOctober1,1976asbeingofsuchconseauenceastobeconsideredasasignificantdeficiencyinconstruc-tionand,therefore,reportableurgertheprovisionsdescribedin10CFRPart50.55(e),(iii).TheimpactofthisdefectisbeinganalyzedbyPL,its,contractors,ardatechnicalconsultant,andwillbefullyaddressedinthefinal,definitivereportregardingthedeficiency.Itisanticipatedthatthedefinitivereportwillbesukmittedwithin30daysaft'erthedefecthasbeenrarovedandblended.Shoulditbecomeapparentthatthisschedulecannotbemet,youwillbepnxnptlyadvised.Thefollowingisanaccountoftherelevantdetailsofthedeficiency,theinvestigationpursuedandthedatawhichhavebeenestablishedtodate:A.ChronologyofEvents1.ThedefectintheBPVUnitI2bottcmheadsiaeplateisbelievedtohavebeencreatedaboutfourmonthsagowhenatemporaryattachmentbetweenthevesselandthesupportskirtwasbL22nedoffaccordingtoCBIProcedureLBP-1.PENN5YLVANIAPOWER8LIGHTCOMPANY 0'IP Mr.J.P.O'ReillyPage2Novanber5,19762.Duetomanpowerconsiderations,thecleanupoftheattachnentareawasdelayeduntilSeptanber28,1976.Intheinterim,theactivitywasunderthecontrolofTravelFolderRZK-20,Itan21A.OnSeptanber28,1976,CBIpersonnelbeganrennvingmetalintheareaofthedefect.RemrkisallowedbyGESpecification21A9340whichprovidesforexcavationofsurfacedefectstodeterminetheirdepth.3.Theareawasexcavatedtoadepthof15/16"andonSeptanber29,1976CBIenteredtheconditionasadefectintheirNonconformancelag.4.OnSeptanber30,1976,GESanJosenotifiedPLofthedefect.Afterevaluationoftheincident,PLunsuccessfullyattanptedtoreachMr.HeishnanofNRCRegionIat3:00p.m.Amessagewaslefttoreturnthecall.5.Mr.Mattiareturnedthecallat8:05a.m.onOctober1,1976andwasadvisedoftheincident.Hewasinformedthatthereportabilityofthedefectwasbeingevaluated,andthataninterimreportorfinaldefinitivereport,ifwarranted,auldbesuhnittedtotheNRCbyNcvanber1,1976.6.OnNovanber1,1976,PLadvisedMr.Mattiathattheevaluationwasnotcompletea+2askedforanextensionofthereportdateuntilNovember8,1976.Thisextensionwasgranted.B.AnalisofSafelicationsl.Evaluationoftheimpactof'thedepthofthedefectonthenominalmaterialthicknessincludingreconciliationofthethicknessreductionwiththestxessreportisbeingpursued.2.Theconsiderationoflowcycle,highstressfatigue,duetothermalstressordeteriorationofthemicrostxucturewithintheheataffectedzoneisbeing'studiedfromametallurgicalaspect.C.CorrectiveMeasuresTakenl.OnOctober10,1976CBIissuedRequestForAcceptanceOfNonconformityAsADeviation(RAD)N8.2.Aspecificremrkprocedureisbeingpreparedtogoverntheoperation.Itisanticipatedthattheareawillbeexcavatedtosoundbasemetal,contourblended,examinedbynondestructiveexamination,acidetchedtodetexminethattheheataffectedzonehasbeenranoved,andthenfinalinspected.D.ConclusionThisdeficiencywasdiscoveredduringaroutineworkoperationandtheinspectionactivityisunderthecontroloftheCBIQualityAssuranceProgram.ThiscontrolisassuredbytheuseoftheCBItravelerfolderwhichissequencedsuchthatworkwillmtprogressuntilthedefectisproperlydispositioned.

Mr.J.P.O'ReillvPage3Novanber5,1976Thedispositionofthedefectisbeinggivenfulldesignconsideration,includingthetechnicalservicesofametallurgicalconsultant.Remrkwillbedoneinaccordancewithapplicablecodeandregulatoryrecuire-mentsandwillbemonitoredbyPLtoassurecanpliance.Intheinterim,theCczmissionwillbeadvisedofanysignificantissuewhichmayarise.Verytrulyyours,N.W.CurtisVicepresidentEng-ineeringeGcnstructicnJZJ:mcbcc:Mr.ErnstVolgenau(15)DirectorOfficeofInspectionandEnforcementU.S.NuclearRegulatoryCamnissionWashington,D.C.20555Mr.G.McDonaldDirectorOfficeofManagementInfoxmationandPnxp:amControlU.S.NuclearRegulatoryGmmissionWashington,D.C.20555