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

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Mr.J.P.O'ReillyDirector-Region IU.S.NuclearRegulatory Qammission 931ParkAvenueKingofPrussia,Pennsylvania 19406SUSQUEHANNA STiRMEU!CZRICSTATICN(SSES)INTERIMREPORTOF.REPORTABLE DEFIC~CvDEFECTINRPVUNITI2POTCHHEM'IDEPLATEDOCKETNO:50-388LICENSENO:CPPR-102ERs100450/100508 FILE840-4PLA-142

DearMr.O'Reilly:

Thisrelatestoadeficiency resulting framadefectintheRPVUnitI2bottomheadsideplate.Thecontractor hasreportedthatthedefectwascausedduringtherEmovalofaten~rarysupportstrut.Thedeficiency wasevaluated andreportedtoMr.MattiaonOctober1,1976asbeingofsuchconseauence astobeconsidered asasignificant deficiency inconstruc-tionand,therefore, reportable urgertheprovisions described in10CFRPart50.55(e),(iii).TheimpactofthisdefectisbeinganalyzedbyPL,its,contractors, ardatechnical consultant, andwillbefullyaddressed inthefinal,definitive reportregarding thedeficiency.

Itisanticipated thatthedefinitive reportwillbesukmitted within30daysaft'erthedefecthasbeenrarovedandblended.Shoulditbecomeapparentthatthisschedulecannotbemet,youwillbepnxnptlyadvised.Thefollowing isanaccountoftherelevantdetailsofthedeficiency, theinvestigation pursuedandthedatawhichhavebeenestablished todate:A.Chronology ofEvents1.ThedefectintheBPVUnitI2bottcmheadsiaeplateisbelievedtohavebeencreatedaboutfourmonthsagowhenatemporary attachment betweenthevesselandthesupportskirtwasbL22nedoffaccording toCBIProcedure LBP-1.PENN5YLVANIAPOWER8LIGHTCOMPANY 0'IP Mr.J.P.O'ReillyPage2Novanber5,19762.Duetomanpowerconsiderations, thecleanupoftheattachnent areawasdelayeduntilSeptanber 28,1976.Intheinterim,theactivitywasunderthecontrolofTravelFolderRZK-20,Itan21A.OnSeptanber 28,1976,CBIpersonnel beganrennvingmetalintheareaofthedefect.RemrkisallowedbyGESpecification 21A9340whichprovidesforexcavation ofsurfacedefectstodetermine theirdepth.3.Theareawasexcavated toadepthof15/16"andonSeptanber 29,1976CBIenteredthecondition asadefectintheirNonconformance lag.4.OnSeptanber 30,1976,GESanJosenotifiedPLofthedefect.Afterevaluation oftheincident, PLunsuccessfully attanpted toreachMr.HeishnanofNRCRegionIat3:00p.m.Amessagewaslefttoreturnthecall.5.Mr.Mattiareturnedthecallat8:05a.m.onOctober1,1976andwasadvisedoftheincident.

Hewasinformedthatthereportability ofthedefectwasbeingevaluated, andthataninterimreportorfinaldefinitive report,ifwarranted, auldbesuhnitted totheNRCbyNcvanber1,1976.6.OnNovanber1,1976,PLadvisedMr.Mattiathattheevaluation wasnotcompletea+2askedforanextension ofthereportdateuntilNovember8,1976.Thisextension wasgranted.B.AnalisofSafelications l.Evaluation oftheimpactof'thedepthofthedefectonthenominalmaterialthickness including reconciliation ofthethickness reduction withthestxessreportisbeingpursued.2.Theconsideration oflowcycle,highstressfatigue,duetothermalstressordeterioration ofthemicrostxucture withintheheataffectedzoneisbeing'studiedfromametallurgical aspect.C.Corrective MeasuresTakenl.OnOctober10,1976CBIissuedRequestForAcceptance OfNonconformity AsADeviation (RAD)N8.2.Aspecificremrkprocedure isbeingpreparedtogoverntheoperation.

Itisanticipated thattheareawillbeexcavated tosoundbasemetal,contourblended,examinedbynondestructive examination, acidetchedtodetexmine thattheheataffectedzonehasbeenranoved,andthenfinalinspected.

D.Conclusion Thisdeficiency wasdiscovered duringaroutineworkoperation andtheinspection activityisunderthecontroloftheCBIQualityAssurance Program.ThiscontrolisassuredbytheuseoftheCBItravelerfolderwhichissequenced suchthatworkwillmtprogressuntilthedefectisproperlydispositioned.

Mr.J.P.O'ReillvPage3Novanber5,1976Thedisposition ofthedefectisbeinggivenfulldesignconsideration, including thetechnical servicesofametallurgical consultant.

Remrkwillbedoneinaccordance withapplicable codeandregulatory recuire-mentsandwillbemonitored byPLtoassurecanpliance.

Intheinterim,theCczmission willbeadvisedofanysignificant issuewhichmayarise.Verytrulyyours,N.W.CurtisVicepresident Eng-ineering eGcnstructicn JZJ:mcbcc:Mr.ErnstVolgenau(15)DirectorOfficeofInspection andEnforcement U.S.NuclearRegulatory Camnission Washington, D.C.20555Mr.G.McDonaldDirectorOfficeofManagement Infoxmation andPnxp:amControlU.S.NuclearRegulatory Gmmission Washington, D.C.20555