ML17263A331

Part 21 Rept Re CCW HXs Mfg by Atlas Industrial Mfg Co.As Result of Eddy Current Exam Performed During 1993 Refueling Outage,Tubes W/Measurable Defects at Tube Plate Locations That Exceeded 70% of Tube Wall Thickness Removed from Svc

ML17263A331
Person / Time
Site:	Ginna
Issue date:	07/20/1993
From:	MECREDY R C ROCHESTER GAS & ELECTRIC CORP.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
REF-PT21-93 NUDOCS 9307290197
Download: ML17263A331 (9)

Text

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DDOCUINIKNT DISTRUTIONSYSTEM*REGULA'INFORMATION DISTRIBUTIO YSTEM(RIDS)TACCESSION,'tJHR:9307290197 DOC.DATE':

93/07/20NOTARIZED:

NODOCKETFACIL:50-.$

44.RobertEmmetGinnaNuclearPlant,Unit1,Rochester G05000244AUTH:IfAME'UTHOR AFFILIATION MECREDY,R.C.

Rochester Gas6ElectricCorp.RECIP.NAME RECIPIENT AFFILIATION DocumentControlBranch(Document ControlDesk)

SUBJECT:

Part21reptreCCWHXsmfgbyAtlasIndustrial MfgCo.Asresultofeddycurrentexamperformed during1993refueling outage,tubesw/measurable defectsattubeplatelocations thatexceeded70%oftubewallthickness removedfromsvc.DZSTRIBDTZON CODE:ZEISDCOPIESRECEIVED:LTR IENCL2SIZE:TITLE:Part21Rept(50DKT)NOTES:License Expdateinaccordance with10CFR2,2.109(9/19/72).

05000244RECIPIENT IDCODE/NAME PD1-3PDCOPIESLTTRENCL11RECIPIENT IDCODE/NAME JOHNSON,A COPIESLTTRENCL11INTERNAL:~0

~EGFILERONRGN3RGNSROAB011111111111NRR/DRIL/RVIB RES/DSIR/EIB RGN2RGN4SECY/PDR1111111111EXTERNAL:

INPORECORDCTRNSICSILVER,E1111NRCPDR11NOTETOALL"RIDS"RECIPIENTS:

PLEASEHELPUSTOREDUCEWASTEICONTACTTHEDOCUMENTCONTROLDESK,ROOMPl-37(EXT.504-2065)

TOELIMINATE YOURNAMEFROMDISTRIBUTION LISTSFORDOCUMENTS YOUDON'TNEED!TOTALNUMBEROFCOPIESREQUIRED:

LTTR15ENCL15

IjjjjIIIP ZZZZItI7P/jill liN7llllld IiixwsjIjI IIIIIIIROCHESTER GASANDELECTRICCORPORATION oROBERTC.MECREDYVlccPrerldent CinnaNuclearProducrion L4a~OlTk/'grcarr1Sr*re89EASTAVENUE,ROCHESTER N.Y.14649-0001 TELEPHONE AREACODE71B5462700July20,1993U.S.NuclearRegulatory Commission DocumentControlDeskWashington, DC20555

SUBJECT:

10CFR2130DayReportR.E.GinnaNuclearPowerPlantDocketNo.50-244Inaccordance with10CFR21,Reporting ofDefectsandNoncompliance, Section21.21(c),

whichrequires"writtennotification totheNRC""ontheidentification ofadefectorafailuretocomply",theattached10CFR21reportisherebysubmitted.

Verytrulyyours,RobertC.Mecredyxc:RegionalAdministrator U.S.NuclearRegulatory Commission RegionI475Allendale RoadKingofPrussia,PA19406U.S.NRCGinnaSeniorResidentInspector iBOCCO9'307290%

97930720'DRADOCH05000244~/~j5syH4d~7 V>qM1.<2't1It$IWP 10CFR2130DAYWRITTENREPORTNAMEANDADDRESSOFTHEINDIVIDUAL INFORMING THECOMMISSION:

NAME:RobertC.MecredyVicePresident GinnaNuclearProduction ADDRESS:Rochester Gas&ElectricCorporation 89EastAvenueRochester, NewYork14649IDENTIFICATION OFTHEFACILITY'HE ACTIVITY'R THEBASICCOMPONENT SUPPLIEDFORSUCHFACILITYWHICHFAILS,TOCOMPLYORCONTAINSADEFECT:Thebasiccomponent istheComponent CoolingWater(CCW)HeatExchanger.

Theseheatexchangers wereinstalled asoriginalplantequipment attheR.E.GinnaNuclearPowerPlant.IDENTIFICATION OFTHEFIRMCONSTRUCTING THEFACILITYORSUPPLYING THEBASICCOMPONENT WHICHFAILSTOCOMPLYORCONTAINSADEFECT:TheCCWheatexchangers weremanufactured by:AtlasIndustrial Manufacturing Company81SomersetPlaceClifton,NewJersey07012NATUREOFTHEDEFECTORFAILURETOCOMPLYANDTHESAFETYHAZARDWHICHISCREATEDORCOULDBECREATEDBYSUCHDEFECTORFAILURETOCOMPLY:Thepurposeofthisnotification istoadvisetheindustryofacondition thatwasnotconsidered intheoriginaldesignofthiscomponent.

Whilethiscondition wasnotconsidered intheoriginaldesignspecifications, itdoespresentapotential mechanism thatcouldoccurwithheatexchangers suppliedunderdesigncriteriaprevalent withthevintageofthiscomponent.

tf~I Thedefectidentified inthedesignoftheComponent CoolingWater(CCW)HeatExchangers wasthepotential forthroughwalltubefailurestooccurwhileoperating attheheatexchanger's rateddesignconditions.

AreviewoftheCCWHeatExchanger designusingcurrentheatexchanger designcriteriaindicated that,atthedesignshellsideflow,theCCWHeatExchangers weresusceptible tolocalized highshellsidevelocities fortubesintheimmediate vicinityoftheshellinletandoutletnozzles.Thesehighvelocities couldresultinflowinducedvibrations leadingtotubethinningfromfrettingdamageattubesupportplatelocations.

Theseconclusions wereconfirmed bydiscussions withAtlasIndustrial.

AtlasIndustrial recommended thattheheatexchanger tubesbeexaminedtocheckforthepresenceoffrettingdamage.AlthoughnoCCWHeatExchanger tubeleakshadbeenexperienced atGinna,thepotential forflowinducedvibration damagecoupledwiththepresenceofasmallnumberoffrettingdefectsduringa1989tubeinspection andthevendor'srecommendation causedRG&Etoscheduleaninspection ofCCWHeatExchanger tubesduringthe1993Refueling Outage.Afulllengtheddycurrentexamination wasperformed oftubesinthevicinityoftheshellinletandoutletnozzles.Thisexamination confirmed thepresenceoftubethinningduetofrettingattubesupportplatelocations fortubesintheimmediate vicinityoftheshellinletnozzle.Notubethinningduetofrettingwasseenattubesupportplatelocations inthevicinityoftheshelloutletnozzles.Tubethinningduetofrettingcould,overtimeifundetected, resultintubeleaksandpotentially incompletetubeseverance atthefrettinglocations.

Tubeleaksand/orseverance couldresultintheCCWHeatExchangers becominginoperable whencalledupontoperformtheirsafetyfunction.

LossofCCWHeatExchangers woulddirectlyaffectthefunctionality oftheResidualHeatRemovalSystemresulting inadegrada-tionintheabilityoftheplant'ssafetyrelatedsystemstomeettheirlongtermcoolingrequirements.

THEDATEONWHICHTHEINFORMATION OFSUCHDEFECTORFAILURETOCOMPLYWASOBTAINED:

Theinformation wasobtainedonApril19,1993,atthecompletion ofthereviewofEddyCurrenttestdatafortheCCWheatexchangers.

INTHECASEOFABASICCOMPONENT WHICHCONTAINSADEFECTORFAILSTOCOMPLYgTHENUMBERANDLOCATIONOFALLSUCHCOMPONENTS INUSEAT~SUPPLIEDFORJORBEINGSUPPLIEDFORGINNASTATION:

TherearetwoCCWheatexchangers, permanently installed intheAuxiliary BuildingatGinnaStation.THECORRECTIVE ACTIONWHICHHASBEEN'SBEINGSORWILLBETAKEN;THENAMEOFTHEINDIVIDUAL ORORGANIZATION RESPONSIBLE FORTHEACTION;ANDTHELENGTHOFTIMETHATHASBEENORWILLBETAKENTOCOMPLETETHEACTION:tAsaresultoftheeddycurrentexamination performed duringthe1993Refueling Outage,RG&Eremovedfromservicealltubeswithmeasurable defectsattubesupportplatelocations thatexceeded704ofthetubewallthickness.

Alltubesthatwereremovedfromservicein1993duetofrettingdefectswerestabilized withatubestakeandthenplugged.Thenumberoftubesremovedfromserviceduringthe1993Refueling Outageduetotubedefectswaslessthan24ofthetotalnumberoftubesintheCCWHeatExchangers.

Thedesignheatremovalrequirements oftheCCWHeatExchangers arestillsatisfied withthisnumberoftubesplugged,sincetheheatexchanger designincludedapproximately 10%marginfortubeplugging.

Duetothelocalized natureoftheflowinducedvibration concern,RG&Eplansonperforming periodicexaminations ofthetubesinthevicinityoftheshellnozzlestomonitorforfrettingdamageattubesupportplatelocations.

Alltubeswithdefectsexceeding thepluggingcriteriawillbestabilized andplugged.RG&Eisresponsible fordetermining thefrequency offutureperiodictubeexaminations.

Additionally, RG&Eisevaluating thefeasibility ofreducingtheCCWHeatExchanger shellsidedesignflowtodecreasethepotential forlocalized flowinducedvibration damagetotubes.ANYADVICERELATEDTOTHEDEFECTORFAILURETOCOMPLYABOUTTHEFACILITY,

ACTIVITY, ORBASICCOMPONENT THATHASBEEN'SBEINGSORWILLBEGIVENTOPURCHASERS ORLICENSES:

ThepresentCCWHeatExchangers weredesignedandbuiltinthelate1960'spriortothedevelopment ofexistingcriteriaforheatexchanger designtoprecludeflowinducedvibration concerns..

Heatexchanger designsfromthisperiodmaybesusceptible toflowinducedvibration damagedepending uponthedesignphilosophy usedbyindividual manufacturers.

Eitherreviewoftheoriginaldesignagainsttoday'sstandards orperiodicexamination oftubesforflowinducedvibration concernswouldprovideanindication thatunexpected damagetotubesisoccurring duetoflowinducedvibrations.

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