Welding Of Zirconium Alloys

2y ago
36 Views
3 Downloads
3.03 MB
47 Pages
Last View : 1d ago
Last Download : 2m ago
Upload by : Rosa Marty
Transcription

ZIRATI2 SPECIAL TOPIC REPORT WELDING OF ZIRCONIUM ALLOYS 2007Welding of Zirconium AlloysAuthorsPeter Rudling,Advanced Nuclear Technology International Europe AB,Skultuna, SwedenAlfred Strasser,Aquarius Services Corp., Sleepy Hollow, NY, USAFriedrich GarzarolliErlangen, GermanyReviewed byLeo van SwamRichland, WA, USAA.N.T. INTERNATIONAL" October 2007Advanced Nuclear Technology InternationalKrongj utarvagen 2C, SE-73 0 50 rnational.com

ZIRATr 2 SPECIAL TOPIC REPORT2007-WELDING OF ZIRCONIUM ALLOYSDisclaimerThe information presented in this report has been compiled and analysed byAdvanced Nuclear Technology International Europe AB (ANT International )and its subcontractors . ANT International has exercised due diligence in this work,but does not warrant the accuracy or completeness of the information.ANT International does not assume any responsibility for any consequencesas a result of the use of the information for any party, except a warrantyfor reasonable technical skill, which is limited to the amount paid for thisassignment by each ZIRAT program member.Copyright Advanced Nuclear Technology International Europe AB, ANT International, 2007.This information is the property of AdvancedNuclear Technology International Europe AB or is licensed for use by Advanced Nuclear Technology International Europe AB by itscustomers or partners. The information may not be given to, shared with, or cited to third party, used for unauthorised purpose, or be copiedor reproduced in any form without the written permission of Advanced Nuclear Technology International Europe AB.II(VII)

ZIRATr 2 SPECIAL TOPIC REPORT2007-WELDING OF ZIRCONIUM ALLOYSAcronyms and QMSRRBMKRBWCopyrightAlternating CurrentAuger Electron SpectroscopyAmerican National Standards InstituteAmerican Society of Mechanical EngineersAmerican Society for QualityAmerican Society for Testing MaterialsBoiling Water ReactorCanadian Deuterium UraniumCode of Federal RegulationsDirect CurrentDestructive testingDuplexElectron BeamEddy CurrentEddy current testing(European) Performance Excellence ModelsExtra -Low SnElectron Microprobe AnalysisFuel AssemblyGeneral ElectricGlobal Nuclear FuelGuide TubeGas Tungsten ArcHeat Affected ZoneHigh Performance AlloyInternational Atomic Energy AgencyInternational Organization for StandardizationInfrared ThermographyKernKraftwerk GosgenLaser BeamLiquid Penetrant InspectionLight Water ReactorMitsubishi Developed AlloyMitsubishi Heavy IndustriesMagnetic Flux Leakage TechniqueMixed OxideMagnetic Particle InspectionNew Developed AlloyNon Destructive TestingNuclear Fuel IndustriesNuclear Regulatory CommissionPellet Cladding InteractionPotential DropPiezo Electric TransducerPressurised Water ReactorQuality AssuranceQuality ControlQuality ManagementQuality Management SystemsResistanceReaktor Bolshoi Mozhnosti Kanalov (in English Large Boiling Water Channel typereactor)Resistance Butt Welding Advanced Nuclear Technology International Europe AB,ANT International,2007. This information is the property of AdvancedNuclear Technology International Europe AB or is licensed for use by Advanced Nuclear Technology International Europe AB by itscustomers or partners. The information may not be given to, shared with, or cited to third party, used for unauthorised purpose, or be copiedor reproduced in any form without the written permission of Advanced Nuclear Technology International Europe AB.III (VII)

ZIRATr 2 SPECIAL TOPIC RZIRATZIRLOCopyright2007-WELDING OF ZIRCONIUM ALLOYSResistance Spot WeldingRadiographyResistance WeldingRecrystallised AnnealedSpot weldingSteam Generating Heavy Water ReactorSecond Phase ParticleStress Relieved AnnealedStainless SteelSpecial Topic ReportTungsten Inert GasTotal Quality ManagementTime Temperature TransitionUpset Shape WeldingUltrasonic TestingVoda Voda Energo Reactor (Russian type PWR)ZIRconium Alloy TechnologyZIRconium Low Oxidation Advanced Nuclear Technology International Europe AB, ANT International, 2007.This information is the property of AdvancedNuclear Technology International Europe AB or is licensed for use by Advanced Nuclear Technology International Europe AB by itscustomers or partners. The information may not be given to, shared with, or cited to third party, used for unauthorised purpose, or be copiedor reproduced in any form without the written permission of Advanced Nuclear Technology International Europe AB.IV(VII)

ZIRATr 2 SPECIAL TOPIC REPORT2007-WELDING OF ZIRCONIUM ALLOYSUnit conversionTEMPERATUREDISTANCE C 273.15 K C*1.S 32 ofx(!.1m)x0.6T(K)T( 2042200MPapsi0.114142STRESS INTENSITY adioactivity1 Sv 100 Rem1 Ci 3.7 x 10108q 37 G8q18qCopyright 1 S·1 Advanced Nuclear Technology International Europe AB,ANT International,2007.This information is the property of AdvancedNuclear Technology International Europe AB or is licensed for use by Advanced Nuclear Technology International Europe AB by itscustomers or partners. The information may not be given to, shared with, or cited to third party, used for unauthorised purpose, or be copiedor reproduced in any form without the written permission of Advanced Nuclear Technology International Europe AB.V(VII)

ZIRATr 2 SPECIAL TOPIC REPORT2007-WELDING OF ZIRCONIUM ALLOYSContentsAcronyms and explanationsIIIUnit conversionVContentsVIIIntroduction (Friedrich Garzarolli and Peter Rudling)I-I2Welding techniques used for different fuel assembly components2-12.12.22.2.12.2.22 . 2·32 . 2·42·32·42· 5Introduction (Alfred Strasser and Peter Rudling)Fuel rod End Cap Welding (Peter Rudling and Alfred Strasser)TICEB and LBResistance WeldingUSWSpacer/grid Welding (Alfred strasser and Peter Rudling)Fuel bundle assembly (Alfred Strasser and Peter Rudling)Fuel outer channels (Alfred Strasser )2-12 -32 -82 -82 -92-1 I2-122-162-193Quality management (Peter Rudling and Alfred Strasser)3.13.23 .2 . 13 .2.23 . 2 .3IntroductionQuality managements systemQ9000, quality management systems - fundamentals and vocabularyQ90 0 1 , quality management systems - requirementsQ9004, quality management systems - guidelines for performanceimprovementsISO 1 4000, series, environmental quality managementTotal quality managementSpecifica tionQualification programsProcess qualificationInspection method qualification (Alfred Strasser)Inspection method typesQualification methodsProcessing and inspection personnel qualification (Alfred Strasser)Personnel typesQualification methodsQuality control (Peter Rudling)QC methodsDestructive testing of weldsMetallogra phyMechanical testsCorrosion testsN on destructive testingEddy current testingUltrasonic testingLeak testingRadiographyAudits (AI Strasser and Peter Rudling)IntroductionAudit checklist3 .2.43 .2 . 53·33·43 .4 . 13 .4 . 23 .4 . 2 . 13 .4 . 2 . 23 33 3 . 13 3 . 23·53.5.13 · 5· 1 . 13 · 5· 1 . 1 . 13 · 5· 1 . 1 . 23 · 5· 1 . 1 .33 · 5· 1 . 23 · 5· 1 . 2 . 13 · 5· 1 . 2 . 23 · 5· 1 . 2·33 · 5· 1 . 2· 43 .63 .6.13 .6.2Copyright Advanced Nuclear Technology International Europe AB,ANT International,2007.3 -43 -43-53 -63 -83 -93-123-123-123 -143 -143 -143-153 - 183 - 183 - 183-213 -213 -2 23 -2 23 -243 -283 -283 -293 -293 -3 2This information is the property of AdvancedNuclear Technology International Europe AB or is licensed for use by Advanced Nuclear Technology International Europe AB by itscustomers or partners. The information may not be given to, shared with, or cited to third party, used for unauthorised purpose, or be copiedor reproduced in any form without the written permission of Advanced Nuclear Technology International Europe AB.VI(VII)

ZIRATr 2 SPECIAL TOPIC REPORT2007-WELDING OF ZIRCONIUM ALLOYS4Factors that can affect the quality of welds (Peter Rudling)4.14· 1 . 14· 1 . 24· 1 .3IntroductionJ oint design and tolerancesExcessive weld corrosion dueExcessive weld corrosion dueHAZExcessive weld corrosion dueExcessive weld corrosion dueto weld contaminationto unfavourable microstructure in weld andto depletion of alloying elementsto welding of dissimilar materialsService failures of welds (Peter Rudling)5-1Summary (Peter Rudling)6-1References7-1Appendix A - Statistics (Peter Rudling)A.IA.I.IA.I. 2A-IA-IA-2A-2Statistical Methodology (Peter Rudling)Descriptive statisticsStochastic modellingAppendix B - Fundamentals of metal welding (Peter Rudling)B-1B. IB.I.IB.2B-1B-1B.2.1B.2.2B·3B· 4B· 5B.6B.6.1B.6.2B. 6·3B . 6·4B . 6· 5Thermal and thermomechanical consider a tions of weldingIntroductionGeneral characteristics of the heat cycle and heat distribution (moving weldsource)Welds without movement of heat sourceWelding residual stresses and stress relieveFormation of the weld metalSolidification of the weld metalPhase transformations during weldingBasics of welding methods used in welding of zirconium alloysTICLaser WeldingElectron Beam WeldingUpset shape weldingResistanceAppendix C - ReferencesCopyrightB-2B-4B-5B-6B-6B-7B- 1 2B-12B - 19B-2 5B-28B-28C-I Advanced Nuclear Technology International Europe AB,ANT International,2007.This information is the property of AdvancedNuclear Technology International Europe AB or is licensed for use by Advanced Nuclear Technology International Europe AB by itscustomers or partners. The information may not be given to, shared with, or cited to third party, used for unauthorised purpose, or be copiedor reproduced in any form without the written permission of Advanced Nuclear Technology International Europe AB.VII(VII)

ZIRATr 2 SPECIAL TOPIC REPORT2007- WELDING OF ZIRCONIUM ALLOYSIntroduction (Friedrich Garzarolli andPeter Rudling)IThe welding of Zirconium Alloy components is one of the most critical manufacturing processesof Nuclear Reactor fuel. Small amounts of contamination resulting from inadequate cleanliness orfrom poor atmospheric control during welding may lead to diminished corrosion resistance of theweld and in severe cases to weld failure. Other weld defects such as piping, pore formation orinsufficient weld penetration may also result in costly fuel failures.This Special Topic Report (STR) describes the different welding processes used for the variousfuel assembly components. A comprehensive discussion of welding Quality Management isincluded. The fundamental aspects of the welding process, focussing on Tungsten Inert Gas (TIC),Electron Beam, Laser and Resistance welding as well as solid state bonding are made an integralpart of the report.This Topical Report has been specifically prepared for the use of utility personnel, engineersand auditors that are involved in the procurement of nuclear fuel and which may have limited in dept knowledge of welding processes and procedures. A discussion of the fundamentals ofZirconium Alloy Welding Metallurgy is for the benefit of metallurgists and welding engineers aswell as for others that wish to obtain greater insight into this topic. However, before we start tolook into the welding technology in the next sections it is instructive to look back in history tofind out which different Zr-alloys were developed, why and, which Zr alloys are being used today.The latter alloys are the ones that should be weldable.The initial fuel rods of early Boiling Water Reactor (BWRs) and Pressurised Water Reactor(PWRs) applied very thin Stainless Steel (SS) clad. This material was selected due to its rather highstrength and excellent corrosion resistance in high temperature water. The behavior of these SScladding was quite good in PWRs but manifested severe longitudinal intergranular cracking inBWRs after burnups in excess of 6 MWd/kgU. Because of these defects and economicconsiderations, ZircaloY-2 and ZircaloY-4 ( see Table I - I ) , Zr-based alloys with very low neutronabsorption cross section developed at the Bettis Atomic Power Laboratory, e.g., Kass, 1962 wereused later for PWRs and BWRs.Copyright Advanced Nuclear Technology International Europe AB,ANT International,2007.This information i s the property o f AdvancedNuclear Technology International Europe AB or is licensed for use by Advanced Nuclear Technology International Europe AB by itscustomers or partners. The information may not be given to, shared with, or cited to third party, used for unauthorised purpose, or be copiedor reproduced in any form without the written permission of Advanced Nuclear Technology International Europe AB.1-1( 1-5)

ZIRATr 2 SPECIAL TOPIC REPORTTable 1-1:2007 -WELDING OF ZIRCONIUM ALLOYSComposition of Zircaloy-2 and Zircaloy-4 (weight%).--Zircaloy-2Zircaloy-4UNS R60802UNS mium0.05-0.150.07-0.13Nickel0.03-0.08---Fe Cr Silicon0.005-0.0120.005-0.012Aluminium 0.0075 0.0075Boron 0.00005 0.00005Cadmium 0.00005 0.00005Carbon 0.0270 0.0270Cobalt 0.0020 0.0020Copper 0.0050 0.0050Hafnium 0.0100 0.0100Hydrogen 0.0025 0.0025Magnesium 0.0020 0.0020Manganese 0.0050 0.0050Molybdenum 0.0050 0.0050--- 0.0070Nitrogen 0.0080 0.0080Tungsten 0.01 0.01Titanium 0.0050 0.0050 0.00035 0.00035Alloying elementsTinFe CrIImpuritiesNickelUranium (total)-----.-The first commercial reactors that used ZircaloY-2 were the PWR Shippingport ( r9 58 ) and theBWR Dresden I ( r960). ZircaloY-2 was also applied for the fuel rod claddings in CanadianDeuterium Uranium (CANDU) reactors. In Russia the Zr-based alloy Zr- r %Nb ( E r ro) wasdeveloped and used for the fuel rod claddings in the Voda Voda Energo Reactor (VVERs ) andReaktor Bolshoi Mozhnosti Kanalov (RBMKs), see Table r - 2 . The E 63 5 material was developedto be used for structural components in both VVER and RBMK reactors.Copyright Advanced Nuclear Technology International Europe AB. ANT Intemational. 2007.This information is the property of AdvancedNuclear Technology International Europe AB or is licensed for use by Advanced Nuclear Technology International Europe AB by itscustomers or partners. The information may not be given to. shared with. or cited to third party. used for unauthorised purpose. or be copiedor reproduced in any form without the written permission of Advanced Nuclear Technology International Europe AB.r-2( r-5)

ZIRATr 2 SPECIAL TOPIC REPORT2007-WELDING OF ZIRCONIUM ALLOYSFor the fuel element structural components originally mostly SS and Ni base alloys were used.Later on the material of more or less all of the components in the active zone of the fuelassemblies, such as BWR flow channel, PWR guide tubes, and spacer grids, were changed from SSto ZircaloY-2 or -4 .For the Pressure tubes of the CANDU reactors ZircaloY-2 were used from the beginning, dueto neutron absorption considerations. Later on the more corrosion resistant Zf2 . 5 %Nb, whichhas also a higher strength, was selected for the pressure tubes of the C ANDU and the RBMKreactors.In the early seventies it became clear that the so-called "Pellet Cladding Interaction" ( P CI)defects were responsible for a significant fraction of the fuel failure rate. The P CI defects werecaused mainly by local power increases associated with control rod manoeuvres, e.g. Cox, 1990and Armij o et aI., 1994. The pel-defect mechanism is stress corrosion of the cladding initiated by thestresses from mechanical interaction between fuel and cladding as well as the release of the fissionproduct iodine during power ramps. Different concepts were examined to improve the resistanceof the cladding against P CI. A soft inner layer (Zr liner/barrier tubing) were tested by GeneralElectric GE (now Global Nuclear Fuel (GNF) ) , Armij o et aI., 1994 and found to significantlydecrease the P CI tendency.In 1988 and several years afterwards, several BWRs experienced defects of Zr liner fuel rodswhich degraded ( secondary defects) resulting in large fission products releases and fuel washout,Jonsson et aI., 199 1 , Armij o, 1994, and Seibold & Woods, 1994. These secondary defectsappeared as long axial cracks. The root cause of these long cracks and the high fission productrelease is mainly the poor corrosion resistance of Zr liners in the steam/hydrogen environmentthat forms inside a fuel rod once coolant has entered through a small primary defect. To improvethe corrosion resistance of the soft liner, Siemens (today AREVA NP) developed a Fe-alloyed Zrliner cladding with 0.4 % Fe, Seibold & Woods, 199 4 . GE (now GNF) assessed, independently ofSiemens, that the tendency for degradation of failed fuel was related to the corrosion resistance ofthe fuel clad inner surface and that addition of Fe was the best way to improve the Zr linercorrosion resistance. However GE added less (400-1 000 ppm) Fe than Siemens added (todayAREVA NP), Lutz et aI., 1999 and Edsinger et aI., 2000. Westinghouse Electric Sweden alsofound a very beneficial effect of small Fe additions to their Zr-Sn liner and decided to add 400700 ppm Fe, Limback & Helmersson, 2 003 .In BWRs, the corrosion performance of the ZircaloY-2 and -4 materials is still adequate andtherefore these materials are still used in BWRs.The most important aspect for Zr-alloy claddings of PWR fuel rods is besides strengthconsiderations the corrosion behavior due to the relatively high maximum operation temperature.The material development of PWR claddings was driven mostly by the fuel-cycle economyachieved by increasing the allowable burnup and local power density. Therefore, broaddevelopment programs to improve the corrosion resistance of ZircaloY-4 cladding were started inthe early 80S . In a first phase, tests were performed on ZircaloY-4 cladding with varying alloyingcontent, impurity content, and material condition. As a result, a ZircaloY-4 cladding with arestricted chemistry, the " Low-Sn-ZrY-4" -cladding, has been specified and applied for reloadssince 1988 . The Low-Sn-ZrY-4 allowed an increase in fuel burnup of about 1 0 MWd/kgU.However, under full-low-leakage core loading conditions with rather high heat fluxes over mostof the exposure time, some of the Low-Sn-ZrY-4 claddings exhibited an increased corrosion.Further tests revealed that the transition metal alloying content and the microstructure alsohave a pronounced effect on corrosion. Broy et aI., 2000 and Seibold & Garzarolli, 2002 havesummarized the results on the effect of transition elements. On the basis of these results the" Optimized Zry-4" was developed by Siemens (today AREVA NP), with Fe in the upper range ofthe American Society for Testing Materials (ASTM) specification and an optimized microstructurewas developed. This type of cladding was used for reloads after 1989 and is still in use formoderate operating conditions today.It was concluded relatively early that even the best Zry-4 does not permit achievement of thefinal target burnup in modern PWRs. Therefore, in a second phase all fuel suppliers developedalternative Zr-alloys with improved corrosion behavior.Copyright Advanced Nuclear Technology International Europe AB, ANT International, 2007.This information is the property of AdvancedNuclear Technology International Europe AB or is licensed for use by Advanced Nuclear Technology International Europe AB by itscustomers or partners. The information may not be given to, shared with, or cited to third party, used for unauthorised purpose, or be copiedor reproduced in any form without the written permission of Advanced Nuclear Technology International Europe AB.

ZIRATr 2 SPECIAL TOPIC REPORT2007-WELDING OF ZIRCONIUM ALLOYSThe different fuel suppliers selected from their development programs different cladding materialsfor their advanced fuel elements. The first new type of cladding that was used for reloads in1988/89 was the DUPLEX (DX ) - Extra-Low Sn (ELS) cladding developed by Siemens (todayAREVA NP). This type of cladding consists of a ZircaloY-4 tube with a metallurgical bondedextra-low Sn (ELS 0.8 ) outer layer, about 1 00 flill thick, and the Zry-4 and the ELS layer are bothin stress relieved condition. The outer corrosion-resistant layer has a Sn level below, and in case ofDX-ELS 0.8b, Fe and Cr levels above the range specified by ASTM for ZrY-4. Later additionalDUPLEX claddings were developed, as the DX 3 b cladding by ABB (today Westinghouse ) fortheir high duty reloads in Siemens-designed PWRs and for further increased corrosion resistancethe DX-D4 cladding.For structural components and fuel cladding for PWRs with moderate duty the modifiedZircaloY-4 was used by Siemens (today AREVA NP) since 199 5 . This alloy has an improvedcorrosion resistance compared to that of low-Sn Zry-4 due to the high Fe Cr content in theformer material Table and a still quite high creep strength.Siemens (today AREVA NP) developed in addition the Zr-alloy High Performance Alloy(HPA-4), which is commercially used since the early 2000'S. This material forms in-PWR onlyvery thin oxide layers ( due to the low Sn content) and furthermore picks up a much lower fractionof the corrosion hydrogen (than that of ZrY-4), due to the replacement of Cr by V.Nuclear Fuel Industries (NFl) developed the New Developed Alloy (NDA) alloy StressRelieved Annealed (SRA ) for their Japanese market. NDA shows a slightly better corrosionbehavior than that of Low-Sn ZrY-4, Sa sakawa et aI., 200 5 .ZIRLO (SRA ) i s the alternative Zr-alloy cladding that was introduced i n the market i n the late1980s by Westinghouse. The alloy is a Zr alloy with a bout 1 % Sn, 1 %Nb and 0. 1 % Fe and isbased on the E63 5 alloy developed in Russia. Westinghouse increased the corrosion resistance ofZIRLO by a reduction of the Sn content ( optimized ZIRLO ) .Mitsubishi Heavy Industries (MHI) developed the Mitsubishi Developed Alloy (MDA) (SRA )alloy for the Japanese market which also exhibits a somewhat improved corrosion resistancecompared to that of Low-Sn ZrY-4, Kitagawa et aI., 200 5 and Watanabe et aI., 200 5 .In 1996 the M 5 alloy Recrystallised Annealed (RXA ) was introduced in the market byFramatome (Today AREVA NP) on a commercial basis. M5 is a fully recrystallized ternaryZrrNbo.I2 50 alloy and was developed on the basis of the Russian Zr alloy EII0 being used ascladding for the VVERs, in an extensive irradiation program starting in 1989, Mardon et aI.,1994·Copyright Advanced Nuclear Technology International Europe AB, ANT International, 2007.This information is the property of AdvancedNuclear Technology International Europe AB or is licensed for use by Advanced Nuclear Technology International Europe AB by itscustomers or partners. The information may not be given to, shared with, or cited to third party, used for unauthorised purpose, or be copiedor reproduced in any form without the written permission of Advanced Nuclear Technology International Europe AB.

ZIRATr 2 SPECIAL TOPIC REPORTTable 1-2:2007 -WELDING OF ZIRCONIUM ALLOYSChemical composition of Zr alloys used in Light Water Reactor (LWRs). Sn%Alloyr---Nb%Fe%Cr%Ni%0%Fuel Vendor.BWRsFuel RodsZircaloy-2 (RXN or SRA)1.2-1.70.07-0.20.015-0.060.03-0.060.40.10Zr Sponge0.25ZrSnZrFeZrFeZircaloy-2 (RXA)--Zircalo)'-4 0.14All fuel vendors0.05-0.10.05-0.10.05-0.10.05-0.1Only used in Japan and RussiaStructural c 0.1-0.140.1-0.14WestinghouseSiemens3GE4--All fuel vendorsAll fuel vendorsPWRsFuel RodsZircaloy-4 (SRA)Low Sn Zircaloy-4 (SRA)Modi! Zry-4 (SRA)ZIRLO (SRA)Low Sn ZIRLO(SRA)M5 (RXA)1.2-1.71.31.310.71O.SNDA(SRA)MDA(SRA)OXELS 0 .Sa 7 (SRA)110.S-1.20.10.5/O.S/O.S0.5 O.S 10 O.SOX ELS O.Sb(SRA)D4 (SRA)3bB (SRA)3b 9 (SRA)D410 20.09-0.120.120.120.20.1Duplex60.10.2All fuel vendorsAll fuel vendorsSiemensWestinghouseWestinghouseFramatome ANp5NFlMHI0.120.12Siemens---Siemens0.12Framatome ANP GmbH 0.6 0.6 0.6Westinghouse Electric SwedenWestinghouse Electric SwedenWestinghouse Electric SwedenStructural comronentsHPA-411Zircaloy-4 (SRA)Low Sn Zircaloy-4 (SRA)Modi! Zry-4 (SRA)ZIRLO(SRA)Low Sn ZIRLO(SRA)M5 (RXA)0.51.2-1.71.31.310.7Fe 0.09-0.12All fuel vendorsAll fuel vendorsSiemensWestinghouseWestinghouseFramatome ANPWER,RBMKE-110 (RXA)E-635 (RXA)E-635M (RXA)1.3O.SAlloy E12 R.el0.9-1.11O.S2.50.0140.4035 0.0030.00350.05-0.079007000.06Fuel CladdingFor structural materialsFor structural materialsPressure tube in RBMKCANDUZircaloy-4 (RXA)1.2-1.7Zr2.5Nb (SRA)2.4-2.S0.1S-0.24 0.15007-0.13-'0.1-0.140.09-0.13Fuel Cladding.,-'Pressure tube, All BWR fuel vendors are using the ZrY-2 material in Recrystallisation Annealed, RXA condition exceptANF (now AREVA NP) that use the Zry-2 material in Stress Relieved Annealed, SRA, condition., In all BWR liner cladding tubes about 90 % of the thickness-the outer part of the cladding tube consists ofZry-2.) Now AREVA NP4NowGNF5Now AREVA NP6All DUPLEX claddings consists of an outer corrosion resistant layer with a thickness 100 microns and therest of the thickness is Zry-4 to provide the mechanical strength.7All Framatome GmbH duplex claddings contains Zry-4 with 1.5 wt%Sn8Zry-4 with 1.3 wt %Sn9Zry-4 with 1.5 %SnwZry-4 with 1. 5 %SnUFor structural components onlyCopyright Advanced Nuclear Technology International Europe AB,ANT Intemational,2007.This information is the property of AdvancedNuclear Technology International Europe AB or is licensed for use by Advanced Nuclear Technology International Europe AB by itscustomers or partners. The information may not be given to, shared with, or cited to third party, used for unauthorised purpose, or be copiedor reproduced in any form without the written permission of Advanced Nuclear Technology International Europe AB.1-5(1-5)

ZIRATr 2 SPECIAL TOPIC REPORT2007- WELDING OF ZIRCONIUM ALLOYSWelding techniques used for different fuelassembly components2Introduction (Alfred Strasser and Peter Rudling)2.1Welding is a fabrication process that j oins materials, usually metals or thermoplastics, by causingcoalescence" . This is often done by melting the workpieces and adding a filler material to form apool of molten material (the weld puddle) that cools to become a strong j oint, with pressuresometimes used in conj unction with heat, or by itself, to produce the weld.The welding processes can be separated into fusion and solid state welding, the latter being aprocess which does not involve melting of the materials to be j oined, Figure 2-1. Resistancewelding is shown in the figure as a solid state welding technique but actually resistance weldingmay also cause some limited fusion zone.Welding of MetalsFusion WeldingSolid State WeldingResistance WeldingUltrasonic WeldingFriction Welding-Figure Redrawn and modihed Irom OIiglnal b,' A r\I ,l I NTERNATlONAL 2007Figure 2-1:Overview of different welding techniques.The following welding methods are currently being used for zirconium fuel assembly components,Table 2-r:r)Fusion weldinga)TICb)Electron Beam, EBc)Laser Beam, LB2)Solid State Weldinga)Resistance (R) weldingi) Spot welding, Sii) Upset Shape Welding, USnTwo (or possibly more) pieces metals are bonded together either by liquefying the places where they are tobe bonded, coalescing these liquids, and allowing the coalesced liquid to solidify or by solid state diffusionbonding across the interface between the parts. At the end of this process the two pieces of metal havebecome one continous solid.Copyright Advanced Nuclear Technology International Europe AB,ANT Intemational,2007.This information is the property of AdvancedNuclear Technology International Europe AB or is licensed for use by Advanced Nuclear Technology International Europe AB by itscustomers or partners. The information may not be given to, shared with, or cited to third party, used for unauthorised purpose, or be copiedor reproduced in any form without the written permission of Advanced Nuclear Technology International Europe AB.

ZIRATr 2 SPECIAL TOPIC REPORTTable 2-1:2007-WELDING OF ZIRCONIUM ALLOYSDifferent welding methods used for manufacturing of different Fuel Assembly components.ComponentFuel rod end plugWelding processTlGR,USLEB'-l'-l'-l'-lSpot'-lGrid/guide tubeSpacer/water rodsGridFuel channel'-l'-l'-l'-l'-lThe welding processes used in the nuclear industry are automated and electronically controlledwith electronic readouts and often-automated in-process inspection. Welding is performed byqualified operators following exacting welding procedures. The electronic controls should be setwithin predetermined process parameters limits set forth in the welding procedures. The controlsshould be audited to ensure that the settings represent actual conditions and are within the limitsset by the procedure. Typically the controls are for voltage, amperage, time at power, weld j ointor arc rotation speed and number of rotations and other parameters that control the weldingprocess. The spacing between the electrodes (tungsten electrode, electron gun, laser) and the weldj oint may be manually controlled.All of the weld processes require qualification of the welding process, qualified welders andinspection of the welds. The qualification should include the examination and evaluation of weldsmade over a range of conditions to establish lower and upper limits of welding parameters. Theevaluation should include metallographic examination for penetration, structure and lack

Welding residual stresses and stress relieve Formation of the weld metal Solidification of the weld metal Phase transformations during welding Basics of welding methods used in welding of zirconium alloys TIC Laser Welding Electron Beam Welding Upset shape welding Resistance Appendix C -R

Related Documents:

Heat-Resistant Alloy Castings 8, 9 Aluminum Alloys 9, 10 Aluminum Casting Alloys 10, 11 Copper Alloys 12, 13 Copper Casting Alloys 13, 14 Magnesium Alloys/ Casting Alloys 14 Magnesium Alloys/Wrought Alloys 15 Nickel Alloys 15 Super Alloys 16-18 Tin Alloys 18 Zinc Alloys 19 Precious Metal Alloys 19 Ni-Cr-Mo alloys 19

6.3 Mechanised/automatic welding 114 6.4 TIG spot and plug welding 115 7 MIG welding 116 7.1 Introduction 116 7.2 Process principles 116 7.3 Welding consumables 130 7.4 Welding procedures and techniques 135 7.5 Mechanised and robotic welding 141 7.6 Mechanised electro-gas welding 143 7.7 MIG spot welding 144 8 Other welding processes 147 8.1 .

affected zone. Welding processes that are commonly used with the corrosion-resistant alloys are shown in Table 1. In addition to these common arc welding processes, other welding processes such as plasma arc welding, resistance spot welding, laser beam welding, electron beam welding, and submerged arc welding can be used. Because of

seam butt welding resistance butt welding flash butt welding resistance butt welding shielded unshielded other process plasma laser resistance butt welding inert gas welding submerged arc welding atomic hydrogen shielded metal arc welding (coated electrode) esepl w w w . e u r e k a e l e c t r o d e s .

the welding processes most often used in today's industry including plasma arc cutting, oxyfuel gas cutting and welding, Gas Metal Arc Welding (GMAW), Flux-Cored Arc Welding (FCAW), Shielded Metal Arc Welding (SMAW), and Gas Tungsten Arc Welding (GTAW). Flat welding positions and basic joints will be practiced. Pipe and tube welding

3. Classification of Underwater Welding Underwater welding may be divided into two main types: a) Wet welding b) Dry welding Fig. 3.1 Classification of underwater welding 3.1 Wet welding 3.1.1. Wet welding with coated electrode Wet welding is performed at ambient pressure with the welder-diver in the water and no physical barrier

welding. Since my M.Tech. thesis work is on Friction stir welding (FSW), a solid state welding process so now onwards, FSW will only be explained in detail. Friction Stir Welding: Friction stir welding (FSW) is an emerging, energy efficient, attractive and eco-friendly solid state welding process invented in 1991 in England [4].

Don Bosco’s “Memoirs of the Oratory”and Bonetti’s “Storia dell’Ora-torio” 127 I. Don Bosco’s “Memoirs of the Oratory of Saint Francis de Sales” 128 Origin and Publication of the “Memoirs” and Related Questions 128 Don Bosco’s Agenda in the “Memoirs” and their Historical Character 140