POST IRRADIATION TESTING CAPABILITIES OF EXPERIMENTAL REACTOR - PowerPoint PPT Presentation

POST IRRADIATION TESTING CAPABILITIES OF EXPERIMENTAL REACTOR COMPONENTS AT THE LECI FACILITY FOR SERVICE LIFE ASSESSMENT P. GAVOILLE, K.COLAS, B. KAPUSTA CEA Saclay, Université Paris- Saclay, DEN, Service d’Etudes des Matériaux Irradiés, F-91191, Gif-sur-Yvette, France Presented by C. GONNIER CEA Cadarache, DEN, Département d’Etude des Réacteurs, 13108 Saint Paul lez Durance, France RRFM – IGORR, SYDNEY, AUSTRALIA, DECEMBER 3-7 TH 2017 RRFM - IGORR, Sydney, Australia, | PAGE 1 December 3-7th 2017

BACKGROUND Assessment of the environmental degradation of experimental core components is crucial for: • Safe et efficient operation of experimental reactors • Determination of achievable service time and replacement schedule Orphee Reactor Feedback is needed in particular on: Saclay, France • Mechanical properties evolution under [Monographies DEN, Research Nuclear Reactors, CEA, 2012] irradiation • Amount of Al to Si transmuted • Corrosion behavior • Swelling RRFM - IGORR, Sydney, Australia, December 3-7th 2017 | PAGE 2

THE LECI FACILITY K Line (Active in 1959) • Hotlab located in Saclay, near Paris, France • Three lines of hotcells • Mission: characterization of non-fissile irradiated materials I Line (1970) • Determination of behavior in normal, accidental or storage conditions • Prediction of in-service lifetime • Materials studied: • Gen 2&3 reactors (RPV Steel, Zr alloys) • MTR (Aluminum alloys) • Gen 4 reactors (sodium or gas cooled FBR) M Line (2005) RRFM - IGORR, Sydney, Australia, December 3-7th 2017 | PAGE 3

CHARACTERIZATION OF MATERIALS AT THE LECI FACILITY Metallography Fractography Microstructure EPMA EDS Orphee 4F cold finger Tensile Fracture Impact tests ICP-AES Toughness LIBS Testing Mechanical Chemical Behavior Analyses | PAGE 4

MECHANICAL BEHAVIOR UNDER IRRADIATION (1/2) Example of hardening of aluminum alloys under irradiation as measured by tensile tests 5754-O ; MELUSINE ; Fth/Fr=0,6 800 5754-NET-O ; OSIRIS ; Fth/Fr=1,1 700 5754-NET-O 5754-NET-O ; RHF ; Fth/Fr=200 à 250 600 5154-O Yield strength Rp 0,2% (MPa) 500 5154-O ; HFR ; Fth/Fr=0,95 400 6061-T6 ; HFIR ; Fth/Fr=2,5 ; v=3E-5 s-1 6061-T6 300 6061-T6 ; HFIR ; Fth/Fr=2,5 ; v=3E-3 s-1 200 6061-T6 ; HFIR ; Fth/Fr=1,66 100 6061-T6 ; BR2 ; Fth/Fr=2,25 0 0 5 10 15 20 25 30 [B.Kapusta, INSTN, Aluminum Behavior Under Fluence thermique (10 22 n/cm2) Thermal fluence Irradiation, 2011] RRFM - IGORR, Sydney, Australia, December 3-7th 2017 | PAGE 5

MECHANICAL BEHAVIOR UNDER IRRADIATION (2/2) Fracture toughness Testing Servo-Hydraulic Machine (100 kN) Application to CT 20 specimen after test surveillance programs of core components for MTRs and NPPs Compact Tension unconventional thickness 350 J Charpy Impact Testing Ductile-Brittle transition (impact tests) 200 180 160 140 120 Energie (Joules) 100 80 60 40 Matériau témoin (non irradié) Points expérimentaux matériau témoin 20 Matériau irradié Points expérimentaux matériau irradié 0 -200 -180 -160 -140 -120 -100 -80 -60 -40 -20 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 Température (°C) RRFM - IGORR, Sydney, Australia, December 3-7th 2017 | PAGE 6

MICROSTRUCTURAL EXAMINATIONS (1/2) Microscopic characterization Fractography of broken tensile sample surfaces Dose: 11.7x10 22 n/cm 2 Nuclearized SEM Dose: 4x10 21 n/cm 2 (Zeiss Supra 55) Brittle behavior Ductile behavior [B.Kapusta, INSTN, Aluminum Behavior Under Irradiation, 2011] Example of foiling corrosion on 5754- NET-O alloy with important hardening RRFM - IGORR, Sydney, Australia, December 3-7th 2017 | PAGE 7

MICROSTRUCTURAL EXAMINATIONS (2/2) Nano-characterization Precipitate-free zone in heavily Sample preparation by irradiated 6061-T6 (2x10 23 n th /cm²) nuclearized FIB or electropolishing TEM (FEI 300 kV) TEM sample [B.Kapusta, INSTN, Aluminum Behavior Under Irradiation, 2011] Mg-Si needles in Si-enriched TAP sample 6061 alloy LEAP 4000X HR Nuclearized Atom Probe Nuclearized FIB-SEM (Zeiss Auriga 40) Nota :This work profited from a French government grant managed by the National Agency of Research under the program “Investments for [K. Buchanan et al. Acta Materialia, v132, 2017] | PAGE 8 the future” (ref. ANR-11-EQPX-0020

CHEMICAL ANALYSES (1/2) Examples of EPMA analyses on 5754-NET-O Nuclearized Electron Probe Micro-Analyzer Observation of precipitation and radiation-induced migration of chemical elements Si Al Mg Mn Cr Fe F th (0,0254 eV) = 8,2 x10 22 n/cm 2 D Si wt = 2,1% [B.Kapusta, INSTN, Aluminum Behavior Under Irradiation, 2011] RRFM - IGORR, Sydney, Australia, December 3-7th 2017 | PAGE 9

CHEMICAL ANALYSES (2/2) • Nuclearized Laser-Induced Breakdown Spectrometer LIBS technique: measurement of Si content on centimeter size samples →information on received dose (transmutation Al-Si) Intensity (A. U.) • Also available ICP-AES technique on Al shavings from massive components →information on Mg, Fe, Si contents Courtesy of N. Coulon CEA, DPC/SEARS Wavelength (nm) Laser To spectrometer Quartz window Fiber optic Focal lens Mirror Plasma Mirror Sample Quartz window RRFM - IGORR, Sydney, Australia, December 3-7th 2017 | PAGE 10

CORRELATION SI CONTENT AND MECHANICAL BEHAVIOR (2/2) Generated Si content (from Al transmutation) is directly linked to embrittlement and hardening of the components of MTRs | PAGE 11 [B.Kapusta, IGORR, 2005]

CORRELATION SI CONTENT AND MECHANICAL BEHAVIOR (2/2) | PAGE 12 [B.Kapusta, IGORR, 2005]

CONCLUSIONS Methods and experimental capacities have been developed over the years at the LECI facility in order to characterize non-fissile materials. These means can be applied to MTRs core components such as pressure vessels, experimental racks, neutron guide tubes for example. Several aspects of the impact of irradiation on aluminum components can be studied: Degradation of mechanical properties (hardening, embrittlement) Microstructure evolution (radiation-induced segregations, precipitation) Enhanced corrosion Swelling Application to Surveillance programs of MTRs Prediction of component lifetime/replacement LECI is open to national and international clients through direct contracts or international scientific collaboration RRFM - IGORR, Sydney, Australia, December 3-7th 2017 | PAGE 13

| PAGE 14 Commissariat à l’énergie atomique et aux énergies alternatives Direction de l’Energie Nucléaire RRFM - IGORR, Sydney, Australia, December Centre de Saclay | 91191 Gif-sur-Yvette Cedex Département des Matériaux pour le Nucléaire 3-7th 2017 T. +33 (0)1 69 08 46 24 | F. +33 (0)1 69 08 90 73 Service d’Etudes des Matériaux Irradiés Etablissement public à caractère industriel et commercial | RCS Paris B 775 685 019