ASTM 19th International Symposium on Zirconium in the Nuclear Industry Ex-situ and in-situ studies of radiation damage mechanisms in Zr-Nb alloys Junliang Liu 1 , Guanze He 1 , Anne Callow 1 , Kexue Li 1 , Sergio Lozano- Perez 1 , Angus Wilkinson 1 , Michael Moody 1 , Chris Grovenor* 1 ,Jing Hu 2 , Mark Kirk 2 , Meimei Li 2 , Anamul Haq Mir 3 , Jonathan Hinks 3 , Stephen Donnelly 3 , Jonna Partezana 4 and Heidi Nordin 5 1 Department of Materials, Oxford University, Oxford, UK. 2 Argonne National Laboratory, Argonne, IL, US 3 School of Computing and Engineering, University of Huddersfield, UK 4 Westinghouse Electric Company, Pittsburgh, PA, US 5 Canadian Nuclear Laboratories, Chalk River, ON, K0J 1J0 Canada 1
What are we interested in? The use of advanced analytical techniques to study the response of Zr cladding materials to corrosion and radiation damage J. Hu et al. Acta Materialia May 2 nd 2019 https://doi.org/10.1016/j.actamat.2019.04.055 2
Materials Autoclave corrosion: Zircaloy-4 and Zr-0.5Nb: 360°C, 18MPa, Pure water Zr-2.5Nb: 300°C, 10 Mpa, D 2 O, PH=10.5(LiOD) 3
Materials CNL Halden reactor samples • In-flux • Out-of-flux but in-reactor water chemistry • Static autoclave with D 2 O (pH=10.5, LiOD), and at 300 ° C and 10 MPa. • In flux 325 o C samples that have been extensively analysed 4
Materials Zr-1Nb sheet TD 20 µm ND RD SRA Zr-2.5Nb tube RD* 2 µm 5 TD* AD
Experiments undertaken Aim of study Material Conditions Sample source 1. Irradiation effects in Zr Autoclave RX Zr-0.5Nb oxides corrosion Westinghouse In-situ heavy ion irradiation 2. Irradiation induced RX Zr-1Nb and CNL elemental redistribution RX and SR Metal Zr-2.5Nb 3. Microstructure of in- Ex-situ characterisation of reactor formed oxide In-reactor SR Zr-2.5Nb CNL in-reactor corroded alloys 4. Irradiation-induced corrosion elemental redistribution 5. The transportation of Autoclave 3D mapping of deuterium hydrogen/deuterium Ziraloy-4 and Westinghouse distribution using through the oxide layer SR Zr-2.5Nb In-reactor and CNL NanoSIMS Corrosion RX: Recrystallised; SR: Stress Relieved 6
Experimental methods STEM/EELS/EDX In-situ TEM Electron Ion beam Electron Ion beam SEM/FIB/EDX beam beam 3D APT Duoplasmatro NanoSIMS 50 n source Cs + source Magnetic sector Sample exchange Analysis chamber Multicollection chamber 7
Irradiation Parameters Temperature Flux Damage rate Experiment Ions Facility (ions.cm -2 .s -1 ) (K) (dpa/s) IVEM 1 MeV Kr ++ 8 x 10 11 1.5x10 -3 50 In-situ irradiation MIAMI2 in oxides 700 keV Kr ++ 1-5 x 10 12 0.5-2.5x10 -3 293 IVEM 1 MeV Kr ++ 8×10 11 1.5x10 -3 50 IVEM In-situ irradiation 1 MeV Kr ++ 8×10 11 1.5x10 -3 293 in SPPs and IVEM 1 MeV Kr ++ 8×10 11 1.5x10 -3 623 metal matrix IVEM 1 MeV Kr ++ 8×10 11 1.5x10 -3 873 MIAMI2 350 keV Kr ++ 6×10 11 1-3x10 -3 623 Halden 4.3-4.7×10 13 ~10 -7 In-Reactor 600, 520 Neutrons Reactor 8
In-situ Ion Irradiation of bulk monoclinic-ZrO 2 on 0.5 %-Nb (210 days) Evolution of oxide structure under in situ 700 keV Kr ++ irradiation at room 3 dpa (5.6x10 15 ions.cm -2 ) 10 dpa (1.9x10 16 ions.cm -2 ) 0 dpa temperature 9
In-situ Ion Irradiation damage in monoclinic-ZrO 2 Simulated patterns Rotationally averaged experimental patterns 700 keV Kr ++ implantation at 293 K to different damage levels; pre-irradiation, 5.6x10 15 ions.cm -2 (3 dpa) and (c) 1.9x10 16 ions.cm -2 (10 dpa) 10
In-situ Ion Irradiation damage in monoclinic-ZrO 2 Atomic-resolution HAADF STEM image from an oxide grain post-irradiation, 1.9x10 16 ions.cm -2 (10 dpa), with corresponding FFT from the whole region, (b) direct measurement of lattice parameters based on the HAADF STEM images 11
In-situ Ion Irradiation damage in monoclinic-ZrO 2 TKD pattern quality and phase maps from typical regions of in-situ irradiated Zr oxide. (a and d) 0 dpa, (b and e) 4 dpa, 7.4x10 15 ions.cm -2 (c and f) 10 dpa, 1.9x10 16 ions.cm -2 0 dpa 4 dpa 10 dpa 97.5% 10.5% 0.4% monoclinic tetragonal 2.5% 4.1% 4.4% 0 85.4% 95.2% cubic Horizontal grain size 63±6 66±11 97±24 (nm) Vertical grain 142±28 76±13 162±49 size (nm) 12
In-situ Ion Irradiation damage in ZrO suboxide In-situ TEM images of suboxide region and metal substrate in the Zr-0.5Nb alloy: (a) pre-irradiation (b) 10 14 ions/cm 2 Pre-irradiation HAADF STEM image of the region followed during in-situ irradiation and (d) O/Zr atomic ratio map from EELS analysis of the pre-irradiation sample. 13
J Liu et al. Preferential amorphisation of ZrO suboxide Journal of Nuclear Materials 513, 226-231 2019 HRTEM images and FFTs from the interface region (a) pre-irradiation (b) irradiated at 293 K to 1.9x10 16 ions.cm -2 (c) irradiated at 50 K to 4 x 10 15 ions.cm -2 14
In-situ Ion Irradiation damage in SPPs in metal matrix Following the same particles during in-situ irradiation • Morphology of SPPs can easily be obscured by dislocation loops, surface oxide and bend contours RT DF g, 3g 350 ℃ BF 15
In-situ Ion Irradiation damage of β -Nb SPPs in metal matrix Before and after irradiation by 1 MeV Kr ++ to 6.4x10 15 ions.cm -2 (15 dpa) at 293 K . (a) pre-irradiation BF (b) post-irradiation BF (c) pre-irradiation SAD (d) post-irradiation SAD ത 2110 α ത 2112 α 01 ത 1 β 0002 α 110 β 101 β EDX line-scan profiles of Nb K a for SPPs irradiated at 293 K, 623 K, and 873 K with 1 B= 01 ത 10 α−Zr MeV Kr ++ to 6.4x10 15 ions.cm -2 (15 dpa). 16 B= ത 111 β−Nb
Size changes in ion-irradiated β -Nb SPPs? β -Nb SPP size after irradiation at different temperatures 60 50% 40% 50 Relative size change Post irradiation 30% 40 Radius (nm) 350 20% 300 30 250 10% Zr Kα1 Zr Kα1 200 Nb Kα1 20 150 Simulated pre Nb 0% 100 10 -10% 50 0 0 -20% 0 20 40 60 80 100 120 140 160 180 200 50 293 623 873 Distance (nm) Irradiation temperatures (K) before after relative size change 17
In-situ Ion Irradiation damage in Lave phase SPPs in metal matrix (a) (b) (c) α -Zr Matrix FFT from SPP SPP Zr(Nb, Fe) 2 FFT from matrix HRTEM images and inset FFTs showing the amorphisation of a Laves phase SPP irradiated at 50 K to 6.8x10 15 ions.cm -2 (16 dpa), with EDX line-scans over the same SPP before and after irradiation 18
How can we study composition changes in in the matrix? APT tips irradiated in Huddersfield MIAMI2 with 650 keV Kr 2+ ions CNL B166 Zr2.5Nb TEM after TEM Before 15 dpa 19
Kr ion irradiation to 5 dpa Nb Fe Metal matrix average Nb ZrO2 content of 0.42 at% (cf 0.45 at% in un-irradiated material. Zr No Clusters detected Sample B166 Zr-2.5%Nb 650 keV Kr+ 5 dpa Zr Nb Fe Cr C O Al 98.5 0.42 0.03 0.01 0.12 0.89 0.01 20
In flux and out of flux CNL samples have been studied to : • Compare pore distributions between in flux and out of flux samples • Analyse differences in oxide grain texture in autoclave and in- reactor samples • Study the growth of nano-scale b -Nb precipitates during n- irradiation • Analyse the rate at which Nb is oxidised in the oxide under different conditions 21
Autoclave In reactor ~ 8 dpa Does neutron-irradiation damage create extra porosity in the ZrO 2 ? Fresnel contrast ( ± 500 nm) bright field TEM images from 2000-day autoclave-corroded samples and 2700-day in-reactor sample (10 22 n.cm -2 , ~8 dpa). Grain boundary nano-porosity is formed in both oxides (yellow arrows) and but voids in the grain interior only in the n-irradiated sample (blue circles). 22
Why are we interested in porosity? Because we can map directly deuterium distributions in oxides. (See Jones et al this afternoon) Distributions of 2 H - in a 700-day CNL Zr-2.5Nb sample Distribution of 2 H - and 18 O - in a 61-day K. Li et al. Applied Surface Science Zircaloy-4 sample showing interconnected 464, 311-320 2019 pathways for deuterium. 23
Comparing pore distribution at different stages of oxidation Autoclave 0.5%Nb samples after 75 and 165 days See Poster: Couet et al 24
Neutron-irradiation damage in ZrO 2 : grain size and shape TKD analysis of oxides on CNL Zr-2.5Nb tubes (a) In-flux, 190 days, 7.6x10 20 n.cm -2 (2 dpa), (b) Out-of-flux, 185 days, (c) autoclave, 150 days and (d) autoclave, 700 days. 25
Neutron induced nano-Nb precipitates B56: 250 o C, in flux, low damage B70: 325 o C, in flux , low B74: 325 o C, in flux , high No detectible nano-Nb damage damage Small nano-Nb particles Larger nano-Nb particles and numerous hydrides All images taken at with B70 B74 B close to [11-20], g = (0002), 4-5g 26
Morphology of Ir Irradiation in induced nano nano-precipitates ~ 2 nm ~ 4.5 nm ~ 1.5 nm B70, In flux 190 days, 325 ⁰C 27
Size and sh Siz shape of nano-precip ipit itates versus damage le level Material Number density Average long axis Average short axis Aspect ratio (No./cm^3) (nm) (nm) 10 16 B70 1.9 dpa 5 ± 1.3 2.4 ± 0.5 2.09 5. 10 15 B74 25.2 dpa 8.3 ± 3.7 3 ± 0.9 2.71 24 18 B74 B74 22 16 B70 B70 20 14 18 16 12 14 10 Count Count 12 8 10 8 6 6 4 4 2 2 0 0 5 10 15 20 1 2 3 4 5 6 long axis (nm) short axis (nm) 28
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