MICROSTRUCTURAL EVOLUTION OF M5™ ALLOY ......III.-Ei tlExperimental RltResults - Native Nb particles in M5 - RditiRadiation-Eh dEnhanced PtilParticles - -Component Loops

MICROSTRUCTURAL EVOLUTION OF M5™ ALLOY IRRADIATED IN PWRs UP TO

HIGH FLUENCES. COMPARISON WITH OTHER Zr BASE ALLOYS.

Authors: S. Doriot, B. Verhaeghe, J. L. Béchade, D. Menut, D. Gilbon, J. P. Mardon, J. M. Cloué, A. Miquet, L. Legras

17th INTERNATIONAL SYMPOSIUM ON ZIRCONIUM IN

CEA| Sylvie DORIOT

17th INTERNATIONAL SYMPOSIUM ON « ZIRCONIUM IN THE NUCLEAR INDUSTRY », HYDERABAD, INDIA,

FEBRUARY 03-07, 201320 FÉVRIER 2013

AIM OF THE STUDY

Irradiation-induced microscopic defects and microchemical modifications can impact the in-service behavior of cladding tubes

- <c>-component loops are responsible for the growth phenomenonD Gilbon et al ASTM STP 1245 1994 pp 521 548

ZyZy--44- D. Gilbon et al. ASTM STP 1245,1994, pp. 521-548

- The level of alloying elements present in solid

l ti i t thsolution can impact the mechanical properties

- Brenner, R., et al., JNM 305 (2002) 175-186.

Bossis, P., et al. ASTM STP 1505, 2009, pp. 430-456.M5M5™™

The The aimaim of of thisthis studystudy waswas to to assessassess the the evolutionevolution of the matrix Nb of the matrix Nb

20 FÉVRIER 2013 | PAGE 2Microstructural evolution of M5™. Doriot et al. | FEBRUARY 2013

content and of the <c>content and of the <c>--component component looploop linearlinear densitydensity versus fluence.versus fluence.

OUTLINE

I.- MaterialsMaterials of the of the studystudy and irradiation conditionsand irradiation conditions

II E perimentalE perimental Proced resProced resII.- ExperimentalExperimental ProceduresProcedures

- Analytical Transmission Electron Microscopy

Synchrotron Transmission X Ray Diffraction at the MARS- Synchrotron Transmission X-Ray Diffraction at the MARS beam-line (Synchrotron SOLEIL facility, France)

III E i t lE i t l R ltR ltIII.- ExperimentalExperimental ResultsResults

- Native Nb particles in M5™

R di ti E h d P ti l- Radiation-Enhanced Particles

- <c>-Component Loops

ConclusionConclusion20 FÉVRIER 2013 | PAGE 3Microstructural evolution of M5™. Doriot et al. | FEBRUARY 2013

I.- MATERIALS OF THE STUDY AND IRRADIATION CONDITIONS

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I.1.- MATERIALS OF THE STUDY

This study is focused on fully RXA M5™ alloy with a

M5™ is compared to Zr1%NbO and Zy-4fully RXA M5™ alloy with a

homogeneous highly refined dispersion of Nb

phase precipitates

Zr1%NbO and Zy 4 alloys also in a fully recrystallized state.

M5™phase precipitates

Z 4 t d d RXAZr1%NbOA and Zr1%NbOB:alignments of fine

Zy-4: standard RXA Zy-4 microstructure with hexagonal Zr(Fe,Cr)2 Laves

RXA-Zy-4 Zr1%NbOA

a g e s o e precipitates.phases evenly

dispersed throughout the matrix .

● If we except Zy-4, the chemical composition of these alloys differs mainly by their iron content in the range of 100 to 650 ppm.


I. 2.- IRRADIATION CONDITIONS

All the samples were irradiated in PWR conditions

Cladding-tubes of M5™ and Zr1%NbOA: fluence level up to about 15x1025 n/m2 (E>1 MeV)

Free-growth test tubes of M5™ and of Zr1%NbOB: fluence level up to about 20x1025 n/m2 (E>1 MeV)

Guide-tubes and free-growth test tubes of RXA Zy-4: fluence level up to about 20x1025 n/m2 (E>1 MeV)( )


II EXPERIMENTAL PROCEDURESII.- EXPERIMENTAL PROCEDURES

- ANALYTICAL TRANSMISSION ELECTRON MICROSCOPY (ATEM)

- SYNCHROTRON TRANSMISSION X-RAY DIFFRACTION (T-XRD)

AT THE MARS BEAM-LINE (SYNCHROTRON SOLEIL FACILITY,(SYNCHROTRON SOLEIL FACILITY,

FRANCE)

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II. 1.- ANALYTICAL TRANSMISSION ELECTRON MICROSCOPY (ATEM)

Observation and size distribution measurement of native and radiation-enhanced particles.

Observation and size distribution measurement of radiation-induced defects as <c>-component loops

Microanalyses of native second phase particles with a FEG STEM microscope and an EDX analyses system.

But for very tiny particles (on the nanometric scale) the use ofsynchrotron–based X-Ray technique is more relevant:

- X-Ray technique, with a bigger volume of the bulk materialsX Ray technique, with a bigger volume of the bulk materialssimultaneously analyzed, is statistically representative.

- Synchrotron permits to analyze very tiny volume fraction of particles(composition and crystallographic parameters)(composition and crystallographic parameters)


II. 2.- MARS A DEDICATED X-RAY BEAM-LINE FOR RADIOACTIVE MATTER AT THE SYNCHROTRON SOLEIL FACILITY

Multi-Analysis on Radioactive Sample (MARS) beam-line, at synchrotron SOLEIL (FRANCE),is fully dedicated to advanced structural and chemical characterizations

of radioactive matter (solid or liquid).Energy range of the X ray beam: 3 5 to 35 keV

4

MIV edge U Es

Electronic properties Solid and liquid characterizationsMOX doping

4

MIV edge U Es

Electronic properties Solid and liquid characterizationsMOX doping

Energy range of the X-ray beam: 3.5 to 35 keV

0

1

2

3

0 5 10 15 20 25 30 35 40

MIV edge

LIII edgeK edge

In Es

K La

ThK

r XeIGa

Pd

Au

RhTcFe

La

Te

Gd

Zr

Pt

CsCr

Ce

Se

0

1

2

3

0 5 10 15 20 25 30 35 40

MIV edge

LIII edgeK edge

In Es

K La

ThK

r XeIGa

Pd

Au

RhTcFe

La

Te

Gd

Zr

Pt

CsCr

Ce

Se

fission products characterization inside fuels

Phase stabilityof actinide alloys

Structural properties of fuels, fuel claddingsand nuclear core elements

Radionuclide speciationin environmental samples

fission products characterization inside fuels

Phase stabilityof actinide alloys

Structural properties of fuels, fuel claddingsand nuclear core elements

Radionuclide speciationin environmental samples

f

Sample maximum dose rate < 2 mSv/h (yellow zone) inside the experimental hutch ;<0.5 µSv/h outside (public area)

Sample maximum activity (after agreement from the French Nuclear Safety Authority ): up to 18.5 GBq per sample for α- and -emitters; including 2.0 GBq per sample for - and n-emitters (unique!)

| PAGE 9Microstructural evolution of M5™. Doriot et al. | FEBRUARY 2013

Development of dedicated experimental set-up including radiologic shielding and specific sample environment to prevent workers from contamination risk

µ (p )

II.2.- MARS A DEDICATED X-RAY BEAM-LINE FOR RADIOACTIVE MATTER AT THE SYNCHROTRON SOLEIL FACILITY

Standard Absorption station Standard Absorption station XAS,XAS, TT--XRDXRD, XRF, XES , XRF, XES

Opened to users : 2010Opened to users : 2010

High Resolution Diffraction High Resolution Diffraction station HR-XRD with 4 circles diffractometer

Opened to users : 2011

MonochromaticMonochromatic branchbranch::

TwoTwo experimental stations are being used alternatively on the monochromatic branch experimental stations are being used alternatively on the monochromatic branch

Standard spot size (Standard spot size (HxVHxV) ~ 300 x ) ~ 300 x 200 µm200 µm22 Flux 5x10Flux 5x101111 ph/s ph/s atat 17 17 keVkeV

with Si(220) ; Si(111) for lower with Si(220) ; Si(111) for lower energies and I = 430mAenergies and I = 430mA

2 symmetric2 symmetricrows of 12

Ge(111) crystals

associatedith 12 N I(Tl)with 12 NaI(Tl) scintillatorscoupled on

fast PM tubes giving a 24


g gchannel point

detector

II.2.- MARS A DEDICATED X-RAY BEAM-LINE FOR RADIOACTIVE MATTER AT THE SYNCHROTRON SOLEIL FACILITY

Standard Absorption station Standard Absorption station XAS,XAS, TT--XRDXRD, XRF, XES , XRF, XES

Opened to users : 2010Opened to users : 2010

High Resolution Diffraction High Resolution Diffraction station HR-XRD with 4 circles diffractometer

Opened to users : 2011

Powder diagram X-Ray line profile

MonochromaticMonochromatic branchbranch::

TwoTwo experimental stations are being used alternatively on the monochromatic branch experimental stations are being used alternatively on the monochromatic branch

T‐XRDStandard spot size (Standard spot size (HxVHxV) ~ 300 x ) ~ 300 x

200 µm200 µm22 Flux 5x10Flux 5x101111 ph/s ph/s atat 17 17 keVkeVwith Si(220) ; Si(111) for lower with Si(220) ; Si(111) for lower

energies and I = 430mAenergies and I = 430mA

2 symmetric2 symmetricrows of 12

Ge(111) crystals

associatedith 12 N I(Tl)with 12 NaI(Tl) scintillatorscoupled on

fast PM tubes giving a 24


g gchannel point

detectorSample holder

II.2.- MARS a dedicated X-ray beam-line for radioactive matter at the synchrotron SOLEIL facilityWhole-pattern profile matching analyses of the unirradiated M5™

α-Zrα-Zr

Z

α-Zr

α-Zr

α-Zr

● Peaks are described by a linear combination of a Lorenzian and a Gaussian function (pseudo-Voigt)

● Mean size of the coherent diffracting domains, usually related to the mean i f th ti l f i it t ith t i t i d f t


size of the particles for precipitates without micro-strains or defects, were evaluated from a Scherrer function

III.- EXPERIMENTAL RESULTS

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III. 1.- NATIVE Nb PARTICLES IN M5™MEAN DIAMETER AND NUMBER DENSITY BY TEMMean diameter Number density

1,82

‐3 stéréoby TEMby TEM7580 by TEMby TEM

0,81

1,21,41,6

ensity 102

0m

150 nm

505560657075

m(nm)

00,20,40,6,

0 2 4 6 8 10 12 14

numbe

r de

3035404550

0 2 4 6 8 10 12 14

m

● Particle size increases from 35 nm to about 50 nm and then

0 2 4 6 8 10 12 14

Fluence 1025 n/m2

0 2 4 6 8 10 12 14

fluence 1025 n/m2

remains constant from the fluence 4x1025 n/m2.

● Number density is about 1x1020 m-3 and shows a slight


continuous decrease during irradiation

III. 1.- NATIVE Nb PARTICLES IN M5™T-XRD ANALYSES

Zoom of the Zoom of the wholewhole––pattern profile pattern profile matchingmatching analyses of the M5analyses of the M5TMTM

withwith increasingincreasing irradiation fluence irradiation fluence levellevel (range 22.9(range 22.9°°--25.325.3°°))

There is a broadening,

-Nb (200)

Unirradiated reference

and a shift toward smaller angles of diffraction.

Th t

Increasing doses

That means an enlargement of the lattice

parameter and a corresponding lowering of

1 cycle

2 cycles corresponding lowering of the Nb content.

y

5 cycles


III. 1.- NATIVE Nb PARTICLES IN M5™ AND IN Zr1%NbOA: Nb CONTENT BY TEM AND T-XRD

Nb content (wt %)Total niobium content (calculated from

volume fraction and Nb content)

95100 M5™ by ATEM

0 91

Nb

60657075808590

Nb %

Zr1%NbOA by ATEM

M5™ by T‐XRD

0 40,50,60,70,80,9

t (%

) in na

tive b

4045505560

0 2 4 6 8 10 12 140

0,10,20,30,4

0 2 4 6 8 10 12 14Total N

b conten

● Decrease of niobium content until it reaches an « equilibrium » value of aboutby TEM and Tby TEM and T--XRDXRD

fluence 1025 n/m2fluence 1025 n/m2

● Decrease of niobium content until it reaches an « equilibrium » value of about 55-60 wt% at the fluence of ≈ 8x1025 n/m2 [observed by TEM, confirmed by T-XRD and previously observed on extraction replica by Shishov and al.]

Th t t l Nb t t i th ti Nb ti l i b t h lf th t t l Nb t t


● The total Nb content in the native Nb particles is about half the total Nb content of the original alloy and is unchanged by irradiation (no Nb rejected into the matrix).

III. 2.- RADIATION-ENHANCED PARTICLES SYNCHROTRON X-RAY DIFFRACTION ANALYSES OFTHE Nb (200) DIFFRACTION LINE ( )

Whole pattern profile matching decomposition of the Whole pattern profile matching decomposition of the NbNb (200) diffraction line of M5™ (200) diffraction line of M5™

Un-irradiated sample after 1 cycle

● Before irradiation contribution of mainly native particlesAfter irradiation rise of a new kind of rise of a new kind of NbNb particlesparticles (supposed to be radiation-

enhanced particles).●We have modeled the different line contributions to get the line position and to


We have modeled the different line contributions to get the line position and to deduce the crystallographic parameter crystallographic parameter and the NbNb content content of the particles.

III. 2.- RADIATION-ENHANCED PARTICLES(A) LATTICE PARAMETER AND Nb CONTENT BY T-XRD

TT--XRDXRDTEMTEM

100 nm

Nb content (wt % ) deduced from the lattice parameter for M5™A alloy, from T-XRD analyses

After irradiation radiation enhanced nanometric particles were● After irradiation, radiation-enhanced nanometric particles were observed for the three materials containing Nb.

● T-XRD analyses confirm they are Nb particles and they form with


● T-XRD analyses confirm they are Nb particles and they form with the « equilibrium » Nb content under irradiation (~ 60 wt%)

III. 2.- RADIATION-ENHANCED PARTICLES(B) WIDTH AND LENGTH VERSUS FAST FLUENCE

● Almost circular at 1 cycle they elongated11

12131415 width by TEM

length by TEM

T‐XRD

TEM and TTEM and T--XRDXRD

cycle, they elongated at longer irradiation time

6789

1011

nm

●The size rises rapidly from 0 to 4 cycles (8x1025 n/m2) and then 1

23456

( )remains constant

● T-XRD

01

0 2 4 6 8 10 12 14 16 18 20

Fluence 1025 n/m2

measurements give rather similar values


III. 2.- RADIATION-ENHANCED PARTICLES(C) NUMBER DENSITY AND VOLUME FRACTION

Volume fractionNumber density

0,4

0,5

n %

by TEMby TEM4

4,55

m‐3 by TEMby TEM

0,1

0,2

0,3

olum

e fraction

11,52

2,53

3,5

r den

sity 102

2

0

0,1

0 2 4 6 8 10 12 14 16 18 20

vo

Fluence 1025 n/m2

00,51

0 2 4 6 8 10 12 14 16 18 20

numbe

Fluence 1025 n/m2

●The number density of « needle-like » particles remains constant all along the irradiation and close to 1.5x1022 m-3.

●The volume fraction increases to about 0.2% at 8x1025 n/m2 and then levels out.


● No impact of iron content in the range of 100 to 650 ppm.

III. 2.- RADIATION-ENHANCED PARTICLES(A+B+C) Nb TAKEN OUT OF THE MATRIX

0,1

0,12

0,14

edles"

0,04

0,06

0,08Nb % in

"ne

e

0

0,02

0 2 4 6 8 10 12 14 16 18 20

N

Fluence 1025 n/m2

● Based on the volume fraction by TEM and the Nb content of the « needles » thanks to T-XRD we can evaluate the total Nb taken out from the matrix by these particles

Fluence 1025 n/m2

particles.

● Total Nb content of needles rises very rapidly until 4 cycles (8x1025 n/m2) and then remains content.

20 FÉVRIER 2013 | PAGE 21Microstructural evolution of M5™. Doriot et al. | FEBRUARY 2013● More than 0.1% Nb is taken out from the matrix

III. 3.- <c>-COMPONENT LOOPSCOMPARISON M5™ AND Zr1%NbOB ALLOYS WITHRXA Zy-4y

≈ 9x1025 n/m2 ≈ 20x1025 n/m2

M5™ Zr1%NbOB

RXA Zy-4● <c>-component loops much more numerous in RXA Zy-4 than

RXA Zy-4


● <c>-component loops much more numerous in RXA Zy-4 than in M5™ and in Zr1%NbOB alloy for the same fluence levels.

III. 3.- <c>-COMPONENT LOOPSLINEAR DENSITY VERSUS FLUENCE

● For M5™ and Zr1%NbO alloys, the linear density of <c>-component loops is rising slowly up to a fluence of 20x1025 n/m2 with a fluenceloops is rising slowly up to a fluence of 20x10 n/m with a fluence threshold (for occurrence) of about 3x1025 n/m2.

● No influence of the iron content in the range of 100 to 650 ppm


●There is a ratio of 5 between M5™ cladding tubes and RXA Zy-4

III. 3.- <c>-COMPONENT LOOPSLINEAR DENSITY AND GROWTH BREAKAWAY REGIME

F RXA Z 4 ll i di t d i PWR diti ( t 320°C) fl● For RXA Zy-4 alloys irradiated in PWR conditions (at~320°C) a fluence level of about 10x1025 n/m2 appeared to correspond already to the growth breakaway regime (S. Doriot et al., ASTM STP 1467, pp 175-201). For this fluence the <c>-loop linear density was measured in our study as high as 10x1013 m/m3.p y y g

● It was previously shown that no growth breakaway occurs for M5TM

cladding tubes for very high doses in PWRs (Mardon et al. Proceeding of LWR Fuel P f M ti T F l/WRFPM 2010 d V Ch b t t l ASTM STP 1529) This is

20 FÉVRIER 2013 | PAGE 24Microstructural evolution of M5™, Doriot et al. | FEBRUARY 2013

Performance Meeting TopFuel/WRFPM, 2010 and V. Chabretou et al., ASTM STP 1529). This is consistent with <c>-component loop linear density much lower than 10x1013 m/m3 in our study.

CONCLUSION

T-XRDallowed to measure for the first time the composition and the lattice parameters of radiation-enhanced nanometric needle-like precipitates:they are Nb particles with ~ 60%Nbthey are Nb particles with 60%Nb. confirms the “equilibrium” Nb content of native Nb under irradiation of ~

60%.ATEM allowed to assess the evolution of microstructural features such as <c>-

component loops native and radiation-enhanced particles as a function of irradiationcomponent loops, native and radiation-enhanced particles as a function of irradiation fluence level up to 20x1025 n/m2.

These two complementary techniques permitted to propose an evaluation of the niobium content in the matrix during irradiation.

M5™ exhibits:M5™ exhibits:no further evolution in size, number density and niobium content of the particles after a fluence of 8x1025 n/m2.moderate linear density of <c>-component loops for cladding-tubes

d t RXA Z 4compared to RXA Zy-4.noticeable decrease in Nb content in the matrix of more than 0.1%.

The iron content in M5™, Zr1%NbOA and Zr1%NbOB alloys has no influence either on <c>-component loop linear density, or on “needle-like” particle size or

20 FÉVRIER 2013 | PAGE 25Microstructural evolution of M5™. Doriot et al. |FEBRUARY 2013

density, in the range of 100 to 650 ppm.

THANK YOU FOR YOUR ATTENTION

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MICROSTRUCTURAL EVOLUTION OF M5™ ALLOY ......III.-Ei tlExperimental RltResults - Native Nb particles in M5 - RditiRadiation-Eh dEnhanced PtilParticles - -Component Loops