POST IRRADIATION TESTING

CAPABILITIES OF EXPERIMENTAL

REACTOR COMPONENTS AT THE

LECI FACILITY FOR SERVICE LIFE

ASSESSMENT

RRFM – IGORR, SYDNEY, AUSTRALIA, DECEMBER 3-7TH 2017

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

| PAGE 1RRFM - IGORR, Sydney, Australia,

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

Feedback is needed in particular on:

• Mechanical properties evolution under

irradiation

• Amount of Al to Si transmuted

• Corrosion behavior

• Swelling

| PAGE 2RRFM - IGORR, Sydney, Australia, December 3-7th 2017

Orphee

ReactorSaclay,

France

[Monographies DEN, Research Nuclear

Reactors, CEA, 2012]

THE LECI FACILITY

| PAGE 3RRFM - IGORR, Sydney, Australia, December 3-7th 2017

M Line (2005)

K Line (Active in 1959)

I Line (1970)

• Hotlab located in Saclay, near Paris,

France

• Three lines of hotcells

• Mission: characterization of non-fissile

irradiated materials

• 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)

CHARACTERIZATION OF MATERIALS AT THE LECI

FACILITY

| PAGE 4

Microstructure

Chemical Analyses

MechanicalBehavior

MetallographyFractography

Tensile

testsFracture

Toughness Impact

TestingLIBS

EPMA EDS

ICP-AES

Orphee 4F cold finger

MECHANICAL BEHAVIOR UNDER IRRADIATION (1/2)

| PAGE 5RRFM - IGORR, Sydney, Australia, December 3-7th 2017

0

100

200

300

400

500

600

700

800

0 5 10 15 20 25 30

Fluence thermique (1022

n/cm2)

Rp

0,2

% (

MP

a)

5754-O ; MELUSINE ; Fth/Fr=0,6

5754-NET-O ; OSIRIS ; Fth/Fr=1,1

5754-NET-O ; RHF ; Fth/Fr=200 à 250

5154-O ; HFR ; Fth/Fr=0,95

6061-T6 ; HFIR ; Fth/Fr=2,5 ; v=3E-5 s-1

6061-T6 ; HFIR ; Fth/Fr=2,5 ; v=3E-3 s-1

6061-T6 ; HFIR ; Fth/Fr=1,66

6061-T6 ; BR2 ; Fth/Fr=2,25

Thermal fluence

Yie

ld s

trength

5754-NET-O

6061-T6

5154-O

Example of hardening of aluminum alloys under

irradiation as measured by tensile tests

[B.Kapusta, INSTN, Aluminum Behavior Under

Irradiation, 2011]

MECHANICAL BEHAVIOR UNDER IRRADIATION (2/2)

| PAGE 6RRFM - IGORR, Sydney, Australia, December 3-7th 2017

0

20

40

60

80

100

120

140

160

180

200

-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)

En

erg

ie (

Jo

ule

s)

Matériau témoin (non irradié)

Points expérimentaux matériau témoin

Matériau irradié

Points expérimentaux matériau irradié

Fracture toughness Testing Servo-Hydraulic Machine (100 kN)

CT 20 specimen after test

350 J Charpy Impact Testing Ductile-Brittle transition

(impact tests)

Application to

surveillance programs

of core components for

MTRs and NPPs

Compact Tension

unconventional

thickness

MICROSTRUCTURAL EXAMINATIONS (1/2)

| PAGE 7RRFM - IGORR, Sydney, Australia, December 3-7th 2017

Microscopic characterization

Nuclearized SEM

(Zeiss Supra 55)

[B.Kapusta, INSTN, Aluminum Behavior Under

Irradiation, 2011]

Example of foiling

corrosion on 5754-

NET-O alloy with

important hardening

Dose: 4x1021 n/cm2

Ductile behavior

Dose: 11.7x1022 n/cm2

Brittle behavior

Fractography of broken tensile sample surfaces

MICROSTRUCTURAL EXAMINATIONS (2/2)

| PAGE 8

TEM

(FEI 300 kV)

TAP sample

TEM sample

Nano-characterization

LEAP 4000X HR

Sample preparation by

nuclearized FIB or

electropolishing

Nuclearized FIB-SEM

(Zeiss Auriga 40)

Nuclearized Atom Probe

[B.Kapusta, INSTN, Aluminum Behavior Under

Irradiation, 2011]

Precipitate-free zone in heavily

irradiated 6061-T6 (2x1023 nth/cm²)

Mg-Si needles in Si-enriched

6061 alloy

[K. Buchanan et al. Acta Materialia, v132, 2017]

Nota :This work profited from a French government grant managed by

the National Agency of Research under the program “Investments for

the future” (ref. ANR-11-EQPX-0020

CHEMICAL ANALYSES (1/2)

| PAGE 9RRFM - IGORR, Sydney, Australia, December 3-7th 2017

Nuclearized Electron Probe

Micro-Analyzer

Examples of EPMA analyses on 5754-NET-O

Observation of precipitation and radiation-induced

migration of chemical elements

F th (0,0254 eV) = 8,2 x1022 n/cm2 DSiwt = 2,1%

Al Si Mg

CrFeMn

[B.Kapusta, INSTN, Aluminum Behavior Under

Irradiation, 2011]

CHEMICAL ANALYSES (2/2)

| PAGE 10RRFM - IGORR, Sydney, Australia, December 3-7th 2017

Wavelength (nm)

Inte

nsity (

A. U

.)

Quartz

window

Laser

SamplePlasma

Focal

lens

To spectrometer

Quartz

window

Mirror

Mirror

Fiber

optic

Nuclearized Laser-Induced Breakdown Spectrometer

Courtesy of N. Coulon

CEA, DPC/SEARS

• LIBS technique: measurement of Si

content on centimeter size samples

→information on received dose

(transmutation Al-Si)

• Also available ICP-AES technique on

Al shavings from massive components

→information on Mg, Fe, Si contents

CORRELATION SI CONTENT AND MECHANICAL

BEHAVIOR (2/2)

| PAGE 11

Generated Si content (from Al transmutation) is directly linked to embrittlement and

hardening of the components of MTRs

[B.Kapusta, IGORR, 2005]

CORRELATION SI CONTENT AND MECHANICAL

BEHAVIOR (2/2)

| PAGE 12[B.Kapusta, IGORR, 2005]

CONCLUSIONS

| PAGE 13RRFM - IGORR, Sydney, Australia, December 3-7th 2017

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

Direction de l’Energie Nucléaire

Département des Matériaux pour le Nucléaire

Service d’Etudes des Matériaux Irradiés

Commissariat à l’énergie atomique et aux énergies alternatives

Centre de Saclay | 91191 Gif-sur-Yvette Cedex

T. +33 (0)1 69 08 46 24 | F. +33 (0)1 69 08 90 73

Etablissement public à caractère industriel et commercial | RCS Paris B 775 685 019

| PAGE 14

RRFM - IGORR, Sydney, Australia, December

3-7th 2017