2020/01/27
FRONTIER Task 3 Workshop @ ORNL

Corrosion experiment
DURING electron irradiation
performed by KURRI-LINAC
Masafumi Akiyoshi
Radiation Research Center, Osaka Prefecture University

Corrosion DURING irradiation
In 2003, ceramics specimens irradiated by japanese experimental
fast-reactor JOYO using CMIR-5 rig were extracted from theircapsules. Two capsules were filled with white infiltrate that showedstrong acid. It was considered Na was infiltrated to the capsules. All
ceramic materials (α-Al2O3, AlN, β-Si3N4 and β-SiC) were stable inliquid Na without irradiation, but these specimens showed severedamage. β-Si3N4 and β-SiC showed good shape but showed largeswelling (up to 10%), and furthermore, α-Al2O3 and AlN weredisrupted into small pieces.

α-Al2O3 and AlN

β-Si3N4 and β-SiC

T62 capsule
5.3×1026 n/m2 (fast) at 502℃

T66 capsule
8.0×1026 n/m2 (fast) at 677℃

4種類の材料間でのスエリングの比較
ID
T61
T63
T64
T65
T67
T68

照射量 照射温度262
α-Al2O3(℃)(10 n/m )2.8502
1.110
3.95911.770
7.35622.590
4.2731
2.260
3.77381.960
6.97662.300

スエリング(%)
AlN
β-Si3N4
2.000
0.193
1.920
0.355
2.240
0.397
2.000
0.229
1.780
0.161
2.300
0.303

β-SiC
0.417
0.399
0.304
0.445
0.351
0.535

α-Al2O3, AlN とβ-Si3N4, β-SiCとの間で明らかな差がある

CMIR-4 及びCMIR-5 T6x 棒状試料の照射後スエリング測定結果（4種の材料間の比較）

転位ループ導入面(1)α-Al2O3 に導入された転位ループと粒界クラック

β-SiC に導入された転位ループ（観察面は{100}面）と粒界クラック

30MeV Electron Irradiation
30MeV Electron Accelerator

KURRI-LINAC
Kyoto University
Research Reactor Institute, Kumatori

Accelerate Energy: 28-32MeV
The beam current: ～230μA
Peak current of pulse: ～600mA
Pulse width: 4μs
Pulse frequency: ～100Hz
Energy Flux: ～7kW in several cm22> the divertor in ITER, 10MW/m
The Range of 30MeV Electron～5cm ( in ceramics )Energy of PKA (max): 125keV → Energy of PKA (average): 225eV
Number of Displacement Atoms per PKA: 3-4 atoms

Mainly Point Defects

Medium Temperature
Irradiation□15mm Al
Square tube

30t = 0.7mm
Cu Specimen Holder

3030MeVElectronBeamCooling WaterBeam

φ10x0.5mmSpecimen

0.4mm Cu Heat Spreader

Ti screw and nut

Vertical orientatedGraphite seat( 90 W/m・K )□15mm Al
Square tube
Cooling Water

Al water pipe
BN spray coatingApertureIndirect Water cooling system
Cu Heat sink and Al water pipe
KURL1302
KURL1301: 300 ℃ / 5.84 kW
32MeV, 4μs x 570mA x 80Hz

Temperature / ℃

KURL1302: 380 ℃ / 5.63 kW
32MeV, 4μs x 550mA x 80Hz

400

Get over the high heat flux
( > 10 MW/m )Achieved a reliable irradiation
at around 400℃

300
soda-lime glass sample
Al sample

20010000Beam Frequency
10 → 100Hz

1000

2000
Time / sec

3000

Radio Activity
High Energy Electrons → Brems. X-rays →Photonuclear Reaction （γ, n）→ Radio-Activation
MT ID KURL1302 (Typical conditions):
32MeV, peak 4μs 560mA, 80Hz
→ surface neutron flux 5.7×109 n/cm2 s
2013/3/11 → 3/14 ( 72h non-stop)
2.8x1020 e → 0.01 dpa
Surface dose rate: 2013/3/17 : 14.2 mSv/h
2014/4/14 : 318 μSv/h
Specimens:
Sapphire, α-Al2O3 (Toray A-999), AlN (Tokuyama SH-50, wo Y2O3), β-SiC (Bridgestone
Pure beta, p-type), β-SiC（Tokai Carbon n-type translucent and non-translucent）, α-SiC（Nippon Steel 4H n-type single crystal）

Cu-64: T1/2 12.7h, Co-60: T1/2 5.27y

Low energy (<10MeV) Irradiation
The Range of 30MeV Electron～5cm ( in ceramics )30MeV, Target: Oxigen atom E_d = 30eV,
Energy of PKA (max): 125keV → Energy of PKA (average): 225eV
Number of Displacement Atoms per PKA: 3.8 atoms

The Range of 8MeV Electron

Mainly Point Defects
Typical 4days irradiation gives
about 3×10^20e in 2cm^2,→ Displacement: O: 0.01dpa～5.4mm ( in SS )～2.2mm ( in tungsten )8MeV, Target: Fe atom E_d = 40eV,
Energy of PKA (max): 2.7keV → Energy of PKA (average): 149eV
Number of Displacement Atoms per PKA: 1.9 atoms
8MeV, Target: W atom E_d = 60eV,
Energy of PKA (max): 0.84keV → Energy of PKA (average): 118eV
Number of Displacement Atoms per PKA: 1.0 atoms

Still Induce Point Defects
Typical 4days irradiation gives
about 3×10^20e in 2cm^2,→ Displacement:
Fe: 0.012dpa
W: 0.011dpa

KURL0602
High Temperature
Irradiation

Temperature Control:
Beam Frequency+ Kanthal heater

KURL0602: 1095℃
Quartz Glass tube and alumina cement, kanthal heater
30MeV, 3μs x 500mA x 30Hz (1.35kW)
KURL0702: 700℃
Alumina tube and alumina cement, kanthal heater
30MeV, 3μs x 530mA x 12Hz (0.57kW)

KURL0702

KURL0604

Liquid Nitrogen Supply

Low Temperature
Irradiation

KURL0604: -165℃ / 1.35kW
Liquid Nitrogen cooled system
30MeV, 3μs x 500mA x 30Hz

Cu heat sink in Water chamber
KURL1201: 80℃ / 6.0kW
32MeV, 4μs x 590mA x 80Hz
KURL1401: 90℃ / 4.7kW
28MeV, 4μs x 600mA x 70Hz
Very Stable andEstablished Irradiation
SystemKURL1201
KURL1401
Cu Heat sink
put inWater chamberTemperature / ℃

KURL1801 First attempt for Liquid-metal corrosion test600

pre heat sink

400

Rear heat sink

200

001000 2000 3000 4000 5000 6000
Time / sec

CT monitor and pre heat sink was burn!

KURL1801 Second attempt for Liquid-metal corrosion test

stainless buffer platewith thermo couple

electron beam

600

T2 / front side

Temperature / ℃

500

cover plate
T3 / rear buffer plate

400liquid Sn containing
specimen holder

300
200
T1 / heat s ink

10000

Rear heat sink was too
effective and thetemperature was notelevated.

1000

2000
3000
Time / sec

4000

Beam time: 2.4×105 sec (66.7h)
Dose: 1.1×1020 e, 4.4 mdpa (for Fe Ed=40keV)

T2 T3 T1

Cu heat sink

KURL1901 Third attempt for Liquid-metal corrosion test

1st specimen (NTK04L, pre oxidation 1000℃ 10h)
Beam time: 1.1×105 sec (32.5h)
Dose: 5.8×1019 e, 2.3 mdpa (for Fe Ed=40keV)
2nd specimen (ODS sp-10 pre oxidation 1000℃ 10h)
Beam time: 1.1×105 sec (32.5h)
Dose: 6.5×1019 e, 2.6 mdpa (for Fe Ed=40keV)

KURL1902 4th attempt for Liquid-metal corrosion test

1st specimen
Temperature monitor was failed becauseof trouble on AD8495 thermo-couple
amplifier.
Another attempt showed:
pre-spacer 630℃, rear-spacer 430℃

rear spacer: 370℃
1st specimen (FeCrAl-ODS / Pb-Li)
Beam time: 1.1×105 sec (32.5h)
Dose: 6.6×1019 e, 2.6 mdpa (for Fe Ed=40keV)
2nd specimen (JLF-1-SS430/Pb-Li )Beam time: 1.1×105 sec (32.5h)
Dose: 6.8×1019 e, 2.7 mdpa (for Fe Ed=40keV)