TOKAI CARBON CO., LTD. Global Leader of Carbon Materials Radiation Effect Study on Tokai Carbon Nuclear Grade Graphite M. Fechter and Y. Katoh Oak Ridge National Laboratory K. Takizawa and A. Kondo Tokai Carbon Presented at the 14 th International Nuclear Graphite Specialists Meeting (INGSM-14) September 16-18, 2013, Seattle, Washington Disclaimer All data included in this presentation are preliminary and are subject to revision after further analysis and certification processes are complete.
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Radiation Effect Study on Tokai Carbon Nuclear Grade Graphite
Radiation Effect Study on Tokai Carbon Nuclear Grade Graphite. M. Fechter and Y. Katoh Oak Ridge National Laboratory K. Takizawa and A. Kondo Tokai Carbon Presented at the 14 th International Nuclear Graphite Specialists Meeting (INGSM-14) September 16-18, 2013, Seattle, Washington. - PowerPoint PPT Presentation
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TOKAI CARBON CO., LTD.Global Leader of Carbon Materials
Radiation Effect Study on Tokai Carbon Nuclear Grade Graphite
M. Fechter and Y. KatohOak Ridge National LaboratoryK. Takizawa and A. KondoTokai CarbonPresented at the 14th International Nuclear Graphite Specialists Meeting (INGSM-14)September 16-18, 2013, Seattle, Washington
DisclaimerAll data included in this presentation are
preliminary and are subject to revision after further analysis and certification processes are complete.
TOKAI CARBON CO., LTD.Global Leader of Carbon Materials
Materials for evaluation Nuclear grade graphite G347A and G458A manufactured by Tokai Carbon are used
for microstructural analysisG347A and G458A are both fine-grained isotropic graphite which have the advantage of being highly strength
G347A G458A
100μm 100μm
GradeBulk
density(g/cm3)
Electrical resistivity(µΩ̜•m)
Flexural strength(Mpa)
Coefficient of thermal expansion
(x10-6/℃)
Thermal conductivity(W/m ・ k)
Young’s modulus
(GPa)
G347A 1.85 11.0 49.0 4.2* (5.5**) 116 10.8
G458A 1.86 9.5 53.9 3.1* (4.4**) 139 11.3
* RT~100℃** RT~1000℃
Reference value
Takizawa et al., ICACC-2012
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Global Leader of Carbon Materials
Irradiation Matrix and Progress• Up to 4 x 1026 n/m2
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Global Leader of Carbon Materials
Multi-Purpose Rabbit Approach1 2
XY
Z
X
Y
Z
813.248821.713
830.179838.644
847.109855.575
864.04872.506
880.971889.436
813.248821.713
830.179838.644
847.109855.575
864.04872.506
880.971889.436
ANSYS 12.0.1 ANSYS 12.0.1 • One rabbit for one irradiation condition.
• Custom-designed “mixed residence” capsule accommodates specimens of various types in a small rabbit vehicle.
• Irradiation temperatures are estimated for individual specimens based on thermal analysis (shown) and measurement of SiC temperature calibration specimens.
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Global Leader of Carbon Materials
Dimensional Evolutions: Volume Changes
• Volume changes are plotted against fluence for nominal irradiation temperatures.
• Actual irradiation temperatures may be significantly off from the nominal irradiation temperatures.
6 Managed by UT-Battellefor the U.S. Department of EnergyTOKAI CARBON CO., LTD.
Global Leader of Carbon Materials
Dimensional Evolutions: G347A Replotted for Estimated Irradiation Temperatures
• Volume changes are plotted for all specimen types.
• Plotted against estimated actual irradiation temperature.– Note that irradiation
temperature analysis is still in progress.
• Key trends are clearly shown. At the highest fluences here, – T < ~450°C: near the bottom
of submergence– T = ~600°C: irradiation strain
regressing to zero– T > ~750°C: already in
swelling regime
7 Managed by UT-Battellefor the U.S. Department of EnergyTOKAI CARBON CO., LTD.
Global Leader of Carbon Materials
Dimensional Evolutions: G347A Replotted for Estimated Irradiation Temperatures
• Volume changes are plotted for all specimen types.
• Key trends are clearly shown. At the highest fluences here, – T < ~450°C: near the
bottom of submergence
– T = ~600°C: irradiation strain regressing to zero
– T > ~750°C: already in swelling regime
8 Managed by UT-Battellefor the U.S. Department of EnergyTOKAI CARBON CO., LTD.
Global Leader of Carbon Materials
Dimensional Evolutions: G347A vs. G458A
• Data from side-by-side irradiation showing clear trends at 750°C.
• Initial contraction rate about the same for two graphite grades.
• Maximum contraction, fluence at contraction maximum, and fluence at zero volume change regression G458A > G347A.
9 Managed by UT-Battellefor the U.S. Department of EnergyTOKAI CARBON CO., LTD.
Global Leader of Carbon Materials
Dimensional Evolutions: G347A (An)Isotropy
• Length changes for beam specimens (considered most accurate and reliable) are plotted.
• Orientations– AG = against gravity
= ~ with grain– WG = with gravity
= ~ against grain • Anisotropy in irradiation
strain is not negligible.– Likely common for
“isotropic” graphite.
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• Aspect ratios and orientation distributions for pores and filler particles: digital microscopy
• Crystallographic orientation distributions for fillers and matrix: ORNL MGEM-2 ellipsometric microscopy
0° 180°
21 Managed by UT-Battellefor the U.S. Department of EnergyTOKAI CARBON CO., LTD.
Global Leader of Carbon Materials
Concluding Remarks• Irradiated properties data for Tokai Carbon nuclear grade graphites were
presented.– 2nd of 3 PIE campaigns in progress– Highest fluence at 2.7x1026 n/m2 fast (~20 dpa)
• Materials so far exhibit decent baseline properties after irradiation.– G347A appears promising for high radiation services – G458A may offer advantage in service life at high temperatures
• Anisotropy in irradiation response for “isotropic” graphite needs attention. • Future work
– More data coming from 2nd PIE campaign– Final PIE campaign anticipated to start in spring 2014– Microscopical analyses: unirradiated and irradiated
22 Managed by UT-Battellefor the U.S. Department of EnergyTOKAI CARBON CO., LTD.
Global Leader of Carbon Materials
23 Managed by UT-Battellefor the U.S. Department of EnergyTOKAI CARBON CO., LTD.
Global Leader of Carbon Materials
Technical Progress Summary
• Pre-irradiation studies– Draft report under final review
• Irradiation program– Progress approximately on schedule
• Post-irradiation examination– Campaign 1 complete– Campaign 2 in progress, on schedule– Data appear reasonable (following expected trend)
and promising
Move to backup
24 Managed by UT-Battellefor the U.S. Department of EnergyTOKAI CARBON CO., LTD.
Global Leader of Carbon Materials
Future Outlook
• PIE Campaign 2– Experimental work will complete soon– Further data analysis to follow
• PIE Campaign 3– After HFIR Operating Cycle 453, expected to start
in spring 2014– Conclusion of technical program anticipated in