Journal of the Korean Ceramic Society (한국세라믹학회지)

The Korean Ceramic Society (한국세라믹학회)
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Direct Strength Evaluation of the CVD SiC Coating of TRISO Coated Fuel Particle with Micro Hemi Spherical Shell Configuration

마이크로 반구 쉘 형상의 화학증착 탄화규소 TRISO 코팅층의 파괴강도 직접평가

  • Lee, Hyeon-Keun (Department of Materials Science and Engineering Korea Advanced Institute of Science and Technology (KAIST)) ;
  • Kim, Do-Kyung (Department of Materials Science and Engineering Korea Advanced Institute of Science and Technology (KAIST))
  • 이현근 (한국과학기술원 신소재공학과) ;
  • 김도경 (한국과학기술원 신소재공학과)
  • Published : 2007.07.31
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Abstract

CVD-SiC coating has been introduced as a protective layer in TRISO nuclear fuel particle of high temperature gas cooled reactor (HTGR) due to its excellent mechanical stability at high temperature. In order to prevent the failure of the TRISO particles, it is important to evaluate the fracture strength of the SiC coating layer. It is needed to develop a new simple characterization technique to evaluate the mechanical properties of the coating layer as a pre-irradiation step. In present work, direct strength measurement method with the specimen of hem i-spherical shell configuration was suggested. The indentation experiment on a hemisphere shell with a plate indenter was conducted. The fracture strength of the coating layer is related with the critical load for radial cracking of the shell. The finite element analysis was used to drive the semi-empirical equation for the strength measurement. The SiC hemispherical shells were successfully recovered from the section-grinding of TRISO coated particle and successive heat treatment in air. The strength of CVD-SiC coating layer was evaluated from the experimentally measured critical load during the indentation on SiC hemisphere shell. Weibull diagram of fracture strength was also constructed. This study suggested a new strength equation and experimental method to measure the fracture strength of CVD-SiC coating of TRISO coated fuel particles.

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References

  1. M. Hrovat, H. Huschka, A.-W. Mehner, and W. Warzawa, 'Spherical Fuel Elements for Small and Medium Sized HTR,' Nucl. Eng. Des., 109 [1] 253-56 (1988) https://doi.org/10.1016/0029-5493(88)90167-7
  2. C. Tang, Y. Tang, J. Zhu, Y. Zou, J. Li, and X. Ni, 'Design and Manufacture of The Fuel Element for The 10MW High Temperature Gas-cooled Reactor,' Nucl. Eng. Des., 218 91- 102 (2002) https://doi.org/10.1016/S0029-5493(02)00201-7
  3. G. K. Miller, D. A. Petti, D. J. Varacalle, and J. T. Maki, 'Statistical Approach and Benchmarking for Modeling of Multi-dimensional Behavior in TRISO-coated Fuel Particles,' J. Nucl. Mater., 317 69-82 (2003) https://doi.org/10.1016/S0022-3115(02)01702-6
  4. D. A. Petti, J. Buongiorno, J. T. Maki, R. R. Hobbins, and G. K. Miller, 'Key Differences in the Fabrication, Irradiation and High Temperature Accident Testing US and German TRISO-coated Particle Fuel, and Their Implications on FuelPerformances,' Nucl. Eng. Des., 222 281-97 (2003) https://doi.org/10.1016/S0029-5493(03)00033-5
  5. K. E. Gilchrist and J. E. Brocklehurst, 'A Technique for Measuring the Strength of High Temperature Reactor Fuel Particle Coatings,' J. Nucl. Mater., 43 347-50 (1972) https://doi.org/10.1016/0022-3115(72)90069-4
  6. B. R. Lawn, Y. Deng, P. Miranda, A. Pajares, H. Chai, and D. K. Kim, 'Overview: Damage in Brittle Layer Structures from Concentrated Loads,' J. Mater. Res., 17 3019-36 (2002) https://doi.org/10.1557/JMR.2002.0440
  7. J. H. Kim, P. Miranda, D. K. Kim, and B. R. Lawn, 'Effect of an Adhesive Interlayer on the Fracture of A Brittle Coating on A Supporting Substrate,' J. Mater. Res., 18 [1] 222- 7 (2003) https://doi.org/10.1557/JMR.2003.0031
  8. H. Chai and B. R. Lawn, 'Fracture Modes in Brittle Coatings with Large Interlayer Modulus Mismatch,' J. Mater. Res., 14 [9] 3805-17 (1999) https://doi.org/10.1557/JMR.1999.0514
  9. H. Chai and B. R. Lawn, 'Fracture Mode Transitions in Brittle Coatings on Compliant Substrates as a Function of Thickness,' J. Mater Res., 19 1752-61 (2004) https://doi.org/10.1557/JMR.2004.0219
  10. Y. Hui-Mei, L. Chang-Wei, Q. Ling-Jun, X. Hua-Qing, X. Tong-Geng, and L. Lan, 'Studies on the Thermal Stability of Nano-SiC Powder with Excessive Free Carbon by TGDTA- MS, XRD and TEM,' J. Thermal Analysis and Calorimetry, 85 [3] 657-0 (2006) https://doi.org/10.1007/s10973-006-7647-6
  11. J. H. Kim, H. K. Lee, and D. K. Kim, 'Strength Measurement of a Brittle Coating With a Trilayer Structure using Instrumented Indentation and in Situ Observation Techniques Strength Measurement of a Brittle Coating with a Trilayer Structure using Instrumented Indentation and in Situ Observation Techniques,' Phil. Mag., 86 33-5 (2006)
  12. H. K. Lee, J. H. Kim, and D. K. Kim, 'Mechanical Properties of Chemical Vapor Deposited SiC Coating Layer(in Korean),' J. Kor. Ceram. Soc., 43 [8] 492-7 (2006) https://doi.org/10.4191/KCERS.2006.43.8.492