DOI QR코드

DOI QR Code

Design of accelerated life test on temperature stress of piezoelectric sensor for monitoring high-level nuclear waste repository

고준위방사성폐기물 처분장 모니터링용 피에조센서의 온도 스트레스에 관한 가속수명시험 설계

  • Hwang, Hyun-Joong (Dept. of Civil and Environmental Engineering, KAIST) ;
  • Park, Changhee (Dept. of Civil and Environmental Engineering, KAIST) ;
  • Hong, Chang-Ho (Disposal Performance Demonstration Research Division, KAERI) ;
  • Kim, Jin-Seop (Disposal Performance Demonstration Research Division, KAERI) ;
  • Cho, Gye-Chun (Dept. of Civil and Environmental Engineering, KAIST)
  • 황현중 (한국과학기술원 건설및환경공학과) ;
  • 박창희 (한국과학기술원 건설및환경공학과) ;
  • 홍창호 (한국원자력연구원 처분성능실증연구부) ;
  • 김진섭 (한국원자력연구원 처분성능실증연구부) ;
  • 조계춘 (한국과학기술원 건설및환경공학과)
  • Received : 2021.10.25
  • Accepted : 2022.11.03
  • Published : 2022.11.30

Abstract

The high-level nuclear waste repository is a deep geological disposal system exposed to complex environmental conditions such as high temperature, radiation, and ground-water due to handling spent nuclear fuel. Continuous exposure can lead to cracking and deterioration of the structure over time. On the other hand, the high-level nuclear waste repository requires an ultra-long life expectancy. Thus long-term structural health monitoring is essential. Various sensors such as an accelerometer, earth pressure gauge, and displacement meter can be used to monitor the health of a structure, and a piezoelectric sensor is generally used. Therefore, it is necessary to develop a highly durable sensor based on the durability assessment of the piezoelectric sensor. This study designed an accelerated life test for durability assessment and life prediction of the piezoelectric sensor. Based on the literature review, the number of accelerated stress levels for a single stress factor, and the number of samples for each level were selected. The failure mode and mechanism of the piezoelectric sensor that can occur in the environmental conditions of the high-level waste repository were analyzed. In addition, two methods were proposed to investigate the maximum harsh condition for the temperature stress factor. The reliable operating limit of the piezoelectric sensor was derived, and a reasonable accelerated stress level was set for the accelerated life test. The suggested methods contain economical and practical ideas and can be widely used in designing accelerated life tests of piezoelectric sensors.

고준위방사성폐기물 처분장은 심지층 처분시스템으로 사용후핵연료를 취급하는 특성상 고온, 방사선 및 지하수 등의 복합적인 환경조건에 노출되어 있다. 지속적인 노출에 의해 시간이 지남에 따라 구조물의 균열 및 열화가 발생할 수 있다. 한편 고준위방사성폐기물 처분장은 초장기 기대수명이 요구되며 이에 따른 장기적인 구조물 건전성 모니터링이 필수적이다. 구조물 건전성 모니터링에는 가속도계, 토압계, 변위계 등 다양한 센서들이 활용될 수 있으며, 이 중 일반적으로 피에조센서가 사용된다. 따라서 피에조센서의 내구성 평가를 바탕으로 고내구성 센서를 개발할 필요가 있다. 본 연구에서는 피에조센서의 내구성 평가 및 수명예측을 위한 가속수명시험을 설계하였다. 문헌연구를 바탕으로 단일 스트레스 인자에 대한 가속 스트레스 수준 수 및 각 수준 별 시료 수를 선정하였다. 또한 고준위방사성폐기물 처분장 환경조건에서 발생할 수 있는 피에조센서의 고장모드 및 고장메커니즘을 분석하였다. 온도 스트레스 인자에 대한 최대 가혹조건 탐색 실험을 두 가지 방법으로 제안하였으며 피에조센서의 신뢰도 높은 동작한계를 도출하였다. 이를 이용하여 가속수명시험의 합리적인 가속 스트레스 수준을 설정하였다. 본 연구에서 제시된 최대 가혹조건 탐색 실험방법은 경제적이며 실용적인 아이디어를 담고 있으며, 추후 피에조센서의 가속수명시험 설계에 널리 활용될 수 있을 것으로 판단된다.

Keywords

Acknowledgement

본 연구는 정부(과학기술정보통신부)의 재원으로 한국연구재단의 지원을 받아 연구되었습니다(NRF-2022M2E3A3015608). 두 번째 저자는 국토교통부의 스마트시티 혁신인재육성사업으로 지원되었습니다.

References

  1. Bae, B.S., Seo, S.K. (2017), "Planning practical multiple-stress accelerated life tests", Journal of Applied Reliability, Vol. 17, No. 2, pp. 112-121.
  2. Catelani, M., Ciani, L., Venzi, M. (2018), "Failure modes and mechanisms of sensors used in oil&gas applications", In Convegno Nazionale Sensori, Springer, Cham, pp. 429-436.
  3. Chapman, N., Hooper, A. (2012), "The disposal of radioactive wastes underground", Proceedings of the Geologists' Association, Vol. 123, No. 1, pp. 46-63. https://doi.org/10.1016/j.pgeola.2011.10.001
  4. Chen, W.H., Gao, L., Pan, J., Qian, P., He, Q.C. (2018), "Design of accelerated life test plans - Overview and prospect", Chinese Journal of Mechanical Engineering, Vol. 31, No. 1, pp. 1-15. https://doi.org/10.1186/s10033-018-0219-4
  5. Choi, H.J., Lee, J.Y., Kim, S.S. (2008), Korean reference HLW disposal system, KAERI/TR-3563/2008, Korea Atomic Energy Research Institute, pp. 1-20.
  6. Escobar, L.A., Meeker, W.Q. (1995), "Planning accelerated life tests with two or more experimental factors", Technometrics, Vol. 37, No. 4, pp. 411-427. https://doi.org/10.1080/00401706.1995.10484374
  7. Field, K.G., Remec, I., Le Pape, Y. (2015), "Radiation effects in concrete for nuclear power plants - Part I: Quantification of radiation exposure and radiation effects", Nuclear Engineering and Design, Vol. 282, pp. 126-143. https://doi.org/10.1016/j.nucengdes.2014.10.003
  8. Jung, Y.M., Joo, W.J., Jeong, S.K. (2012), "Investigation into the worst stress condition for an accelerated life test of a compressor in refrigerators-acceleration factor and the reducible test time under high temperature", Journal of Power System Engineering, Vol. 16, No. 3, pp. 44-50. https://doi.org/10.9726/kspse.2012.16.3.044
  9. Kessler, S.S., Spearing, S.M. (2002), "Design of a piezoelectric-based structural health monitoring system for damage detection in composite materials", Proceedings of the Smart Structures and Materials 2002: Smart Structures and Integrated Systems, SPIE, San Diego, Vol. 4701, pp. 86-96.
  10. Kim, E.J., Cho, S., Sim, S.H. (2015), "A recent research summary on smart sensors for structural health monitoring", Journal of the Korea Institute for Structural Maintenance and Inspection, Vol. 19, No. 3, pp. 10-21. https://doi.org/10.11112/JKSMI.2015.19.3.010
  11. Kim, H.M., Wi, S.H., Lee, H.B. (2011b), "Life assessment of tire pressure sensor with accelerated life test", Proceedings of the Korean Reliability Society Conference, Gyeongsan, pp. 41-48.
  12. Kim, J.J. (2009), "Accelerated life test and example", Journal of KSME, Vol. 49, No. 12, pp. 60-64.
  13. Kim, J.S., Kwon, S.K., Sanchez, M., Cho, G.C. (2011a), "Geological storage of high level nuclear waste", KSCE Journal of Civil Engineering, Vol. 15, No. 4, pp. 721-737. https://doi.org/10.1007/s12205-011-0012-8
  14. Kim, S.H., Yeom, J., Baek, I.S., Kim, J.S., Sung, S.I. (2020), "Determining the statistical sample size for reliability testing", Journal of Applied Reliability, Vol. 20, No. 1, pp. 84-93. https://doi.org/10.33162/jar.2020.3.20.1.84
  15. Lim, S.Y., Jang, I.H., Lee, Y.J., Lim, H.W. (2015), "Improvement through failure modes and failure mechanisms of piezoelectric sensors using the AVC", Journal of Advanced Engineering and Technology, Vol. 8, No. 2, pp. 135-140. https://doi.org/10.35272/jaet.2015.8.2.135
  16. Ma, Q., Guo, R., Zhao, Z., Lin, Z., He, K. (2015), "Mechanical properties of concrete at high temperature - A review", Construction and Building Materials, Vol. 93, pp. 371-383. https://doi.org/10.1016/j.conbuildmat.2015.05.131
  17. Seo, S.K., Yum, B.J. (1991), "Accelerated life test plans under intermittent inspection and type-I censoring: The case of weibull failure distribution", Naval Research Logistics (NRL), Vol. 38, No. 1, pp. 1-22. https://doi.org/10.1002/1520-6750(199102)38:1<1::AID-NAV3220380103>3.0.CO;2-3
  18. Sung, S.I. (2015), "A review on the accelerated life test plan: 2006~2015", Journal of Applied Reliability, Vol. 15, No. 2, pp. 84-89.
  19. Wlodkowski, P.A. (1999), Physics of failure modes in accelerometers utilizing single crystal piezoelectric materials, Doctoral Dissertation, University of Maryland, College Park, pp. 64-125.