DOI QR코드

DOI QR Code

화강암의 실내 가열실험에 대한 수치해석적 검토

Numerical Analysis of Laboratory Heating Experiment on Granite Specimen

  • 윤동준 (한국건설기술연구원 지반연구본부) ;
  • 손장윤 (과학기술연합대학원대학교 토목환경공학) ;
  • 장리 (한국건설기술연구원 미래스마트건설연구본부)
  • Dong-Joon, Youn (Department of Geotechnical Engineering Research, Korea Institute of Civil Engineering and Building Technology) ;
  • Changlun, Sun (Department of Civil and Environmental Engineering, University of Science and Technology) ;
  • Li, Zhuang (Department of Future & Smart Construction Research, Korea Institute of Civil Engineering and Building Technology)
  • 투고 : 2022.12.16
  • 심사 : 2022.12.28
  • 발행 : 2022.12.31

초록

고준위방사성폐기물의 지중저장 안정성 평가의 일환으로 가열 중인 화강암의 온도변화와 열응력 발생 양상을 파악하기 위하여 가열실험을 실시하였다. 폐기물의 붕괴열 발생조건을 가정하고 정육면체 형태의 화강암 시편에 적용하여 온도와 변위의 분포를 측정하였다. 시편의 온도는 가열봉에서 발생하는 전도로 인하여 즉각적으로 상승하지만 동시에 외기에 노출되거나 하중재하장치에 접촉되어 있는 표면을 통하여 상당한 양의 열에너지가 소산되었다. 해당 실험에 대한 분석과 이해를 위해 실험조건을 삼차원 유한요소 수치해석으로 재구현하였다. 실험에서 관찰된 열-역학 연계 현상과 주변조건의 변화를 해석에 적용하고 이를 실내실험 결과와 비교하여 검증하였다. 이를 통해 가열실험에 영향을 주는 인자들을 분석하고 향후 관련 연구에서 고려되어야 할 부분을 요약하였다.

The evolution of temperature and thermal stress in a granite specimen is studied via heating experiment in the context of a high-level radioactive waste repository. A heating condition based on the decay-induced heat is applied to a cubic granite specimen to measure the temperature and stress distributions and their evolution over time. The temperature increases quickly due to heat conduction along the heated surfaces, but a significant amount of thermal energy is also lost through other surfaces due to air convection and conduction into the loading machine. A three-dimensional finite element-based model is used to numerically reproduce the experiment, and the thermo-mechanical coupling behavior and modeling conditions are validated with the comparison to the experimental results. The most crucial factors influencing the heating experiment are analyzed and summarized in this paper for future works.

키워드

과제정보

본 연구는 한국건설기술연구원 자체사업 "고준위 방사성폐기물 심층처분시 암석불연속면의 열-수리-역학적 복합 거동 규명연구(No. 20220392-001)"의 일환으로 수행되었습니다.

참고문헌

  1. Blanco-Martin, L., Wolters, R., Rutqvist, J., Lux, K.-H., and Birkholzer, J.T., 2016, Thermal-hydraulic-mechanical modeling of a large-scale heater test to investigate rock salt and crushed salt behavior under repository conditions for heat-generating nuclear waste, Computers and Geotechnics, 77, 120-133.  https://doi.org/10.1016/j.compgeo.2016.04.008
  2. Cho, W.-J., Kwon, S., and Park, J.-H., 2008, KURT, a small-scale underground research laboratory for the research on a high-level waste disposal, Annals of Nuclear Energy, 35(1), 132-140.  https://doi.org/10.1016/j.anucene.2007.05.011
  3. Faybishenko, B., Birkholzer, J., Sassani, D., and Swift, P., 2016, International approaches for deep geological disposal of nuclear waste: geological challenges in radioactive waste isolation: fifth worldwide review. Lawrence Berkeley National Laboratory Report. LBNL-1006984. https://eesa.lbl.gov/wwr5/. Berkeley, CA, USA, 474p 
  4. Lee, C.S., Cho, W.J., Kim, J.S., and Kim, G.Y., 2020, Penetration of compacted bentonite into the discontinuity in the excavation damaged zone of deposition hole in the geological repository, Tunnel and Underground Space, 30(3), 193-213.  https://doi.org/10.7474/TUS.2020.30.3.193
  5. Min, K.B., Rutqvist, J., Tsang, C.F., and Jing, L., 2005, Thermally induced mechanical and permeability changes around a nuclear waste repository - a far-field study based on equivalent properties determined by a discrete approach. International Journal of Rock Mechanics and Mining Sciences. 42(5-6), 765-780.  https://doi.org/10.1016/j.ijrmms.2005.03.014
  6. Park, B., Kwon, S., and Min, K.B., 2017, The Status and outlook of high-level radioactive waste disposal in deep borehole focusing on behavior of large-diameter deep borehole, Journal of the Korean Society of Mineral Energy Resource Engineers, 54(4), 377-388.  https://doi.org/10.12972/ksmer.2017.54.4.377
  7. Park, S., Kim, J-S., Kim, G.Y., and Kwon, S., 2019, Evaluation of mechanical properties of KURT granite under simulated coupled condition of a geological repository. Journal of Korean Tunnelling and Underground Space Association, 21(4), 501-518.  https://doi.org/10.9711/KTAJ.2019.21.4.501
  8. Rutqvist, J., Barr, D., Birkholzer, J.T., Fujisaki, K., Kolditz, O., Liu, Q.-S., Fujita, T., Wang, W., and Zhang, C.-Y., 2009, A comparative simulation study of coupled THM processes and their effect on fractured rock permeability around nuclear waste repositories, Environmental Geology, 57, 1347-1360.  https://doi.org/10.1007/s00254-008-1552-1
  9. Rutqvist, J., 2020, Thermal management associated with geological disposal of large spent nuclear fuel canisters in tunnels with thermally engineered backfill, Tunnel and Underground Space Technology, 102, 103454. https://doi.org/10.1016/j.tust.2020.103454
  10. Swedish Nuclear Fuel and Waste Management Company(SKB), 2010a, Choice of method - evaluation of strategies and systems for disposal of spent nuclear fuel, P-10-47, Stockholm, Sweden, 87p. 
  11. Swedish Nuclear Fuel and Waste Management Company(SKB), 2010b, THM-issues in repository rock: Thermal, mechanical, thermo-mechanical, and hydro-mechanical evolution of the rock at the Forsmark and Laxemar sites, TR-10-23, Stockholm, Sweden, 268p. 
  12. Swedish Nuclear Fuel and Waste Management Company(SKB), 2011, Long-term safety for the final repository for spent nuclear fuel at Forsmark: Main report of the SR-Site project, TR-11-01, Stockholm, Sweden, 276p. 
  13. Swedish Nuclear Fuel and Waste Management Company(SKB), 2014, Uppdatering av rapporten Jamforelse mellan KBS-3-metoden och deponering I djupa borrhal for slutligt omhandertagande av anvant karnbransle, P-14-21, Stockholm, Sweden, 80p. 
  14. Sun, C., Zhuang, L., Jung, S.G., Lee, J., and Yoon, J.S., 2022, Thermally induced slip of a single sawcut granite fracture under biaxial loading. Geomechanics and Geophysics for Geo-energy and Geo-resources, 7(96), 1-13. 
  15. Wang, J., Chen, L., Su, R., and Zhao, X., 2018, The Beishan underground research loboratory for geological disposal of high-level radioactive waste in China: Planning, site selection, site characterization and in situ tests, Journal of Rock Mechanics and Geotechnical Engineering, 10(3), 411-435.  https://doi.org/10.1016/j.jrmge.2018.03.002
  16. Yoon, J.S., and Zang, A., 2019, 3D thermo-mechanical coupled modeling of thermo-seismic response of a fractured rock mass related to the final disposal of spent nuclear fuel and nuclear waste in hard rock. Project Final Report 2009: 15, Swedish Radiation Safety Authority, Sweden.