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Effects of Excavation Damaged Zone on Thermal Analysis of Multi-layer Geological Repository

다층 심지층처분장 열해석에 미치는 암반손상대의 영향

  • Received : 2018.11.13
  • Accepted : 2019.02.22
  • Published : 2019.03.31

Abstract

As the present single-layer repository concept requires too large an area for the site of the repository, a multi-layer repository concept has been suggested to improve the disposal density. The effects of the excavation damaged zone around the multi-layer repository constructed in the deep host rock on the temperature distribution in the repository were analyzed. For the thermal analysis of the multi-layer repository, the hydrothermal model was used to consider the resaturation process occurring in the buffer, backfill and rock. The existence of an excavation damaged zone has a significant effect on the temperature distribution in the repository, and the maximum peak temperatures of double-layer and triple-layer repositories can rise to $7^{\circ}C$ and $12^{\circ}C$, respectively depending on the size of the excavation damaged zone and the degree of decrease of the thermal conductivity. The dominant factor affecting the peak temperature in the multi-layer repository is the decrease of thermal conductivity in the excavation damaged zone, and the excavation damaged zone formed around the deposition hole has more significant effects on the peak temperature than does the excavation damaged zone formed around the disposal tunnel.

현재 고려되고 있는 단층 심지층처분장 개념은 부지 소요면적이 지나치게 크기 때문에, 처분밀도를 향상시키기 위한 다층 심지층처분장 개념이 제안되고 있다. 심부암반에 건설된 다층 심지층처분장 주위에 형성된 암반손상대가 심지층처분장의 온도 분포에 미치는 영향이 분석되었다. 다층 심지층처분장의 열해석에는 완충재, 뒤채움재 및 암반에서 일어나는 재포화 현상을 고려한 열-수리 모델이 사용되었다. 암반손상대의 존재는 심지층처분장의 온도 분포에 큰 영향을 미치는 것으로 나타났으며, 손상대의 크기와 열전도도 저하 정도에 따라 복층 및 삼층 심지층처분장의 최고첨두온도를 각각 최대 $7^{\circ}C$$12^{\circ}C$까지 증가시킬 수 있다. 다층 심지층처분장의 첨두온도에 영향을 크게 미치는 인자는 암반손상대에서의 열전도도 저하이며, 처분공 주위에 형성된 암반손상대가 처분터널 주변에 형성된 암반손상대보다 첨두온도에 더 큰 영향을 미친다.

Keywords

References

  1. Swedish Nuclear Fuel and Waste Management Company, Design Premises for a KBS-3V Repository based on Results from the Safety Assessment SR-Can and Some Subsequent Analyses, SKB Technical Report, SKBTR-09-22 (2009).
  2. K. Ikonen, Thermal Condition of Open KBS-3H Tunnel, Swedish Nuclear Fuel and Waste Management Company Technical Report, SKB-R-08-24 (2008).
  3. Japan Nuclear Cycle Development Institute, H12 Project to Establish Technical Basis for HLW Disposal in Japan - Supporting Report 2 - Repository Design and Engineering Technology, JNC TN1410 2000-003 (2000).
  4. G.R. Simmons and P. Baumgartner. The Disposal of Canada's Nuclear Fuel Waste: Engineering for a Disposal Facility, Atomic Energy of Canada Limited Report, AECL-10715, COG-93-5 (1994).
  5. P. Wersin, L.H. Johnson, and I.G. Mckinley, "Performance of the Bentonite Barrier at Temperatures beyond $100^{\circ}C$: A Critical Review", Phys. Chem. Earth, Parts A/B/C., 32(8-14), 780-788 (2007). https://doi.org/10.1016/j.pce.2006.02.051
  6. I. Gaus, L. Johnson, K. Wieczorek, A. Gens, J.L. Garcia-Sineriz, T. Trick, R. Senger, U. Kuhlman, A. Dueck, M.V. Villar, O. Leupin, O. Czaikowski, B. Garitte, K. Schuster, and J.C. Mayor, "EBS Performance at Temperatures above $100^{\circ}C$ - PEBS Case 2", Proc. of Int. Conf. on the Performance of Engineered Barriers, 17-18, February 6-7, 2014, Hannover.
  7. W.J. Cho and G.Y. Kim, "Reconsideration of Thermal Criteria for Korean Spent Fuel Repository", Ann. Nucl. Energy, 88, 73-82 (2016). https://doi.org/10.1016/j.anucene.2015.09.012
  8. S. Kwon and J.W. Choi, "Themo-mechanical Stability Analysis for a Multi-level Radioactive Waste Disposal Concept", Geotech. Geol. Eng., 24(2), 361-377 (2006). https://doi.org/10.1007/s10706-004-7935-5
  9. Itasca Consulting Group Inc., FLAC3D-Fast Lagrangian Analysis of Continua in Three Dimensions, Ver. 1.1 Users Manual (1996).
  10. J.L. Carvalho and C.M. Steed. Themo-mechanical Analysis of a Multi-level Repository for Used Nuclear Fuel, Nuclear Waste Management Organization Report, NWMO TR-2012-19 (2012).
  11. J. Lee, H. Kim, M. Lee, H.J. Choi, and K. Kim, "Analyses of the Double-Layered Repository Concepts for Spent Nuclear Fuels", J. Nucl. Fuel Cycle Waste Technol., 15(2), 151-159 (2017). https://doi.org/10.7733/jnfcwt.2017.15.2.151
  12. Dassault Systems Simulia Corp., ABAQUS/CAE 6.14 User's Manual (2014).
  13. W.J. Cho, J.S. Kim, and H.J. Choi, "Hydrothermal Modeling for the Efficient Design of Thermal Loading in a Nuclear Waste Repository", Nucl. Eng. Design, 276, 241-248 (2014). https://doi.org/10.1016/j.nucengdes.2014.06.005
  14. W.J. Cho, C. Lee, and G.Y. Kim, "Feasibility Analysis of the Multilayer and Multicanister Concepts for a Geological Spent Fuel Repository", Nucl. Technol., 200(3), 225-240 (2017). https://doi.org/10.1080/00295450.2017.1369804
  15. C.F. Tsang, F. Bernier, and C. Davies, "Geohydromechanical Processes in the Excavation Damaged Zone in Crystalline Rock, Rock Salt, and Indurated and Plastic clays - in the Context of Radioactive Waste Disposal", Int. J. Rock Mech. Min. Sci., 42(1), 109-125 (2005). https://doi.org/10.1016/j.ijrmms.2004.08.003
  16. T. Sato, T. Kikuchi, and K. Sugihara, "In-situ Experiments on an Excavation Disturbed Zone induced by Mechanical Excavation in Neogene Sedimentary Rock at Tono Mine, Central Japan", Eng. Geol., 56(1-2), 97-108 (2000). https://doi.org/10.1016/S0013-7952(99)00136-2
  17. S. Emsley, O. Slsson, L. Seinberg, H.J. Alheid, and S. Falls, ZEDEX- A Study of Damage and Disturbance from Tunnel Excavation by Blasting and Tunnel Boring, Swedish Nuclear Fuel and Waste Management Company Technical Report, SKB-TR 97-30 (1997).
  18. P. Marschall, E. Fein, H. Kull, W. Lanyon, L. Liedtke, I. Muller-Lyda, and H. Shao, Conclusions of the Tunnel Near-field Programme (CTN), National Cooperative for the Disposal of Radioactive Waste Technical Report, NAGRA TR-99-07 (1999).
  19. H. Matsui, T. Sato, K. Sugihara, and T. Kikuchi, Overview of the EDE (Excavation Disturbance Experiment)-II at Kamaishi Mine, Kamaishi Int. Workshop Proc., PNC TN7413 98-023, August 24-25, 1998, Japan Nuclear Cycle Development Institute, Tokyo.
  20. W.J. Cho, J.S. Kim, C. Lee, and H.J. Choi, In-situ Experiments for the Performance of Engineered Barrier in KURT, Korea Atomic Energy Research Institute Technical Report, KAERI/TR-4729/2012 (2012).
  21. W.J. Cho, J.S. Kim, C. Lee, and H.J. Choi, "Gas Permeability in the Excavation Damaged Zone at KURT", Eng. Geol., 164, 222-229 (2013). https://doi.org/10.1016/j.enggeo.2013.07.010
  22. C. Lee, S. Kwon, J. Choi, and S. Jeon, "An Estimation of the Excavation Damaged Zone at the KAERI Underground Research Tunnel", J. Kor. Rock. Mech., 21(5), 359-369 (2011).
  23. K. Pruess, C. Oldenburg, and G. Moridis, TOUGH2 User's Guide, Version 2.0, Lawrence Berkeley National Laboratory Report, LBNL-43134 (1990).
  24. M.A. Grant, "Permeability Reducing Factors at Wairakei", Paper 77-HT-52, presented at AICHE-ASME Heat Transfer Conference, August 15-17, 1977, Salt Lake City, Utah.
  25. I. Fatt and W.A. Klikoff, "Effect of Fractional Wettability on Multiphase Flow through Porous Media", Trans. AIME, 216, 426-432 (1959).
  26. M.T. van Genuchten, "A Closed-form Equation for Predicting the Hydraulic Conductivity of Unsaturated Soils", Soil Sci. Soc. Am. J., 44, 892-898 (1980). https://doi.org/10.2136/sssaj1980.03615995004400050002x
  27. W. Tanikawa and T. Shimamoto, "Comparison of Klinkenberg-corrected Gas Permeability and Water Permeability in Sedimentary Rocks", Int. J. Rock Mech. Min. Sci., 46(2), 229-238 (2009). https://doi.org/10.1016/j.ijrmms.2008.03.004
  28. N.H. Chen and D.F. Othmer, "New Generalized Equation for Gas Diffusion Coefficient", J. Chem. Eng. Data, 7(1), 37-41 (1962). https://doi.org/10.1021/je60012a011
  29. H.J. Choi, J.Y. Lee, and S.S. Kim, Korean Reference HLW Disposal System, Korea Atomic Energy Research Institute Technical Report, KAERI/TR-3563/2008 (2008).
  30. W.J. Cho, J.O. Lee, and S. Kwon, "Analysis of Thermo-hydro-mechanical Process in the Engineered Barrier System of a High-level Waste Repository", Nucl. Eng. Design, 240(6), 1688-1698 (2010). https://doi.org/10.1016/j.nucengdes.2010.02.027
  31. W.J. Cho, J.O. Lee and C.H. Kang, Hydraulic Properties of Domestic Bentonite-Sand Mixture as a Backfill Material in the High-level Waste Repository, Korea Atomic Energy Research Institute Technical Report, KAERI/TR-1487/2000 (2000).
  32. W.J. Cho, J.O. Lee, and C.H. Kang, "Influence of Temperature Elevation on the Sealing Performance of Buffer in a High-level Waste Repository", Ann. Nucl. Energy, 27(14), 1271-1284 (2000). https://doi.org/10.1016/S0306-4549(99)00124-3
  33. W.J. Cho, J.O. Lee, and H.J. Choi. Thermal Conductivity of Domestic Compacted Bentonite and Bentonite-Sand Mixture, Korea Atomic Energy Research Institute Technical Report, KAERI/TR-5561/2014 (2014).
  34. W.J. Cho, J.O. Lee, and S. Kwon, "An Empirical Model for the Thermal Conductivity of Compacted Bentonite and a Bentonite-sand Mixture", Heat Mass Transf., 47(11), 1385-1393 (2011). https://doi.org/10.1007/s00231-011-0800-1
  35. W.J. Cho and S. Kwon, "Estimation of the Thermal Conductivity for Partially Saturated Granite", Eng. Geol., 115(1-2), 132-138 (2010). https://doi.org/10.1016/j.enggeo.2010.06.007
  36. J.O. Lee, W.J. Cho, and S. Kwon. Water Potential Characteristics of Domestic Bentonite, Korea Atomic Energy Research Institute Technical Report, KAERI/TR-4232/2010 (2010).
  37. Y. Mualem, "A New Model for Predicting the Hydraulic Conductivity of Unsaturated Porous Media", Water Resour. Res., 12(3), 513-522 (1976). https://doi.org/10.1029/WR012i003p00513
  38. R.H. Perry and C.H. Chilton. Chemical Engineer's Handbook, 5th ed., McGraw-Hill, New York (1973).