터널과지하공간 (Tunnel and Underground Space)

  • 제19권5호
  • /
  • Pages.373-387
  • /
  • 2009
  • /
  • 1225-1275(pISSN)
  • /
  • 2287-1748(eISSN)
한국암반공학회 (Korean Society for Rock Mechanics and Rock Engineering)
권호 표지

방사성폐기물의 심지층 처분터널에서의 시멘트 물질 적용에 관한 기술현황

The State of the Technology: Application of Cementitious Materials to Deep Repository Tunnels for Radioactive Waste Disposal

  • 김진섭 (한국원자력연구원 방사성폐기물기술개발부) ;
  • 권상기 (한국원자력연구원 방사성폐기물기술개발부) ;
  • 조원진 (한국원자력연구원 방사성폐기물기술개발부) ;
  • 조계춘 (카이스트(KAIST) 건설 및 환경공학과)
  • 발행 : 2009.10.30
PDF 다운로드
⟨ 이전 논문 다음 논문 ⟩

초록

방사성폐기물의 심지층 처분과 관련하여 현재의 건설기술 및 연구수준을 감안할 때 처분터널의 건설시 시멘트 물질의 사용은 피할 수 없는 선택일 것이다. 하지만 방사성폐기물 처분의 초장기적인 설계 개념을 고려할 때, 최소한의 환경적 안정성을 감안하면 low-pH 시멘트의 개발이 매우 중요한 사안이 된다. 본 연구에서는 현재 실제 고준위폐기물 처분 후보지를 건설하고 있는 핀란드를 중심으로 스웨덴, 스위스, 프랑스 그리고 일본 등에의서 Low-pH 시멘트에 관한 연구동향에 대해 살펴보았다. Low-pH 시멘트의 규정은 완충재로서의 벤토나이트의 물리.화학적 안정성을 고려하여 $pH{\leq}11$로 설정하고 있으며, pH 저하를 위해 포졸란 계열의 혼화재를 사용하였다. 처분장 조건 및 pH 제한치를 만족시키기 위해서는 전체 건조중량의 약 40% 이상을 실리카 퓸으로 대체하고 Ca/Si 비를 0.8 이하로 유지해야 하며, 높은 단위수량 요구에 대해 선택적인 초유동화제의 주입을 적극 고려하고 있다.

Considering the current construction technology and research status of deep repository tunnels for radioactive waste disposal, it is inevitable to use cementitious materials in spite of serious concern about their long-term environmental stability. Thus, it is an emerging task to develop low pH cementitious materials. This study reviews the state of the technology on low pH cements developed in Sweden, Switzerland, France, and Japan as well as in Finland which is constructing a real deep repository site for high-level radioactive waste disposal. Considering the physical and chemical stability of bentonite which acts as a buffer material, a low pH cement limits to $pH{\leq}11$ and pozzolan-type admixtures are used to lower the pH of cement. To attain this pH requirement, silica fume, which is one of the most promising admixtures, should occupy at least 40 wt% of total dry materials in cement and the Ca/Si ratio should be maintained below 0.8 in cement. Additionally, selective super-plasticizer needs to be used because a high amount of water is demanded from the use of a large amount of silica fume.

키워드

참고문헌

  1. Al-Manaseer, A.A., Keil, L.D., 1992, Physical properties of cement grout containing silica fume and sperplasticizer, ACI, Materials Journal, pp.154-160
  2. Axelsson, M., 2006, Strength criteria on grouting agents for hard rock, Laboratory studies performed on gelling liquids and cementitious grouts, Licentiate Thesis. pp. 24-42
  3. Bethke, C.M., 1996, Geochemical reaction modeling, Oxford university press, pp.46
  4. Bhanja, S., Sengupta, B., 2003, Optimum Silica Fume Content and its Mode of Action on Concrete, ACI Material Journal, Vol.100, No.5, pp.407-412
  5. Boden, A., Sievanen, U., 2006, Low-pH injection grout for deep repositories, Posiva Working Report 2005-24, pp.13-16, Olkiluoto, Finland
  6. Butron, C., 2005, Mechanical behaviour of silica sol., Laboratory studies under controlled stress conditions during the first five months of hardening process. Master Thesis, Chalmers University of Technology, Sweden, pp.19-37
  7. Cau Dit Coumes, C., Codina, M., Bourbon, X., Leclercq, S., Courtois, S., 2005, Formulating a low-alkalinity, high-resistance and low-heat concrete for radioactive waste repositories, ESDRED, Proceedings of the 2nd Low-pH workshop, Madrid June 15-16, pp.77-90 https://doi.org/10.1016/j.cemconres.2006.10.005
  8. Chandler, N.A., Martino, J.B., and Dixon, D.A, 2002, The tunnel sealing experiment. Sixth International Workshop on Design and Construction of Final Repositories, Backfilling in Radioactive Waste Disposal, Brussels, Belgium
  9. Claesson L-A, Nilsson G, 2003, Drilling of a flushing water well, HFM01, and two groundwater monitoring wells, HFM02 and HFM03 at drill site DS1. Forsmark site investigation. P-03-30, Svensk Karnbranslehantering AB. Stockholm
  10. Fernandez, L., Alonso, M.C., Garcia, J.L., Hidalgo, A., 2005, Shotcrete development for low-pH cements, ESDRED, Proceedings of the 2nd Low-pH workshop, Madrid June 15-16, pp.161-171
  11. Fries, T., Weber, H., Wetzig, V., 2007, Low pH shotcrete field tests on Opalinus clay samples, ESDRED, Proceedings of the 2nd Low-pH workshop, Madrid June 15-16, pp.107-115
  12. Funehag, J., 2007, Grouting of fractured rock with silica sol.: Grouting design based on penetration length. Doctoral Thesis, Chalmers University of Technology, Department of Civil and Environmental Engineering, Division of GeoEngineering, Geology, Goteborg pp.36-59
  13. Glasser, F.P., 1996, Properties of cement waste composites. Waste Management vol. 16, pp.159-168 https://doi.org/10.1016/S0956-053X(96)00059-1
  14. Gray, M.N., and Shenton, B.S., 1998, Design and development of low-heat, high performance reactive powder concrete. International Symposium on High Performance and Reactive Powder Concretes, Sherbrooke, Canada., pp.37-43
  15. Hansen, J., Lyytinen, T., Sievänen, U., Kronlof, A., 2005, Low-pH grouting cement testing at the laboratory and in the field, 2nd low-pH workshop, Madrid, June 15-16, Enresa, SKB and the ESDRED-Project, pp.111-121
  16. Holt E., 2007, Durability of low-pH Injection grout. A literature survey, Posiva Working Report 2007-57, Posiva Oy, Olkiluoto, Finland, pp.21-53
  17. Hooton, R.D., Konecny, L,. 1990, Permeability of grouted fractures in granite. Concrete International, pp. 48-56
  18. Kobayashi, Y., Yamada, T., Matsui, H., Nakayama, M., Mihara, M., Naito, M., Yui, M., 2007, Development of low-alkali cement for application in a JAEA URL, R&D on low-pH cement for a geological repository, 3rd workshop, Paris June 13-14, pp.98-106
  19. Kronlof, A., 2004. Injection Grout for Deep Repositories -Low pH Cementitious grout for large fracture: Testing technical performance of materials, Posiva working report 2004-45, pp.171
  20. Kronlof, A., 2005, Injection grout for deep repositories -Low-pH injection grout for larger fratures: Testing effect of superplasticizer on technical performance. Posiva Oy, Olkiluoto, Finland. Working Report 2005-08, pp.5-7
  21. Martino, J.B., 2007, Low-heat high-performance concrete used in a full-scale tunnel seal, AECL, ESDRED, Proceedings of the 3rd Low-pH workshop, Paris June 13-14, pp.89-97
  22. Mihara, M., Iriya, K., Neyama, A., Ito, M., 1997, Experimental and Modelling Studies on the Interaction between Cement Paste with Silica Fume and Distrilled Water, Radioactive Wasted Research, Vol.3, No.2, pp.71-80
  23. Onofrei, M., Malcolm, G., Coons, W., Alcorn, S, 1992 High performance cement-based grouts for use in a nuclear waste disposal facility, Waste Management, vol. 12, pp.133-154 https://doi.org/10.1016/0956-053X(92)90045-K
  24. Orantie, K., Kuosa, H., 2008, Durability 2007 Injection Grout Investigation-Bacground Description, Posiva Working Report, 2008-54, pp.45-72
  25. Owada, H., Mihara, M., Iriya, K., Matsui, J., 2000, An Investigation of Cementitious Materials for Radioactive Waste Repository -Mechanic Properties of Low Alkalinity Cementitious Materials-Japan Nuclear Cycle Development Institute, JNC TN8400 99-057
  26. Sievanen, U., Raivio, P., Vuorinen, U., Hansen, J., Norokallio J., Syrjanen, P., 2006, Optimization of technical properties of low-pH cementitious injection grout: Laboratory tests and pilot field test 3. Posiva Oy, Olkiluoto, Finland, Working Report 2006-85, pp.10-19
  27. Sievanen, U., Syrjanen P., Ranta-aho, S., 2004, Injection grout for deep repositories-Low pH cementitious grout for larger fractures: Sub-project 3: Field testing in Finland pilot tests, pp.17-36
  28. Snellman, M., Ervanne, H., Holgersson, S., Imoto, H., Yamamoto, T., 2007, Superplasticizers and other organic cement/concrete admixtures-Long-term safety aspects, ESDRED, Proceedings of the 3rd Low-pH workshop, Paris June 13-14, pp. 9-19
  29. Yamamoto, T., Imoto, H., Ueda, H., Hironaga, M., 2007, Leaching alteration of cementitious materials and release of organic additives-Study by NUMO and CRIEP, ESDRED, Proceedings of the 3rd Low-pH workshop, Paris June 13-14, pp.52-61
  30. Yunekura, R., 1997, The developing process and the new concepts of chemical grout in Japan, Proceedings of the 2nd Internation Conference on Ground Improvement Geosystems, Tokyo, 1996, pp.889-901