Thermohydromechanical Stability Study on the Joint Characteristics and Depth Variations in the Region of an Underground Radwaste Repository

절리 발달 특성 및 심도 변화에 의한 방사성폐기물 처분장 주변영역에서의 열수리역학적 안정성 연구

  • Published : 2003.04.01

Abstract

The objective of this present study is to understand long term(500 years) thermohydromechanical interaction behavior in the vicinity of a repository cavern on the joint location and repository depth variations. The model includes a saturated discontinuous granitic rock mass, PWR spent nuclear fuel in a disposal canister surrounded with compacted bentonite inside a deposition hole, and mixed bentonite backfilled in the rest of the space within a repository cavern. It is assumed that two joint sets exist within the model. Joint set 1 includes joints of 56$^{\circ}$ dip angle, spaced at 20 m, and joint set 2 is in the perpendicular direction to joint set 1 and includes joints of 34$^{\circ}$ dip angle, spaced at 20 m. In order to understand the behavior change on the joint location variations, 5 different models of 500m in depth are analyzed, and additional 3 different models of 1000 m in depth are analyzed to understand the effect of depth variation.

본 연구의 목적은 지하 고준위 방사성폐기물 처분공동 주변에서의 절리 위치 변화 및 처분공동의 지하심도 변화에 따른 처분공동 및 주변 절리에서의 장기간(500년)에l 걸친 열수리역학적 연성거동 변화를 분석하고, 앞으로 처분 개념 설정에 활용 하고자 하는 것이다. 해석모델은 포화된 불연속 화강 암반, 처분공내 압축 벤토나 이트로 둘러쌓인 PWR 사용후 핵연료 및 처분용기, 그리고 처분동굴 내에 채워진 혼합 벤토나이트를 포함한다. 해석모델 내에는 2개의 절리 세트가 존재하는 것으로 가정하였다: 절리세트 1은 20m 간격의 56도 경사의 절리들로 구성되었고, 절리세트 2는 절리세트 1에 수직방향으로 20m 간격의 34도 경사의 절리들로 구성되었다. 절리위치 변화의 영향을 파악하기 위하여 500m 깊이의 모델5개, 지하 심도 영향파악을 위하여 추가로 3개의 1000m 깊이의 모델을 해석하였다.

Keywords

References

  1. Coupling behavior of rock joints, in Rock Joints Tsang, C.F.;N. Barton(ed.);O. Stephansson(ed.)
  2. Proc. GEOVAL-90 Symp. Rock mass response to glaciation and thermal loading from nuclear waste Shen, B.;O. Stephansson
  3. Ph.D. Thesis, Univ. of Minn. A fully coupled thermal-mechanical fluid flow model for nonlinear geologic system Hart, R.D.
  4. J. Geophy. Res. v.89 Coupled thermal- hydraulic- mechanical phenomenon in saturated fractured porous rocks-numerical approach Noorishad, J.;C.F. Tsang;P.A. Witherspoon
  5. UDEC(Universal Distinct Element Code), version 3.0 Itasca Consulting Group, Inc.
  6. KAERI and Sandia National Lab., Rep. Of Korea Preliminary conceptual design and performance assessment of a deep geological repository for high level wastes in the Republic of Korea Kang, C.H.(et al.)
  7. Stripa Project 91-22 Distinct element modeling of joint behavior in nearfield rock Hokmark, H.;I. Israelsson
  8. Stripa Project 91-01 Distinct element method of fracture behavior in near field rock Hokmark, H.
  9. Report YJT-91-21 Rock mechanical, thermomechanical, and hydraulic behavior of the near field for spent nuclear fuel Johansson, E.;M. Hakala;L.J. Lorig
  10. Results from pre-investigations and detailed site characterizations: Summary Report, Aspo HRL-Geoscientific Evaluation 1997/2. SKB Technical Report 97-03 SKB
  11. Results from pre-investigations and detailed site characterization: Summary report, Aspo HRL-Geoscientific Evaluation 1997/2. SKB Technical Report 97-04 SKB