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2026 Vol.63, Issue 1S Preview Page

Research Paper

Thermo-mechanical Analysis of a High-level Radioactive Waste Repository Considering the Excavation-damaged Zone (EDZ) Length

암반손상대 규모에 따른 고준위 방사성 폐기물 심층처분장 내 열-역학적 거동의 수치해석적 분석

Seohee Park1
,
Hoyoung Jeong1*
박 서희1
,
정 호영1*
1Department of Energy Resources Engineering, Pukyong National University, Busan, Korea
1국립부경대학교 에너지자원공학과
*Corresponding Author
28 February 2026. pp. 133-149
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Abstract

This study evaluated the influence of the length of the excavation-damaged zone (EDZ) on the thermomechanical response and stability around deposition tunnels in a KRS+-based deep geological repository using three-dimensional finite element analysis. Time-dependent thermal analysis was performed by applying decay heat after the cooling period as a volumetric heat source, and the resulting temperature field was coupled to a quasi-static mechanical analysis in a one-way manner. The EDZ is represented as a damaged zone with reduced thermal transport properties and degraded mechanical parameters relative to intact rock. Failure proximity was quantified using the Mohr–Coulomb stress ratio. The EDZ length affected both the temperature distribution and stress redistribution patterns with pronounced, location-dependent sensitivity, particularly near the buffer–backfill interface and corner regions. These findings suggest that the extent of the EDZ should be treated as a design variable and explicitly considered in long-term safety assessments.

Keywords
excavation-damaged zone (EDZ)
deep geological repository
thermo-mechanical behavior
finite element analysis

본 연구는 KRS+ 기반 심층처분장에서 굴착손상영역(EDZ) 길이가 처분공 주변의 열·역학적 거동과 안정성에 미치는 영향을 3차원 유한요소해석으로 평가하였다. 냉각 이후 붕괴열을 체적 열원으로 고려한 시간의존 열 해석을 수행하고, 산정된 온도장을 일방향 연성 방식으로 준정적 역학해석에 연계하였다. EDZ는 건전암 대비 열전달 특성과 역학 물성이 저하된 손상대로 모델링하였으며, Mohr-Coulomb 기반 응력비를 이용해 파괴 근접도를 정량적으로 평가하였다. 해석 결과, EDZ 길이는 온도 분포와 응력 재분배 양상에 영향을 주었고, 완충재·뒤채움재 경계 및 코너부 등에서 위치별 민감도 차이가 두드러졌다. 또한 EDZ 길이 변화에 따른 취약 구간의 상대적 변화가 확인되어, 설계 변수화와 장기 안전성 평가 시 EDZ의 범위에 대한 고려가 필요함을 시사한다.

키워드
암반손상대
심층 처분장
열-역학적 거동
유한요소해석
References
1

Cho, W.J., Kim, J.S., and Kim, G.Y., 2019. Effects of excavation damaged zone on thermal analysis of multi-layer geological repository, Journal of Nuclear Fuel Cycle and Waste Technology, 17(1), p.75-94.

10.7733/jnfcwt.2019.17.1.75
2

Kim, K.I., Lee, C.S., Cho, D., and Rutqvist, J., 2024. Enhancement of disposal efficiency for deep geological repositories based on three design factors - Decay heat optimization, increased thermal limit of the buffer and double-layer concept, Tunnelling and Underground Space Technology, 153, 106017.

10.1016/j.tust.2024.106017
3

Kim, K.I., Lee, C., Cho, D., Kim, J.S., and Rutqvist, J., 2026. Effect of excavation damaged zone on the long-term coupled thermo-hydro-mechanical behaviors of deep geological repositories in granitic rock masses, International Journal of Rock Mechanics and Mining Sciences, 197, 106353.

10.1016/j.ijrmms.2025.106353
4

Kim, K.I., Lee, C., and Kim, J.S., 2021. A numerical study of the performance assessment of coupled thermo-hydro-mechanical (THM) processes in improved Korean reference disposal system (KRS+) for high-level radioactive waste, Tunnel & Underground Space, 31(4), p.221-242.

10.7474/TUS.2021.31.4.221
5

Korea Atomic Energy Research Institute, 1999. Effect of dry density and temperature on the hydraulic conductivity of domestic compacted bentonite as a buffer material in the high-level waste repository, KAERI/TR-1223/99, Daejeon, Korea, 54p.

6

Korea Atomic Energy Research Institute, 2008. Korean reference HLW disposal system, KAERI/TR-3563/2008, Daejeon, Korea, 205p.

7

Korea Atomic Energy Research Institute, 2010. Analysis of thermo-hydro-mechanical behavior of the engineered barrier system of a high-level waste repository, KAERI/TR-4142/2010, Daejeon, Korea, 71p.

8

Korea Atomic Energy Research Institute, 2014. Characterization of thermal and mechanical properties of granite at KAERI Underground Research Tunnel, KAERI/TR-5566/2014, Daejeon, Korea.

9

Lee, C., Cho, W.J., Lee, J., and Kim, G.Y., 2019a. Numerical analysis of coupled thermo-hydro-mechanical (THM) behavior at Korean reference disposal system (KRS) using TOUGH2-MP/FLAC3D simulator, Journal of Nuclear Fuel Cycle and Waste Technology, 17(2), p.183-202.

10.7733/jnfcwt.2019.17.2.183
10

Lee, C., Jeon, S., Kwon, S., Cho, W.J., Seo, Y.H., Park, H.I., and Nam, Y.D., 2006. Evaluation of the excavation damaged zone at the KAERI underground research facility, Proceedings of the Korean Society for Rock Mechanics Conference & Seminar, Korean Society for Rock Mechanics, Seoul, Korea, p.15-24.

11

Lee, C., Kwon, S., Choi, J., and Jeon, S., 2011. An Estimation of the Excavation Damaged Zone at the KAERI Underground Research Tunnel, Tunnel & Underground Space, 21(5), p.359-369.

10.7474/TUS.2011.21.5.359
12

Lee, C., Lee, J., Park, S., Kwon, S., Cho, W.J., and Kim, G.Y., 2020a. Numerical analysis of coupled thermo-hydro-mechanical behavior in single- and multi-layer repository concepts for high-level radioactive waste disposal, Tunnelling and Underground Space Technology, 103, 103452.

10.1016/j.tust.2020.103452
13

Lee, C., Yoon, S., Cho, W.J., Jo, Y.G., Lee, S.D., Jeon, S.W., and Kim, G.Y., 2019b. Study on thermal, hydraulic, and mechanical properties of KURT granite and Gyeongju bentonite, Journal of Nuclear Fuel Cycle and Waste Technology, 17(S), p.65-80.

10.7733/jnfcwt.2019.17.S.65
14

Lee, J., Cho, D., Choi, H., and Choi, J., 2007. Concept of a Korean reference disposal system for spent fuels, Journal of Nuclear Science and Technology, 44(12), p.1565-1573.

10.1080/18811248.2007.9711407
15

Lee, J., Kim, I., Ju, H.J., Choi, H., and Cho, D., 2020b. Proposal of an improved concept design for the deep geological disposal system of spent nuclear fuel in Korea, Journal of Nuclear Fuel Cycle and Waste Technology, 18, p.1-19.

16

Lee, J., Kim, M., and Kwon, S., 2023. Analysis of Hydro-Mechanical Coupling Behavior Considering Excavation Damaged Zone in HLW Repository, Explosives & Blasting, 41(3), p.38-61.

10.22704/KSEE.2023.41.3.038
17

Park, S.H., 2020. An Investigation of the Thermal and Mechanical Characteristics in the Near-field for the Stability Evaluation of a Deep Geological Repository, Ph.D. Dissertation, Inha University, Incheon, Korea, 182p.

18

Rutqvist, J., 2020. Thermal management associated with geologic disposal of large spent nuclear fuel canisters in tunnels with thermally engineered backfill, Tunnelling and Underground Space Technology, 102, 103454.

10.1016/j.tust.2020.103454
19

Yoon, S., Cho, W.H., Lee, C., and Kim, G.Y., 2018. Thermal conductivity of Korean compacted bentonite buffer materials for a nuclear waste repository, Energies, 11(9), 2269.

10.3390/en11092269
Information
  • Publisher :The Korean Society of Mineral and Energy Resources Engineers
  • Publisher(Ko) :한국자원공학회
  • Journal Title :Journal of the Korean Society of Mineral and Energy Resources Engineers
  • Journal Title(Ko) :한국자원공학회지
  • Volume : 63
  • No :1
  • Pages :133-149
  • Received Date : 2025-12-30
  • Revised Date : 2026-01-21
  • Accepted Date : 2026-01-21
  • DOI :https://doi.org/10.32390/ksmer.2026.63.1.133
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