Hydraulic Characteristics of Fractured Rock Mass in KURT by Single Hole Test and Cross-Hole Connectivity Test

SeongHo Bae; Seungbeom Choi; Jin-Seop Kim; Hagsoo Kim; Jangsoon Kim

doi:10.7474/TUS.2024.34.5.571

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2024 Vol.34, Issue 5 Preview Page Next Page

Original Article

Hydraulic Characteristics of Fractured Rock Mass in KURT by Single Hole Test and Cross-Hole Connectivity Test 단일 시추공 시험과 시추공 간 수리 연결성 시험에 의한 KURT 내 균열 암반의 수리특성 연구

31 October 2024. pp. 571-598

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Abstract

Nuclear power generation, which belongs to the eco-friendly energy category, has a comparative advantage over other power generation methods in terms of cost and efficiency, and its share of electricity energy has recently shifted to an increasing trend worldwide. In Korea, various empirical studies have been conducted centering on KURT (KEARI Underground Research Tunnel) to secure elemental technology necessary for safe and efficient disposal of high-level radioactive waste inevitably generated during the operation of nuclear power plants. Considering the domestic rock type and geological conditions, the multi-barrier system is evaluated as the most effective among various high-level radioactive waste disposal methods. The objectives of this study were, first, to evaluate the hydraulic characteristics of deep and low-permeable rock masses and second, to secure quantitative information on the hydraulic connectivity between boreholes for establishing a large-scale in-situ test system necessary for the proper design and stability evaluation of the multi-barrier system. In this regard, diverse borehole tests using DHTS (Deep borehole Hydraulic Testing System) were performed in the two research modules in KURT, and in particular, the injection type cross-hole hydraulic connectivity tests were successfully completed for the first time in Korea. In this paper, we briefly introduced MDST (Mini Downhole Shut-in Tool) developed to update the performance of DHTS and mainly discussed the key results obtained from the stepwise in-situ borehole tests.

Keywords

Multi-barrier system

Hydraulic characteristics

Pulse test

Cross-hole hydraulic connectivity

MDST

친환경에너지 범주에 속하는 원자력 발전은 비용과 효율성 측면에서 다른 발전 방법들에 비해 비교우위 장점을 가지기 때문에 최근 들어 세계적으로 비중이 점차 증가 추세로 전환되고 있다. 원자력 발전소 운영 과정에서 필연적으로 발생되는 고준위 방사성폐기물의 안전하고 효율적인 처분에 필요한 요소 기술들을 확보하기 위해 한국에서는 KURT (KEARI Underground Research Tunnel)를 중심으로 다양한 실증 연구들이 진행되어 오고 있다. 국내 분포하는 암종 및 지질 조건을 고려할 때 다중방벽 시스템은 다양한 고준위 방사성폐기물 처분 방법 중 가장 효과적인 것으로 평가되고 있다. 본 연구의 목적은 첫째, 펄스시험을 통해 대심도 저투수성 암반 구간의 수리특성을 평가하고 둘째, 다중방벽 시스템의 적정 설계와 안정성 평가에 필요한 대규모 현장 실험 설계와 시스템 구축을 위해 시추공 간 수리 연결성에 대한 정량적 정보를 확보하는데 있다. 이와 관련하여 KURT 내 2개 연구 구역에서 대심도 수리특성 조사 시스템 (DHTS)을 기반으로 다양한 시추공 시험들을 수행하였으며 특히 주입 방식의 시추공 간 수리 연결성 시험은 국내 최초로 성공적으로 시행되었다. 본 논문에서는 DHTS 성능 개선을 위해 개발된 공내 차단장치 (MDST)를 간략히 소개하고 단계적으로 수행된 현장 시추공 조사에서 획득된 주요 결과들을 중점적으로 논의하였다.

키워드

다중방벽시스템

수리특성

펄스시험

시추공간수리연결성

공내차단장치

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Information

Publisher :Korean Society for Rock Mechanics and Rock Engineering
Publisher(Ko) :한국암반공학회
Journal Title :Tunnel and Underground Space
Journal Title(Ko) :터널과 지하공간
Volume : 34
No :5
Pages :571-598
Received Date : 2024-10-10
Revised Date : 2024-10-18
Accepted Date : 2024-10-21
DOI :https://doi.org/10.7474/TUS.2024.34.5.571

Tunnel and Underground SpaceISSN:1225-1275(Print) 2287-1748(Online)한국암반공학회

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