Journal of the Korean Geotechnical Society (한국지반공학회논문집)

Korean Geotechnical Society (한국지반공학회)
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Evaluation for the Manufacturing Characteristics and Thermal Conductivity of Engineering Scale Bentonite-Sand Buffer Blocks

공학규모 벤토나이트-모래 완충재 블록의 성형특성 및 열전도도 평가

  • Lee, Deuk-Hwan (Disposal Safety Evaluation Research Division, KAERI) ;
  • Yoon, Seok (Disposal Safety Evaluation Research Division, KAERI) ;
  • Kim, Jin-Seop (Disposal Performance Demonstration Research Division, KAERI) ;
  • Lee, Gi-Jun (Disposal Safety Evaluation Research Division, KAERI) ;
  • Kim, Ji-Won (Disposal Performance Demonstration Research Division, KAERI) ;
  • Kim, Min-Jun (Deep Geologic Disposal&storage Research Center, KIGAM)
  • 이득환 (한국원자력연구원 저장처분기술관리부) ;
  • 윤석 (한국원자력연구원 저장처분기술관리부) ;
  • 김진섭 (한국원자력연구원 처분성능실증연구부) ;
  • 이기준 (한국원자력연구원 저장처분기술관리부) ;
  • 김지원 (한국원자력연구원 처분성능실증연구부) ;
  • 김민준 (한국지질자원연구원 심층처분환경연구센터)
  • Received : 2022.12.01
  • Accepted : 2022.12.19
  • Published : 2022.12.31
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Abstract

The required density relationship according to the press pressure of the floating die method and the homogeneity of the density distribution in the buffer block was evaluated to analyze the manufacturing characteristics of engineering scale bentonite-sand buffer blocks. In addition, the thermal conductivity was measured and compared with that of the pure bentonite buffer block to evaluate the level of thermal conductivity performance improvement of the bentonite-sand buffer material. As a result, it was confirmed that the standard deviation of dry density decreased to 0.011 and showed a homogeneous density distribution under the condition of press pressure greater than 400 kg/cm2. Furthermore, as a result of the thermal conductivity test, the thermal conductivity of the buffer with optimum moisture content conditions was 1.345 and 1.261 W/(m·K) under the press pressure of 400 and 600 kg/cm2, respectively. It increased by 16.1% and 11.0% compared to the pure bentonite buffer material. Based on the results of this study, it is judged that it can be used as fundamental data for manufacturing a homogeneous bentonite-sand buffer block on an engineering scale.

본 연구에서는 공학규모 벤토나이트-모래 완충재 블록의 성형특성을 분석하기 위해 플롯팅 다이(floating die) 방식의 프레스 압력에 따른 소요 밀도 관계 및 완충재 내 밀도분포 편차에 대한 균질도를 평가하였다. 또한 벤토나이트-모래 완충재의 열전도도 성능향상 수준을 분석하기 위해 최적함수비 조건에서 열전도도를 측정하고, 순수 벤토나이트 완충재의 열전도도와 비교하였다. 연구 결과 프레스 압력이 400kg/cm2 이상의 조건에서 건조밀도 표준편차가 0.011로 감소하고 균질한 밀도분포를 나타내는 것으로 확인되었다. 열전도도 측정 결과 프레스 압력이 400, 600kg/cm2일 때의 최적함수비 조건에서 각각 1.345, 1.261W/(m·K)으로 측정되었으며, 이는 순수 벤토나이트 완충재와 비교했을 때 각각 16.1, 11.0% 상승한 것으로 분석되었다. 본 연구 결과를 기반으로 공학규모의 균질한 벤토나이트-모래 완충재 블록 제작을 위한 기초자료로 활용할 수 있을 것으로 판단된다.

Keywords

Acknowledgement

본 연구는 한국연구재단 원자력연구개발사업(2021M2E3A2041351)과 한국지질자원연구원의 기본사업인 '심지층 개발과 활용을 위한 지하심부 특성평가 기술개발(과제코드 GP2020-010)'의 지원을 받아 수행되었으며, 이에 깊은 감사를 드립니다.

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