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2021 Vol.37, Issue 4 Preview Page

Research Article

An Influence Analysis on the Gap Space of an Engineered Barrier for an HLW Repository

고준위폐기물처분장 공학적방벽의 갭 공간이 미치는 영향 분석

Seok Yoon1
,
Changsoo Lee2
,
Min-Jun Kim3*
윤 석1
,
이 창수2
,
김 민준3*
1Member, Principal Researcher, Radioactive Waste Disposal Research Division, KAERI
2Senior Researcher, Radioactive Waste Disposal Research Division, KAERI
3Member, Senior Researcher, Deep Subsurface Research Center, KIGAM
1정회원, 한국원자력연구원 방사성폐기물처분연구부 책임연구원
2비회원, 한국원자력연구원 방사성폐기물처분연구부 선임연구원
3정회원, 한국지질자원연구원 심지층연구센터 선임연구원
*Corresponding Author
30 April 2021. pp. 19-26
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Abstract

The high-level radioactive waste (HLW) produced from nuclear power plants is disposed in a rock-mass at a depth of hundreds meters below the ground level. Since HLW is very dangerous to human being, it must be disposed of safely by the engineered barrier system (EBS). The EBS consists of a disposal canister, backfill material, buffer material, and so on. When the components of EBS are installed, gaps inevitably exist not only between the rock-mass and buffer material but also between the canister and buffer material. The gap can reduce water-retarding capacity and heat release efficiency of the buffer material, so it is necessary to investigate properties of gap-filling materials and to analyze gap spacing effect. Furthermore, there has been few researches considering domestic disposal system compared to overseas researches. In this reason, this research derived the peak temperature of the bentonite buffer material considering domestic disposal system based on the numerical analysis. The gap between the canister and buffer material had a minor effect on the peak temperature of the bentonite buffer material, but there was 40% difference of the peak temperature of the bentonite buffer material because of the gap existence between the buffer material and rock mass.

Keywords
Engineered barrier system
Gap spacing
High-level radioactive waste
Numerical analysis

원자력발전소에서 발생되는 고준위폐기물은 지하 수백 미터 깊이의 암반에 처분된다. 이러한 고준위폐기물은 인체에 유해하기에 공학적방벽시스템에 의해 안전하게 처분되어야 하며, 공학적방벽시스템은 처분용기, 뒤채움재, 완충재 등으로 구성된다. 고준위폐기물처분장에 이러한 공학적방벽시스템의 구성요소를 설치하게 되면, 처분용기 및 완충재 사이, 완충재와 자연 암반 사이 등에 갭이 존재하게 된다. 이러한 갭의 존재로 인해 공학적방벽재의 차수능과 열전달 효율이 떨어질 수 있기에, 갭 공간의 크기 및 갭채움재 특성 평가 등의 연구가 반드시 필요하다고 할 수 있다. 해외에 비해 국내 처분시스템을 고려한 갭 공간 및 갭채움재에 대한 연구는 아직 진행되고 있지 않는 상황이기에, 본 연구에서는 수치해석을 통해 국내 처분시스템을 고려한 갭 공간이 공기로 채워져 있는 조건하에서 갭의 크기에 따른 벤토나이트 완충재의 첨두 온도를 도출하였다. 처분용기와 완충재 사이의 갭 공간이 완충재의 첨두 온도에 미치는 영향은 미미하였으나, 완충재와 자연 암반 사이의 갭 공간에 따른 완충재의 첨두 온도는 최고 약 40%의 차이를 나타냈다.

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Information
  • Publisher :The Korean Geotechnical Society
  • Publisher(Ko) :한국지반공학회
  • Journal Title :Journal of the Korean Geotechnical Society
  • Journal Title(Ko) :한국지반공학회 논문집
  • Volume : 37
  • No :4
  • Pages :19-26
  • Received Date : 2021-02-19
  • Revised Date : 2021-03-25
  • Accepted Date : 2021-03-30
  • DOI :https://doi.org/10.7843/kgs.2021.37.4.19
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