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2017 Vol.33, Issue 10 Preview Page
Thermal Properties of Buffer Material for a High-Level Waste Repository Considering Temperature Variation

고준위폐기물 처분시설 완충재의 온도변화에 따른 열물성

Seok Yoon1
,
Geon-Young Kim2*
,
Tae-Jin Park3
,
Jae-Kwang Lee2*
윤 석1
,
김 건영2*
,
박 태진3
,
이 재광2*
1Member, Senior Researcher, Radioactive Waste Disposal Research Division, KAERI
2Principal Researcher, Radioactive Waste Disposal Research Division, KAERI
3Senior Researcher, Radioactive Waste Disposal Research Division, KAERI
1한국원자력연구원 방사성폐기물처분연구부 선임연구원
2한국원자력연구원 방사성폐기물처분연구부 책임연구원
3한국원자력연구원 방사성폐기물처분연구부 선임연구원
*교신저자. *Corresponding Author. 
31 October 2017. pp. 25-31
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Abstract

The buffer is one of the major components of an engineered barrier system (EBS) for the disposal of high-level radioactive waste (HLW). As the buffer is located between a disposal canister and host rock, it is indispensable to assure the disposal safety of high-level radioactive waste. It can restrain the release of radionuclide and protect the canister from the inflow of groundwater. Since high quantity of heat from a disposal canister is released to the surrounding buffer, thermal properties of the buffer are very important parameters for the analysis of the entire disposal safety. Especially, temperature criteria of the compacted bentonite buffer can affect the design of HLW repository facility. Therefore, this paper investigated thermal properties for the Kyungju compacted bentonite buffer which is the only bentonite produced in South Korea. Hot wire method and dual probe method were used to measure thermal conductivity and specific heat capacity of the compacted bentonite buffer according to the temperature variation. Thermal conductivity and specific heat capacity were decreased dramatically when temperature variation was between 22°C～110°C as degree of saturation decreased according to the temperature variation. However, there was little variation under the high temperature condition at 110°C～150°C.

Keywords
Compacted bentonite buffer
Thermal conductivity
Specific heat capacity
Temperature variation

완충재는 고준위폐기물을 처분하기 위한 공학적방벽 시스템에서 중요한 구성요소 중 하나이다. 완충재는 처분공 내 사용후핵연료가 담긴 처분용기와 암반사이에 채워지는 물질로써 고준위폐기물의 안전한 처분을 위해 필수적인 요소라고 할 수 있다. 완충재는 지하수 유입으로부터 처분용기를 보호하고, 방사성 핵종 유출을 저지한다. 처분용기로 부터 발생하는 고온의 열량은 완충재로 전파되기에 완충재의 열물성은 처분시스템의 안전성 평가에 매우 중요하다고 할 수 있다. 특히, 완충재의 설정온도는 고준위폐기물 처분시설의 설계에 큰 영향을 끼칠 수 있다. 따라서 본 연구에서 는 온도변화에 따른 국내 경주산 압축 벤토나이트 완충재에 대한 열물성을 규명하고자 하였다. 열선법과 이중 탐침법 을 이용하여 온도변화에 따른 압축 벤토나이트 완충재의 열전도도와 비열을 측정하였다. 22℃와 110℃ 구간에서는 온도 증가에 따라 포화도가 변화되기에 열전도도와 비열은 급격하게 감소하는 경향을 보였으나 110℃와 150℃ 사이 의 고온 구간에서는 열전도도와 비열의 추가 변화가 거의 발생하지 않았다.

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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 : 33
  • No :10
  • Pages :25-31
  • Received Date : 2017-06-11
  • Accepted Date : 2017-10-11
  • DOI :https://doi.org/10.7843/kgs.2017.33.10.25
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