• 방사성폐기물학회지
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• 제20권4호
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• pp.469-488
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• 2022

Technology for high-level-waste disposal employing a multibarrier concept using engineered and natural barrier in stable bedrock at 300-1,000 m depth is being commercialized as a safe, long-term isolation method for high-level waste, including spent nuclear fuel. Managing heat generated from waste is important for improving disposal efficiency; thus, research on efficient heat management is required. In this study, thermal management methods to maximize disposal efficiency in terms of the disposal area required were developed. They efficiently use the land in an environment, such as Korea, where the land area is small and the amount of waste is large. The thermal effects of engineered barriers and natural barriers in a high-level waste disposal repository were analyzed. The research status of thermal management for the main bedrocks of the repository, such as crystalline, clay, salt, and other rocks, were reviewed. Based on a characteristics analysis of various heat management approaches, the spent nuclear fuel cooling time, buffer bentonite thermal conductivity, and disposal container size were chosen as efficient heat management methods applicable in Korea. For each method, thermal analyses of the disposal repository were performed. Based on the results, the disposal efficiency was evaluated preliminarily. Necessary future research is suggested.

• 방사성폐기물학회지
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• 제15권4호
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• pp.301-312
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• 2017

The concept of deep borehole disposal (DBD) for high-level nuclear wastes has been around for about 40 years. Now, the Department of Energy (DOE) in the United States (U.S.) is re-examining this concept through recent studies at Sandia National Laboratory and a field test. With DBD, nuclear waste will be emplaced in boreholes at depths of 3 to 5 km in crystalline basement rocks. Thinking is that these settings will provide nearly intact rock and fluid density stratification, which together should act as a robust geologic barrier, requiring only minimal performance from the engineered components. The Nuclear Waste Technical Review Board (NWTRB) has raised concerns that the deep subsurface is more complicated, leading to science, engineering, and safety issues. However, given time and resources, DBD will evolve substantially in the ability to drill deep holes and make measurements there. A leap forward in technology for drilling could lead to other exciting geological applications. Possible innovations might include deep robotic mining, deep energy production, or crustal sequestration of $CO_2$, and new ideas for nuclear waste disposal. Novel technologies could be explored by Korean geologists through simple proof-of-concept experiments and technology demonstrations.

• 방사성폐기물학회지
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• 제21권4호
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• pp.489-502
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• 2023

This article presents the crucial role played by the French underground research laboratory (URL) in initiating the deep geological repository project Cigéo. In January 2023, Andra finalized the license application for the initial construction of Cigéo. Depending on Government's decision, the construction of Cigéo may be authorized around 2027. Cigéo is the result of a National program, launched in 1991, aiming to safely manage high-level and intermediate level long-lived radioactive wastes. This National program is based on four principles: 1) excellent science and technical knowledge, 2) safety and security as primary goals for waste management, 3) high requirements for environment protection, 4) transparent and open-public exchanges preceding the democratic decisions and orientations by the Parliament. The research and development (R&D) activities carried out in the URL supported the design and the safety demonstration of the Cigéo project. Moreover, running the URL has provided an opportunity to gain practical experience with regard to the security of underground operations, assessment of environmental impacts, and involvement of the public in the preparation of decisions. The practices implemented have helped gradually build confidence in the Cigéo project.

• 방사성폐기물학회지
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• 제3권4호
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• pp.349-358
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• 2005

본 연구에서는 고준위 방사성폐기물 심지층 처분시설의 규모 및 layout설정에 필요한 요소인 처분터널 및 처분공 간격에 대한 분석을 수행하였다. 이를 위하여, 기준 처분개념과 공학적 방벽 개념을 바탕으로 다양한 조건의 처분터널 및 처분공 단면을 설정하고, 단층 배치 및 복층 배치 개념 에 따른 처분동굴의 구조적, 열적 안정성을 분석하였다. 분석 결과를 바탕으로 설계에 있어서 주요한 고려인자 중의 하나인 굴착량을 감소시킬 수 있는 처분동굴 및 처분공 간격을 제안하였다. 본 연구의 결과는 심지층 처분시설 설계시 활용될 것이며, 향후, 부지에 대한 불확실성을 줄이기 위하여 정확한 부지특성 자료를 통한 상세한 분석이 필요하다.

• 방사성폐기물학회지
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• 제8권4호
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• pp.279-291
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• 2010

고준위방사성폐기물처분을 위한 부지특성평가 기술을 구축하고, 이를 활용하여 심부지질환경을 이해하기 위해 1997년부터 지금까지 한국원자력연구원 주변 지역을 고준위폐기물처분을 위한 연구지역으로 선정하여 다양한 지질 관련 연구를 수행해왔다. 특히, 2002년에는 고준위폐기물의 처분 대상 심도의 시추공(지하 500 m)을 굴착하였으며, 2006년에는 지하처분연구시설(KURT, KAERI Underground Research Tunnel)을 준공하여 연구지역에 대한 심부지질환경 규명을 위해 노력하고 있다. 현재, 지하처분연구터널의 좌측 연구용 모듈 내에 500 m 길이의 장심도 시추공을 굴착하여 다양한 부지특성평가 연구를 수행 중에 있다. 본 연구는 고준위폐기물의 심지층 처분을 위한 요소 기술인 심부영역의 부지특성평가기술 구축을 위해 장심도 시추공 자료를 이용하여 KURT 주변의 지질구조 분석하였다. 연구지역의 장심도 시추공에서 지구물리탐사, 시추공 지질조사 등 다양한 현장 조사를 수행하였으며, 그 결과 총 7개의 지질구조를 도출하였다. 이 연구 결과는 KURT 지역의 부지특성연구의 주요한 한 부분으로서 기존에 구축된 지질모델을 보완하는데 이용될 예정이다.

• 방사성폐기물학회지
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• 제19권4호
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• pp.517-532
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• 2021

Safe geological disposal of spent nuclear fuel (SNF) requires knowledge of the deep hydrochemical characteristics of the repository site. Here, we conducted a set of deep hydrochemical investigations using a 750-m borehole drilled in a model granite system in Wonju, South Korea. A closed investigation system consisting of a double-packer, Waterra pump, flow cell, and water-quality measurement unit was used for in situ water quality measurements and subsequent groundwater sampling. We managed the drilling water labeled with a fluorescein dye using a recycling system that reuses the water discharged from the borehole. We selected the test depths based on the dye concentrations, outflow water quality parameters, borehole logging, and visual inspection of the rock cores. The groundwater pumped up to the surface flowed into the flow cell, where the in situ water quality parameters were measured, and it was then collected for further laboratory measurements. Atmospheric contact was minimized during the entire process. Before hydrochemical measurements and sample collection, pumping was performed to purge the remnant drilling water. This study on a model borehole can serve as a reference for the future development of deep hydrochemical investigation procedures and techniques for siting processes of SNF repositories.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2002년도 춘계공동학술발표회요약집
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• pp.278-278
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• 2002

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1999년도 추계학술발표회요약집
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• pp.312.2-312
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• 1999

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2018년도 추계학술논문요약집
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• pp.235-236
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• 2018

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.470-473
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• 2005

Spent nuclear fuels are regarded as a high level radioactive waste and they will be disposed in a deep geological repository. To maintain the safety of the repository for hundreds of thousands of years, the spent fuels are encapsulated in a disposal canister and the canister containing spent fuels should have the structural integrity and the corrosion resistance below the several hundreds meters from the ground surface. In this study, the concept of the spent fuel encapsulation process and the process equipment fur deep geological disposal were established. To do this, the design requirements, such as the functions and the spent fuel accumulations, were reviewed. Also, the design principles and the bases were established. Based on the requirements and the bases, the encapsulation process and the equipment from spent fuel receiving process to transferring canister into the underground repository including hot cell processes was established. The established concept of the spent fuel encapsulation process and the process equipment will be improved continuously with the future studies. And this concept can be effectively used in implementing the reference repository system of our own case.