• Tunnel and Underground Space
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• v.14 no.6 s.53
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• pp.429-439
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• 2004

The deep underground High Level Waste (HLW) repository to dispose of 36,000tons of spent fuel from the reactors in Korea needs about $4km^2$ repository area. In this study, the deep undergrond repository layout was optimized to minimize the excavation rock volume as well as underground repository area. In the optimization, the results from thermal analysis were used to define the influence of tunnel and deposition hole spacings on repository layout. The repository area and excavation rock volume could be reduced with longer disposal tunnel length. When it is necessary to reduce the repository area with satisfying thermal criteria, it is better to reduce tunnel spacing and increase deposition hole spacing. In contrast, the excavation rock volume can be reduced by increasing the tunnel spacing and decreasing the hole spacing.

• Tunnel and Underground Space
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• v.14 no.3
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• pp.175-187
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• 2004

고준위방사성폐기물 처분의 경우 심부 암반에 만들어진 처분장에 영구 처분하는 것이 최선의 방안으로 여겨지고 있다. 하지만 지하 심부의 암반에 대한 물리적, 화학적, 역학적, 열적, 수리적 물성과 이들과 핵종 이동의 관계, 처분환경에서의 공학적 방벽 및 암반의 거동이 처분장 안정성 및 안전성에 미치는 영향 등을 파악해야하는 어려움이 따른다. 특히 고준위폐기물 처분의 경우 장기간의 안전성을 고려해야하기 때문에 자연방벽과 공학적 방벽의 시간에 따른 거동변화도 고려하여야 할 필요가 있다. (중략)

• Tunnel and Underground Space
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• v.18 no.3
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• pp.165-174
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• 2008

Thermo-hydro-chemico-mechanical evolution of the radioactive waste repository and surrounding geological media is one of the key issues for the radioactive waste disposal. This article describes not only the basic context for the site selection but also a reasonable strategy for the repository related research based on the results of the French repository project carried out by ANDRA (National radioactive waste management agency). To have some alternatives for the determination of a preferable depth and geological media, it would be recommendable to establish a database system. The curing process of the fractures or microfissures in the EDZ (Excavation Disturbed Zone) during operation time has to be examined considering the evolution of the EDZ and the reversibility of the repository. It is prerequisite to carry out a feasibility study and to validate the design concept and design parameters in a properly constructed underground research laboratory (URL) in Korea.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.3 no.2
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• pp.135-148
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• 2005

In the stage of conceptual design for the construction and operation of the geologic repository for radioactive wastes, it is important to consider a repository ventilation system which serves the repository working environment, hygiene & safety of the public at large, and will allow safe maintenance like moisture content elimination in repository for the duration of the repositories life, construction/operation/closure, also allowing safe waste transportation and emplacement. This paper describes the possible ventilation system design criteria and requirements for the prospective Korean radioactive waste repositories with emphasis on the underground rock cavity disposal method in the both cases of low & medium-level and high-level wastes. It was found that the most important concept is separate ventilation systems for the construction (development) and waste emplacement (storage) activities. In addition, ventilation network system modeling, natural ventilation, ventilation monitoring systems & real time ventilation simulation, and fire simulation & emergency system in the repository are briefly discussed.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2011.05a
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• pp.69-70
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• 2011

본 논문은 사용후핵연료의 장기저장으로 인하여 발생할 처분지연에 대한 경제적 효과를 분석하였다. 분석 결과, 사용후핵연료 장기저장을 통하여 고준위방사성폐기물의 지하처분장 건설을 190년 지연시킬 경우, 2040년에 처분장을 건설할 경우와 비교하여 약 1/3의 비용이 소요되는 것으로 계산되었다. 이러한 결과는 경수로핵연료 2만톤과 CAMDU 1만6천톤을 처분하는 것을 가정하여 순전히 경제적인 관점에서 산출된 결과이다.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.5 no.1
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• pp.65-78
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• 2007

The pollutants (Rn, CH, CO, HS, radioactive gas from radiolysis) were generated from the process of construction and operation of underground repository, and after disposal of low-intermediate radioactive waste inside there must be controlled by a ventilation system to distribute them in area where enough air is supported. Therefore, a suitable technical approach is needed especially at an underground repository that is equipped with many entry tunnels, storage tunnels, exhaust-blowing tunnels, and vertical shafts in complicated network form. For the technical approach of such a ventilation system, WIPP (Waste Isolation Pilot Plant) in U. S and SFR (Slutforvar for Reaktorafall) low-intermediate radioactive waste repository in Sweden were selected as the models, for calculating the required air quantity, organizing a ventilation network considering cross section, length, surface roughness of the air passage, and describing a calculation of resistance of each circuit. Based on these procedures, a best suited ventilation system was completed with designing proper capacity of fans and operating plan of vertical shafts. As a result of comparing the two repositories based on the geometry dimensions and ventilation facility equipment operation, more parallel circuit as in WIPP, brought decrease in resistance for entire system leading to reduce of operating costs, and the larger cross-sectional area of the SFR, the greater the percentage of disposal capacity. Accordingly, the mixture of parallel circuit of WIPP repository for reducing resistance and SFR repository formation for enlargement of disposal capacity would be the most rational and efficient ventilation system.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2006.06a
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• pp.62-62
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• 2006

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2006.06a
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• pp.66-67
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• 2006

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05d
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• pp.229-234
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• 1996

방사성폐기물 영구처분장과 같은 대규모 지하 원자력시설의 운영중 안전성 평가를 위하여 지하 구조물의 지진 취약도 해석기법을 제안하였다. 지상구조물에 대해 적용되고 있는 Zion 방법을 모체로 하였으며 지하구조물의 특성 및 기술현황을 반영하였다. 지하구조물의 파괴양상은 구조물의 크기 및 형태, 수평 지압의 크기, 암반의 특성 등 많은 요인에 의해 달라진다. 처분동굴의 개념설계 결과에 대한 지진취약도 분석결과 수평지압계수의 영향이 매우 크며, 벽체부 또는 천정부에서의 숏크리트의 압축파괴가 가장 취약한 것으로 밝혀졌다.

• Tunnel and Underground Space
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• v.33 no.6
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• pp.445-471
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• 2023

Long-term safety over millennia is the top priority consideration in the construction of disposal sites. However, ensuring the mechanical stability of deep geological repositories for spent fuel, a.k.a. radwaste, disposal during construction and operation is also crucial for safe operation of the repository. Imposing restrictions or limitations on tunnel support and lining materials such as shotcrete, concrete, grouting, which might compromise the sealing performance of backfill and buffer materials which are essential elements for the long-term safety of disposal sites, presents a highly challenging task for rock engineers and tunnelling experts. In this study, as part of an extensive exploration to aid in the proper selection of disposal sites, the anticipation of constructing a deep geological repository at a depth of 500 meters in an unknown state has been carried out. Through a review of 2D and 3D numerical analyses, the study aimed to explore the range of properties that ensure stability. Preliminary findings identified the potential range of rock properties that secure the stability of central and disposal tunnels, while the stability of the vertical tunnel network was confirmed through 3D analysis, outlining fundamental rock conditions necessary for the construction of disposal sites.