• 한국임상약학회지
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• 제29권4호
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• pp.286-294
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• 2019

Background: At the end of the'Waste Drug Disposal Project', collection and disposal of waste drugs remain a social issue. Objective: This study aimed to provide suggestions to improve the drug waste management system in Korea by comparing domestic and overseas relevant programs. Methods: This is a comparative study between South Korea, Australia, Canada, France, and the US. These overseas countries were selected because they have been operating waste drug management programs continuously to date. Comparison was conducted by a pre-determined analysis frame including legal regulation, enforcement program and its performance. Results: All selected countries except Australia had legal regulations on drug wastes. The US had the largest variety of drug waste disposal methods. Canada had recommended that pharmacies actively participate in drug waste withdrawal programs. France had the largest variety of methods to promote relevant programs, including window sticker, SNS, and app, as well as the highest level of awareness and participation. Australia had the lowest level of awareness and participation in pharmaceutical waste management programs. Pharmaceutical companies took responsibility of paying for these programs in the selected overseas countries. Conclusion: Further efforts should be made to establish a clear guideline including the role of pharmaceutical companies, and to develop various methods for the public to be aware of appropriate ways of disposing drug wastes in Korea.

• 플랜트 저널
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• 제4권4호
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• pp.62-70
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• 2008

PGV(Plasma Gasification & Vitrification) system has been developed based on a pyrolysis melting gasification technology that provides the possibilities of acquiring renewable energy. As volume of wastes increases with the rapid industrialization and population growth, eco friendly disposal is drawing more social attention. Pyrolysis plasma technology is regarded as the best environmentally friendly process for the waste disposal among numerous waste disposal processes. Introduced in this paper is the behavior of the plasma torch and a computational fluid simulation dynamics is discussed for designing the melting furnace. Some PGV applications have also been discussed.

• 자원환경지질
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• 제56권4호
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• pp.421-433
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• 2023

원자력발전소의 사용후핵연료(Spent Nuclear Fuel: SNF)에 대한 최종처분은 지하 심부의 지질학적 저장소에서 이루어진다. 사용후핵연료를 감싸는 금속처분용기는 주철과 구리 등으로 제작되어 방사성핵종을 장기간 격리할 예정이며, 공학적방벽과 천연방벽으로 구성된 다중방벽처분시스템에 의해 보호를 받도록 설계된다. 지하 심부의 환경(심층처분환경)은 점차 무산소의 환원환경으로 바뀌게 되며, 이러한 환경에서 구리처분용기의 부식을 일으킬 수 있는 유력한 물질 중 하나는 황화물이다. 황화물에 의한 응력균열부식은 구리처분용기의 안정성을 크게 저하시켜 처분장의 장기안전성에 큰 영향을 미칠 수 있다. 심층처분환경에는 황산염이 다양한 형태로 존재 또는 유입될 수 있으며, 황산염환원미생물에 의해 황화물로 전환되어 구리처분용기의 부식에 기여할 수 있다. 완충재와 뒤채움재의 유력한 후보물질인 벤토나이트에는 주로 석고(CaSO₄)와 같은 산화형태의 황산염 광물이 포함되어 있다. 심층처분환경 내에 미생물이 생장할 만한 공간이 있고 유기 탄소 등 전자공여체가 충분히 공급된다면 미생물 활동에 의해 황산염이 황화물로 환원될 수 있다. 하지만 근계영역에서 생성된 황화물과 지권으로부터 유입되는 황화물 중 대부분은 완충재에 의해 차단되어 극히 일부만이 처분용기에 도달할 것이다. 처분환경에서 존재가능한 황화철 광물 중 하나인 황철석은 용해과정에서 황산염을 발생시켜 구리처분용기의 부식에 기여할 수 있다. 하지만 황철석의 극히 낮은 용해도로 인해 산화 생성물의 양은 매우 적을 것이고 포화된 벤토나이트의 낮은 수리전도도로 인해 처분용기로 산화 생성물의 이동은 제한될 것이다. 우리는 심층처분환경에서 황산염의 존재와 환원 그리고 황화물과 황철석의 형성 및 거동 특성 등에 관한 주요 연구 사례 등을 종합적으로 분석, 정리하였고, 고준위방사성폐기물 처분장의 장기안전성에 대한 황산염과 황화물의 영향을 이해하고자 하였다.

• 방사성폐기물학회지
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• 제20권2호
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• pp.243-253
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• 2022

Spent filters with a high radiation dose rate of 2 mSv·hr^-1 or more are not easily managed. So far, the Korean policy for spent filter disposal is to store them temporarily at nuclear power plants until the waste filters can be easily managed. Nuclear power plant decommissioning in Korea is starting with Kori unit 1. Volume reduction of waste generated during decommissioning can reduce the cost and optimize the space usage at disposal site. Therefore, efficient volume reduction is a very important factor during the decommissioning process. A conceptual method, based on the experiences of developing 200 and 800 ton compactors at Orion EnC, has been developed considering worker exposure with the followings a crusher (upgrade of compaction efficiency), an automatic dose measuring system with a NaI(Tl) detector, a shield box, an inner drum to prepare for easy handling of drums and packaging, a 30 ton compactor, and an automatic robot system. This system achieves a volume reduction ratio of up to 85.7%; hence, the system can reduce the disposal cost and waste volume. It can be applied to other types of wastes that are not easily managed due to high dose rates and remote control operation necessity.

• Nuclear Engineering and Technology
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• 제55권11호
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• pp.4120-4124
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• 2023

High-level radioactive waste produced by nuclear power plants are disposed subterraneously utilizing an engineered barrier system (EBS). A gap inevitably exists between the disposal canisters and buffer materials, which may have a negative effect on the thermal transfer and water-blocking efficiency of the system. As few previous experimental works have quantified this effect, this study aimed to create an experimental model for investigating differences in the temperature changes of bentonite buffer in the presence and absence of air gaps between it and a surrounding stainless steel cell. Three test scenarios comprised an empty cell and cells partially or completely filled with bentonite. The temperature was measured inside the buffers and on the inner surface of their surrounding cells, which were artificially heated. The time required for the entire system to reach 100℃ was approximately 40% faster with no gap between the inner cell surface and the bentonite. This suggests that rock-buffer spaces should be filled in practice to ensure the rapid dissipation of heat from the buffer materials to their surroundings. However, it can be advantageous to retain buffer-canister gaps to lower the peak buffer temperature.

• 방사성폐기물학회지
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• 제6권3호
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• pp.217-224
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• 2008

사용후핵연료 심지층처분에 있어서 처분용기의 건전성 확보는 내부에 적재되어 있는 사용후핵연료로부터 방사성물질이 누출되는 것을 방지하고 격리하여 처분장의 안전성을 보증하기 위한 필수적인 인자이다. 이러한 처분용기는 심지층 처분의 목적인 방사성 독성이 인간 및 자연환경에 영향을 미치지 않도록 장기간 동안 격리하고 누출을 지연시키기 위한 공학적 방벽의 중요한 요소 중의 하나이다. 심지층 처분장 설계시 주요한 요건은 처분시스템의 안전성을 유지를 위하여 처분용기에 적재되어 있는 폐기물로부터 발생된 붕괴열로 인하여 완충재의 온도가 100$^{\circ}C$를 넘지 않도록 하는 것이다. 또한, 처분용기는 지하 심부 500 m 깊이에서의 수압과 완충재의 팽윤압 등 하중에 구조적 건전성을 유지하여야 한다. 본 연구에서는 직접 처분대상으로 고려하고 있는 중수로(CANDU) 사용후핵연료에 대한 처분용기의 개선된 개념을 설정하고, 심지층 처분환경에서의 열적 및 구조적 안정성을 분석하였다. 열적 안정성 해석결과 처분터널 및 처분공 간격이 40 m, 3 m 인 경우 처분 후 37년이 경과한 후에 처분용기 표면온도가 최고 온도에 도달하며, 이때 온도는 88.9$^{\circ}C$로서 처분장 온도제한 요건(100$^{\circ}C$)에 만족하였다. 또한, 정상적인 경우와 극 상황에 따른 하중에 대한 처분용기 구조해석 결과 안전율은 각각 2.9와 1.33 으로 나타나 심한 지층 처분환경에서 처분용기는 구조적 건정성을 유지하는 것으로 판단되었다.

• 한국정보시스템학회지:정보시스템연구
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• 제12권1호
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• pp.159-175
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• 2003

During the early stage of radioactive disposal programs, important issues related with quality assurance of data sets, methodologies, R&D procedures are recognized as important ones. This paper focused on the development of web-based workflow standards for the QA procedures of the radioactive waste disposal programs. The flow of process was analyzed based on workflow concepts proposed by the Workflow Management Coalition (WfMC). QA system is based on the principles of T2R3. T2R3 Workflow was used to standardize and restructure the business and/or work process in the industry or organization. The WfMC has identified five functional interfaces to a workflow service as part of its standardization program. They are composed of process definition interface, worklist handler, application program interface, interface between workflows, and system management. The task flow and QA program were defined based on the workflow ideas. QA procedures for the R&D results of radiation disoposal were analyzed following the reference model of workflow. In addition, six program run list were created and implemented. The creation, revision, and approval of the test data were designed to be inplemented on the web environment. Through this system, R&D procedures such as planning, research, documentation, internal review and future independent peer review processes could be well organized and stored more systematically on the database and knowledge base. This will encourage the usage and data sharing between interested parties through it's clear and transparent workflow standards.

• Nuclear Engineering and Technology
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• 제35권5호
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• pp.387-398
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• 2003

For reference human intrusion scenarios constructed in previous study, a probabilistic safety assessment to derive the radionuclide concentration limits for the low- and intermediate- level radioactive waste disposal facility is conducted. Statistical approach by the Latin Hypercube Sampling method is introduced and new assumptions about the disposal facility system are examined and discussed. In our previous study of deterministic approach, the post construction scenarios appeared as most limiting scenario to derive the radionuclide concentration limits. Whereas, in this statistical approach, the post drilling and the post construction scenarios are mutually competing for the scenario selection according to which radionuclides are more important in safety assessment context. Introduction of new assumption shows that the post drilling scenario can play an important role as the limiting scenario instead of the post-construction scenario. When we compare the concentration limits between the previous and this study, concentrations of radionuclides such as Nb-94, Cs-137 and alpha-emitting radionuclides show elevated values than the case of the previous study. Remaining radionuclides such as Sr-90, Tc-99 I-129, Ni-59 and Ni-63 show lower values than the case of the previous study.

• Nuclear Engineering and Technology
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• 제32권3호
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• pp.274-282
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• 2000

The simulation of water balance was conducted for suggested four alternative multi-layer cover design of near-surface radioactive waste disposal facility under domestic climate condition. The analysis was also conducted for the most favorable one out of four alternative cover design under conservative scenarios. Until 100 years after closure of disposal vault, the infiltration flux for the most favorable cover design was negligible even under doubling of the ambient precipitation condition. When the degradation of asphalt and geomembrane after 100 years of closure was considered, the infiltration flux significantly increased almost to the design criteria of cover system in I' Aube disposal facility. And it was found that the hydraulic conductivity of bentonite/sand as a bottom barrier should be no greater than 1$\times$10$^{-7}$ cm/sec recommended by U.S. EPA.

• 방사성폐기물학회지
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• 제7권1호
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• pp.63-72
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• 2009

방사성폐기물 처분에서 미생물에 대한 연구는 최근에 중요한 연구 결과들이 지속적으로 발표됨에 따라 그 중요성에 대한 인식이 차츰 확대되고 있는 추세이다. 본 연구에서는 방사성폐기물 처분에서 미생물의 역할과 영향들에 대한 연구결과 및 연구동향을 조사 분석하였다. 방사성폐기물 처분시스템에서 고려되고 있는 다중방벽들인 인공방벽과 자연방벽에서의 미생물들의 역할 및 연구결과를 정리하여 제시하였다. 인공방벽에서는 처분용기의 부식에 대한 영향과 압축된 완충재에서의 미생물의 생존가능성 및 역할에 대해 논의하였다. 천연방벽에서는 지하수 및 암반에 존재하는 미생물들의 역할을 자연유사연구 결과와 함께 정리하여 제시하였다. 또한 지하매질을 통한 핵종이동 및 지연특성에서 미생물의 역할과 다양한 작용과정들 및 영향을 최근 연구동향과 함께 분석하고 정리하여 제시하였다. 따라서 향후 심부 지하 환경에서 처분시스템의 거동 및 지중매질을 통한 방사성 핵종의 이동 등에 미치는 미생물의 영향에 대한 심도 있는 연구가 본격적으로 수행된다면 미생물의 중요성 및 역할에 대한 엄격한 평가를 할 수 있을 것으로 사료된다.