• Nuclear Engineering and Technology
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• 제54권12호
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• pp.4809-4818
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• 2022

The decommissioning project of a nuclear facility is a large-scale process that is expected to take about 15 years or longer. The range of risks to be considered is large and complex, then, it is expected that various risks will arise in decision-making by area during the project. Therefore, in this study, the risk family derived from the Decommissioning Risk Management (DRiMa) project was reconstructed into a decommissioning project risk profile suitable for the Kori Unit 1. Two criteria of uncertainty and importance are considered in order to prioritize the selected 26 risks of decommissioning project. The uncertainty is scored according to the relevant laws and decommissioning plan preparation guidelines, and the project importance is scored according to the degree to which it primarily affects the triple constraints of the project. The results of risks are divided into high, medium, and low. Among them, 10 risks are identified as medium level and 16 risks are identified as low level. 10 risks, which are medium levels, are classified in five categories: End state of decommissioning project, Management of waste and materials, Decommissioning strategy and technology, Legal and regulatory framework, and Safety. This study is a preliminary assessment of the risk of the decommissioning project that could be considered in the preparation stage. Therefore, we expect that the project risks considered in this study can be used as an initial data for reevaluation by reflecting the detail project progress in future studies.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2018년도 춘계학술논문요약집
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• pp.275-276
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• 2018

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2004년도 Proceedings of the 4th Korea-China Joint Workshop on Nuclear Waste Management
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• pp.96-105
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• 2004

The decommissioning project of the KRR 1 & 2 was started in January 1997. The actual decommissioning activity was started at the RI production facility and was finished at the end of 2002. The dismantling works of all components including the reactor structure of the KRR-2 was started in January, 2003 and will be carried out for 2 years till the end of 2004. The project schedule is estimated to delay for 4∼5 months beyond the original plan because of delaying on the cutting of thermal column nose and removal of the graphite bricks, but it may be caught up during the removal working of concrete from biological shielding structure. This paper summarizes the general status of the KRR 1 & 2 and decommissioning activities.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2018년도 춘계학술논문요약집
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• pp.257-258
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• 2018

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2004년도 학술논문집
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• pp.58-71
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• 2004

연구용원자로를 해체하는 과정에서 발생되는 각종 자료들은 여러 장소에서 상호 호환성 없는 형태로 발생하므로 관리와 활용이 용이하지 않다. 연구로 1, 2호기를 해체하면서 발생되는 자료를 해체시설, 해체작업, 방사선학적 그리고 해체폐기물 정보영역별로 분류하여 자료를 관리하고 보다 객관적이고 정확한 정보 분석이 가능하도록 데이터베이스 시스템을 개발하였다. 연구용 원자로 해체활동 자료에 대한 체계가 구축됨으로써 해체사업을 보다 더 효율적으로 수행하는 데 도구로 활용할 수 있을 것이다. 해체 현장 자료 입력, 분석 및 평가를 통하여 연구로 1, 2호기 해체활동 자료에 대하여 보다 객관적이고 정확한 평가가 가능하게 되었고, 이를 바탕으로 연구로 1, 2호기 해체프로젝트를 보다 효율적으로 수행할 수 있게 될 것이다.

• Journal of Nuclear Fuel Cycle and Waste Technology
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• 제1권1호
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• pp.83-92
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• 2013

A novel methodology to evaluate remote dismantling equipment for a reactor pressure vessel (RPV) in a decommissioning project is presented in this paper. The remote dismantling equipment, mainly composed of cutting tools and positioning equipment, is absolutely required to cut and handle highly radioactive and large components in nuclear power plants (NPPs); this equipment has a great effect on the overall success of the decommissioning project. Conventional evaluation methods have only focused on cutting technologies or positioning equipment, although remote dismantling equipment cannot achieve its goal without organic interaction between the cutting tools and the positioning equipment. In this paper, the cutting tools and the positioning equipment are evaluated by performance parameters according to their original characteristics, the relationship between the two systems, and common factors. Finally, the remote dismantling equipment used in recent decommissioning projects has been evaluated based on the proposed methodology. The results of this paper are expected to be useful for future decommissioning projects.

• 방사성폐기물학회지
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• 제19권3호
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• pp.297-306
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• 2021

In this study, basic strategies for the decommissioning and site remediation of the Fukushima Daiichi Nuclear Power Station (FDNPS) were investigated. Six scenarios were formulated based on two of the three decommissioning strategies of nuclear power plants defined by the International Atomic Energy Agency (IAEA): immediate dismantling and deferred dismantling. A multicriteria decision analysis was performed to analyze the preferences of the options from the viewpoints of the timeframe to complete decommissioning, the resulting waste, the site usability, and the availability of the radioactive waste disposal route. The same six scenarios were applied to both the FDNPS and the nuclear power plants that ceased operation after a normal plant life cycle for comparison. For the FDNPS, the decommissioning project involved fuel debris retrieval, dismantling, and site remediation. The analysis results suggest that the balance between the amount of waste and the time to achieve the end state may be one of the most critical factors to consider when planning the decommissioning and site remediation of the FDNPS.

• Nuclear Engineering and Technology
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• 제49권2호
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• pp.442-449
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• 2017

Risk management of the Fukushima Daiichi Nuclear Power Station decommissioning is a great challenge. In the present study, a risk management framework has been developed for the decommissioning work. It is applied to fuel assembly retrieval from Unit 3 spent fuel pool. Whole retrieval work is divided into three phases: preparation, retrieval, and transportation and storage. First of all, the end point has been established and the success path has been developed. Then, possible threats, which are internal/external and technical/societal/management, are identified and selected. "What can go wrong?" is a question about the failure scenario. The likelihoods and consequences for each scenario are roughly estimated. The whole decommissioning project will continue for several decades, i.e., long-term perspective is important. What should be emphasized is that we do not always have enough knowledge and experience of this kind. It is expected that the decommissioning can make steady and good progress in support of the proposed risk management framework. Thus, risk assessment and management are required, and the process needs to be updated in accordance with the most recent information and knowledge on the decommissioning works.

• 에너지공학
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• 제13권3호
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• pp.191-198
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• 2004

연구용 원자로 1, 2호기가 효용가치가 상실되어 운전을 정지하고 해체가 진행되고 있다. 연구용 원자로 해체 활동 중에 발생 자료가 여러 장소에서 상호 호환성 없는 형태로 발생함으로써 자료 관리와 활용이 어렵다. 연구로 1, 2호기를 해체하면서 발생되는 자료를 해체시설, 해체작업, 방사선학적 그리고 해체폐기물 정보영역별로 분류하여 자료를 관리하고 보다 객관적이고 정확한 정보 분석이 가능하도록 데이터베이스 시스템을 개발하였다. 연구용 원자로 해체활동 자료에 대한 체계가 구축됨으로써 해체 프로젝트를 보다 더 효율적으로 수행하는 데 도구로 활용할 수 있을 것이다.

• Nuclear Engineering and Technology
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• 제53권11호
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• pp.3505-3516
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• 2021

During nuclear facility decommissioning, workers are continuously exposed to high-level radiation. Hence, adequate path planning is critical to protect workers from unnecessary radiation exposure. This work discusses recent development in radioactive path planning and the algorithms recommended for the task. Specifically, we review the conventional methods for nuclear decommissioning path planning, analyze the techniques utilized in developing algorithms, and enumerate the decision factors that should be considered to optimize path planning algorithms. As a major contribution, we present the quantitative performance comparison of different algorithms utilized in solving path planning problems in nuclear decommissioning and highlight their merits and drawbacks. Also, we discuss techniques and critical consideration necessary for efficient application of robots and robotic path planning algorithms in nuclear facility decommissioning. Moreover, we analyze the influence of obstacles and the environmental/radioactive source dynamics on algorithms' efficiency. Finally, we recommend future research focus and highlight critical improvements required for the existing approaches towards a safer and cost-effective nuclear-decommissioning project.