• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2003년도 가을 학술논문집
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• pp.701-706
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• 2003

A study on the electrosorption of U(VI) onto porous activated carbon fibers (ACFs) was performed to treat uranium-containing lagoon sludge. Effective U(Ⅵ) removal is accomplished when a negative potential is applied to the activated carbon fiber(ACF) electrode. For a feed concentration of 100mg/L, the concentration of U(VI) in the cell effluent is reduced to less than 1mg/L. The adsorbed uranium could be deserted from the ACF by passing a 1M NaCl solution through the cell and applying a positive potential onto the electrode. The regeneration of ACF from the cycling experiments was confirmed.

• 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.

• Nuclear Engineering and Technology
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• 제53권8호
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• pp.2570-2575
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• 2021

The exchange behaviors of hydrogen isotopes between protonated lithium metal compounds and deuterated water or tritiated water were investigated. The various protonated lithium metal compounds were prepared by acid treatment of lithium metal compounds with different crystal structures and metal compositions. The protonated lithium metal compounds could more effectively reduce the deuterium concentration in water compared with the corresponding pristine lithium metal compounds. The H⁺ in the protonated lithium metal compounds was speculated to be more readily exchangeable with hydrons in the aqueous solution compared with Li⁺ in the pristine lithium metal compounds, and the exchanged heavier isotopes were speculated to be more stably retained in the crystal structure compared with the light protons. When the tritiated water (157.7 kBq/kg) was reacted with the protonated lithium metal compounds, the protonated lithium manganese nickel cobalt oxide was found to adsorb and retain twice as much tritium (163.9 Bq/g) as the protonated lithium manganese oxide (69.9 Bq/g) and the protonated lithium cobalt oxide (75.1 Bq/g) in the equilibrium state.

• Nuclear Engineering and Technology
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• 제56권1호
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• pp.64-69
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• 2024

According to the market research report, the nuclear decommissioning services market is currently experiencing considerable growth, with a projected Compound Annual Growth Rate (CAGR) of nearly 13% during the 2020-2024 forecast period. This expansion is primarily fueled by the advancement of Industry 4.0, in conjunction with the emergence of cutting-edge technologies such as the Internet of Things, big data, artificial intelligence, and 5G. Even though the fact that robots have already been utilized in the nuclear industry, their adoption has been hindered by conservative regulations. However, the nuclear decommissioning market presents an opportunity for the advancement of robotics technology. The British have already invested heavily in encouraging the use of intelligent robots for nuclear decommissioning, and other countries, such as Taiwan, should follow suit. Taiwan's flourishing robotics development industry in manufacturing, logistics, and other domains can be leveraged to introduce advanced robotics in the decommissioning of its nuclear power plants. By doing so, Taiwan can establish itself as a competitive player in the nuclear decommissioning services market for the next two decades.

• 시스템엔지니어링학술지
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• 제14권1호
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• pp.63-71
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• 2018

This paper discusses decommissioning procedure requirements management using requirement engineering to systematically manage the technical requirements and criteria that are required in decontamination and decommissioning activities, and the regulatory requirements that should be complied with in a decommissioning strategy for research reactors and nuclear power plants. A schema was designed to establish the traceability and change management related to the linkage between the regulatory requirements and technical criteria after classifying the procedures into four groups during the full life-cycle of the decommissioning. The results confirmed that the designed schema was successfully traced in accordance with the regulatory requirements and technical criteria required by various fields in terms of decontamination and decommissioning activities. In addition, the changes before and after the revision of the Nuclear Safety Act were also determined. The dismantling procedure requirement management system secured through this study is expected to be a useful tool in the integrated management of radioactive waste, as well as in the dismantling of research reactor and nuclear facilities.

• 에너지공학
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• 제16권3호
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• pp.93-102
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• 2007

본 논문에서는 해체 시나리오를 정량적 및 정성적 고려사항을 반영하여 평가하기 위하여 계층적분석이론(Analytic Hierarchy Process, AHP)을 이용한 평가모델을 개발하였으며 또한 해체 시나리오의 정량적인 자료산출을 위하여 해체일정, 폐기물량, 방사화 가시화, 해체비용, 작업자 피폭량 등과 같은 해체정보산출모듈을 개발하였다. 그리고 해체공정을 가상환경에서 구현하여 해체절차를 파악하기 위하여 디지털 목업(Digital Mock-Up, DMU)을 개발하였으며 DMU 시스템은 해체정보산출모듈, 해체 DB 및 해체 시나리오 평가 모듈을 통합적으로 관리하도록 개발되었다. 마지막으로 개발된 해체 DMU 시스템과 계층분석과정 모델을 연구로 1호기(Korea Research Reactor-1, KRR-1) thermal column의 플라즈마 절단 시나리오와 nibbler 절단 시나리오에 적용하여 비교 평가하였다.

• 한국산학기술학회논문지
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• 제16권9호
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• pp.6297-6304
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• 2015

우리나라 최초의 원자력발전소인 고리 원전 1호기의 폐쇄가 결정됨에 따라 원전 해체가 화두가 되고 있다. 원전 해체는 우리나라에서 한번도 경험해 보지 못한 일로 해체 과정도 어렵고 시간도 많이 소요된다. 그 일부분인 해체물량 또한 파악이 어렵다. 본 연구에서는 최근 건설산업에 많이 활용되고 있는 BIM 기술을 원전 해체 물량산출에 활용할 수 있는 방안을 제시하였다. 그 결과, 원전 해체 공법선정 및 공정 확립, BIM 모델링 환경 준비, 작업분류체계 구축, 객체분류체계 구축, BIM 통합모델 작성, BIM 객체에 물량 속성 배분 등의 방안을 제시하였다. 제시한 방안은 영구정지 대상 원전이 집중적으로 발생하는 시기부터 유용하게 활용될 수 있다. 이에 기반한 기술확보를 통해 나아가 해외 원전 해체 사업 수주에도 유리하게 작용할 것으로 기대된다.

• Nuclear Engineering and Technology
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• 제51권4호
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• pp.1098-1108
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• 2019

Korea's first commercial nuclear power plant at Kori site was permanently shut down in 2017 and is currently in transition stage. Preparatory activities for decommissioning such as historical site assessment, characterization, and dismantling design are being actively carried out for successful D&D (Dismantling and Decontamination) at Kori site. The ultimate goal of decommissioning will be to ensure the safety of workers and residents that may arise during the decommissioning of nuclear facilities and, thereby finally returning the site to its original status in accordance with the release criteria. Upon completion of decommissioning, the resident's safety at a site released will be assessed from the evaluation of dose caused by radionuclides expected to be present or detected at the site. Although the U.S. commercial nuclear power plants with decommissioning experience use different site release criteria, most of them are 0.25 mSv/y. In Korea, both the unrestricted and restricted release criteria have been set to 0.1 mSv/y by the Nuclear Safety and Security Commission. However, since the dose is difficult to measure, measurable concentration guideline levels for residual radionuclides that result in dose equivalent to the site release criteria should be derived. For this derivation, site reuse scenario, selection of potential radionuclides, and systematic methodology should be developed in planning stage of Kori site decommissioning. In this paper, for calculation of a preliminary site-specific Derived Concentration Guideline Levels (DCGLs) for the Nuclear Power Plant site, a novel approach has been developed which can fully reflect practical reuse plans of the Kori site by taking into account multiple site reuse scenarios sequentially, thereby striking a remarkable distinction with conventional approaches which considers only a single site scenario.

• Nuclear Engineering and Technology
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• 제48권3호
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• pp.840-846
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• 2016

Great amounts of solid radioactive waste (second waste) and waste solution are generated from the remediation of uranium-contaminated soil. To reduce these, we investigated washing with a less acidic solution and recycling the waste solution after removal of the dominant elements and uranium. Increasing the pH of the washing solution from 0.5 to 1.5 would be beneficial in terms of economics. A high content of calcium in the waste solution was precipitated by adding sulfuric acid. The second waste can be significantly reduced by using sorption and desorption techniques on ampholyte resin S-950 prior to the precipitation of uranium at pH 3.0.