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        검색결과 780

        21.
        2023.11 구독 인증기관·개인회원 무료
        Activated carbon (AC) is used for filtering organic and radioactive particles, in liquid and ventilation systems, respectively. Spent ACs (SACs) are stored till decaying to clearance level before disposal, but some SACs are found to contain C-14, a radioactive isotopes 5,730 years halflife, at a concentration greater than clearance level concentration, 1 Bq/g. However, without waste acceptance criteria (WAC) regarding SACs, SACs are not delivered for disposal at current situation. Therefore, this paper aims to perform a preliminary disposal safety examination to provide fundamental data to establish WAC regarding SACs SACs are inorganic ash composed mostly of carbon (~88%) with few other elements (S, H, O, etc.). Some of these SACs produced from NPPs are found to contain C-14 at concentration up to very-low level waste (VLLW) criteria, and few up to low-level waste (LLW) criteria. As SACs are in form of bead or pellets, dispersion may become a concern, thus requiring conditioning to be indispersible, and considering VLL soils can be disposed by packaging into soft-bags, VLL SACs can also be disposed in the same way, provided SACs are dried to meet free water requirement. But, further analysis is required to evaluate radioactive inventory before disposal. Disposability of SACs is examined based on domestic WAC’s requirement on physical and chemical characteristics. Firstly, particulate regulation would be satisfied, as commonly used ACs in filters are in size greater than 0.3 mm, which is greater than regulated particle size of 0.2 mm and below. Secondly, chelating content regulation would be satisfied, as SACs do not contain chelating chemicals. Also, cellulose, which is known to produce chelating agent (ISA), would be degraded and removed as ACs are produced by pyrolysis at 1,000°C, while thermal degradation of cellulose occurs around 350~600°C. Thirdly, ignitability regulation would be satisfied because as per 40 CFR 261.21, ignitable material is defined with ignition point below 60°C, but SACs has ignition point above 350°C. Lastly, gas generation regulation would be satisfied, as SACs being inorganic, they would be targeted for biological degradation, which is one of the main mechanism of gas generation. Therefore, SACs would be suitable to be disposed at domestic repositories, provided they are securely packaged. Further analysis would be required before disposal to determine detailed radioactive inventories and chemical contents, which also would be used to produce fundamental data to establish WAC.
        22.
        2023.11 구독 인증기관·개인회원 무료
        The development of existing radioactive waste (RI waste) management technologies has been limited to processing techniques for volume reduction. However, this approach has limitations as it does not address issues that compromise the safety of RI waste management, such as the leakage of radioactive liquid, radiation exposure, fire hazards, and off-gas generation. RI waste comes in various forms of radioactive contamination levels, and the sources of waste generation are not fixed, making it challenging to apply conventional decommissioning and disposal techniques from nuclear power plants. This necessitates the development of new disposal facilities suitable for domestic use. Various methods have been considered for the solidification of RI waste, including cement solidification, paraffin solidification, and polymer solidification. Among these, the polymer solidification method is currently regarded as the most suitable material for RI waste immobilization, aiming to overcome the limitations of cement and paraffin solidification methods. Therefore, in this study, a conceptual design for a solidification system using polymer solidification was developed. Taking into account industrial applicability and process costs, a solidification system using epoxy resin was designed. The developed solidification system consists of a pre-treatment system (fine crush), solidification system, cladding system, and packing system. Each process is automated to enhance safety by minimizing user exposure to radioactive waste. The cladding system was designed to minimize defects in the solidified material. Based on the proposed conceptual design in this paper, we plan to proceed with the specific design phase and manufacture performance testing equipment based on the basic design.
        23.
        2023.11 구독 인증기관·개인회원 무료
        Domestic waste acceptance criteria (WAC) require flowable or homogeneous wastes, such as spent resin, concentrated waste, and sludge, etc., to be solidified regardless of radiation level, to provide structural integrity to prevent collapse of repository, and prevent leaching. Therefore, verylow level (VLL) spent resin (SR) would also require to be solidified. However, such disposal would be too conservative, considering IAEA standards do not require robust containment and shielding of VLL wastes. To prevent unnecessary cost and exposure to workers, current WAC advisable to be amended, thus this paper aims to provide modified regulation based on reviewed engineering background of solidification requirement. According to NRC report, SR is classified as wet-solid waste, which is defined as a solid waste produced from liquid system, thus containing free-liquid within the waste. NRC requires liquid wastes to be solidified regardless of radiation level to prevent free liquid from being disposed, which could cause rapid release of radionuclides. Furthermore, considering class A waste does not require structural integrity, unlike class B and C wastes, dewatering would be an enough measure for solidification. This is supported by the cases of Palo Verde and Diablo Canyon nuclear power plants, whose wet-solid wastes, such as concentrated wastes and sludge, are disposed by packaging into steel boxes after dewatering or incineration. Therefore, dewatering VLL spent resin and packaging them into structural secure packaging could satisfy solidification goal. Another goal of solidification is to provide structural support, which was considered to prevent collapse of soil covers in landfills or trenches. However, providing structural support via solidification agent (ex. Cement) would be unnecessary in domestic 2nd phase repository. As the domestic 2nd phase repository is cementitious structure, which is backfilled with cement upon closure, the repository itself already has enough structural integrity to prevent collapse. Goldsim simulation was run to evaluate radiation impact by VLL SR, with and without solidification, by modelling solidified wastes with simple leaching, and unsolidified wastes with instant release. Both simulations showed negligible impact on radiation exposure, meaning that solidifying VLL SR to delay leaching would be irrational. Therefore, dewatering VLL SR and packaging it into a secure drum (ex. Steel drum) could achieve solidification goals described in NRC reports and provide enough safety to be disposed into domestic repositories. In future, the studied backgrounds in this paper should be considered to modify current WAC to achieve efficient waste management.
        24.
        2023.11 구독 인증기관·개인회원 무료
        EU taxonomy requires to solve problems for safe management of radioactive waste and disposal of spent fuel, which is a precondition for growing demand for nuclear power plant. Currently, Korea manages about 18,000 tons of high-level radioactive waste at temporary storage facilities in nuclear power plant sites, but such temporary storage facilities are expected to become saturated sequentially from 2031. Therefore, it is necessary to secure a permanent disposal facility to safely treat high-level radioactive waste. In accordance with the second basic plan for high-level radioactive waste management in 2021, it is necessary to establish requirements for regulatory compliance for the site selection and site acquisition, investigation and evaluation, and construction for the establishment of a deep geological disposal facility. In this study, we analyzed the regulatory policies and cases of leading foreign countries related to deep geological disposal facilities for high-level radioactive waste disposal waste such as IAEA, USA, Sweden, and Finland using data analysis methodology. To analyze a large amount of textbased document data, text mining is applied as a major technology and a verification standard that secures validity and safety based on the regulatory laws described so far is developed to establish a regulatory base suitable for domestic deep geological disposal status. Based on the collected data, preprocessing and analysis with Python were performed. Keywords and their frequency were extracted from the data through keyword analysis. Through the measured frequency values, the contents of the objects and elements to be regulated in the statutory items were grasped. And through the frequency values of words co-occurring among different sections through the analysis of related words, the association was obtained, and the overall interpretation of the data was performed. The results of analyzing regulations of major foreign countries using text mining are visualized in charts and graphs. Word cloud can intuitively grasp the contents by extracting the main keywords of the contents of the regulations. Through the network connection graph, the relationship between related words can be visually structured to interpret data and identify the causal relationship between words. Based on the result data, it is possible to compare and analyze the factors to be supplemented by analyzing domestic nuclear safety case and regulations.
        25.
        2023.11 구독 인증기관·개인회원 무료
        The National R&D Innovation Act emphasizes the improvement of the quality of R&D activities. The research institute is making efforts to improve the quality of research and effectively manage research implementation. KINAC has conducted various R&D projects regarding nuclear nonproliferation and nuclear security, and their scope and scale have been gradually more widened and increased. It consequently becomes important how to successfully manage research projects and ensure their qualification with the growth and complexity of research in KINAC. Unfortunately, no attempt was made to introduce and apply project management methodologies. Therefore, the objective of this study is to introduce project management standards and guidelines as an initial step towards improving the overall research quality of the institute. Project management is the well-organized application of knowledge and techniques to efficiently and effectively initiate, plan, control, and close projects, in order to achieve specific goals and meet success criteria. There are some guidelines regarding project management, including PMBOK (the Project Management Body of Knowledge), PRINCE2 (Projects in Controlled Environments), ISO 21500 (Guidance on Project Management), and PMP (Project Management Professionals), etc. They are international standards that consist of processes, guidelines, and best practices for project management. They provide structured processes and approaches to plan, execute, monitor, control, and complete projects. By reviewing the guidelines, the commonly important factors, including schedule, cost, quality, resources, communication, and risk management were introduced to apply to KINAC R&D project implementation. In addition to the management standards, systematic efforts are also continued to enhance the R&D qualities of the institute. These efforts include the implementation of a quality management system (ISO 9001:2015), development of an integrated research achievements management system, regulation development, and distribution of guidebooks for project managers and researchers. These efforts have been evaluated as improving the quality of the research.
        26.
        2023.11 구독 인증기관·개인회원 무료
        ISO 9001:2005 is the international standard for implementing a Quality Management System (QMS), which provides a framework and principles for managing an organization’s quality management. The aim is to ensure that the organization continuously provides products and services that satisfy regulatory requirements. The “process approach” in ISO 9001 is defined as a systematic method of achieving organizational goals by comprehending and managing the interconnected processes as a cohesive system. Recently, KINAC has decided to develop standard processes in the field of R&D and performance management based on the framework of the ISO 9001:2015 quality management system. The objective of this study is to establish standardized processes for conducting research and development, as well as managing the outputs and performance of R&D activities. It involves identifying, designing, implementing, monitoring, and continually improving processes to ensure consistency, efficiency, and effective management of KINAC R&D and its achievements. Firstly, R&D and the research performance management process were defined, and the processes were categorized by function according to the requirements of ISO 9001:2015. Second, the ISO 9001 requirements were compared to the institute’s existing regulations and documents in order to identify any additional processes and procedures needed to meet the quality management requirements. Finally, the lists of quality documentation were determined for the institute’s QMS. As a result, a total of 30 QMS documents were listed, including 1 manual, 12 quality processes and procedures, and 17 quality instructions. The documents can be categorized into four process groups: the management and planning process group, the R&D and achievements management process group, the analysis and improvement process group, and the support process group. All input and output information of each process are connected and interrelated. The implementation of quality management standards and procedures for R&D in KINAC could lead to improved research practices, more reliable data collection and analysis, and increased efficiency in conducting R&D activities. For further study, it is planned to create detailed, high-quality documents that adhere to standard requirements and guidelines.
        27.
        2023.11 구독 인증기관·개인회원 무료
        The Republic of Korea (ROK), as a member state of the IAEA, is operating the State’s System of Accounting for and Control (SSAC) and conducting independent national inspections. Furthermore, an evaluation methodology for the material unaccounted for (MUF) is being developed in ROK to enhance capabilities of national inspection. Generally, physical and chemical changes of nuclear material are unavoidable due to the operating system and structure of facilities, an accumulation of material unaccounted for (MUF) has been issued. IAEA developed statistical MUF evaluation method that can be applied to all facilities around the world and it mainly focuses on the diversion detection of nuclear materials in facilities. However, in terms of the national safeguard inspection, an evaluation of accountancy in facilities is additionally needed. Therefore, in this research, a new approach to MUF evaluation is suggested, based on the Guide to the Expression of Uncertainty in Measurement (GUM) that an evaluation of measurement uncertainty factors is straightforward. A hypothetical list of inventory items (LII) which has 6,118 items at the beginning and end of the material balance period, along with 360 inflow and outflow nuclear material items at a virtual fuel fabrication plant was employed for both the conventional IAEA MUF evaluation method and the proposed GUM-based method. To calculate the measurement uncertainty, it was assumed that an electronic balance, gravimetry, and a thermal ionization mass spectrometer were used for a measurement of the mass, concentration, and enrichment of 235U, respectively. Additionally, it was considered that independent and correlated uncertainty factors were defined as random factors and systematic factors for the ease of uncertainty propagation by the GUM. The total MUF uncertainties of IAEA (σMUF) and GUM (uMUF) method were 37.951 and 36.692 kg, respectively, under the aforementioned assumptions. The difference is low, it was demonstrated that the GUM method is applicable to the MUF evaluation. The IAEA method demonstrated its applicability to all nuclear facilities, but its calculated errors exhibited low traceability due to its simplification. In contrast, the calculated uncertainty based on the GUM method exhibited high reliability and traceability, as it allows for individual management of measurement uncertainty based on the facility’s accounting information. Consequently, the application of the GUM approach could offer more benefits than the conventional IAEA method in cases of national safeguard inspections where factor analysis is required for MUF assessment.
        28.
        2023.10 구독 인증기관·개인회원 무료
        마늘은 백합과 알리움속에 속하는 영양체작물로 누대재배시 수확량이 감소하는 특성을 보인다. 마늘의 화경 끝에는 주아가 생성되는데, 주아를 파종하여 2년이상 누대재배시 수확량이 약 15% 이상 증가하기 때문에 주아재 배를 통한 종구 갱신이 필요하다. 마늘 주아를 수확 후 저장시 파총채벌레, 파좀나방 등이 발생하며, 저장 중 주아 는 매년 평균 20% 이상의 부패한다. 주아재배를 원활히 하기 위해 주아 저장 시 해충의 방제를 통해 부패율을 줄이는 것이 중요하다. 본 연구에서 주아에서의 해충 발생밀도 및 방제방법에 대한 연구를 진행하였다. 연구결과 주아에서 파총채벌레는 7월 3주차, 파좀나방은 7월 2주차에 각각 발생최성기를 보였으며, 약제 침지시 방제가가 90% 이상 관찰되었다. 약제 침지된 주아 파종시 약해는 발생하지 않아, 주아 해충 방제시 침지법을 활용하여 해충의 밀도를 조절 할 수 있을 것으로 판단된다.
        29.
        2023.10 구독 인증기관·개인회원 무료
        마늘은 백합과 알리움속에 속하는 작물로 약용, 양념채소로 많이 소비되어져 왔다. 마늘은 6월에 수확하여 1개월 간의 건조과정을 거치게 되는데 보통 장마기와 겹치게 되어 연평균 부패율은 5%이상으로 높다. 마늘의 저장중 병해충은 뿌리응애, 마늘혹응애, 마른썩음병 등으로 섭식에 따른 부패를 유발하며, 건조시기를 단축하고 효율적인 건조를 통하여 감모율을 줄이는 것이 중요하다. 마늘의 병해충 피해를 줄이기 위해 개발한 열풍 흡기식 건조장치를 포함하여 관행, 열풍 건조기, 흡기식 건조 등 4가지 방법으로 마늘을 건조하였으며, 방법별 건조소요 일수, 부패율 등을 조사하였다. 연구결과 열풍-흡기식 건조장치의 순환 공기의 온습도는 외기대비 7.8℃ 높았고, 28.6% 낮았으며, 건조 소요일수는 관행건조 대비 31% 수준으로 우수하였다. 또한 병해충 피해 양상은 관행 건조 대비 4.4%p낮아 건조 기간 및 정상품율이 관행 대비 우수하여, 관행 건조를 대체 가능할 것으로 생각된다.
        30.
        2023.10 구독 인증기관·개인회원 무료
        Although ethylformate and phosphine fumigants are widely used for pest quarantine, studies related to their mechanism of action and metabolic physiological changes in Drosophila models are still unclear. In this study, we investigated how key metabolites altered by fumigants and cold treatment are associated with and affect insect physiology by comparative metabolome analysis. Fumigant treatment significantly altered cytochrome P450 and glutathione metabolites involved in the detoxification mechanism and showed lower expression of PGF2α involved in the immune response compared to the control. Additionally, most of the metabolites functioned in metabolic pathways related to the biosynthesis of amino acids, nucleotides and cofactors.
        31.
        2023.10 구독 인증기관·개인회원 무료
        기존에는 생산되는 키틴과 키토산의 대부분이 게, 새우등 갑각류 껍질에서 유래하였다. 하지만 어업에 의존하 는 기존 갑각류 비해 친환경적이며 품질 유지에 이점을 가지는 곤충으로부터 유래한 키틴이 최근 주목 받기 시작 하며 연구가 활발해지고 있다. 이에 키토산이 남조류의 응집을 통해 녹조 제거 효과를 가지며 기존에 녹조를 억제하기 위해 널리 사용되던 살조제들이 독성을 띠어 환경에 악영향을 미치는 문제를 해결할 수 있다는 연구를 참고하여 매미 탈피각으로부터 추출한 키토산을 녹조 방제에 활용해 보고자 하였다. 매미 탈피각으로부터 키토 산을 추출하고 대표적인 녹조 원인종인 Microcystis aeruginosa 배양 후 추출한 키토산을 처리하여 녹조의 응집 효과를 관찰하였다. 본 연구에서 새로운 키토산 추출 원으로서 매미 탈피각의 가능성을 제시하였으며 이를 녹조 방제에 활용함으로써 버려지는 자원인 매미 탈피각의 활용 방안을 제시하였다.
        36.
        2023.07 구독 인증기관·개인회원 무료
        This research examines the impact of visualizing virtual luxury products in the metaverse on consumers' perceptions of luxury products in the real world. We explore the metaverse as a marketing platform and investigate the relationship between the quality of visualization of virtual luxury products and consumers’ evaluations of real luxury products. The study hypothesizes that poor visualization quality of virtual luxury products will decrease the evaluation of authentic luxury goods, and this effect will be mediated by decreased perceived authenticity. Additionally, we predict that the negative effect will be mitigated by high-quality visualization.
        37.
        2023.07 구독 인증기관·개인회원 무료
        Blockchain is an immutable ledger that records transactions and tracks assets using a common communication protocol. It stores a copy of the blockchain and implements a consensus function to verify transactions. Blockchain is applied to industries beyond finance, such as retail, to maintain security and transparency. Consumers with knowledge of blockchain technology are likely to be affected when evaluating products with blockchain embedded, impacting their product evaluation. The study investigates the impact of blockchain technology on consumers' product evaluation and how knowledge of blockchain and product quality moderate its effects.
        38.
        2023.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        APro, developed in KAERI for the process-based total system performance assessment (TSPA) of deep geological disposal systems, performs finite element method (FEM)-based multiphysics analysis. In the FEM-based analysis, the mesh element quality influences the numerical solution accuracy, memory requirement, and computation time. Therefore, an appropriate mesh structure should be constructed before the mesh stability analysis to achieve an accurate and efficient process-based TSPA. A generic reference case of DECOVALEX-2023 Task F, which has been proposed for simulating stationary groundwater flow and time-dependent conservative transport of two tracers, was used in this study for mesh stability analysis. The relative differences in tracer concentration varying mesh structures were determined by comparing with the results for the finest mesh structure. For calculation efficiency, the memory requirements and computation time were compared. Based on the mesh stability analysis, an approach based on adaptive mesh refinement was developed to resolve the error in the early stage of the simulation time-period. It was observed that the relative difference in the tracer concentration significantly decreased with high calculation efficiency.
        4,300원
        39.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This research proposes a novel approach to tackle the challenge of categorizing unstructured customer complaints in the automotive industry. The goal is to identify potential vehicle defects based on the findings of our algorithm, which can assist automakers in mitigating significant losses and reputational damage caused by mass claims. To achieve this goal, our model uses the Word2Vec method to analyze large volumes of unstructured customer complaint data from the National Highway Traffic Safety Administration (NHTSA). By developing a score dictionary for eight pre-selected criteria, our algorithm can efficiently categorize complaints and detect potential vehicle defects. By calculating the score of each complaint, our algorithm can identify patterns and correlations that can indicate potential defects in the vehicle. One of the key benefits of this approach is its ability to handle a large volume of unstructured data, which can be challenging for traditional methods. By using machine learning techniques, we can extract meaningful insights from customer complaints, which can help automakers prioritize and address potential defects before they become widespread issues. In conclusion, this research provides a promising approach to categorize unstructured customer complaints in the automotive industry and identify potential vehicle defects. By leveraging the power of machine learning, we can help automakers improve the quality of their products and enhance customer satisfaction. Further studies can build upon this approach to explore other potential applications and expand its scope to other industries.
        4,000원
        40.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        To improve the quality of jujube (Zizyphus jujuba Miller var. hoonensis), which is a fruit of health functional, the effect of polyphenol preparation treatment on the fruit characteristics of two cultivars (cv. Bokjo and cv. Sangwang) of jujube was investigated. There was no difference in the height and breast diameter of jujubes tested between the polyphenol treatments and non treatment. Jujube trees treated with polyphenol preparation produced significantly more fruit than untreated in both cultivars. In cvultivar of Bokjo, the polyphenol preparation treatment increased the fruit's fresh weight and dry weight more than two times, respectively, compared to the untreated treatment. Polyphenol preparation tr eatments also changed the leaf characteristics of jujube trees. In the polyphenol-treated trees, leaf thickness tended to be thickest at the top and thinnest at the bottom. Polyphenol preparation treated jujube trees showed no difference in chlorophyll content. Moisture content was slightly higher in the untreatment than in the treatments. Visually, the polyphenol preparation treatment had a dark green color. Jujubes treated with polyphenol preparations showed differences in polyphenol content in fruits. The polyphenol content in both peel and flesh of the treatments were much higher than that of the untreatment. Reducing sugar was contained more in the peel than in the flesh and was higher in the untreatment than in the polyphenol preparation treatments. Treatment with polyphenol preparation showed differences in fruit appearance. As described above, it was found that the treatment of polyphenol preparation changed the leaves, fruit shapes and components of jujube trees. In particular, jujubes treated with polyphenol preparations are expected to contribute significantly to eco-friendly and highly functional jujube cultivation, as they appear to produce many fruits and increase the content of polyphenols and sugars.
        4,200원
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