• Title/Summary/Keyword: Technology assessment

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Engineering critical assessment of RPV with nozzle corner cracks under pressurized thermal shocks

  • Li, Yuebing;Jin, Ting;Wang, Zihang;Wang, Dasheng
    • Nuclear Engineering and Technology
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    • v.52 no.11
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    • pp.2638-2651
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    • 2020
  • Nozzle corner cracks present at the intersection of reactor pressure vessels (RPVs) and inlet or outlet nozzles have been a persistent problem for a number of years. The fracture analysis of such nozzle corner cracks is very important and critical for the efficient design and assessment of the structural integrity of RPVs. This paper aims to perform an engineering critical assessment of RPVs with nozzle corner cracks subjected to several transients accompanied by pressurized thermal shocks. The critical crack size of the RPV model with nozzle corner cracks under transient loading is evaluated on failure assessment curve. In particular, the influence of cladding on the crack initiation of nozzle corner crack under thermal transients is studied. The influence of primary internal pressure and secondary thermal stress on the stress field at nozzle corner and SIF at crack front is analyzed. Finally, the influence of different crack size and crack shape on the final critical crack size is analyzed.

Evaluation of Results and Workloads of the Horizon Scanning of the Emerging Health Technology in Korea (국내 신개발 유망의료기술 탐색활동 결과 및 업무량 분석)

  • Joo, Yea Il;Lee, Hyeong Il;Song, Yeong Chae;Park, Joo Yeon;Shin, Ho Gyun
    • The Journal of Health Technology Assessment
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    • v.6 no.2
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    • pp.156-161
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    • 2018
  • Objectives: To evaluate results and workloads of the horizon scanning of the emerging health technology since 2014 to 2016. Methods: In order to analyze the results of the emerging health technology, we identified the number of research procedure between 2014 and 2016. The sixteen findings were calculated annual workload by person, and categorized by medical phase, classification of disease, and healthcare technology. Results: An average of 5.67 personnel were involved over three years, assessment of each emerging healthcare technology was performed for each person of identifying 54 cases, filtering 2.4 cases, prioritizing 0.9 cases were performed. According to the mapping by healthcare technologies, nine medical devices (56.3%), six drugs (37.5%), and one material of the medical treatment (6.3%) were assessed. Among sixteen findings, fifteen cases were health technologies for treatment and only one case for diagnosis. Conclusion: Future plans of the horizon scanning of the emerging health technology is required appropriate manpower in charge each target number of assessment. And a legal basis should be provided for policy reflection rate. Furthermore, an evaluation criteria and procedures should be transparent to avoid a conflict of interest.

Improvement of the Marine Environmental Assessment for Dredging and Ocean Disposal of Coastal Sediment in Korea (연안준설 및 준설토 해양투기 해양환경평가 개선방안)

  • Lee, Dae-In;Park, Dal-Soo;Eom, Ki-Hyuk;Kim, Gui-Young;Cho, Hyeon-Seo;Kim, Jong-Kyu;Seo, Young-Kyo;Baeck, Gun-Wook
    • Journal of Environmental Impact Assessment
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    • v.18 no.3
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    • pp.131-141
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    • 2009
  • We studied improvement in marine environmental impact assessment and related management systems of coastal sediments that are dredged inshore but disposed offshore. After reviewing and diagnosing the existing assessment procedures and problems, we recommend to design the core assessment items and improve the reliability of assessment byenhancing the quality assurance/quality control (QA/QC) and verification processes. We proposed eco-friendly disposal plan for dredging sediment such as reuse system in land development was explored. A marine environmental database system was established to support the assessment processes. Guidelines for marine research and modelling were proposed for improving assessment of dredging and disposal of coastal sediment. Also, applying of screening and scoping for marine environmental assessment was reviewed.

Develop of Instructional Process Plan and Performance Assessment Instrument for 'Energy and Transportation Technology' Unit at the Subject 'Technology-Home Economics' in Middle School (중학교 기술·가정과 '에너지와 수송 기술' 단원의 수업과정안 및 수행평가 도구 개발)

  • Yi, Sang-bong;Lee, Do-Hyun
    • 대한공업교육학회지
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    • v.40 no.2
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    • pp.196-215
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    • 2015
  • The purpose of this study was to develop the instructional process plan and performance assessment instrument to do problem-solving activity for 'Energy and Transportation Technology' unit at the subject 'Technology-Home Economics' in middle school. This study was conducted by the following these stage. First, it was documents research and analysis of the 'Energy and Transportation Technology' unit. Second, topics for transportation technology hands-on and problem-solving activity were selected, and the organized for designed instructional process plan and performance assessment instrument related transportation technology in the development step. Third, developed instructional process plan and performance assessment instrument were conducted in order to amend and improved by expert and have gone through the field test for further improvement. The theme of transportation technology for hand-on and problem-solving activity was 'Created a hovercraft', and were consist of instructional process plan for 8 class period and performance assessment instrument in 4 type of observation, assessment finished, portfolios and student self-assessment.

Improvement of delayed hydride cracking assessment of PWR spent fuel during dry storage

  • Hong, Jong-Dae;Yang, Yong-Sik;Kook, Donghak
    • Nuclear Engineering and Technology
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    • v.52 no.3
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    • pp.614-620
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    • 2020
  • In a previous study, delayed hydride cracking (DHC) assessment of pressurized water reactor (PWR) spent fuel during dry storage using the threshold stress intensity factor (KIH) was performed. However, there were a few limitations in the analysis of the cladding properties, such as oxide thickness and mechanical properties. In this study, those models were modified to include test data for irradiated materials, and the cladding creep model was introduced to improve the reliability of the DHC assessment. In this study, DHC susceptibility of PWR spent fuel during dry storage depending on the axial elevation was evaluated with the improved assessment methodology. In addition, the sensitivity of affecting parameters such as fuel burnup, hydride thickness, and crack aspect ratio are presented.

Overview of Environmental Impact Assessment and Environmental Protection Technology in Tunnel Construction (터널 건설에 따른 환경영향 평가 및 대응기술 개발 방향)

  • Bae Gyu-Jin
    • 한국터널공학회:학술대회논문집
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    • 2005.04a
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    • pp.63-74
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    • 2005
  • The environmental influence in tunnel construction is the drying of the ground water, the drop of the ground water level, and noise and vibration by tunnel excavation. The environmental influence can cause the change of natural ecosystem and the source of popular complaints. In case of popular complaints, the tunnel construction can be stopped or the construction period can be extended. Also, the financial loss may be reached to hundreds of billions won. The technology development to minimize the environmental influence in the tunnel construction is very important in order to control popular complaints and to preserve ecosystem. It should be required the investigation, the evaluation, and the assessment of environmental impact to reduce environmental influence in the tunnel construction. The objective of this research is to review the environmental impact assessment in Korea and to introduce the environmental protection technology which minimizes the environmental influence generated in the tunnel construction.

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Process Life Cycle Assessment with Modified Allocating Method in PCB Producing Factory

  • Haepyo Chun;Kim, Young-Suk;Han, Sung-Ho;Han, Myung-Keun;Lee, Hong-Kee
    • Proceedings of the IEEK Conference
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    • 2001.10a
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    • pp.301-306
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    • 2001
  • Applying life cycle assessment in PCB (printed circuit board) production, most of environmental impacts come from outside-factory-process due to power generation, especially, and other raw material productions. Relatively, small environmental impacts of inside-factory-process make it difficult to compare them. To overcome this problem allocating environmental impacts of outside-factory-process on inside-factory-process. It helps to identify the environmental impacts of each process and find sources of environmental impacts. Also, life cycle assessment shows reduction of environmental impacts after copper recycling process.

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A Study on the Guidelines for Creating Alternative Habitats through Environmental Impact Assessment (환경영향평가 협의 시 대체서식지 조성을 위한 가이드라인 마련)

  • Shim, Yun-Jin;Park, Yong-Su
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.22 no.5
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    • pp.69-79
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    • 2019
  • The purpose of this study is to suggest a guideline that can be used as a standard for consultation and review by environmental impact assessment consultation and review practitioner to enhance the practical effectiveness of creating alternative habitats. The consultation stage of environmental impact assessment was significantly divided into 1) preparation of draft environmental impact assessment reports and gathering of consensus thereon, 2) preparation of environmental impact assessment reports and consultation thereon, 3) follow-up survey of environmental impacts(under construction) and 4) follow-up survey of environmental impacts(in operation). And it was suggested that the procedures of creating alternative habitat by each consultation stage were linked in order of 1) planning, 2) designing, 3) construction, and 4) post-monitoring and maintenance. The basic principles were also proposed for each stage of consultation on environmental impact assessment and procedure for the creation of alternate habitats. Then, issues and methods to be reviewed by the consulting agency and review agency of environmental impact assessment were presented in detail. The guideline of this study provides important information not only to environmental impact assessment consultation and review practitioner, but also to developers and environmental impact assessment agents who plan, construct, and manage alternative habitats.