• Title/Summary/Keyword: 해체시스템

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Review for Applying Spent Fuel Pool Island (SFPI) during Decommissioning in Korea (원전해체시 독립된 사용후핵연료저장조 국내 적용 검토)

  • Baik, Jun-ki;Kim, Chang-Lak
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.13 no.2
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    • pp.163-169
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    • 2015
  • In many nuclear power plant sites in Korea, high density storage racks were installed in the spent fuel pool to expand the spent fuel storage capacity. Nevertheless, the capability of the Hanbit nuclear site will be saturated by 2024. Also, 10 NPPs will reach their design life expiration date by 2029. In the case of the US, SFPI (Spent Fuel Pool Island) operated temporarily as a spent fuel storage option before spent nuclear fuels were transported to an interim storage facility or a final disposal facility. As a spent fuel storage option after shutdown during decommissioning, the SFPI concept can be expected to have the following effects: reduced occupational exposure, lower cost of operation, strengthened safety, and so on. This paper presents a case study associated with the regulations, operating experiences, and systems of SFPI in the US. In conclusion, the following steps are recommended for applying SFPI during decommissioning in Korea: confirmation of design change scope of SFPI and expected final cost, the submission of a decommissioning plan which is reflected in SFPI improvement plans, safety assessment using PSR, application of an operating license change for design change, regulatory body review and approval, design change, inspection by the regulatory body, education and commissioning for SFPI, SFPI operation and periodic inspection, and dismantling of SFPI.

Comparison of Compton Image Reconstruction Algorithms for Estimation of Internal Radioactivity Distribution in Concrete Waste During Decommissioning of Nuclear Power Plant (원전 해체 시 방사성 콘크리트 폐기물 내부 방사능 분포 예측을 위한 컴프턴 영상 재구성 방법의 비교)

  • Lee, Tae-Woong;Jo, Seong-Min;Yoon, Chang-Yeon;Kim, Nak-Jeom
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.18 no.2
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    • pp.217-225
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    • 2020
  • Concrete waste accounts for approximately 70~80% of the total waste generated during the decommissioning of nuclear power plants (NPPs). Based upon the concentration of each radionuclide, the concrete waste from the decommissioning can be used in the determination of the clearance threshold used to classify waste as radioactive. To reduce the cost of radioactive concrete waste disposal, it is important to perform decontamination before self-disposal or limited recycling. Therefore, it is necessary to estimate the internal radioactivity distribution of radioactive concrete waste to ensure effective decontamination. In this study, the performance metrics of various Compton reconstruction algorithms were compared in order to identify the best strategy to estimate the internal radioactivity distribution in concrete waste during the decommissioning of NPPs. Four reconstruction algorithms, namely, simple back-projection, filtered back-projection, maximum likelihood expectation maximization (MLEM), and energy-deconvolution MLEM (E-MLEM) were used as Compton reconstruction algorithms. Subsequently, the results obtained by using these various reconstruction algorithms were compared with one another and evaluated, using quantitative evaluation methods. The MLEM and E-MLEM reconstruction algorithms exhibited the best performance in maintaining a high image resolution and signal-to-noise ratio (SNR), respectively. The results of this study demonstrate the feasibility of using Compton images in the estimation of the internal radioactive distribution of concrete during the decommissioning of NPPs.

A Study on the Constructability of Modular Steel Frame (해체.조립식 모듈러 철골조 건물의 시공성에 관한 연구)

  • Zheng, Sheng-Lin;Kang, Joo-Won;Park, Sung-Moo
    • Journal of Korean Association for Spatial Structures
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    • v.8 no.4
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    • pp.65-71
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    • 2008
  • The object of this paper is to evaluate on constructability of modular steel frame with the hollow structural steel section to LEB C-shape. A modular building is built with factory-manufacture and site-construction. The advantage of a Modular building presents that enhanced building quality, shortened construction period and easy at an expansion and enlargement for buildings but also has demerits such as size restriction of the modular units according to the Road Traffic Law and Inflexibility of the unit composition. So in this study we use light-weighted structure members with bolted joint for easy Knock-down and traffic, also we evaluated the constructability of this bolted joints type modular buildings.

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Cost Analysis of Construction Phase in Basement Composite Wall Form (지하 합벽 거푸집의 시공단계별 원가 분석에 관한 연구)

  • Choi, Oh-Young;Heo, Kyoung-Moo;Kim, Tae-Hui;Kim, Jae-Yeob;Kim, Gwang-Hee
    • Journal of the Korea Institute of Building Construction
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    • v.9 no.6
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    • pp.189-195
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    • 2009
  • Recently, the urban centralization phenomenon appears to be growing. As a result, many vigorous efforts for the use of underground space are being made. In particular, the basement depth of construction in the downtown area has deepened and construction is often done close to adjacent buildings. In this case, generally, the underground construction approach mainly used is the composite basement wall system. However, a cost analysis of the basement composite wall system does not exist. Therefore, in this study, the cost of the composite basement wall system was analyzed. The percentage breakdown of costs were: buttress work processes, 3% form work processes, 26% reinforcement work processes, 12% support work processes, 42% and other processes,17%. Accordingly, it will be necessary when developing new technology and construction methods to determine the development focus.