• Title/Summary/Keyword: Dismantling System

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A Study on the Development of System Scaffolding for Elevator Installation Work (엘리베이터 설치 작업용 시스템 비계 개발에 관한 연구)

  • Hwang, Jong Moon;Lee, Ki Yeol;Lee, Kyung-Sun;Jeon, Du Seung
    • Journal of the Korean Society of Safety
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    • v.37 no.4
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    • pp.51-57
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    • 2022
  • In recent years, the government's urban housing expansion policy has resulted in increased construction and remodeling work of residential houses and apartments, causing more industrial accidents at elevator installation sites. Typically, accidents occur during the installation and dismantling of work scaffolds inside the hoistways or using non-standardized work scaffolds due to their structural instability. In view of this, the present study deals with the development of a standardized elevator system scaffolding that can be safely installed outside the hoistway, securing the work platform inside the hoistway. An improved version of the scaffolding system eliminates the need to enter the hoistway for the scaffolding installation, thereby preventing accidents.

Development of the Selection of Optimal Conceptual Design for the Noise-reduced Aluminum System Form

  • Hong, Jong Hyun;Yeom, Dong Jun;Seo, Jung Hoon;Kim, Young Suk
    • International conference on construction engineering and project management
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    • 2015.10a
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    • pp.708-709
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    • 2015
  • In Korea, a series of noise-reduced aluminum forms are being recently used in apartment housing construction. However, their complicated and time-consuming work processes, and the noise which is still generated due to the inherent property of aluminum when especially installing and dismantling them are have been pointed out as a problem to be certainly solved for increasing their practical use in construction sites. The primary objectives of this study are to propose a conceptual design of a newly designed noise-reduced aluminum form in which the noise can be enormously decreased during form works. The conceptual design in this study improved problems of conventional system aluminum forms, and, later, a system aluminum form developed based on this conceptual design will be able to ensure noise-reduction and safety as well as excellent applicability.

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Technology Trends in Spent Nuclear Fuel Cask and Dry Storage (사용후핵연료 운반용기 및 건식저장 기술 동향)

  • Shin, Jung Cheol;Yang, Jong Dae;Sung, Un Hak;Ryu, Sung Woo;Park, Yeong Woo
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.16 no.1
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    • pp.110-116
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    • 2020
  • As the management plan for domestic spent nuclear fuel is delayed, the storage of the operating nuclear power plant is approaching saturation, and the Kori 1 Unit that has reached its end of operation life is preparing for the dismantling plan. The first stage of dismantling is the transfer of spent nuclear fuel stored in storage at plants. The spent fuel management process leads to temporary storage, interim storage, reprocessing and permanent disposal. In this paper, the technical issues to be considered when transporting spent fuel in this process are summarized. The spent fuels are treated as high-level radioactive waste and strictly managed according to international regulations. A series of integrity tests are performed to demonstrate that spent fuel can be safely stored for decades in a dry environment before being transferred to an intermediate storage facility. The safety of spent fuel transport container must be demonstrated under normal transport conditions and virtual accident conditions. IAEA international standards are commonly applied to the design of transport containers, licensing regulations and transport regulations worldwide. In addition, each country operates a physical protection system to reduce and respond to the threat of radioactive terrorism.

Assessment of the Radiological Inventory for the Reactor at Kori NPP Using In-Situ Measurement Technology (In-Situ 측정법을 이용한 고리 원자로 방사선원항 평가)

  • Jeong, Hyun Chul;Jeong, Sung Yeop
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.12 no.2
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    • pp.171-178
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    • 2014
  • After the expiration of operating license of a plant, all infrastructures within the plant must be safely dismantled to the point that it no longer requires measures for radiation protection. Despite the fact that Kori 1 and Wolsong 1 are close to the expiration of their operating license, sufficient technologies for radiological characterization, decontamination and dismantling is still under development. The purpose of this study is to develop one of methods for radiological inventory assessment on measuring object by using direct measure of large component with In-Situ measurement technique. Radiological inventory was assessed by analyzing nuclide using portable gamma spectroscopy without dismantling reactor head, and the result of direct measurement was supplemented by performing indirect measurement. Radiochemical analysis were performed on surface contamination samples as well. During the study, radiological inventory of reactor vessel calculated expanding the result. Based on the result and the radioactivity variation of each radionuclides time frame for decommissioning can be decided. Thus, it is expected that during the decommissioning of plants, the result of this study will contribute to the reduction of radiation exposure to workers.

The Status and Prospect of Decommissioning Technology Development at KAERI (한국원자력연구원의 해체기술 개발 현황 및 향후 전망)

  • Moon, Jeikwon;Kim, Seonbyung;Choi, Wangkyu;Choi, Byungseon;Chung, Dongyong;Seo, Bumkyoung
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.17 no.2
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    • pp.139-165
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    • 2019
  • The current status and prospect of decommissioning technology development at KAERI are reviewed here. Specifically, this review focuses on four key technologies: decontamination, remote dismantling, decommissioning waste treatments, and site remediation. The decontamination technologies described are component decontamination and system decontamination. A cutting method and a remote handling method together with a decommissioning simulation are described as remote dismantling technologies. Although there are various types of radioactive waste generated by decommissioning activities, this review focuses on the major types of waste, such as metal waste, concrete waste, and soil waste together with certain special types, such as high-level and high-salt liquid waste, organic mixed waste, and uranium complex waste, which are known to be difficult to treat. Finally, in a site remediation technology review, a measurement and safety evaluation related to site reuse and a site remediation technique are described.

Development on Test Procedure of Pitch and Yaw Bearings for Wind Turbine (풍력발전기용 피치/요 베어링의 시험절차 개발)

  • Nam, Ju Seok;Han, Jeong Woo
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.24 no.3
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    • pp.355-362
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    • 2015
  • Test procedure for the design verification of wind turbine pitch and yaw bearings has been developed. Test items were selected to evaluate operational reliability of pitch and yaw bearings by considering loading and operational conditions, and by analyzing the design criteria of pitch and yaw bearings. The developed test items consisted of preliminary test, fatigue load test, extreme load test, low temperature environmental test and dismantling inspection after all the test were completed. Because it reflects the actual operational conditions of the pitch and yaw bearings, the developed test procedure has high reliability and can verify the basic design considerations in the international standard and guidelines.

RISK ASSESSMENT USING BIM BASED SAFETY MANAGEMENT SYSTEM

  • Hongseob Ahn;Hyunjoo Kim;Wooyoung Kim
    • International conference on construction engineering and project management
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    • 2011.02a
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    • pp.107-110
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    • 2011
  • The key role in safety management is to identify any possible hazard before it occurs by identifying any possible risk factors which are critical to risk assessment. This planning/assessment process is considered to be tedious and requires a lot of attention due to the following reasons: firstly, falsework (temporary structures) in construction projects is fundamentally important. However, the installation and dismantling of those facilities are one of the high risk activities in the job sites. Secondly, temporary facilities are generally not clearly delineated on the building drawings. It is our strong belief that safety tools have to be simple and convenient enough for the jobsite people to manage them easily and be flexible for any occasions to be occurred at various degrees. In order to develop the safety assessment system, this research utilizes the BIM technology and collects important information by importing data from BIM models and use it in the planning stage.

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An experimental study on the development and verification of NCC(new concrete cutting) system

  • Park, Jong-Hyup;Han, Jong-Wook
    • Structural Engineering and Mechanics
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    • v.65 no.2
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    • pp.203-211
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    • 2018
  • This paper introduces the development process of NCC(New Concrete Cutting) system and analyzes first verification test. Based on the first verification test results, some problems of NCC system have been newly modified. We carry out the second verification test. We tried to verify cutting performance and dust control efficiency of NCC system through the cutting test of concrete bridge piers. In particular, this verification test strives to solve the problem of concrete dust, which is the biggest problem of dry cutting method. The remaining dust problems in cutting section tried to solve through this verification test. This verification test of the NCC system shows that the dust problem of dry cutting method is closely controlled and solved. In conclusion, the proposed NCC method is superior to the dry cutting method in all aspects, including cutting performance, dust vacuum efficiency and cooling effect. The proposed NCC system is believed to be able to provide eco-friendly cutting technology to various industries, such as the removal of the SOC structures and the dismantling of nuclear plants, which have recently become a hot issue in the field of concrete cutting.

A study on Transformation of Archives System and Archival Science (아카이브와 기록학 전환을 위한 시론)

  • Yi, Kyoung Yong
    • The Korean Journal of Archival Studies
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    • no.80
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    • pp.167-196
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    • 2024
  • This article argued for the need for a transformation of archives system and archival science through a review of the archival circles' discussion of dismantling and reconstructing the current national archive system. By sharply contrasting the cases of civil society 'archiving activities' with the cases of 'national archive sites', we attempted to present solutions to the current archive system from a micro perspective. In this process, the need for a shift in archival research methodology centered on archival materials was derived in relation to the deepening of awareness of archival information organization and hierarchical description to ensure archive accessibility and the meaning of policy shift.

An Analytical Study on the Change of System Supports according to the Brace Installation (가새 설치 여부에 따른 시스템 동바리 거동변화에 대한 해석적 연구)

  • Oh, Byoung-Han;Choi, Byong J.
    • Journal of the Korean Society of Safety
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    • v.33 no.2
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    • pp.104-111
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    • 2018
  • System supports are widely used in concrete construction due to the convenience and structural safety at the point of both installation and dismantling. However, there were frequent collapses in the construction sites due to the absence of both structural review and brace installations. Therefore, this paper examines the importance of braces in the system supports. In order to examine the importance of the brace, four types of braces were considered: 100% braces, 50% braces, 25% braces, and without braces. The maximum displacement of the 100% braced model was 0.97 mm, the 50% braced model was 1.13 mm, the 25% braced model was 1.16 mm and the non-braced model was 24.3 mm, respectively. Compared to the model with the without-braces, the model with 100% of the braces installed has a displacement of 4.0%, the model with 50% of the braces showed a displacement of 4.7%, and the model with 25% of the braces appeared to be a displacement of 4.8%. That is, the installation of the braces is effective in reducing the maximum displacement of the system supports and is effective in reducing the maximum displacement with only small number of braces installed.