• Title/Summary/Keyword: Dismantling process

Search Result 131, Processing Time 0.023 seconds

Development of Cesium-selective Paramagnetic Core Inorganic Composite Agent for Water Decontamination (수질오염 제염을 위한 세슘 선택성 상자성 코어 무기복합제염제 개발)

  • Seong Pyo Hong;Bo-Sun Kang
    • Journal of Radiation Industry
    • /
    • v.18 no.2
    • /
    • pp.127-132
    • /
    • 2024
  • Large amounts of liquid radioactive waste or radioactive contaminated water could be produced during the treatment of radiation accidents or during the dismantling and decontamination process of nuclear power plants. Since most of the decontamination agents to date are difficult to recover after adsorption of radioactive isotopes, their use in open environments such as rivers, reservoirs, or oceans is limited. In this study, as a radioactive decontamination agent that can overcome the current limitations when used in an open environment, a paramagnetic core inorganic composite (PMCIC) decomposite agent with high selectivity to cesium ions was developed. PMCore was prepared by synthesizing paramagnetic iron oxide nanoparticles, and inorganic crystals such as metal-ferrocyanide were conjugated to the surface so that PMCore could be selective to cesium ions. The developed PMCIC could be easily recovered from the water by magnetism and could adsorb up to 94 μM of Cs atoms per 1 g of PMCIC.

A Study on the Construction of Cutting Scenario for Kori Unit 1 Bio-shield considering ALARA

  • Hak-Yun Lee;Min-Ho Lee;Ki-Tae Yang;Jun-Yeol An;Jong-Soon Song
    • Nuclear Engineering and Technology
    • /
    • v.55 no.11
    • /
    • pp.4181-4190
    • /
    • 2023
  • Nuclear power plants are subjected to various processes during decommissioning, including cutting, decontamination, disposal, and treatment. The cutting of massive bio-shields is a significant step in the decommissioning process. Cutting is performed near the target structure, and during this process, workers are exposed to potential radioactive elements. However, studies considering worker exposure management during such cutting operations are limited. Furthermore, dismantling a nuclear power plant under certain circumstances may result in the unnecessary radiation exposure of workers and an increase in secondary waste generation. In this study, a cutting scenario was formulated considering the bio-shield as a representative structure. The specifications of a standard South Korean radioactive waste disposal drum were used as the basic conditions. Additionally, we explored the hot-to-cold and cold-to-hot methods, with and without the application of polishing during decontamination. For evaluating various scenarios, different cutting time points up to 30 years after permanent shutdown were considered, and cutting speeds of 1-10nullm2/h were applied to account for the variability and uncertainty attributable to the design output and specifications. The obtained results provide fundamental guidelines for establishing cutting methods suitable for large structures.

Development of Risk Breakdown Structure of Nuclear Power Plant Decommissioning Project: Focusing on Structural Damage / Work Process Risks (원전 차폐 콘크리트 구조물 제염해체공사 리스크 분류체계 구축: 구조적 / 작업 리스크를 중심으로)

  • Kim, Byeol;Lee, Joo-Sung;Ahn, Yong-Han
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.22 no.3
    • /
    • pp.38-45
    • /
    • 2018
  • The purpose of this study is to deduct the structural damage / work process risks factors which can be occurred during the decommissioning in the NPP containment concrete structure. To achieve these purpose, risk profile specified in the construction industry is analyzed, and the work process of NPP decommissioning and the construction project were matched based on the similarity of each works. Accordingly, human and physical risk factors are classified. Finally, the risk associated with the building structure and work process was classified as per their process activities, and risk typology explaining the disaster which put the structure, equipments, machine and workers in serious danger was developed.

Overview and Recent Development of Recycling Waste Refrigerators (폐(廢) 냉장고(冷藏庫) 재활용(再活用) 현황(現況)과 기술(技術) 전망(展望))

  • Yang, Hyunseok;Kim, Geon-Hong;Kong, Man-Sik;Park, Kiejin;Lee, Gwang Weon;Kim, Bo Saeng
    • Resources Recycling
    • /
    • v.22 no.4
    • /
    • pp.70-80
    • /
    • 2013
  • Waste refrigerator is the most large amount of item being recycled and the recycling process is the most complicated in WEEE (Waste Electrical and Electronic Equipment) because refrigerator is biggest product and consists of various parts and materials such as ferrous, non-ferrous, and plastics. Recently, recycling process of waste refrigerator has been being more complex since large capacity 2 door refrigerators and standing Kimchi refrigerators with various material are distributed on custom market. In addition, recycling of valuable resource from waste refrigerator is mandatory by WEEEs recycling legislation; therefore, high efficiency recycling enough for economic and environment-friendly recovery of valuable resource through present technical situation analysis and comparison of recycling technologies of waste refrigerator with advanced country.

Dismantling and Restoration of the Celadon Stool Treasure with an Openwork Ring Design (보물 청자 투각고리문 의자의 해체 및 복원)

  • KWON, Ohyoung;LEE, Sunmyung;LEE, Jangjon;PARK, Younghwan
    • Korean Journal of Heritage: History & Science
    • /
    • v.55 no.2
    • /
    • pp.200-211
    • /
    • 2022
  • The celadon stools with an openwork ring design which consist of four items as one collection were excavated from Gaeseong, Gyeonggi-do Province. The celadon stools were designated and managed as treasures due to their high arthistorical value in the form of demonstrating the excellence of celadon manufacturing techniques and the fanciful lifestyles during the Goryeo Dynasty. However, one of the items, which appeared to have been repaired and restored in the past, suffered a decline in aesthetic value due to the aging of the treatment materials and the lack of skill on the part of the conservator, raising the need for re-treatment as a result of structural instability. An examination of the conservation condition prior to conservation treatment found structural vulnerabilities because physical damage had been artificially inflicted throughout the area that was rendered defective at the time of manufacturing. The bonded surfaces for the cracked areas and detached fragments did not fit, and these areas and fragments had deteriorated because the adhesive trickled down onto the celadon surface or secondary contaminants, such as dust, were on the adhesive surface. The study identified the position, scope, and conditions of the bonded areas at the cracks UV rays and microscopy in order to investigate the condition of repair and restoration. By conducting Fourier-transform infrared spectroscopy(FT-IR) and portable x-ray fluorescence spectroscopy on the materials used for the former conservation treatment, the study confirmed the use of cellulose resins and epoxy resins as adhesives. Furthermore, the analysis revealed the addition of gypsum(CaSO4·2H2O) and bone meal(Ca10 (PO4)6(OH)2) to the adhesive to increase the bonding strength of some of the bonded areas that sustained force. Based on the results of the investigation, the conservation treatment for the artifact would focus on completely dismantling the existing bonded areas and then consolidating vulnerable areas through bonding and restoration. After removing and dismantling the prior adhesive used, the celadon stool was separated into 6 large fragments including the top and bottom, the curved legs, and some of the ring design. After dismantling, the remaining adhesive and contaminants were chemically and physically removed, and a steam cleaner was used to clean the fractured surfaces to increase the bonding efficacy of the re-bonding. The bonding of the artifact involved applying the adhesive differently depending on the bonding area and size. The cyanoacrylate resin Loctite 401 was used on the bonding area that held the positions of the fragments, while the acrylic resin Paraloid B-72 20%(in xylene) was treated on cross sections for reversibility in the areas that provided structural stability before bonding the fragments using the epoxy resin Epo-tek 301-2. For areas that would sustain force, as in the top and bottom, kaolin was added to Epo-tek 301-2 in order to reinforce the bonding strength. For the missing parts of the ring design where a continuous pattern could be assumed, a frame was made using SN-sheets, and the ring design was then modeled and restored by connecting the damaged cross section with Wood epos. Other restoration areas that occurred during bonding were treated by being filled with Wood epos for aesthetic and structural stabilization. Restored and filled areas were color-matched to avoid the feeling of disharmony from differences of texture in case of exhibitions in the future. The investigation and treatment process involving a variety of scientific technology was systematically documented so as to be utilized as basic data for the conservation and maintenance.

Study on a Creative Fashion Design Development Process through Idea Classification (아이디어 발상 유형화를 통한 창의적 패션 디자인 전개 프로세스 연구)

  • Kim, Yoon-Kyoung;Park, Hye-Won
    • Journal of the Korean Society of Costume
    • /
    • v.60 no.9
    • /
    • pp.95-105
    • /
    • 2010
  • The purpose of this study is in allowing thinking about the design development process which is more towards the visual and perceptional aspects related to the form structure by more diverse methods by typology of idea generation. To accomplish such goal, researches in the psychology, pedagogy, engineering, and consilient studies as well as related precedent researches and reference data in architecture, promotion, industrial design, and other art fields and fashion designs are collected and analyzed to see the study trend. In addition, in the content analysis method based on such, the idea generation was classified into types in consideration of relevancy, usefulness, and suitability with fashion. First, a concentrated thinking of a limited space is a method of leading an optimal design by focusing on solving the cause of a problem within a space which generates the problem. Second, plan thinking per section of structure decomposition is a method of dismantling the design problems per organization, thinking type, factor, and characteristic into sub-modules to re-interpret and re-organize the problems in various aspects. Third, an associated thinking through interpreting relationships among vocabularies is a method of selecting the marginal languages that allow a person to come up with concrete forms and the key words related to fashion to import the characteristics and attributes of the marginal languages and thematic relationship between the two terms to search the relevancy. Lastly, the free integrated thinking of language extension is a method of groping integration between other fields and fashion by free integration among the extended terms by extending the vocabularies through inferring metaphorical expressions founded upon individual's memories or knowledge concepts regarding theme words that do not allow concrete forms to come up.

A Study on a Creative Design Development Using a Traditional Pattern - Focusing on the Arrangement and Color-scheme of the Pattern - (전통 물고기문양을 모티브로 한 창의적 디자인 개발 연구 - 문양의 배치 및 색채 배색 과정을 중심으로 -)

  • Mok, So-Ri;Cho, Jean-Suk
    • Journal of the Korea Fashion and Costume Design Association
    • /
    • v.16 no.2
    • /
    • pp.81-100
    • /
    • 2014
  • The purpose of this study is to link traditional patterns to mordern clothing. Of all the traditional patterns, the fish pattern was chosen for use during the development of a creative one-piece design for woman and shirts design for man. This study is based upon document searches, including research papers. Through these searches, it investigates the symbolic meaning, formation of the fish pattern and the creative design process. Based on this investigation, the study attempts to modernize the fish pattern and apply the fish patterns to the design of a one-piece dress and shirts. The design procedure includes three sub-processes: selection, arrangement and color-scheme. The selection process, the form of the pattern was edited using Adobe Photoshop. The arrangement of the pattern was made through the checklist conception method, containing the following functions: expand, reset, repeat, omission and dismantling. For the color-scheme of the pattern, Paul Klee(1879-1940)work was selected, and the colors in his work were adopted when dyeing the rest of the one-piece dress and shirts as well as fish features. In conclusion, six designs of the one-pieces dress and shirts were created by using one of Korea's traditional patterns-the fish pattern. This kind of study not only let the world know about the unique beauty of nations but also helps to inspire people who has a profession in design, by suggesting design development process based on design competitiveness improvement factor from fusion of tradition and modern.

  • PDF

Mold Woodworking Tools and musculoskeletal disorders of the correlation analysis (형틀 목공이 사용하는 작업공구와 근골격계 질환의 상관관계 분석)

  • Kwark, Dong-Jin;Park, Jung-Lo;Kim, Jae-Jun
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2012.11a
    • /
    • pp.5-7
    • /
    • 2012
  • Repeated using carpentry workers work at working tools because of occupational low back pain, such as musculoskeletal disorders, occupational diseases are on the rise. For this purpose, through the analysis of musculoskeletal disorders and work tools and studies are underway to improve the working conditions of the workers. However, existing previous studies may not reflect the working tools used for carpentry worker dies when working at a construction site that Therefore, in this study, the work in the form of construction, one of the jobs of worker dies classified according to the working tools of musculoskeletal disorders correlated to analyze. The results of this study are as follows. working tools of a total of seven different dies used in the installation process. Musculoskeletal disorders, waist / drill such correlation was very strong. Also showed that a total of three of the tools used in the formwork dismantling cutter musculoskeletal disorders of the arm / elbow and a very strong correlation.

  • PDF

3-D Temporary Facility Visualization Using BIM(Building Information Modeling) Technology

  • Kim, Hyun-Joo;Ahn, Hong-Seob;Kim, Woo-Young
    • Journal of Construction Engineering and Project Management
    • /
    • v.1 no.2
    • /
    • pp.37-42
    • /
    • 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. It is well known that falsework (temporary facilities) in construction projects is fundamentally important. This planning/assessment process is considered to be tedious and requires a lot of attention due to the following reasons: firstly, 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. Therefore, 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 a safety identification system of temporary facilities, this research utilizes the BIM technology in retrieving important information by importing data from BIM models and use it in the safety planning stage.

Worker Safety in the Rare Earth Elements Recycling Process From the Review of Toxicity and Issues

  • Shin, Seo-Ho;Kim, Hyun-Ock;Rim, Kyung-Taek
    • Safety and Health at Work
    • /
    • v.10 no.4
    • /
    • pp.409-419
    • /
    • 2019
  • Although the rare earth elements (REEs) recycling industry is expected to increase worldwide in hightech industry, regulations for worker safety have yet to be established. This study was conducted to understand the potential hazard/risk of REE recycling and to support the establishment of regulations or standards. We review the extensive literature on the toxicology, occupational safety, and health issues, and epidemiological surveys related to the REEs, and propose suitable management measures. REE recycling has four key steps such as collection, dismantling, separation, and processing. In these processes, hazardous substances, such as REEs-containing dust, metals, and chemicals, were used or occurred, including the risk of ignition and explosion, and the workers can be easily exposed to them. In addition, skin irritation and toxicities for respiratory, nervous, and cardiovascular systems with the liver toxicity were reported; however, more supplementary data are needed, owing to incompleteness. Therefore, monitoring systems concerning health, environmental impacts, and safety need to be established, based on additional research studies. It is also necessary to develop innovative and environment-friendly recycling technologies, analytical methods, and biomarkers with government support. Through these efforts, the occupational safety and health status will be improved, along with the establishment of advanced REE recycling industry.