• Title/Summary/Keyword: Barrier Concept

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A Study on Thermal Load Management in a Deep Geological Repository for Efficient Disposal of High Level Radioactive Waste

  • Jongyoul Lee;Heuijoo Choi;Dongkeun Cho
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.20 no.4
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    • pp.469-488
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    • 2022
  • Technology for high-level-waste disposal employing a multibarrier concept using engineered and natural barrier in stable bedrock at 300-1,000 m depth is being commercialized as a safe, long-term isolation method for high-level waste, including spent nuclear fuel. Managing heat generated from waste is important for improving disposal efficiency; thus, research on efficient heat management is required. In this study, thermal management methods to maximize disposal efficiency in terms of the disposal area required were developed. They efficiently use the land in an environment, such as Korea, where the land area is small and the amount of waste is large. The thermal effects of engineered barriers and natural barriers in a high-level waste disposal repository were analyzed. The research status of thermal management for the main bedrocks of the repository, such as crystalline, clay, salt, and other rocks, were reviewed. Based on a characteristics analysis of various heat management approaches, the spent nuclear fuel cooling time, buffer bentonite thermal conductivity, and disposal container size were chosen as efficient heat management methods applicable in Korea. For each method, thermal analyses of the disposal repository were performed. Based on the results, the disposal efficiency was evaluated preliminarily. Necessary future research is suggested.

Performance Assessment of Engineered Barrier for Retardation of Radionuclide Release in a Low- and Intermediate-Level Radioactive Waste Repository (중저준위방사성폐기물 처분장 인공방벽의 핵종유출 저지능 평가)

  • Cho, W.J.;Lee, J.O.;Hahn, P.S.;Park, H.H.
    • Nuclear Engineering and Technology
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    • v.25 no.3
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    • pp.447-456
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    • 1993
  • A simplified model to assess the performance of engineered barrier for the retardation of radionuclide release in a low- and intermediate-level radioactive waste repository was developed. The model is based on the repository design concept being suggested in Korea, and considers two types of release scenario ; a design-bas release for the design of engineered barrier and a realistic release for the performance assessment. For the numerical illustration, the sample calculations were performed for five radionuclides with different chemical characteristics, and the results were analyzed.

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Biomaterial development for oral and maxillofacial bone regeneration

  • Sulzer, Lindsay S. Karfeld;Weber, Franz E.
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.38 no.5
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    • pp.264-270
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    • 2012
  • Many oral and maxillofacial bone defects are not self-healing. Guided bone regeneration (GBR), which uses a barrier membrane to prevent the soft tissues from invading the defect to enable slower-growing bone cells to penetrate the area, was developed as a therapy in the 1980s. Although there has been some success with GBR in some clinical situations, better treatments are needed. This review discusses the concept of GBR focusing on bioactive membranes that incorporate osteoconductive materials, growth factors and cells for improved oral and maxillofacial bone regeneration.

Calcium Sulfo Aluminate (CSA) Cement from Coal Ash Utilized as Barriers for Radioactive Waste Disposal

  • Ramakrishna, Chilakala;Thriveni, Thenepalli;Whan, Ahn Ji
    • Journal of Energy Engineering
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    • v.27 no.1
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    • pp.33-39
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    • 2018
  • In this paper, we reviewed briefly about the barrier materials for the radioactive waste disposal. The primary concept of the radioactive waste disposal is safety. The goal of the radioactive waste management is to assure that the environment is not adversely affected and also public. There are a wide variety of materials are available for the radioactive waste disposal or storage. Among those coal fly ash is one of the significant materials are used as a barrier material. Here we reported, the Calcium sulfo aluminate (CSA) from coal fly ash is effectively suitable for the radioactive waste disposal. This is one of the ways of utilization of waste and manufactured the valuable materials for future indeeds.

Planning for Safely Control on Hazardous Material Distribution Depot.

  • Roh, S.K.;Jun, S.W.;Kang, T.H.;Seo, Y.M.
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 1997.11a
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    • pp.260-268
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    • 1997
  • The safety of LPG vessel storage has been simply designed and controled with blast wave barrier structure concept regardless of its quantity or hazardous situation. The limit of regal controls on LPG vessel storage need to be identified in terms of safety buffer distance from LPG explosion. The level of overpressure effect and heat radiation In the safety structure and neighbouring human activity required to be estimated to find the gap between existing controls on such storage. To this content the paper discuss the issues on the approach In the blast wave barrier and safety separation distances.

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Hazard Prevention using Multi-Level Debris Flow Barriers (다단식(다단식) 토석류 방호책을 이용한 재해방지 시스템)

  • Lee, Sung-Uk;Choi, Seung-Il;Choi, Yu-Kyung
    • Proceedings of the KSR Conference
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    • 2008.11b
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    • pp.815-829
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    • 2008
  • Debris flows are a natural hazard which looks like a combination of flood, land and rock slide. Large rainfall in July 2006 produced several large scale debris flows and many small debris flows that resulted in loss of life and considerable property and railway damage, as was widely reported in the national media. The hazard "debris flow" is still insufficiently researched. Furthermore debris flows are very hard to predict. Flexible Ring net barriers are multi-functional mitigation devices commonly applied to rock fall or floating wood protection in floods, snow avalanches and also mud flows or granular debris flows, if properly dimensioned for the process or processes for which they are intended. Overtopping of the barriers by debris flows and sediment transport is possible, supporting the design concept that a series of barriers may be used to stop volumes of debris larger than are possible using only one barrier. The future for these barrier concepts looks promising because these barriers represent the state of art for such applications and are superior to many other available options.

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A Study on the Planning Concept of Elderly Housing in Aged society (고령사회에 대응한 고령자주택의 계획개념에 관한 연구)

  • Han, Kyun;Kwon, SoonJung
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.19 no.2
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    • pp.7-17
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    • 2013
  • Purpose: This basic research tries to provide planning concept of elderly housing which can cope with the needs of the aged society. Methods: This study has been conducted mainly by literature investigation research. Previous researches include Universal and Barrier-Free Design, Elderly Housing Standards, Elderly Welfare Act and other related acts, various papers related to elderly housing, and so on. To set up the Planning concept of elderly housing, elements or indices of previous studies have been comparatively analysed. Results: Elderly housing has been divided into individual type, group type and facility type according to the residents' health and operation system of the housing. This paper focuses on the individual type among three categories. Seven concepts of the elderly housing have been derived as the outcome of this research - Safety, Accessibility, Amenity, Distinguishment, Adaptability, Convenience, and Sociality. Implications: This concept will provide the planning direction on the construction and renovation for Elderly Housing in the future.

A Landscape Design of Sangsaengjiwon (상생지원(相生池苑) 기본계획)

  • Park, Kyung-Bok
    • Journal of the Korean Institute of Landscape Architecture
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    • v.36 no.1
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    • pp.12-27
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    • 2008
  • The purpose of this plan was to introduce the imaginary environment concept to modem environment design which was drawn by comparison of historic and cultural landscape. An area of $19,056m^2$ in I1-ja mountain water reservoir, located in 94 Dun-Chon-Dong, Gangdong-Gu, Seoul was selected for this planning. The concepts of Barrier-Free Design and Universal Design were introduced in order to accept the demands of various social classes. Based on the results of natural and cultural environment, Animism, Heaven, Earth and Man Theory and Yin-Yang and the Five Elements Theory these concepts were introduced for the philosophical background. Concept planning, topic selection, space planning and axis establishment were conducted during the framework step of the plan. Circulation planning, planting planning, facility and pavement planning, and light planning were conducted during the initial planning step. Lastly, detailed designing was performed for the major spaces. In addition, the imaginary environment concept was applied, ranging from the structural aspect of the space to designing factors of the facility in order to achieve placeness and practicality. In conclusion, this may be the first case design applying the imaginary environment concept to the environmental design with natural environment factors such as animals, plants, terrains and climate, and cultural such as cities, places, time, thoughts and symbols which are all factors to be considered in the existing environment design.

R&D Review on the Gap Fill of an Engineered Barrier for an HLW Repository (고준위폐기물처분장 공학적방벽의 갭채움재 기술현황)

  • Lee, Jae Owan;Choi, Young-Chul;Kim, Jin-Seop;Choi, Heui-Joo
    • Tunnel and Underground Space
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    • v.24 no.6
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    • pp.405-417
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    • 2014
  • In a high-level waste repository, the gap fill of the engineered barrier is an important component that influences the performance of the buffer and backfill. This paper reviewed the overseas status of R&D on the gap fill used engineered barriers, through which the concept of the gap fill, manufacturing techniques, pellet-molding characteristics, and emplacement techniques were summarized. The concept of a gap fill differs for each country depending on its disposal type and concept. Bentonite has been considered a major material of a gap fill, and clay as an inert filler. Gap fill was used in the form of pellets, granules, or a pellet-granule blend. Pellets are manufactured through one of the following techniques: static compaction, roller compression, or extrusion-cutting. Among these techniques, countries have focused on developing advanced technologies of roller compression and extrusion-cutting techniques for industrial pellet production. The dry density and integrity of the pellet are sensitive to water content, constituent material, manufacturing technique, and pellet size, and are less sensitive to the pressure applied during the manufacturing. For the emplacement of the gap fill, pouring, pouring and tamping, and pouring with vibration techniques were used in the buffer gap of the vertical deposition hole; blowing through the use of shotcrete technology and auger placement and compaction techniques have been used in the gap of horizontal deposition hole and tunnel. However, these emplacement techniques are still technically at the beginning stage, and thus additional research and development are expected to be needed.

The Concept Analysis of Self-Control (자기통제의 개념 분석)

  • Eun, Young;Lee, In-Sook;Lee, Keung-Sook;Song, Keung-Ja;Choi, Eun-Ok;Shu, Soon-Rim;Yang, Young-Hee;Park, Young-Im;Gu, Mee-Ok;Kim, Sung-Jae;Kim, In-Ja;Lee, Eun-Nam;Park, Song-Ja;Lee, Dong-Suk;Lee, Eun-Ok
    • Journal of Korean Academy of Nursing
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    • v.29 no.4
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    • pp.951-962
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    • 1999
  • Today human needs for health promotion and maintenance are increasing. The nursing profession as a great responsibility to develop the knowledge for helping clients to practice good health behavior under self-control. But there are few studies about the concept of self-control, or the operational definition of self-control. The purpose of this study was to analyze and clarify the meaning of the concept of self-control. This study used Walker and Avant's process of concept analysis. Antecedents of self control consist of 1) perception of the conflict situation to change his or her behavior ; 2) perception of self as the causes of the barrier for a certain behavior ; 3) internal standard or belief such as self-efficacy and learned resourcefulness ; 4) internal motivation for change of behavior. Critical attributes of self-control were 1) goal-orientation ; 2) self-decision ; 3) time sequence ; 4) effort ; 5) possibility of being learned ; 6) individuality ; 7) social desirability. Consequences occurring as a results of self-control consist of 1) achievement of the controlled behavior whose purposes were planned ; 2) enhancement of the internal standard such as self-efficacy and learned resourcefulness ; 3) eventual elevation of physical and emotional wellness. Therefore, this concept is defined as a cognitive behavior which is attempted by his or her decision when one is confronted with the conflict situation, which is characterized by being changed by time, learned by effort and individual characteristics. One is taking such behavior with the perception of self as the causative barrier for a certain behavior, planning a specific objective for a certain behavior which demands self sacrifice, supplies the internal reward, is socially desirable with the internal standard of self-efficacy and learned resourcefulness and environmental factors.

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