• Title/Summary/Keyword: long-term integrity

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A Study on the Long-Term Integrity of Polymer Concrete for High Integrity Containers

  • Young Hwan Hwang;Mi-Hyun Lee;Seok-Ju Hwang;Jung-Kwon Son;Cheon-Woo Kim;Suknam Lim
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.21 no.3
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    • pp.411-417
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    • 2023
  • During the operation of a nuclear power plant (NPP), the generation of radioactive waste, including dry active waste (DAW), concentrates, spent resin, and filters, mandates the implementation of appropriate disposal methods to adhere to Korea's waste acceptance criteria (WAC). In this context, this study investigates the potential use of polymer concrete (PC) as a high-integrity container (HIC) material for solidifying and packaging these waste materials. PC is a versatile composite material comprising binding polymers, aggregates, and additives, known for its exceptional strength and chemical stability. A comprehensive analysis of PC's long-term integrity was conducted in this study. First, its compressive strength, which is crucial for ensuring the structural stability of HICs over extended periods, was evaluated. Subsequently, the resilience of PC was tested under various stress conditions, including biological, radiological, thermal, and chemical stressors. The findings of this study indicate that PC exhibits remarkable long-term properties, demonstrating exceptional stability even when subjected to diverse stressors. The results therefore underscore the potential viability of PC as a reliable material for constructing high-integrity containers, thus contributing to the safe and sustainable management of radioactive waste in NPPs.

Durability Characteristics of RC containing Different Chloride Contents based on Long Term Exposure Test and Accelerated Test (장기폭로시험과 촉진시험에 근거한 염화물 함유량에 따른 철근콘크리트의 내구특성)

  • 권성준;송하원;신수철;변근주
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.10a
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    • pp.759-762
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    • 1999
  • The concrete structures possessing good structural integrity can face durability problems due to deteriorations of concrete structures under various environmental conditions. The durability problems weaken the structural integrity in the long run. Especially, the excessive use of sea sand causes serious reinforcement corrosion and carbonation in concrete structures. An accelerated test is often used to predict deterioration as a qualitative measure, but without long term exposure test results or understanding of the relationship between the accelerated test and the long term exposure test, the accelerated test result alone can not be used effectively as a quantitative measure. In this paper, a methodology is proposed to predict the long term deteriorations, based on the result of the short-term accelerated test, of concrete containing different contents of chloride ions. Then, the correlation between two results on the steel corrosion ratio and the carbonation depth is analyzed for concrete with different chloride contents.

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Design for Enhancing the Visibility of Street Cleaners' Light-emitting Uniforms toward Safety and Long-term Usability (안전과 장기적 사용을 고려한 환경미화원 발광형 유니폼의 시인성 향상 디자인)

  • Yujin Oh;Mee Jekal
    • Journal of the Korean Society of Clothing and Textiles
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    • v.48 no.4
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    • pp.808-822
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    • 2024
  • This study aims to develop a smart uniform with embedded luminescence for street cleaners to enhance visibility, safety, and long-term usability, informed by real users' opinions. It employed mixed-methods research comprising three phases: first, a pre-interview to identify existing problems; second, experiments to evaluate the visibility and durability of the technology embedded in smart uniforms during machine washing; and third, a post-survey and observation to assess user satisfaction regarding safety, long-term usability, and aesthetic aspects. Prototypes were developed to evaluate long-term usability and safety based on users' opinions. The findings indicated users desired long-term usage without the need for additional wear and highlighted concerns about the glare from light-emitting devices. The developed prototypes demonstrated long-term usability, remaining functional after more than 25 machine washes without reducing brightness or structural integrity. Regarding participant satisfaction, 83.5% of users were satisfied with the design, both aesthetically and functionally. This study offers a viable approach to developing user-centered designs incorporating light-emitting devices, which enhance visibility and provide aesthetic satisfaction while ensuring long-term usability. The results hold significant implications for future design research focused on vulnerable populations, emphasizing integrated satisfaction in terms of safety and long-term usability.

A Comparative Analysis of Long-Term Preservation Policies in Foreign Electronic Records: NARA, LAC, TNA, NAA, and SFA (국외 전자기록물의 장기보존 정책 비교 분석 - 미국, 캐나다, 영국, 호주, 스위스를 중심으로 -)

  • So, Jeong-Eui;Han, Hui-Jeong;Yang, Dongmin
    • Journal of Korean Society of Archives and Records Management
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    • v.18 no.4
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    • pp.125-148
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    • 2018
  • This study was intended to investigate the long-term preservation policy of electronic records published abroad to derive and compare the policy elements necessary for policy establishment. The U.S., Canada, United Kingdom, Australia, and Switzerland archives were selected, which officially announced the e-Record Preservation Policy. Research and analysis of the long-term preservation policies of the five selected countries resulted in six main policy elements. These six policy elements are preservation scope, long-term preservation strategy, risk management, integrity assurance methods, preservation infrastructure, and reference models. We compared and analyzed five long-term preservation policies through policy elements and found six implications as a result. The implications were focused on establishing a long-term preservation strategy in line with the actual state of the institution and using long-term preservation policies outside of the country as advanced cases for various types of electronic records.

The Effect of Functional Disability on Ego Integrity and Depression among the Elderly in the Residential Care Facility (장기요양시설 노인의 기능장애와 자아통합감, 우울과의 관계)

  • Lee, HyunJi;Nam, HyunJoo
    • 재활복지
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    • v.21 no.3
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    • pp.49-63
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    • 2017
  • The purpose of this study is to investigate the association of functional disability, ego integrity and depressive symptoms, and analyze the mediating effect of ego integrity among the elderly, residing in the long-term care facilities. The data were collected by using non-random purposive and convenient sampling methods and 247 elderly who reside in the nursing home care, located in Daegu city and Kyungpook provinces participated in this study. Findings of this study indicates that there are statistically significant relationships among functional disability, ego integrity and depressive symptoms of participants. In addition, the mediating effect of ego integrity on the relationship between functional disability and depressive symptoms is statistically significant and shows partial mediating effect. Based on the findings of this study, possible practice implications for improving functional and mental health of the elderly in residential care home and recommendation for further study were provided.

A Study on the Standardization of JPEG Format as a Long-Term Preservation Master File for Paper Archives in the Central Archives of Korea (중앙기록물관리기관의 종이기록물 영구보존용 마스터 파일로서 JPEG 포맷의 표준화에 대한 연구)

  • Kang, HyenMin
    • Journal of Korean Library and Information Science Society
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    • v.47 no.4
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    • pp.489-510
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    • 2016
  • It is defined in the internal standard of the NAK namely a NAK/G8-1:2013(v.1.) such as TIFF, PNG, PDF/A, JPEG 2000 as a Long-Term Preservation Master File for internal Standardization of Paper Archives in the Central Archives of Korea. This study reviewed the possibility that JPEG format could be a standard as a Long-Term Preservation Master File for internal Standardization of Paper Archives in the Central Archives of Korea. I pointed to the unique characteristics of JPEG file format and analysed and compared with TIFF format that is a representative master file. Through this study, I suggested that JPEG format also should be additionally included in the standard, as a master file, because it meets a qualification and functional requirements of master file and can guarantee the authenticity, reliability, integrity and usability. The meaning of this study is that JPEG format, be added to master file standard, can set up a environment that has lots of benefit in the domain of usability, compatibility to user as well as the authenticity, reliability, integrity.

Evaluation of Long-term Performance of Metal Seal Through Accelerated Test (가속화 시험을 통한 금속 밀봉재 장기성능 평가)

  • Choi, Woo-seok;Lim, Jongmin;Yang, Yun-young;Cho, Sang Soon
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.18 no.2_spc
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    • pp.237-245
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    • 2020
  • Metal seals are the main components that establish the containment boundary in bolted casks, which store spent nuclear fuel. These seals are degraded by heat and radiation. In addition, creep occurs when the seals are exposed to intense heat for an extended period. This creep results in the stress relaxation of the seals, which consequently impairs the seal integrity. The stress relaxation can reduce the sealing performance of the metal seal, which can further cause leakage in the storage cask. Moreover, the reduction of bolt tension leads to sealing performance degradation. In this study, the results of high-temperature-accelerated tests were obtained to evaluate the containment integrity of metal seals and the decrease in bolt tension. During the tests, the leakage rate, bolt strain, and ambient temperature of the metal seals were measured and analyzed. The metal seals were found to maintain containment integrity for 50 years of storage. The validity of the acceleration test was also investigated.

THINNED PIPE MANAGEMENT PROGRAM OF KOREAN NUCLEAR POWER PLANTS

  • Lee, S.H.;Lee, Y.S.;Park, S.K.;Lee, J.G.
    • Corrosion Science and Technology
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    • v.14 no.1
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    • pp.1-11
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    • 2015
  • Local wall thinning and integrity degradation caused by several mechanisms, such as flow accelerated corrosion (FAC), cavitation, flashing and/or liquid drop impingements, are a main concern in carbon steel piping systems of nuclear power plant in terms of safety and operability. Thinned pipe management program (TPMP) had been developed and optimized to reduce the possibility of unplanned shutdown and/or power reduction due to pipe failure caused by wall thinning in the secondary side piping system. This program also consists of several technical elements such as prediction of wear rate for each component, prioritization of components for inspection, thickness measurement, calculation of actual wear and wear rate for each component. Decision making is associated with replacement or continuous service for thinned pipe components. Establishment of long-term strategy based on diagnosis of plant condition regarding overall wall thinning is also essential part of the program. Prediction models of wall thinning caused by FAC had been established for 24 operating nuclear plants. Long term strategies to manage the thinned pipe component were prepared and applied to each unit, which was reflecting plant specific design, operation, and inspection history, so that the structural integrity of piping system can be maintained. An alternative integrity assessment criterion and a computer program for thinned piping items were developed for the first time in the world, which was directly applicable to the secondary piping system of nuclear power plant. The thinned pipe management program is applied to all domestic nuclear power plants as a standard procedure form so that it contributes to preventing an accident caused by FAC.