• Title, Summary, Keyword: Integrity

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Structural Integrity and Safety Margin Evaluation for Thinned Pipe Component (감육배관의 구조건전성 및 안전여유도 평가 기술)

  • Lee, Sung-Ho;Kim, Tae-Ryong;Kim, Bum-Nyun
    • Proceedings of the KSME Conference
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    • pp.264-267
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    • 2004
  • Wall thinning of carbon steel pipe components due to Flow-Accelerated Corrosion (FAC) is one of the most serious threats to the integrity of steam cycle piping systems in Nuclear Power Plants (NPP). Since the mid-1990s, secondary side piping systems in Korean NPPs have experienced wall thinning, leakages and ruptures caused by FAC. Korea Electric power Research Institute (KEPRI) and Korea Hydro & Nuclear Power Co., LTD. (KHNP) have conducted a study to develop the methodology for systematic pipe management and established the Korean Thinned Pipe Management Program (TPMP). To effectively maintain the integrity of piping system, FAC engineer should understand the criterions of the structural integrity evaluation and the safety margin assessment for the thinned pipe component. This paper describes the technical items of TPMP, and shows the example of the integrity evaluation and safety margin assessment for three thinned pipe component of a NPP.

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Development of Fitness for Service Evaluation Programs (기간설비 사용적합성 평가 프로그램 개발)

  • Park, Young-Jae;Yun, Kang-Ok;Chang, Yoon-Suk;Kim, Young-Jin;Cho, Kyung-Shik
    • Proceedings of the KSME Conference
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    • pp.160-165
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    • 2004
  • An effective integrity evaluation system is essential to manage the fitness for service issues on infra-structure because the evaluation processes usually take long times and are detrimental for productivity point of view. In this paper, the key structures and procedures of four integrity evaluation programs which have been developed based on currently available codes and standards are described. The proposed programs are not only flexible to adopt advances in fitness for purpose type assessment methodologies but also convenient for field engineers. The developed programs which will be unified as an integrity evaluation system are expected to play a prominent role for integrity evaluation of major infra-structure.

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Maintaining Integrity Constraints in Spatiotemporal Databases

  • Moon Kyung Do;Woo SungKu;Kim ByungCheol;Ryu KeunHo
    • Proceedings of the KSRS Conference
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    • pp.726-729
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    • 2004
  • Spatiotemporal phenomena are ubiquitous aspects of real world. In the spatial and temporal databases, integrity constraints maintain the semantics of specific application domain and relationship between domains when proceed update in the database. Efficient maintenance of data integrity has become a critical problem, since testing the validity of a large number of constraints in a large database and after each transaction is an expensive task. Especially, in spatiotemporal domain, data is more complex than traditional domains and very active. Additionally, it is not considered that unified frameworks deal with both spatial and temporal properties to handle integrity constraints. Therefore, there need a model to maintain integrity constraints in the unified frameworks and enforcement and management techniques in order to preserve consistence.

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The Influences of Loss Experiences and Depression on Ego-integrity and Transcendence of Elderly Korean Men and Women (남녀노인의 상실경험과 우울이 자아통합감과 초월에 미치는 영향)

  • An, Jeong-Shin;Park, Gyu-Ri
    • The Korean Journal of Community Living Science
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    • v.27 no.3
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    • pp.405-418
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    • 2016
  • This study was conducted to explore the influences of loss experiences and depression on ego-integraty and transcendence of elderly Koreans and to identify gender differences in the relationships among loss experiences, depression, ego-integrity, and transcendence from 146 men and 194 women aged over 60 years in Busan, Gyeong-Nam, and Gyeong-Buk area. The main results were as follows: elderly men reported more loss experiences and transcendence than elderly women. Next, loss experiences influenced ego-integrity and depression mediated the relationship between loss experiences and ego-integrity. Also, ego-integrity had a direct effect on transcendence. Last, depression of elderly men fully mediated the relationship between loss experiences and transcendence. The relationship between loss experiences and ego-integration was partially mediated by depression for elderly women. These results were discussed in terms of gero-education and elderly welfare.

A Study on the Precautions Effects of the Enclosure Integrity Test for the Gaseous Extinguishing Systems: Focusing on the Power Plant (가스계 소화설비의 밀폐도 시험에 영향을 미치는 사전조치에 관한 연구: 발전소를 중심으로)

  • Kim, Young-Chul;Jo, Il-Hyun;Lee, Su-Kyung
    • Fire Science and Engineering
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    • v.29 no.1
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    • pp.60-66
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    • 2015
  • The present study was aimed to analyze enclosure integrity test, which is the performance experiment of soaking time, in a fire zone equipped with gaseous extinguishing system in an effort to find understand the effect of precaution factors upon the success of fire extinguishment. To achieve the goal of this study, it divided the fire zones of internal and external power plants into ones taking precaution measures and not taking them and then enclosure integrity test was given respectively. Therefore, this study examined the success rate if the test according to the presence and absence of the precaution measure and confirmed the failure factors, designed concentration soaking time and proportion of leakage area to total volume area by type of gaseous extinguishing system and rooms. Precaution measures were applied to the fire zones without them to confirm the increase of the success rate of enclosure integrity test. By doing so, it was found that reduced number of experiments caused by failure led to cost saving.

Development of Integrity Evaluation System for CANDU Pressure Tube (CANDU 압력관에 대한 건전성 평가 시스템 개발)

  • Kwak, Sang-Log;Lee, Joon-Seong;Kim, Young-Jin;Park, Youn-Won
    • Proceedings of the KSME Conference
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    • pp.843-848
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    • 2000
  • The pressure tube is a major component of the CANDU reactor, which supports nuclear fuel bundle and it's containment vessel. If a flaw is found during the periodic inspection from the pressure tubes, the integrity evaluation must be carried out, and the safety requirements must be satisfied for continued service. In order to complete the integrity evaluation, complicated and iterative calculation procedures are required. Besides, a lot of data and knowledge for the evaluation are required for the entire integrity evaluation process. For this reason, an integrity evaluation system, which provides efficient way of evaluation with the help of attached databases, was developed. The developed system was built on the basis of ASME Sec. XI and FFSG(Fitness For Service Guidelines for zirconium alloy pressure tubes in operating CANDU reactors) issued by the AECL, and covers the delayed hydride cracking(DHC). Various analysis methods are provided for the integrity evaluation of pressure tube. In order to verify the developed system, several case studies have been performed and the results were compared with those from AECL. A good agreement was observed between those two results.

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Development of Nuclear Piping Integrity Expert System(I) - Evaluation Method RecomMendation and Material Properties Inference - (원자력배관 건전성평가 전문가시스템 개발(1) - 평가법 제시 및 재료물성치 추론 -)

  • Kim, Yeong-Jin;Seok, Chang-Seong;Choe, Yeong-Hwan
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.20 no.2
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    • pp.575-584
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    • 1996
  • The objective of this paper is to develop an expert system for nuclear piping integrity. This paper describes the selection methodology of integrity evalution method and the inference of material properties. To select the integrity evaluation method, the weight factor for respective material properties was obtained by the sensitivity analysis of the effect of material properties on integrity evaluation method. Subsequently the possession ratio for respective integrity evaluation method was computed, and the most appropriate integrity evaluation method for given input information is selected. In the material properties inference, stress-strain curves and J-R curves were predicted from tensile properties such as yield strength and tensile strength.

Estimation of Fatigue Integrity for Small Aircraft Engine Mount Strut (소형 항공기 엔진 마운트 구조물의 피로 건전성 평가)

  • Lee, Mu-Hyoung;Park, Ill-Kyoung;Kim, Sung-Joon;Ahn, Seok-Min
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.19 no.4
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    • pp.58-66
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    • 2011
  • The estimation of fatigue integrity is very important for aerospace structures such as engine mount strut. The reason is that the fatigue integrity is essential analysis process to establish the structural stability in aerospace field. Therefore, in this paper, the process of fatigue analysis and test was performed for engine mount strut to prove the structural fatigue integrity. First of all, the fatigue load spectrum is constructed by considering the small aircraft operating condition. Fatigue analysis is done for the cluster near the welding zone which may have F.C.L.(fracture critical location). The fatigue life of engine mount strut was estimated by the Miner's rule which is the damage summation method. Finally, Fatigue test is performed to verify the fatigue integrity. The estimation process of fatigue integrity for engine mount strut of small aircraft may help the design.