• Title/Summary/Keyword: Protection System

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A Safety Assessment Methodology for a Digital Reactor Protection System

  • Lee Dong-Young;Choi Jong-Gyun;Lyou Joon
    • International Journal of Control, Automation, and Systems
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    • v.4 no.1
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    • pp.105-112
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    • 2006
  • The main function of a reactor protection system is to maintain the reactor core integrity and the reactor coolant system pressure boundary. Generally, the reactor protection system adopts the 2-out-of-m redundant architecture to assure a reliable operation. This paper describes the safety assessment of a digital reactor protection system using the fault tree analysis technique. The fault tree technique can be expressed in terms of combinations of the basic event failures such as the random hardware failures, common cause failures, operator errors, and the fault tolerance mechanisms implemented in the reactor protection system. In this paper, a prediction method of the hardware failure rate is suggested for a digital reactor protection system, and applied to the reactor protection system being developed in Korea to identify design weak points from a safety point of view.

A Study on establishing countermeasures to security threats due to the introduction of information protection system. (정보보호시스템도입에 따른 보안위협요소 대응방안수립에 관한 연구)

  • Kyung, ji-hun;Jung, Sung-Jae;Bae, Yu-Mi;Sung, Kyung
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2013.05a
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    • pp.693-696
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    • 2013
  • Information protection system (Information protection system)-based IT environment built popularity in public agencies and businesses take advantage of the resources for the integration of the information system one essential environment began to recognize, cloud systems (Cloud System), cloud security (Cloud Security), big data (Big Data), big data security (Big Data Security), industrial security (Security Industry), as well as the issue. Due to the influence of these information protection system (Information protection system) in response to my external security threats based on the analysis plan. In this paper, data protection systems (Information protection system), resulting in the introduction, there are a number of security threats and particularly industrial security aspects and internal and external security threats in response by lighting about aspects of the plan is based on knowledge.

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Engineering Technology Far-end Telecontrol Cathodic Protection on the Structure of Jetty Bridge Cap Beams

  • Liu, Yi-Hsiung;Lim, Pau-Yee;Shih, Chien-Chis
    • Corrosion Science and Technology
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    • v.2 no.1
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    • pp.47-52
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    • 2003
  • 23 cap beams on the 1 Km length jetty bridge in Shin-da power plant (Taipower co., Taiwan) utilize far-end telecontrol cathodic protection technology which is the first case ever used in Taiwan. The system comprises cathodic protection system and te1econtrol monitoring system. The control and monitoring such as protection current adjustment, protection potential and depolarization measurement of the 23 cap beams can be adjusted through system telecontrol operations. Thereby allows monitoring and control of the 23 anode zones in a convenient and cost effective way. This system is at present still in its best running condition since Sept. 1997 when it was completed. All the 23 cap beams can achieve the 100 mV depolarization potential criteria of protection. It meet the specifications of reinforced concrete cathodic protection standard and proved to be very excellent.

The effect of cathodic protection system by means of zinc sacrificial anode on pier in Korea

  • Jeong, Jin-A;Jin, Chung-Kuk
    • Journal of Advanced Marine Engineering and Technology
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    • v.38 no.10
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    • pp.1206-1211
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    • 2014
  • This study has been conducted to confirm the effect of sacrificial anode cathodic protection system for 90 days to protect corrosion on pier that is located in Korea. The cathodically protected structure was a slab and a pile cap. Before the construction of cathodic protection system, the macrography was carried out. As a result of the macrography, many corrosion traces were confirmed in this structure. The trace was mainly focused on joint and zones that concrete cover was eliminated. To apply the cathodic protection system, many onsite techniques have been adopted. In addition, to confirm the inner state of steel in concrete properly, a corrosion monitoring sensor (DMS-100, Conclinic Co. Ltd) has been applied. Test factors were corrosion & cathodic protection potential, 4 hour depolarization potential, resistivity and current density. After 90 days from the installation of cathodic protection system, it could confirm that proper corrosion protection effect was obtained by considering the result of tests.

Protection Level Evaluation of Distribution Systems Based on Dempster-Shafer Theory of Evidence (Dempster-Shafer 증거 이론을 이용한 배전계통 보호도 평가)

  • Kim, He-Chul;Lee, Seung-Jae;Kang, Sang-Hee;Ahn, Bok-Shin;Park, Jong-Kuk
    • Proceedings of the KIEE Conference
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    • 1998.07c
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    • pp.896-898
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    • 1998
  • Recent development of the digital computer and communication technology has made the concept of the adaptive protection possible, which is to adapt the operating parameters of the protective devices to the system changes, so that the best protection function can be maintained all the time. In order to achieve the adaptive protection, it is necessary to have the way to determine whether the change of the settings is needed under the certain system change or how good the current protection level is. This paper proposed the protectability index, which is a way to evaluate the protection level of the system under arbitary conditions and the operating strategy of the adaptive protection utilizing this index. It is based on an hierachical evaluation model and the evidence combination rule of the Dempster-Shafer theory.

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The Advanced Protection Coordination Scheme using Phase Angle of Zero-Sequence Current in Ungrounded System (비접지 계통에서 영상전류 위상을 이용한 개선된 보호협조 방안)

  • Choi, Young-Jun;Lim, Hee-Taek;Choi, Myeon-Song;Lee, Seung-Jae
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.59 no.1
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    • pp.19-25
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    • 2010
  • Most faults are single-phase-to-ground fault in ungrounded system. The fault currents of single-phase-to-ground are much smaller than detection thresholds of measurement devices, so detecting single-phase-to-ground faults is difficult and important in ungrounded system. The protection coordination method using SGR(Selective Ground Relay) and OVGR(Overvoltage Ground Relay) is generally used in ungrounded system. But this method only detects fault line and it has the possibility of malfunction. This paper proposed to advanced protection coordination method in ungrounded system. The method just using zero-sequence current can detect fault line, fault phase, fault section at terminal device. The general protection method is used to back up protection. In the case study, the proposed method has been testified in demo system by Matlab/Simulink simulations.

REAL-TIME PERSONAL DOSE MEASUREMENT AND MANAGEMENT SYSTEM RESEARCH IN CHINA

  • Zhang, Z.Y.;Cheng, C.;Liu, Z.S.;Yang, H.T.;Deng, C.M.;Zhang, X.;Guo, Z.J.
    • Journal of Radiation Protection and Research
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    • v.26 no.3
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    • pp.281-286
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    • 2001
  • The composition and design of a real-time personal dose measurement and management system are described in this paper. Accordingly, some pertinent hardware circuits and software codes including their operation modes have also been presented.

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Critical Design Issues on the Cathodic Protection Systems of Ships

  • Lee, Ho Il;Lee, Chul Hwan;Jung, Mong Kyu;Baek, Kwang Ki
    • Corrosion Science and Technology
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    • v.6 no.3
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    • pp.90-95
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    • 2007
  • Cathodic protection technology has been widely used on ship's outer hull and inner side of ballast water tanks as a supplementary corrosion protection measure in combination with protective organic coatings. Impressed current cathodic protection system is typically opted for the ship's hull and, sacrificial anode system, for ballast water tanks. The anticipation and interest in cathodic protection system for ships has been surprisingly low-eyed to date in comparison with protective coatings. Computational analysis for the verification of cathodic protection design has been tried sometimes for offshore marine structures, however, in commercial shipbuilding section, decades old design practice is still applied, and no systematic or analytical verification work has been done for that. In this respect, over-rotection from un-erified initial design protocol has been also concerned by several experts. Especially, it was frequently reported in sacrificial anode system that even after full design life time, anode was remaining nearly intact. Another issue for impressed current system, for example, is that the anode shield area design for ship's outer hull should be compromised with actual application situation, because the state-of-the-art design equation is quite impractical from the applicator's stand. Besides that, in this study, some other critical design issues for sacrificial anode and impressed current cathodic protection system were discussed.

The ICRP and Its System of Radiological Protection (국제방사선방호위원회와 방사선방호체계)

  • Kun-Woo Cho
    • Journal of Environmental Health Sciences
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    • v.50 no.1
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    • pp.1-5
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    • 2024
  • International Commission on Radiological Protection (ICRP) is an independent international organization that advances the science of radiological protection for the public benefit, particularly by providing recommendations and guidance on all aspects of protection against ionizing radiation. The ICRP is a community of more than 380 globally-recognized experts in radiological protection science, policy, and practice from more than 50 countries. As of January 2024, the ICRP is comprised of a Main Commission, the Scientific Secretariat, four Standing Committees, and 30 Task Groups under the four committees. The ICRP has released well over one hundred publications on all aspects of radiological protection. Most address a particular area within radiological protection, but a handful of the publications, the so-called fundamental recommendations, describe the overall system of radiological protection. The system for radiological protection is based on the current understanding of the science of radiation exposure and its effects along with value judgements. The ICRP offers recommendations to regulatory and advisory agencies and provides advice to management and professional staff with responsibilities for radiological protection. Legislation in most countries adheres closely to ICRP recommendations. The International Atomic Energy Agency's (IAEA) International Basic Safety Standards are based heavily on ICRP recommendations. ICRP recommendations form the core of radiological protection standards, legislation, programs, and practice worldwide.

A Study on Corrosion of Sprinklers System Fire Protection (스프링클러 소방설비의 부식에 관한 연구)

  • Kim, Dong-Jun;Ko, Heung;NamKung, Seung-Tae
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 2008.11a
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    • pp.41-48
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    • 2008
  • We studied on corrosion of sprinklers system fire protection, a cause on corrosion of fire installations and a source of the problem. We investigated the influence of fluid mechanics on the corrosion shape of sprinklers system fire protection installations. And we known a problem of early fire extinguishing in fire protection with corrosion.

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