• Title/Summary/Keyword: Emergency Diesel Generator(EDG)

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A Study on the Analysis of Failures Related to Emergency Diesel Generators in Overseas Nuclear Power Plants (원전용 비상디젤발전기 국외 손상사례 분석에 관한 연구)

  • Chang, Jung-Hwan;Kim, Jin-Sung;Chung, Hae-Dong;Cho, Kwon-Hae
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.5 no.1
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    • pp.32-37
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    • 2009
  • The emergency diesel generator (EDG) in a nuclear power plant (NPP) shall start within 10 secondss and supply electrical power to engineered safety features within one minute and less if a loss of offsite power (LOOP), A design-basis event, or their combination occur. Each NPP has an EDG set consisting of two diesel generators for redundancy. In addition to the EDG set, an alternate Alternating Current Diesel Generator (AAC DG) is installed and shared by several units to cope with a station black out (SBO), i.e., loss of the offsite power concurrent with reactor trip and unavailability of the EDG set. The objective of this study is to analyze the failure data of emergency diesel generators reported in overseas nuclear power plants.

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Seismic Risk Evaluation of Isolated Emergency Diesel Generator System (면진된 비상디젤발전기의 지진위험도 평가)

  • Kim, Min-Kyu;Ohtori, Yasuki;Choun, Young-Sun
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2007.04a
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    • pp.217-222
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    • 2007
  • An Emergency Diesel Generator (EDG) is one of the safety related equipments of a Nuclear Power Plant. The seismic capacity of an EDG in nuclear power plants influences the seismic safety of the plants significantly. A recent study showed that the increase of the seismic capacity of the EDG could reduce the core damage frequency (CDF) remarkably. It is known that the major failure mode of the EDG is a concrete coning failure due to a pulling out of the anchor bolts. The use of base isolators instead of anchor bolts can increase the seismic capacity of the EDG without any major problems. This study introduces a seismic risk analysis method and presents sample results about the seismically isolated and conventional EDG system.

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A Study on the Development of EDG Engine Condition Diagnosis Program in Power Plant (발전용 비상디젤발전기 엔진 상태진단 프로그램 개발 연구)

  • Lee, Sang-Guk;Kim, Dae-Woong
    • Journal of Power System Engineering
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    • v.19 no.5
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    • pp.67-72
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    • 2015
  • The reliable operation of onsite emergency diesel generator(EDG) should be ensured by a conditioning monitoring system designed to maintain, monitor and forecast the reliability level of diesel generator. The purpose of this paper is to develop condition diagnosis algorithm(logic) and analysis program of engine for the accurate diagnosis in actual condition of emergency diesel generator engine. As a result of this study, we confirmed that developed engine condition diagnosis algorithm and analysis program could be efficiently applied for actual EDG engine in nuclear power plant.

A PERFORMANCE ASSESSMENT OF A BASE ISOLATION SYSTEM FOR AN EMERGENCY DIESEL GENERATOR IN A NUCLEAR POWER PLANT

  • Choun, Young-Sun;Kim, Min-Kyu
    • Nuclear Engineering and Technology
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    • v.40 no.4
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    • pp.285-298
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    • 2008
  • This study evaluates the performance of a coil spring-viscous damper system for the vibration and seismic isolation of an Emergency Diesel Generator (EDG) by measuring its operational vibration and seismic responses. The vibration performance of a coil spring-viscous damper system was evaluated by the vibration measurements for an identical EDG set with different base systems - one with an anchor bolt system and the other with a coil spring-viscous damper system. The seismic performance of the coil spring-viscous damper system was evaluated by seismic tests with a scaled model of a base-isolated EDG on a shaking table. The effects of EDG base isolation on the fragility curve and core damage frequency in a nuclear power plant were also investigated through a case study.

Development of Ultrasonic Sensor for Engine Condition Diagnosis of EDG (비상디젤발전기 엔진 상태진단 초음파 탐촉자 개발)

  • Lee, Sang-Guk;Choi, Kwang-Hee
    • Journal of Power System Engineering
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    • v.17 no.4
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    • pp.31-35
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    • 2013
  • The emergency AC power supply system of the nuclear power plant is designed to supply the power to the nuclear power plant at the emergency operating condition. The safety function of the diesel generator at the nuclear power plant is to supply AC electric power to the safety system whenever the preferred AC power supply is unavailable. The reliable operation of onsite standby diesel generator should be ensured by a condition monitoring system designed to maintain, monitor and forecast the reliability level of diesel generator. The purpose of this paper is to improve the existing ultrasonic sensor used for condition diagnosis of engine fuel pump and cylinder head for the accurate diagnosis in actual engine condition of emergency diesel generator(EDG). As a result of this study, we could design and develop much more reliable ultrasonic sensor than existing ones.

Operating Vibration Reduction Effect Evaluation of EDG at the NPP Site (원자력발전소 비상디젤발전기의 가동중 진동저감 효과)

  • Kim, Min-Kyu;Choun, Young-Sun
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2006.11a
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    • pp.111-118
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    • 2006
  • The Emergency Diesel Generator(EDG) is a very important piece of equipment for the safety of a Nuclear Power Plant(NPP). In this study, the operating vibration or three kinds or EDG system was measured. The target EDG systems art Yonggwang 5 unit, Ulchin 2 unit and Ulchin 3 unit. The Yonggwang 5 and Ulchin 3 unit EDG system is the same type but the foundation systems are different. One is an anchor bolt type and the other is a spring and viscous-damper type. The purpose of this measurement is for a verification of the vibration isolation effect according to the foundation system. As a result. it can he said that the spring and viscous damper system of the EDG performed well for the vibration isolation.

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Safety Assessment for Emergency Diesel Generator(EDG) Allowed Outage Time(AOT) Extension using Risk-informed (리스크정보를 활용한 비상디젤발전기 허용정지시간 연장시 안전성평가)

  • Lim, Hyuk-Soon;Kim, Doo-Hyun
    • Journal of the Korean Society of Safety
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    • v.25 no.3
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    • pp.118-122
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    • 2010
  • In order to provide the necessary operation flexibility during the Nuclear power operation, the extension of existing allowed outage time(AOT) is needed. The extension of AOT affects the Nuclear power plant safety. The validity of changed technical specification requirements should be proved by the safety assessments. In this paper, we evaluated the extension of emergency diesel generator AOT for a single inoperable emergency diesel generator(EDG) from 3days to 7days, 10days and 14days. Finally, the AOT extension contributes the NPP performances through decreasing the unexpected plant trips, reinforcing maintenance and avoiding risks due to unnecessary operation mode changes when the NPP is under the surveillance tests or maintenance.

Application Study of Condition Monitoring Technology for Emergency Diesel Generator at Nuclear Power Plant (원자력발전소 비상디젤발전기 상태감시 기술 적용 연구)

  • Choi, K.H.;Park, J.H.;Park, J.E.;Lee, S.G.
    • Journal of Power System Engineering
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    • v.13 no.1
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    • pp.53-58
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    • 2009
  • The emergency diesel generator(EDG) of the nuclear power plant is designed to supply the power to the nuclear reactor on Station Black Out(SBO) condition. The operation reliability of onsite emergency diesel generator should be ensured by a conditioning monitoring system designed to monitor and analysis the condition of diesel generator. For this purpose, we have developing the technologies of condition monitoring for the wolsong unit 3&4 standby diesel generator including diesel engine performance. In this paper, technologies of condition monitoring for the wolsong standby diesel generator are described about three step. First is for selection of operating parameter for monitoring. Second is for technologies of online condition monitoring, Third is for monitoring of engine performance.

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Retrofit of Safety Class 1E Emergency Diesel Generator in Nuclear Power Plant (원자력발전소 안전 등급 1E 비상디젤발전기 리트로피트 (Retrofit))

  • Kim, Chul-Hyo;Chang, Choong-Koo
    • Proceedings of the KIEE Conference
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    • 2015.07a
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    • pp.689-690
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    • 2015
  • 국내 최초 원전인 고리1호기는 지난 2007년 30년의 운전수명을 마친 뒤 정부의 안전점검을 거쳐 10년간 연장운전에 들어갔다. 이 과정에서 원전의 비상 전원 계통 신뢰성 확보를 위해 설계수명을 초과한 35년 된 노후 비상디젤발전기(Emergency Diesel Generator, 이하 EDG)를 지난 2013년 4월부터 9월까지 약 6개월에 걸쳐 교체하게 되었으며, 국내 원전 EDG 총 42대 중 18대가 20년 넘게 운영되고 있고, 2025년까지 고리 1호기를 후속으로 월성1호기, 고리2호기, 고리3호기, 고리4호기, 한빛1호기 순으로 40년 승인된 운전 인허가 기간이 만료된다.[1]. 본 연구에서, Class 1E EDG 교체 시 신규 EDG 설계기준, 용량결정, 해석 및 평가에 대한 기술적 방법들을 고리1호기의 사례를 통해 고찰하였다.

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The Proposal for Reliability Improvement of Emergency Diesel Engines through the Evaluation of the Maintenance Program and Overseas Cases for their Applications (정비프로그램 평가 및 해외사례 분석을 통한 비상디젤엔진의 신뢰성 향상방안)

  • Cho, K.H.;Jeong, H.J.;Ahn, S.K.
    • Journal of Power System Engineering
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    • v.8 no.2
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    • pp.5-11
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    • 2004
  • The failure frequency of the Emergency Diesel Generator(EDG) at Nuclear Power Plants(NPPs) is not so much lower than that of the Marine engines, whereas the running hours of the diesel engine at NPPs is much less than those of the engines for commercial service. The primary factor results from the severe surveillance test requirements such as fast start, large number of starting test, fast load-run, high load running, etc. The other factor comes from the excessive maintenance based on the engine maker's instruction manual that did not incorporate the peculiar characteristics of the diesel engines at NPPs. In this paper, the present preventive maintenance program on the basis of the Pielstick diesel engines was reviewed for the purpose of securing the reliability of the emergency diesel generator at NPPs and the ways for its improvement were presented by referring to the overseas cases for their applications.

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