• 제목/요약/키워드: accident scenario

검색결과 304건 처리시간 0.026초

Analysis of severe accident progression and Cs behavior for SBO event during mid-loop operation of OPR1000 using MELCOR

  • Park, Yerim;Shin, Hoyoung;Kim, Seungwoo;Jin, Youngho;Kim, Dong Ha;Jae, Moosung
    • Nuclear Engineering and Technology
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    • 제53권9호
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    • pp.2859-2865
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    • 2021
  • One of the important issues raised from the Fukushima-Daiichi accident is the safety of multi-unit sites when simultaneous accidents occur at the site and recently a multi-unit PSA methodology is being developed worldwide. Since all operation modes of the plant should be considered in the multi-unit PSA, the accident analysis needs to be performed for shutdown operation modes, too. In this study, a station blackout during the mid-loop operation is selected as a reference scenario. The overall accident progression for the mid-loop operation is slower than that for the full-power operation because the residual heat per mass of coolant is about 6 times lower than that in the mid-loop scenario. Though the fractions of Cs released from the core to the RCS in both operation modes are almost the same, the amount of Cs delivered to the containment atmosphere is quite different due to the chemisorption in the RCS. While 45.5% of the initial inventory is chemisorbed on the RCS surfaces during the full-power operation, only 2.2% during the mid-loop operation. The containment remains intact during the mid-loop operation, though 83.9% of Cs is delivered to the containment.

Evaluation of radiological safety according to accident scenarios for commercialization of spent resin mixture treatment device

  • Choi, Woo Nyun;Byun, Jaehoon;Kim, Hee Reyoung
    • Nuclear Engineering and Technology
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    • 제54권7호
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    • pp.2606-2613
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    • 2022
  • Spent resin often exceeds radiation limits for safe disposal, creating a need for commercial-scale treatment techniques to reduce resin radioactivity. In this study, the radiological safety of a commercialized spent resin treatment device with a treatment capacity of 1 ton/day was evaluated. The results confirm that the device is radiologically safe in the event of an accident. This device desorbs 14C from the spent resin, allowing disposal as low-level waste instead of intermediate-level waste. The device also reduces overall waste by recycling the extracted 14C. Potential accident scenarios were explored to enable dose assessments for both internal and external exposure while preventing further spillage of the device and processing the spilled resin. The scenarios involved the development of a surface fracture on the resin mixture separator and microwave systems, which were operated under pressure and temperature of 0-6 bar and 0-150 ℃, respectively. In the case of accidents with separator and microwave device, the maximum allowable working time of worker were derived, respectively, considering external and internal exposures. When wearing the respirator corresponding to APF 50, in the case of the microwave device accident scenario, the radiological safety was confirmed when the maximum worker worked within 132.1 h.

Therblig 기법을 활용한 철도비상대응직원의 적정 비상대응조치 시간 도출 방안 (A Method on a Proper Time Evaluation for Railway Emergency Response Staffs using the Therblig Analysis)

  • 박민규;김시곤;심영록
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2007년도 추계학술대회 논문집
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    • pp.689-695
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    • 2007
  • This Paper introduced a proper time evaluation for railway emergency response staffs using the Therblig Analysis. We defines what Activities the emergency response staffs should take when the fire occurs on the railway. This has been possible through the development of the scenario that is focused on the fire accident and it also has been driven to minimize the spread and damage of the accident. Gilbreth's Therblig Analysis has been used here to derive the reasonable time that would take for the emergency response staffs to respond to the fire accident on the railway system. We developed Emergency Response Scenario against Accidents and defined the Activity of the main Action for Emergency Response staffs.

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한국형 고속전철 동력차 최종설계의 충돌안전도 평가 연구 (An Evaluation of Crashworthiness for the final design of the KHST power-car)

  • 노규석;구정서
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2002년도 추계학술대회 논문집(I)
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    • pp.38-46
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    • 2002
  • This paper evaluates crashworthiness of KHST carbodies under the SNCF accident scenario (collision against a movable rigid mass of 15 tons at 110 kph) and the scenario of train-to-train collision at 30 kph. The numerical results show that the final design of the KHST power-car doesn't have a good response on crashworthiness. So an improved design has been suggested for it. The improved design has shown good performances in the viewpoint of energy absorption and survival space at several numerical simulations, such as the accident collided against a deformable dump truck of 15 tons at 110 kph, the driver's dummy analysis, and the accident of train-to-train collision for the first three units at 30 kph.

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COMPARATIVE ANALYSIS OF STATION BLACKOUT ACCIDENT PROGRESSION IN TYPICAL PWR, BWR, AND PHWR

  • Park, Soo-Yong;Ahn, Kwang-Il
    • Nuclear Engineering and Technology
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    • 제44권3호
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    • pp.311-322
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    • 2012
  • Since the crisis at the Fukushima plants, severe accident progression during a station blackout accident in nuclear power plants is recognized as a very important area for accident management and emergency planning. The purpose of this study is to investigate the comparative characteristics of anticipated severe accident progression among the three typical types of nuclear reactors. A station blackout scenario, where all off-site power is lost and the diesel generators fail, is simulated as an initiating event of a severe accident sequence. In this study a comparative analysis was performed for typical pressurized water reactor (PWR), boiling water reactor (BWR), and pressurized heavy water reactor (PHWR). The study includes the summarization of design differences that would impact severe accident progressions, thermal hydraulic/severe accident phenomenological analysis during a station blackout initiated-severe accident; and an investigation of the core damage process, both within the reactor vessel before it fails and in the containment afterwards, and the resultant impact on the containment.

Smart support system for diagnosing severe accidents in nuclear power plants

  • Yoo, Kwae Hwan;Back, Ju Hyun;Na, Man Gyun;Hur, Seop;Kim, Hyeonmin
    • Nuclear Engineering and Technology
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    • 제50권4호
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    • pp.562-569
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    • 2018
  • Recently, human errors have very rarely occurred during power generation at nuclear power plants. For this reason, many countries are conducting research on smart support systems of nuclear power plants. Smart support systems can help with operator decisions in severe accident occurrences. In this study, a smart support system was developed by integrating accident prediction functions from previous research and enhancing their prediction capability. Through this system, operators can predict accident scenarios, accident locations, and accident information in advance. In addition, it is possible to decide on the integrity of instruments and predict the life of instruments. The data were obtained using Modular Accident Analysis Program code to simulate severe accident scenarios for the Optimized Power Reactor 1000. The prediction of the accident scenario, accident location, and accident information was conducted using artificial intelligence methods.

국내 실사고 기반 자율주행차 교차로 사고 시뮬레이션 (Intersections Accident Simulation of Automated Vehicles based on Actual Accident Database)

  • 신윤식;박요한;신재곤;정재일
    • 자동차안전학회지
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    • 제13권4호
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    • pp.106-113
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    • 2021
  • In this study, The behavior of an autonomous vehicle in an intersection accident situation is predicted. Based on a representative intersection accident situation from actual intersection accident database, simulation was performed by applying the automatic emergency braking algorithm used in the autonomous driving system. Accident reconstruction was performed based on the accident report of the representative accident situation. After applying the autonomous driving system to the accident-related vehicle, the tendency of intersection accidents that may occur in autonomous vehicles was identified and analyzed.

전로사고 예방을 위한 인적오류 분석 (A Case Study on the Human Error Analysis for the Prevention of Converter Furnace Accidents)

  • 신운철;권준혁;박재희
    • 대한안전경영과학회지
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    • 제16권3호
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    • pp.195-200
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    • 2014
  • Occupational fatal injury rate per 10,000 population of Korea is still higher among the OECD member countries. To prevent fatal injuries, the causes of accidents including human error should be analyzed and then appropriate countermeasures should be established. There was an severe converter furnace accident resulting in five people death by chocking in 2013. Although the accident type of the furnace accident was suffocation, many safety problems were included before reaching the death of suffocation. If the safety problems are reviewed throughly, the alternative measures based on the review would be very useful in preventing similar accidents. In this study, we investigated the converter furnace accident by using human error analysis and accident scenario analysis. As a result, it was found that the accident was caused by some human errors, inappropriate task sequence and lack of control in coordinating work by several subordinating companies. From the review of this case, the followings are suggested: First, systematic human error analysis should be included in the investigation of fatal injury accidents. Second, multi man-machine accident scenario analyis is useful in most of coordinating work. Third, the more provision of information on system state will lessen human errors. Fourth, the coordinating control in safety should be performed in the work conducting by several different companies.

A Systems Engineering Approach for Uncertainty Analysis of a Station Blackout Scenario

  • de Sousa, J. Ricardo Tavares;Diab, Aya
    • 시스템엔지니어링학술지
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    • 제15권1호
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    • pp.51-59
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    • 2019
  • After Fukushima Dai-ichi NPP accident, the need for implementation of diverse and flexible coping strategies (FLEX) became evident. However, to ensure the effectiveness of the safety strategy, it is essential to quantify the uncertainties associated with the station blackout (SBO) scenario as well as the operator actions. In this paper, a systems engineering approach for uncertainty analysis (UA) of a SBO scenario in advanced pressurized water reactor is performed. MARS-KS is used as a best estimate thermal-hydraulic code and is loosely-coupled with Dakota software which is employed to develop the uncertainty quantification framework. Furthermore, the systems engineering approach is adopted to identify the requirements, functions and physical architecture, and to develop the verification and validation plan. For the preliminary analysis, 13 uncertainty parameters are propagated through the model to evaluate the stability and convergence of the framework. The developed framework will ultimately be used to quantify the aleatory and epistemic uncertainties associated with an extended SBO accident scenario and assess the coping capability of APR1400 and the effectiveness of the implemented FLEX strategies.

재난·안전 사고 대응 시나리오 모바일 앱 서비스 (Mobile App Service of Disaster and Safety Accident Response Scenario)

  • 김기환;송준혁;정덕길
    • 한국정보통신학회:학술대회논문집
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    • 한국정보통신학회 2018년도 춘계학술대회
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    • pp.254-257
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    • 2018
  • 이 논문에서는 재난 안전사고의 증가에 따른 인명 피해, 안전의식 저조 등을 방지하기 위해 스마트폰을 통해 쉽게 접할 수 있는 재난 안전사고에 대응하는 시나리오를 구현하는 모바일 어플리케이션을 구현한다. 기존의 사고 대응 시나리오와 관련한 모바일 어플리케이션들은 수가 적으며, 대부분 매뉴얼 형식으로 구성되어 있다. 따라서 이 논문에서는 지진이나 쓰나미와 같은 재난이나 일상에서 발생 가능한 안전사고 등의 다양한 시나리오들을 친근한 캐릭터들이 등장하는 진행하는 모바일 어플리케이션을 구현한다. 이 어플리케이션은 캐릭터를 통한 행동 선택지 형식으로 구성하여 연령대에 구애받지 않고 이용할 수 있으며, 명확한 대응방안을 제공함으로써 만일의 사고 상황에 올바른 대응할 수 있도록 한다.

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