• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.658-661
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• 1996

Information that can be obtained from nuclear power plant trip cases is important for the efforts to reduce the trip occurrences. However, trip case reports, generally printed in documents, have shortcomings in using the contents. A database system called Information System of Trip Event Cases (INSTEC) is being developed to improve the use of trip information. INSTEC will provide the information obtained from the analysis of Korean nuclear power plant trips, such as component failures or human errors that induced the trips, problems contributed to the trips, and the sequence of unit events. In this study, in the process of INSTEC development, information analysis has been performed and a prototype of the system was developed. The prototype of INSTEC with user interface was presented to plant personnel to collect their opinion on INSTEC by using a questioninnaire. As results, it is confirmed that INSTEC would be helpful and useful for plant personnel to review the trip case information.

• Proceedings of the KSME Conference
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• 2001.11b
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• pp.885-890
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• 2001

This simulation shows turbine trip on range mode, combined operation of 4 boilers and 5 turbines, for shoaiba desalination plant which is being operated in Saudi Arabia. In this model, unit master controller controls load demand, fuel and air flowrate to be consumed during operating of the plant. Feedwater controller controls drum level to compensate feedwater with superheater steam flow. This analysis was performed by constructing a dynamic model of the plant using ProTRAX and running it through the appropriate.

• Journal of Drive and Control
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• v.8 no.3
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• pp.44-47
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• 2011

• Journal of the Ergonomics Society of Korea
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• v.15 no.1
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• pp.27-38
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• 1996

A total of 77 unanticipated trip cases induced by human errors in Korean nuclear power plants were collected from the nuclear power plant trip event reports and analyzed to investigate the areas of high priority for human error reduction. Prior to this analysis, a classification system was made on the four task-related categories including plant systems, work situations, task types, and error types. The erroneous actions affecting the unanticipated plant trips were indentified by reviewing carefully the description of trip events. Then, the events with erroneous action were analyzed by using the classification system. Based on the results for the individual cases, human error occurrences were counted for each of the four categories, also for the selected pairs of categories, to find out the relationships between the two categories in aspects of human errors. As a result, the plant systems, work situations, and task types, and error types which are dominant in human error occurrences were identified.

• Nuclear Engineering and Technology
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• v.48 no.4
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• pp.1047-1057
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• 2016

Design engineering process for field programmable gate array (FPGA)-based reactor trip functions are developed in this work. The process discussed in this work is based on the systems engineering approach. The overall design process is effectively implemented by combining with design and implementation processes. It transforms its overall development process from traditional V-model to Y-model. This approach gives the benefit of concurrent engineering of design work with software implementation. As a result, it reduces development time and effort. The design engineering process consisted of five activities, which are performed and discussed: needs/systems analysis; requirement analysis; functional analysis; design synthesis; and design verification and validation. Those activities are used to develop FPGA-based reactor bistable trip functions that trigger reactor trip when the process input value exceeds the setpoint. To implement design synthesis effectively, a model-based design technique is implied. The finite-state machine with data path structural modeling technique together with very high speed integrated circuit hardware description language and the Aldec Active-HDL tool are used to design, model, and verify the reactor bistable trip functions for nuclear power plants.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.1
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• pp.38-43
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• 2012

For safe and stable operations of power plants, it is essential to monitor closely crucial measurement values related to power plant trips. In this paper, an intelligent power plant operating state monitoring technique enabling the operating crew member to monitor conveniently the status of the important measurement values and to perceive almost instantly the significance of the implications of those measurement values is developed. The proposed technique is called a "POST(Plant Operating State Tracking) Chart" technique and provides the foundations in developing an intelligent and integrated power plant operating state monitoring support system called the "P-OASIS"(Plant Operation Assessment and Support Intelligent System). The P-OASIS is applied to a thermal power plant of 500[MW] capacity and exhibited impressive performances.

• Journal of Science Education
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• v.46 no.1
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• pp.53-65
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• 2022

In the application and composition of learning content, the field trip learning of scientific inquiry could provide a positive effect. Also, it can arouse an experience of various inquiry activities through open thinking. In addition, it could take a positive effect by providing the diversity and specificity of wildlife experience for the living organism. The biology inquiry program of the field trip is a necessary process to acquire ecological experiences in the learning context. However, there is some problem to solve before the performance of field trip learning as professional knowledge of the outdoors inquiry. Therefore, this study developed a field trip inquiry program for the plant in a coastal dune using artificial intelligence to assist professional knowledge. The researcher carried out literature reviews and analysis related to studies and programs to investigate learning steps, content, and strategy. Also, this study investigated the effects of the program on the affective domain of gifted elementary science students. According to the results of this study, the program can provide a positive effect on motivation, task commitment, and attitude level. Consequently, the field trip learning program for plant in the coastal dune using artificial intelligence developed in this study can arouse a positive effect on the affective domain. Therefore, additional study is necessary related to inquiry programs of the field trip for various students and sites.

• International Journal of Safety
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• v.11 no.1
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• pp.26-32
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• 2012

This paper introduces a feasibility evaluation method for prognosis systems based on an empirical model in nuclear power plants. By exploiting the dynamical signature characterized by abnormal phenomena, the prognosis technique can be applied to detect the plant abnormal states prior to an unexpected plant trip. Early $operator^{\circ}{\emptyset}s$ awareness can extend available time for operation action; therefore, unexpected plant trip and time-consuming maintenance can be reduced. For the practical application in nuclear power plant, it is important not only to enhance the advantages of prognosis systems, but also to quantify the negative impact in prognosis, e.g., uncertainty. In order to apply these prognosis systems to real nuclear power plants, it is necessary to conduct a feasibility evaluation; the evaluation consists of 4 steps (: the development of an evaluation method, the development of selection criteria for the abnormal state, acquisition and signal processing, and an evaluation experiment). In this paper, we introduce the feasibility evaluation method and propose further study points for applying prognosis systems from KHNP's experiences in testing some prognosis technologies available in the market.

• Journal of the Korean Society of Safety
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• v.30 no.5
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• pp.123-130
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• 2015

Wolsong Unit 2,3&4 has been performing a containment integrity test during power operation. This test could impact to the safe operation during test. If an accident occurs during pressure dropping phase, reactor trip can be delayed because of the increased pressure difference which causes a time delay to reach the trip set-point. On the contrary, if an accident occurs during pressure increasing phase, reactor trip could be accelerated because the pressure difference to the trip set-point decrease. Point Lepreau nuclear power plant, which installed GCLMS (Gross Containment Leakage Monitoring System) in 1990, has discontinued the test since 1992 due to these adverse effects. Therefore, we evaluated the risk to obviate the GCLMS test based on PWR's ILRT (Integrated Leak Rate Test) extension methodologies. The results demonstrate that risk increase rate is not high in case of performing only ILRT test at every 5 years instead of doing GCLMS test at every 1.5 years. In addition, the result shows that GCLMS test can be removed on a risk-informed perspective since risk increasement is in acceptable area of regulatory acceptance criteria.

• Nuclear Engineering and Technology
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• v.51 no.4
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• pp.1017-1023
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• 2019

The increase of the alternate current frequency results in increased rotational speed of the electrical motors and connected pumps. The consequence for the reactor coolant pumps is increased flow in primary coolant system. Increase of the current frequency can be initiated by the subsynchronous resonance phenomenon (SSR). This paper analyses the implications of the SSR and consequential increase of the frequency on the nuclear power plant safety. The Simulink $MATLAB^{(R)}$ model of the steam turbine and governor system and RELAP5 computer code of the pressurized water reactor are used in the analysis. The SSR results in fast increase of reactor coolant pumps speed and flow in the primary coolant system. The turbine trip value is reached in short time following SSR. The increase of flow of reactor coolant pumps results in increase of heat removal from reactor core. This results in positive reactivity insertion with reactor power increase of 0.5% before reactor trip is initiated by the turbine trip. The main parameters of the plant did not exceed the values of reactor trip set points. The pressure drop over reactor core is small discarding the possibility of core barrel lift.