• Nuclear Engineering and Technology
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• v.53 no.1
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• pp.121-130
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• 2021

Cascading failure is the main cause of large blackouts in electrical power systems; this paper analyzes a cascading failure in Hanbit nuclear power plant unit two (2) caused by a circuit breaker (CB) operation failure. This malfunction has been expanded to the loss of offsite power (LOOP). In this study, current practices are reviewed and then the methodologies of how to prevent cascading failures in protection power systems are introduced. An overview on the implementation of IEC61850 GOOSE messaging-based zone selective interlocking (ZSI) scheme as key solution is proposed. In consideration of ZSI blocking time, all influencing factors such as circuit breaker opening time, relay I/O response time and messages travelling time in the communication network should be taken into account. The purpose of this paper is to elaborate on the effect of cascading failure in NPP electrical power protection system and propose preventive actions for this failures. Finally, the expected advantages and challenges are elaborated.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05b
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• pp.631-636
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• 1996

This paper presents a Reliability Centered Maintenance (RCM) framework for implementation on safety system of nuclear power plant (NPP). RCM is a systematic methodology to optimize the surveillance and maintenance tasks for critical components which provides efficiently and effectively reliability of system and safety of plant. Maintenance of the safety systems is essential for its safe and reliable operation. Reliability Centered Maintenance at NPP is the program which assure that plant system remains within original design criteria and that is not adversely affected during the plant life time. Aim of this paper is to provide the RCM framework to implement it on safety systems. RCM framework is described in four major steps.

• Nuclear Engineering and Technology
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• v.31 no.2
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• pp.226-235
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• 1999

Applying digital network technology for advanced nuclear plant requires deterministic communication for tight safety requirements, timely and reliable data delivery for operation-critical and mission-critical characteristics of nuclear plant. Communication protocols, such as IEEE 802/4 Token Bus, IEEE 802/5 Token Ring, FDDI, and ARCnet, which have deterministic communication capability are partially applied to several nuclear power plants. Although digital communication technologies have many advantages, it is necessary to consider the noise immunity from electromagnetic interference (EMI), electrical interference, impulse noise, and heat noise before selecting specific digital network technology for nuclear plant. In this paper, we consider the token frame loss and data frame loss rate due to the link error event, frame size, and link data rate in different protocols, and evaluate the possibility of failure to meet the hard real-time requirement in nuclear plant.

• Journal of the Korean Society of Systems Engineering
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• v.11 no.2
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• pp.31-40
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• 2015

KEPCO International Nuclear Graduate School (KINGS) is dedicated to nurturing leadership-level professionals in nuclear power plant (NPP) engineering. KINGS have designed curriculum based on two philosophies. First, we balance aspects of discipline engineering, specialty engineering, and management engineering in the framework of systems engineering. Second, KINGS have designed the curriculum so that students can learn and experience the know-what, know-how and know-why level knowledge of NPP engineering and management. The specialization programs are opened during the 2nd year for 3 trimesters and those are a process of learning through practical project courses. The objectives of the specialization programs are to help students to learn the NPP life cycle technologies in highly structured and systematic ways. The systems engineer program (SEP) is one of the specialization programs. A practical case of the SEP which was applied to the project course for the NPP electric power system design education will be elaborated in this paper.

• Economic and Environmental Geology
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• v.32 no.3
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• pp.273-280
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• 1999

In order to protect inhabitans' health and to collect data for prediction of the effcts from accidental emission of rasioactive materials from nuclear power plant, exposed dose rate be monitored within the limit dose rate. This research was carried out to investigate the accumulation of environmental radioactivity around Younggwang Nuclear Power Plant, and to infer and in infer and assay the additional exposed dose rate of inhabitants in Younggwang site from the operation of nuclear plant operation. External radiation dose rate, radiation environmental samples, and exposed dose rate of inhabitants in Younggwang site were investigated for estimaing environment activity in the vicinity of the nuclear power plant area. For the external radiation dose rate, the result showed that range of normal variation was found and any artificial radioisotope was not deteted in the analysis of environmental samples. Exposed dose rate of inhabitants was lower than 0.4% of the limit value of ICRP and it may be concluded that there was no effect on inhabitants and environment from the operation of nuclear power plant.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.8 no.1
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• pp.25-32
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• 2012

Korea Hydro & Nuclear Power Co. (KHNP) has developed and implemented the maintenance effectiveness monitoring (MR) programs for the operating nuclear power plants. The MR program is developed by reflecting design characteristics of the operating nuclear power plants to monitor the plant performance for improving the safety and reliability. Recently, KHNP has built a new nuclear power plant, and developed the MR program to establish the advanced maintenance system by reflecting unique design characteristics based on the OPR1000 standard model. So, the MR program developed in this study has another characteristics in comparison with the OPR1000 standard model, and we will verify the suitability of the MR program through evaluating initial performance of the plant. The safety and reliability of the new plant will be improved by developing and implementing the MR program.

• Journal of Veterinary Clinics
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• v.20 no.3
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• pp.364-368
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• 2003

Cytogenetic and hematological analysis was performed in peripheral blood from the cattle associated with abnormal delivery around nuclear power plant area. The frequency of micronuclei (MN) in peripheral blood lymphocytes from cattle was used as a biomarker of radiobiological effects resulting from exposure to environmental radiation. An estimated dose of radiation was calculated by best fitting linear-quadratic model based on the radiation-induced MN data over the range from 0 Gy to 4 Gy from the bovine lymphocytes with in vitro irradiation. MN rates in live malformed calf, dams of malformed calves and other cattle living in the same barn from the regions around nuclear power plant, and cattle in control area were 9/1000, 10.8/1000, 13.3/1000 and 10.0/1000, respectively. There were no significant differences in MN frequencies and hematological values between the cattle associated with abnormal delivery around nuclear power plant area and those of control area. This study indicates that the congenital abnormalities near nuclear power plant seemed to be caused by other aetiology.

• Journal of the Korean Society of Radiology
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• v.10 no.8
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• pp.583-590
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• 2016

The subjects in this study are the residents of Busan, analyzing the perception gap between the residents adjacent to the nuclear plant and living in town, about the lawsuit of thyroid cancer damage nearby the nuclear plant, to distinguish the citizen's acceptance level about the nuclear power. 551 people(269 people adjacent to nuclear plant, 282 people in town) were face-to-face surveyed and the result showed that people's perceptions of the nuclear power has changed after the thyroid cancer damage lawsuit. In the case of the residents adjacent to the nuclear plant, it became clear that the negative perception of nuclear power became stronger due to increasing distrust and anxiety about nuclear power after the lawsuit of thyroid cancer damage nearby the nuclear plant. On the other hand, people living in town showed their positive perceptions of nuclear power despite the thyroid cancer damage lawsuit. However, two-sided perception was shown compared to the acceptance of nuclear power, since the safety and reliability of the nuclear power was analyzed as negative perception. Therefore, for the constant increased use of nuclear power in the future, national understanding and credibility, including the communication with the nation or the residents in the neighboring area of nuclear power plant, will be necessary.

• Proceedings of the Korean Nuclear Society Conference
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• 2005.05a
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• pp.737-738
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• 2005

• Nuclear Engineering and Technology
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• v.53 no.4
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• pp.1176-1180
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• 2021

The current study relates to RADAR (RAdio Detection and Ranging) application for level measurement of vitrified radioactive liquid nuclear waste. The vitrification of radioactive liquid waste is carried out in special equipment called 'Melters'. The study is directed towards the design and frequency modulation used in the level measurement of vitrified waste. More specifically, the RADAR design and frequency used for level measurement in a melter. This level measurement technique can also be used for dynamic vitrification process and can be used to measure the level variations without using any external medium/material and using only electromagnetic waves. Also, this technique is durable and accurate even under the high radioactive environment present inside the melter.