• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.9
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• pp.599-605
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• 2015

The revised U.S. Nuclear Regulatory Commission(NRC), Regulatory Guide(RG) 1.20, rev.3 requires the evaluation of the potential adverse effects from pressure fluctuations and vibrations on piping and components for the reactor coolant, steam, feedwater, and condensate systems. Detailed vibration analyses for the systems attached to the steam generator are very difficult, because these piping systems are very complicated. This paper suggests a screening method for the flow-induced vibration of acoustic resonances and pump-induced vibration of the piping systems attached to the steam generator in order to conduct the APR1400 comprehensive vibration assessment program. This paper seeks to address the areas such as potential vibration sources, and methods to prevent the occurrence of acoustic resonances and pump-induced vibration of piping systems attached to the steam generator, for conducting the APR1400 comprehensive vibration assessment program. The screening method in this paper will be used to estimate the flow-induced vibration of the piping systems attached to the steam generator for the APR1400.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2005.06a
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• pp.205-210
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• 2005

The proposed regulation for low and intermediate level radioactive waste disposal facility, scheduled to be revised, recommends that the waste generator should verify the radioactive waste conforms to the disposal requirements before disposing of it. According to the regulation, the radionuclide concentration of the radioactive waste, and its physical and chemical characteristics and safety must be confirmed prior to the disposal of low and intermediate level radioactive wastes, and the waste generator is required to deliver this information to the disposal facility operator. In addition, the disposal facility operator must assess the safety of the disposal site to establish the SWAC (Site Specific Waste Acceptance Criteria) in consideration of the characteristics of the site, whereas the waste generator must comply with the criteria in managing, disposing of and delivering low and intermediate level radioactive wastes. To abide by the afore-mentioned regulation and criteria, the waste generator must verify that the radioactive wastes to be disposed of are suitable for disposal before they are transported to the disposal facility, and to this end a radioactive waste certification program must be developed. This study conducted an in-depth analysis of the radioactive waste certification programs enforced in countries advanced in atomic energy to develop a draft of a certification program applicable to local power plants, and the program is currently applied as pilot to Uljin Power Plants No. 1 & 2 to prove its applicability. This study is going to analyze the results of the pilot application with a view to developing a radioactive waste certification program suitable to local conditions.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.9
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• pp.486-491
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• 2017

The water discharged from sewage treatment plants has been considered to be useless, due to itslack of economic utility for small hydro power generation. Considering that most sewage treatment facilities have a water head of less than 2 meters and their flow rate is constant, it is necessary to develop a small hydro power generation device capable of maintaining stable power generation and efficiency. This paper presents the development of anintegrated small hydro power generation system and presents its performance evaluation and results. Then, the economics and use of the system for practical applications are suggested. As a result, it is foundthat the generator efficiency is 92%, the electric energy produced is 10kWh and the economic efficiency, as described by the B/C ratio,is 1.0 or more. Particularly, if the operating level of the generation device is maintained at 80% or more of the rated power, it is possible to secure its economic efficiency and, after 23 years, the investment cost will bereturned. The integrated hydro power generation device is expected to have a positive effect not only in terms of the water discharged from the sewage treatment plant, but also in terms of facilities capable of securing similar flow characteristics.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.12
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• pp.1637-1639
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• 2014

In the past, the analog protection relays have been widely used for the safety-related systems in the nuclear power plants due to their stability and reliability. Meanwhile, as the high performance digital system has been developed, the digital systems have been adopted in the non-safety systems. However, since the digital systems currently used in the non-safety systems were not developed according to Q-class standard, Commercial Grade Item Dedication (CGID) procedure should be performed in order to apply them to the safety-related system. The purpose of this paper is to describe the CGID procedure including the analysis of the hardware architecture as well as the software embedded in protective relay to apply to the emergency diesel generator in the nuclear power plant. The entire CGID procedure was performed strictly according to the international standard and regulations.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.4
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• pp.325-331
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• 2016

Computational fluid numerical analysis using the commercial code CFX was performed to develop a Pelton turbine for a pico hydro power generator using the circulating water of a cooling tower in a large building. The performance of the Pelton turbine was examined for different design factors, such as the bucket shape, in which the Pelton wheel was connected in an appropriate manner to the pipe section, and the number of buckets in order to find the optimal design of Pelton turbine for a pico hydro power using surplus water. A benchmark test was carried out on the manufactured small scale Pelton turbine to validate the design method of the Pelton turbine by numerical analysis. The results obtained by comparing the flow characteristics and power output measured using the ultrasonic flowmeter, the pressure transducer and the oscilloscope with the numerical results confirmed the validity of the analytical design method. The possibility of developing Pelton turbines for kW class pico hydro power generators using surplus water with an average circulation velocity of 1.2 m/s for the chosen bucket shape and number of buckets in a 30 m high building was confirmed.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.69-70
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• 2008

Automatic control systems(AVR, Governor, Synchronizer) installed $1970{\sim}1980$ in K-water were considered to be rehabilitated around 2000. Moreover, Korea Power Exchange market system was changed from PPA (Power Purchase Agreement) to a bidding system. Therefore, depending on the power quality, the power provider could achieve additional profits. It is the excitation system and governor that have the functions of enhancing power necessities. During the 20 to 30 years of generator operation, there were many major and minor problems. Examples are SCR burnout (Andong: Excitation system), hunting (Imha: governor), field circuit breaker failure (Chungju 1st: excitation system), the rise of leakage current (Chungju 2nd: excitation system), power supply burnout (Chungju 2nd: governor). These are the typical examples of malfunction which hindered the generator operation and, consequently, diminished the profit of power business. In order to satisfy the needs of the power market and prevent malfunctions mentioned above, the rehabilitation of AVRs and governors were executed. A new system was made to have the flexibility of ancillary service (GF, AGC, etc.), PSS function. With user friendly HMI software, it is more convenient for the operator to fulfill suitable maintenance. It was possible to connect SCADA system by opening protocol of AVR, governor for the efficiency of operation and maintenance.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.9
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• pp.1491-1499
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• 2008

This paper presents a study on reliability evaluation of a power system considering wind turbine generators (WTG) with multi-state. Renewable energy resources such as wind, wave, solar, micro hydro, tidal and biomass etc. are becoming importance stage by stage because of considering effect of the environment. Wind energy is one of the most successful sources of renewable energy for the production of electrical energy. But, reliability evaluation of generating system with wind energy resources is a complex process. While the wind turbine generators can not modelled as two-state model as like as conventional generators, they should be modelled as multi-state model due to wind speed random variation. The methodology for obtaining reliability evaluation index of wind turbine generators is different from it of the conventional generators. A method for making outage capacity probability table of WTG for reliability is proposed in this paper. The detail process is presented using case study of simple system.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.9
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• pp.44-52
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• 2013

This paper presents the development of 10 kW permanent magnet synchronous generator (PMSG) for small hydropower plants considering flow rates and net head. The initial and detailed design are determined using a load distribution method (LDM) which is a well-known method for designing an electric machine and a 2D-FEA which is performed for more accurate analysis of PMSG. The characteristic analysis results of proposed model with straight line magnet are satisfied with the initial model with curved magnet. Finally, the analysis and the design results are confirmed by the experimental results.

• Journal of the Korean Society for Nondestructive Testing
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• v.33 no.5
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• pp.465-471
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• 2013

A steam generator in nuclear power plant is a heatexchager which is used to convert water into steam from heat produced in a nuclear reactor core, and the steam produced in steam generator is delivered to the turbine to generate electricity. Because of damage to steam generator tubing may impair its ability to adequately perform required safety functions in terms of both structural integrity and leakage integrity, eddy current testing is periodically performed to evaluate the integrity of tubes in steam generator. This assessment is normally performed during a reactor refueling outage. Currently, the eddy current testing for steam generator of nuclear power plant in Korea is performed in accordance with KEPIC & ASME Code requirements, the eddy current testing system is consists of remote data acquisition unit and data analysis program to evaluate the acquired data. The KEPIC & ASME Code require that the electrical properties of remote data acquisition unit, such as total harmonic distortion, input & output impedance, amplifier linearity & stability, phase linearity, bandwidth & demodulation filter response, analog-to-digital conversion, and channel crosstalk shall be measured in accordance with the KEPIC & ASME Code requirements. In this paper, the measurement requirements of electrical properties for eddy current testing instrument described in KEPIC & ASME Code are presented, and the measurement results of newly developed eddy current testing instrument by KHNP(Korea Hydro & Nuclear Power Co., LTD) are presented.

• Proceedings of the KIEE Conference
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• 2008.11a
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• pp.19-21
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• 2008

Renewable energy resources such as wind, wave, solar, micro hydro, tidal and biomass etc. are becoming importance stage by stage because of considering effect of the environment. Solar energy is one of the most successful sources of renewable energy for the production of electrical energy following wind energy. And, the solar/photovoltaic cell generators can not make two-state model as conventional generators, but should be modeled as multi-state model due to solar radiation random variation. The method of obtaining reliability evaluation index of solar cell generators is different from the conventional generators. This paper presents a basic study on reliability evaluation of power system considering solar cell generators with multi-states.