• Nuclear Engineering and Technology
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• v.53 no.4
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• pp.1369-1377
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• 2021

Nowadays, it is necessary to accelerate the construction of new power plant in face of rising energy demand in such a way that the electricity will be generated at the lowest cost while reducing emissions caused by that generation. The expansion planning is one of the most important issues in electricity management. Nuclear energy comes forward with the low-carbon technology and increasing competitiveness to expand the share of generated energy by introducing Gen IV reactors. In this paper, the generation expansion planning of these new Gen reactors is investigated using the WASP software. Iran power grid is selected as a case of study. We present a comparison of the twenty-one year perspective on the future with the development of (1) traditional thermal power plants and Gen II reactors, (2) Gen III + reactors with traditional thermal power plants, (3) Gen IV reactors and traditional thermal power plants, (4) Gen III + reactors and the new generation of the thermal power plant, (5) the new generation of thermal power plants and the Gen IV reactors. The results show that the Gen IV reactors have the most developing among other types of power plants leading to reduce the operating costs and emissions. The obtained results show that the use of new Gen of combined cycle power plant and Gen IV reactors make the emissions and cost to be reduced to 16% and 72% of Gen II NPPs and traditional thermal power plants, respectively.

• Journal of Korean Society for Quality Management
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• v.45 no.4
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• pp.969-980
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• 2017

Purpose: The purpose of this study was to estimate the lifetime, and verify the target lifetime at steady state temperature, of communication cable jackets used in nuclear power plants. Method: This study was completed according to test and analysis methods required by international standards. After measuring the residual elongation(%) of specimens at specific points in time with the accelerated degradation test, average failure time of each temperature was computed. Thus, the activation energy could be derived by applying the temperature-Arrhenius law to estimate cable jacket lifetime at steady state temperature. Results: The cable jacket lifetime was estimated as 363.8 years assuming a normal nuclear power plant operating temperature of $90^{\circ}C$. Conclusion: To ascertain stable operating conditions for a nuclear power plant, accelerated degradation tests were performed according to the Arrhenius law for components of the nuclear power plants. The lifetime was estimated from the degradation data collected during the accelerated degradation test.

• Corrosion Science and Technology
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• v.9 no.5
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• pp.187-195
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• 2010

Hyper duplex stainless steels have been developed in Korea for the purpose of application to the seawater system of Korean nuclear power plants. This system supplies seawater to cooling water heat exchanger tubes, related pipes and chlorine injection system. In normal operation, seawater is supplied to heat exchanger through the exit of circulating water pump headers, and the heat exchanged sea water is extracted to the discharge pipes in circulating water system connected to the circulating water discharge lines. The high flow velocity of some part of seawater system in nuclear power plants accelerates damages of components. Therefore, high strength and high corrosion resistant steels need to be applied for this environment. Hyper duplex stainless steel (27Cr-7.0Ni-2.5Mo-3.2W-0.35N) has been newly developed in Korea and is being improved for applying to nuclear power plants. In this study, the physical & mechanical properties and corrosion resistance of newly developed materials are quantitatively evaluated in comparative to commercial stainless steels in other countries. The properties of weld & HAZ (heat affected zone) are analyzed and the best compositions are suggested. The optimum conditions in welding process are derived for ensuring the volume fraction of ferrite(${\alpha}$) and austenite(${\gamma}$) in HAZ and controlling weld cracks. For applying these materials to the seawater heat exchanger, CCT and CPT in weldments are measured. As a result of all experiments, it was found that the newly developed hyper duplex stainless steel WREMBA has higher corrosion resistance and mechanical properties than those of super austenitic stainless steels including welded area. It is expected to be a promising material for seawater systems of Korean nuclear power plants.

• Korean journal of communication and information
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• v.76
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• pp.124-150
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• 2016

The aim of this study is to see the change of the general characteristics and frame of nuclear power plant news in Korea from comparing the before Fukushima nuclear accident in Japan on March 11, 2011 with the after. To this aim, the national daily newspapers and the local daily newspapers in Busan located nuclear power plants were selected, and the content analysis of the newspaper stories about nuclear power plants was done. In research results, the stories about nuclear power plants in Korean newspapers increased greatly after Fukushima nuclear accident. Before the accident the nuclear power plant stories about economy held a large majority, while after the accident the stories about society held. Fukushima nuclear accident served as the momentum that the nuclear power plant stories in Korea became main news. Meanwhile, the frame of nuclear power plant stories in Korean newspapers changed greatly after the accident. Justly the environmental security frame increased greatly, because of increasing greatly the stories about security of nuclear power plants with Fukushima nuclear accident. Particularly in the local daily newspapers in Busan before the accident the environmental security frame was 29.3% of stories about nuclear power plants, and after the accident the frame was 77.6%.

• Journal of the Korean Professional Engineers Association
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• v.33 no.3
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• pp.15-19
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• 2000

The importance of the nuclear energy as one of the national energy sources, safety consideration of the nuclear power plants and status of nuclear power generation and nuclear fuel cycle in Korea are discussed.

• The Transactions of the Korean Institute of Power Electronics
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• v.24 no.5
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• pp.342-348
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• 2019

The emergency power supplies (EPSs) are required to increase battery sizing for protecting power source loss above designed criteria. This study proposes a sizing method for lithium-based batteries for EPSs in nuclear power plants on the basis of the calculation method for the required energy under variable conditions. The variable conditions are related with the characteristics of lithium-based batteries, such as the temperature of the location of EPS installation, aging, and design margin. The usage of lithium-based battery reduces the cost and installation space and enables the safe and long-term supply of power compared with the use of lead-acid battery.

• The Journal of the Korea Contents Association
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• v.12 no.6
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• pp.238-248
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• 2012

This research examined the effect of risk perception on risk attitude and risk acceptance of nuclear power plants. For this study, we carried out a survey targeting local residents living in Gyeong-ju..And we examined how risk perception of nuclear power plants have influences the risk attitude and risk acceptance including distrust on government's polices and perceived benefit. First, The findings showed that risk perception of nuclear power plants influenced positively on risk attitude. Second, risk attitude of nuclear power plants influenced negatively on risk acceptance. Third, distrust on government's polices influenced negatively on risk acceptance. Fourth, perceived benefit influenced positively on risk acceptance.

• Proceedings of the KIEE Conference
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• 2006.10c
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• pp.500-502
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• 2006

Recently, nuclear power plants have been testing for application of wireless communication system to improve communication easier. Improving the availability of communication in NPPs, plant operation ability and good communication have contributed to the lower reactior trip frequency. In these regards, the possibilities of improvement in communication systems are reviewed detail. Especially, we reviewed the wire communication system, facility effect, regulation and new technologies. In this paper, we described the application of wireless in NPPs by studying EMI/RFI, EMC effect.

• Nuclear Engineering and Technology
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• v.54 no.4
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• pp.1230-1244
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• 2022

This paper proposes an algorithm for signal validation using unsupervised methods in emergency situations at nuclear power plants (NPPs) when signals are rapidly changing. The algorithm aims to determine the stuck failures of signals in real time based on a variational auto-encoder (VAE), which employs unsupervised learning, and long short-term memory (LSTM). The application of unsupervised learning enables the algorithm to detect a wide range of stuck failures, even those that are not trained. First, this paper discusses the potential failure modes of signals in NPPs and reviews previous studies conducted on signal validation. Then, an algorithm for detecting signal failures is proposed by applying LSTM and VAE. To overcome the typical problems of unsupervised learning processes, such as trainability and performance issues, several optimizations are carried out to select the inputs, determine the hyper-parameters of the network, and establish the thresholds to identify signal failures. Finally, the proposed algorithm is validated and demonstrated using a compact nuclear simulator.

• Transactions of the Korean hydrogen and new energy society
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• v.29 no.2
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• pp.226-234
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• 2018

Even though the nuclear power plants has many advantages, safety issues of nuclear power plants are crucial factors of reliable operation. A tritium detector is a useful sensor to analyze amount of exposed radiation from the nuclear power plants. Currently, concentration of underwater tritium is measured precisely but it takes very long time. Since electrolysis is extracted hydrogen from the coolant of nuclear power plant, it can motivate to develop new type of real-time sensor. In this study, Proton Exchange Membrane (PEM) electrolyzer is studied for candidate as preprocessor of real-time tritium detector. Characteristics of the unit PEM electrolyzer were experimentally investigated. A simulation model is developed to understand physical behavior of unit PEM electrolyzer under dynamic operation.