• Tribology and Lubricants
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• v.10 no.4
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• pp.51-58
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• 1994

Condition monitoring technology has recently been received much attention in the light of its significance on the maintenance of complex machineries such as turbines in power plants. Currently, turbines in power plants are maintained by scheduled overhaul based on the manufacturer's recommendations and the utility's experience. Although this preventive maintenance is known to be very effective, operators have less access to identify failure of elements when it happens between overhaul period. Therefore, in this study, a development of a on-line condition monitoring system through wear debris analysis of lubricating oils is aimed with a view to detecting abnormal wear behaviour of bearings and other wet-components at an early stage, allowing better outage scheduling and minimizing forced outages. For field application purposes, the on-line system developed was installed on the turbine of the No.4 unit at Ulsan Power Plant and its performance has been evaluated on site.

• Journal of the Korean Society of Safety
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• v.26 no.2
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• pp.20-25
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• 2011

The fire event occurred in fire proof zone often causes serious electrical problems such as shorts, ground faults, or open circuits in nuclear power plants. These would be directed to the loss of safe shutdown capabilities performed by safety related systems and equipments. The fire event can treat the basic design principle that safety systems should keep their functions with redundancy and independency. In case of a multi-core cable fire, operators can not perform their mission properly and can misjudge the situation because of spurious operation, wrong indication or instrument. These would deteriorate the plant capabilities of safety shutdown and make disastrous conditions. In this paper, the characteristic of cable fire is investigated and the heat-flux evaluation for cable fire is studied. Moreover, a diagnostic methodology for degraded cable in nuclear power plants is presented.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.498-503
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• 2000

A safety-related equipment for use in Nuclear Power Plant should be needed an Equipment Qualification. This paper presents the approach, methods, philosophies, and procedures for qualifying the large squirrel-cage induction electric pump motors for use in ULCHIN 5&6 Nuclear Power Plants. In this paper, the method of qualification is a combination of type test and analysis method, which is composed of Radiation exposure test, Seismic simulation test, Thermal aging analysis for non-metallic materials and Seismic analysis. It is found that the motor performs its safety function with no failure mechanism under postulated service conditions.

• International Journal of Fluid Machinery and Systems
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• v.10 no.3
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• pp.264-273
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• 2017

In order to be able to predict the maximum Annual Energy Production (AEP) for tidal power plants, an AEP optimization tool based on Evolutionary Algorithms was developed by ANDRITZ HYDRO. This tool can simulate all operating modes of the units (bi-directional turbine, pump and sluicing mode) and provide the optimal plant operation that maximizes the AEP to the control system. For the Swansea Bay Tidal Power Plant, the AEP optimization evaluated all different hydraulic and operating concepts and defined the optimal concept that led to a significant AEP increase. A comparison between the optimal plant operation provided by the AEP optimization and the full load operating strategy is presented in the paper, highlighting the advantage of the method in providing the maximum AEP.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1997.04a
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• pp.217-224
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• 1997

The safety related equipments for use in nuclear power plants should be subjected to the seismic qualification in order to insure the safety of the nuclear power plant. This paper summarizes the seismic qualification test on the Low Voltage Motor Control Centers(MCC's) for use in Wolsong Nuclear Power Plants, Units 2, 3 and 4. The seismic qualification test was performed on the two prototype MCC's(a two-bay wide unit for Phase #1 Test and a five-bay wide unit for Phase #2 Test). The specimens were electrically powered and monitored during the test process. It was demonstrated that the specimens possessed sufficient structural and electrical integrity to withstand the required seismic conditions.

• Corrosion Science and Technology
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• v.15 no.1
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• pp.6-12
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• 2016

Flow-Accelerated Corrosion (FAC) is a well-known degradation mechanism that attacks the secondary piping in nuclear power plants. Since the Surry Unit 2 event in 1986, most nuclear power plants have implemented management programs to deal with damages in carbon and low-alloy steel piping. Despite the utmost efforts, damage induced by FAC still occurs in power plants around the world. In order to predict FAC wear, some computer programs were developed such as CHECWORKS, CICERO, and COMSY. Various data need to be input to these programs; the chemical composition of secondary piping, flow operating conditions and piping geometries. CHECWORKS, developed by the Electric Power Research Institute (EPRI), uses a geometry code to calculate geometry effects. Such a relatively simple geometry code is limited in acquiring the accuracy of FAC prediction. Recently, EPRI revisited the geometry code with the intention of updating it. In this study, numerical simulations were performed for two adjacent $90^{\circ}$ elbows and the results were analysed in terms of the proximity effect between the two adjacent elbows.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.22 no.52
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• pp.311-322
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• 1999

Major problems involved in an electrical utility expansion planning within a time horizon are how to efficiently deal with objectives considering multiple factors and uncertainty. But justification factors in study these days have considered only quantitative factors except qualitative factors. Therefore, the purpose of this paper is to develop a new model for economic evaluation of nuclear power plants through the scoring model with the quantitative and qualitative factors under uncertainty. The quantitative factors use a levelized generation cost method considering time value of money. Especially, the environmental, risk, and safety factors in this paper have been also explained for the rational economic justification of the qualitative factors under uncertainty. This paper not only proposes a new approach method using the scoring model in evaluating economy of the nuclear power plant in the long term, but also provides the more efficient decision making criterion for nuclear power plants under uncertainty.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.6
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• pp.72-77
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• 2007

A safety-related equipment for the nuclear power plant should be needed an equipment qualification. In this paper, the approach, methods, philosophies, and procedures for qualifying the large squirrel-cage induction electric pump motors for use in ULCHIN 5, 6 Nuclear Power Plants were presented. The method of qualification is a combination of experimental test and analytic method, which is composed of radiation exposure test, seismic simulation test, thermal aging analysis for non-metallic materials, and seismic analysis. The results showed that the motor performed its safety function with no failure mechanism under postulated service conditions.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.402-405
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• 2008

SunPower's corporate mission is to reduce the installed cost of solar electricity 50% by 2012. As part of that mission, the company is continually exploring novel technologies that might enable progress towards the goal. This paper describes SunPower's efforts to decrease the levelized cost of electricity for solar power plants through the use of bifacial cell and system technology. The results of the first production run of SunPower bifacial cells and modules are presented. Future bifacial system development plans are reviewed.

• Journal of the Korean Professional Engineers Association
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• v.30 no.5
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• pp.82-95
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• 1997

A Study of Improvement in Reactor Thermal Power Measurement Method using Kalman Filter. The objectives of the safety analysis of nuclear power plants are to maintain the surface temperature of fuel and fuel cladding within limit value in case of Loss of Coolant accident (LOCA) so that it ensures the safety and reliability of nuclear power plants. The new technique evaluating the reactor power and improvement of existing plant system increase the safety margin of nuclear power plant operation, and accordingly, economic effect will be anticipated. Hereby, 1 would like to introduce reactor power measurement method using Kalman filter that enables to calculate the reactor power more precisely combining the parameters, for example, turbine output as the 1 st stage pressure of high pressure turbine, and reactor power using energy equilibrium relation. It is expected that the new technique will enhance the accuracy of measurement of reactor power and maintain the reliability of nuclear power operation by increasing operational safety margin, and gain the economic benefit