• Proceedings of the Korean Nuclear Society Conference
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• 1996.05c
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• pp.290-295
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• 1996

The purpose of this study is to establish the pressure/temperature curves of Reactor Coolant System for brittle fracture prevention. The pressure/temperature curve is the basis to select RC Pump and limits to operate the plant. Based on the plant operation experience, this curve should be re-generated periodically in order to ensure the structural integrity using data from the test of reactor vessel surveilance materials to compensate for the irradiation effects. This study provides the procedure of pressure/temperature curve generation in term of brittle fracture prevention of reactor vessel. Using the UCN 3&4 data, the sample pressure/temperature curve was generated, and it was compared with those of YGN 3&4 based on the stress and $RT_{NDT}$value.

• Journal of Plant Biotechnology
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• v.34 no.2
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• pp.95-101
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• 2007

The transport biofuel is emerging a promising option to realize the sustainable growth of our society. Two biofuels, bioethanol and biodiesel, are currently used in the transport sector. As the production of biofuels is getting activated, the stable supply of the feedstocks is becoming a critical issue. Active works have been carried out to secure the stable supply of the raw materials for the production of biofuels. One approach is the breeding of the energy crops to get higher productivity and / or the desirable fuel properties. The other approach is finding new energy crops which may not be used for edible purpose. First current aspects and challenging issues for the implementation of biofuels have been introduced. Finally the recent works and future prospects on the development of the energy crops are summarized.

• Journal of Energy Engineering
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• v.2 no.1
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• pp.83-94
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• 1993

In this paper, the performance of an energy conversion system is analyzed using two efficiency concepts, one of conventional and the other of energetic efficiently. The objective of this analysis was to improve and optimize the energy conversion system in point, namely, and LNG-fired Combined Heat and Power Plant (CHP). To this end, energies which represent the true efficiency figures were evaluated for various flows of the system with a set of system configurations given. Then the economic values of the energies were assigned to respective flows and subsystems. With these economic data locations of inefficiencies and opportunities for improvement are identified.

• Nuclear Engineering and Technology
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• v.45 no.5
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• pp.597-604
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• 2013

Containment Filtered Vent Systems (CFVSs) have been mainly equipped in nuclear power plants in Europe and Canada for the controlled depressurization of the containment atmosphere under severe accident conditions. This is to keep the containment integrity against overpressure during the course of a severe accident, in which the radioactive gas-steam mixture from the containment is discharged into a system designed to remove the radionuclides. In Korea, a CFVS was first introduced in the Wolsong unit-1 nuclear power plant as a mitigation measure to deal with the threat of over pressurization, following post-Fukushima action items. In this paper, the overall features of a CFVS installation such as risk assessments, an evaluation of the performance requirements, and a determination of the optimal operating strategies are analyzed for the Wolsong unit 1 nuclear power plant using a severe accident analysis computer code, ISAAC.

• Journal of Environmental Impact Assessment
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• v.23 no.1
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• pp.11-17
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• 2014

Since the Renewable Portfolio Standard (RPS) would be started in 2012, the use of renewable energy should be 11% of total energy use including bio-fuel in 2030. The economic efficiency for renewable energy in B power plant was considered with the bio-diesel, wind power and solar power. The Net Present Value (NPV) and Benefit/Cost Ratio(BC) were used for the economic efficiency with the cost and benefit analysis. In case of bio-diesel, the cost resulted from the fuel conversion and the benefit would be created with trade and environmental improvement. With regard to wind power and solar power, the construction cost would be required and benefit factors would be same as the bio-diesel. The wind power was the best of economic efficiency of renewable energy as the results of NPV and BC ratio. Whereas, the market of wind power was very popular and the techniques of wind power has been developing rapidly.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05a
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• pp.244-250
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• 1996

Uncertainties in core neutronic calculations of CASMO-3/MASTER, which is a KAERI developed core nuclear design code system, were evaluated via comparisons with measured data. Comparisons were performed with plant measurement data from one Westinghouse type and one ABB-CE type plant and two Korean standard type plants. The CASMO-3/MASTER capability and levels of accuracy are concluded to be sufficient for the neutronics design including safety related parameters related with reactivity, power distributions, temperature and power coefficients, inverse boron worth and control bank worth.

• Nuclear Engineering and Technology
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• v.35 no.2
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• pp.121-132
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• 2003

To reduce the construction cost and enhance the safety of sodium cooled liquid metal reactors, various kinds of new design concepts were evaluated using the KALIMER operation condition. The required equipment sizes were set for plant electricity output to be similar to that of KALIMER. The evaluations were made focusing on the plant performance and implementation practicality. Each design concept was evaluated for the concept itself and design impacts to interfacing systems. Through the evaluation of the concepts, it was found that the most favorable design concept is the integrated steam generator with forced convection using lead bismuth as the intermediate heat transfer fluid between the primary sodium tube and feed water/steam tube in the steam generator.

• Asia-Pacific Journal of Business
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• v.9 no.4
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• pp.67-84
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• 2018

This study is about comparing coal thermal plant to LNG combined power plant in respect of environmental and economic cost analysis. In addition sensitive analysis of power cost and discount rate is conducted to compare the result of change in endogenous and exogenous variable. For environmental assessment, when they generate 10,669GWh yearly, coal thermal power plant emits sulfur oxides 959ton, nitrogen oxide 690ton, particulate matter 168ton and LNG combined power plant emits only nitrogen oxide 886ton respectively every year. Regarding economic cost analysis on both power plants during persisting period 30 years, coal thermal power plant is more cost effective 4,751 billion won than LNG combined taking in account the initial, operational, energy and environmental cost at 10,669GWh yearly in spite of only LNG combined power plant's energy cost higher than coal thermal. In case of sensitive analysis of power cost and discount rate, as 1% rise or drop in power cost, the total cost of coal thermal power plant increases or decreases 81 billion won and LNG combined 157 billion won up or down respectively. When discount rate 1% higher, the cost of coal thermal and LNG combined power plant decrease 498 billion won and 539 billion won for each. When discount rate 1% lower, the cost of both power plant increase 539 billion won and 837 billion won. With comparing each result of change in power cost and discount rate, as discount rate is weigher than power cost, which means most influential variable of power plan is discount rate one of exogenous variables not endogenous.

• Journal of Hydrogen and New Energy
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• v.23 no.5
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• pp.559-571
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• 2012

Dimethyl ether (DME) is a new clean fuel as an environmentally-benign energy resource. DME can be manufactured from various energy sources including natural gas, coal, and biomass. In addition to its environmentally friendly properties, DME has similar characteristics to those of LPG. The aim of this article is to represent the development of new DME process with KOGAS's own technologies. KOGAS has investigated and developed new innovative DME synthesis process from synthesis gas in gaseous phase fixed bed reactor. DME has been traditionally produced by the dehydration of methanol which is produced from syngas, a product of natural gas reforming. This traditional process is thus called the two-step method of preparing DME. However, DME can also be manufactured directly from syngas (single-step). The single-step method needs only one reactor for the synthesis of DME, instead of two for the two-step process. It can also alleviate the thermodynamic limitations associated with the synthesis of methanol, by converting the produced methanol into DME, thereby potentially enhancing the overall conversion of syngas into DME. KOGAS had launched the 10 ton/day DME demonstration plant project in 2004 at Incheon KOGAS LNG terminal. In the mid of 2008, KOGAS had finished the construction of this plant and has successively finished the demonstration plant operation. And since 2008, we have established the basic design of commercial plant which can produce 3,000 ton/day DME.

• Journal of Korean Society on Water Environment
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• v.32 no.3
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• pp.253-260
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• 2016

To reduce energy consumption in wastewater treatment plants (WWTPs), renewable energy applications such as small hydropower, solar energy, and wind energy are popular. However, it should be noticed that energy originated from operation of wastewater treatment process can be reduced through optimized operation based on analysis of factors affecting energy. In this research, the relationship to the various operational variables and influent factors was explored using correlation analysis and decision tree algorithm. Due to the non-linear characteristics of the process, it was difficult to find clear linear patterns through correlation analysis. However, decision tree algorithm showed its usefulness in uncovering hidden patterns that consume energy. As operational factors, influent flowrate, the amount of aeration, nitrate recycling pumping rate, and sludge wasting pumping rate were selected as important factors. For environmental factors associated with influent compositions and removal rate, BOD and T-N removal rate were selected as significant factors.