• Korean Journal of Environmental Agriculture
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• v.29 no.1
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• pp.61-65
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• 2010

Phytoextraction is a method of phytoremediation using plants to remediate metal-contaminated soils. Recently, various chelating agents were used in this method to increase the bioavailability of metals in soils. Even though phytoextraction is an economic and environment-friendly method, this cannot be applied in highly metal-contaminated areas because plants will not normally grow in such conditions. This research focuses on identifying chelating agents which are biodegradable and applicable to highly metal-contaminated areas. Lead (Pb) as a target metal and cysteine (Cys), histidine (His), citrate, malate, oxalate, succinate, and ethylenediamine (EDA) as biodegradable chelating agents were selected. Ethylenediamine tetraacetic acid (EDTA) was used as a comparative standard. Plants were grown on agar media containing various chelating agents with Pb to analyze the effect on root growth. Cys strongly increased the inhibitory effect of Pb on root growth of plants, while, His did not affect on it significantly. The inhibitory effect of oxalate is weak, and malate, citrate, and succinate did not show significant effects. Both EDTA and EDA diminished the inhibitory effect of Pb on root growth. The effect of EDA is correlated with decreased Pb uptake into the plants. In conclusion, as biodegradable chelating agents, EDA is a good candidate for highly Pb-contaminated area.

• Water for future
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• v.29 no.4
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• pp.131-138
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• 1996

The objective of this study is to develop an optimal operation model for the sewage treatment plants using nonlinear programming (NLP) technique and the QUAL2E model. The model finds the minimum-cost operation of sewage treatment plants while satisfying all design constraints and water quality (BOD) standard. The model is applied to four sewage treatment plants in Han River for the city of Seoul. It has been found that optimal operation schedule for the sewage treatment plants can be computed and it is more economic to operate the plants according to the schedule which satisfies the water quality constraints in the river. In addition, the water quality in the river can be predicted using the model under the treatment policy.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.45 no.4
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• pp.31-41
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• 2022

As the environmental impacts of fossil fuel energy sources increase, the South Korean government has tried to change non-environmental-friendly enery sources to environmental-friendly energy sources in order to mitigate environmental effects, which lead to global warming and air pollution. With both a limited budget and limited time, it is essential to accurately evaluate the economic and environmental effects of renewable energy projects for the efficient and effective operation of renewable energy plants. Although the traditional economic evaluation methods are not ideal for evaluating the economic impacts of renewable energy projects, they can still be used for this purpose. Renewable energy projects involve many risks due to various uncertainties. For this reason, this study utilizes a real option method, the Geske compound model, to evaluate the renewable energy projects on Jeju Island in terms of economic and environmental values. This study has developed an economic evaluation model based on the Geske compound model to investigate the influences of flexibility and uncertainty factors on the evaluation process. This study further conducts a sensitivity analysis to examine how two uncertainty factors (namely, investment cost and wind energy production) influence the economic and environmental value of renewable energy projects.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.11 no.3
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• pp.207-212
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• 2013

Since the Fukushima nuclear power plant accident in March 2011, critical views on the increase in operation of nuclear power plants including the safety and the economic feasibility thereof have been expanding across the world. In these circumstances, we are to find out solutions to the controversial questions on whether nuclear power plants are economically more feasible than other energy sources, while the safety thereof is fully maintained. Thereby, nuclear power plants will play a key role as a sustainable energy source in the future as well as at present. To measure the social safety level that Korean people are actually feeling after the Fukushima accident, a method of cost-benefit analysis called the Contingent Valuation Method(CVM) was used, whereby we wanted to estimate the amount of expenses the general public would be willing to pay for the safety based on their acceptance rather than the social safety. As a result of calculating the trade-off value of the economic feasibility versus the safety in nuclear power plants through the survey thereon, it caused the nuclear power generation cost to be increased by 4.75 won/kWh. Reflecting this on the current power generation cost of 39.11 won/kWh would increase the cost to 43.86 won/kWh. It is thought that this potential cost is still more competitive than the coal-fired power generation cost of 67 won/kWh. This result will be available as a basic data for the 2nd Energy Basic Plan to be drawn up this year, presenting policy implications at the same time.

• Journal of Korea Port Economic Association
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• v.19 no.1
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• pp.189-206
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• 2003

This Paper deals with the development of Incheon International Airports and Pusan and Kwangyang Ports as Hub Ports in order to systemize nationwide logistics networks. Now, Korea has core competences in terms of social overhead capital, telecommunication, information technologies, all fields of manufacturing plants, and the other infra-structure. As the environments of North-East Asian countries changes dynamically, at least we should keep up with the situations which require to meet the globalized level of international logistics services in Pusan and Kwangyang Ports to be a competitive Hub Ports in this region.

• Proceedings of the Korea Port Economic Association Conference
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• 2003.07a
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• pp.325-342
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• 2003

This Paper deals with the development of Incheon International Airports and Pusan and Kwangyang Ports as Hub Ports in order to systemize nationwide logistics networks. Now, Korea has core competences in terms of social overhead capital, telecommunication, information technologies, all fields of manufacturing plants, and the other infra-structure. As the environments of North-East Asian countries changes dynamically, at least we should keep up with the situations which require to meet the globalized level of international logistics services in Pusan and KwangYang Ports to be a competitive Hub Ports in this region.

• Nuclear Engineering and Technology
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• v.11 no.4
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• pp.263-274
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• 1979

A statistical approach is used to investigate the relative economic advantages of pressurized water reactor (PWR) and pressurized heavy water reactor (PHWR-CANDU) nuclear power plants for hypothetical 900Mwe systems with the throwaway fuel cycle to be built in the Republic of Korea. Power cost is decomposed into the cost components related to the plant capital, operation and maintenance, working capital requirements and fuel cycle operation. The calculation of construction cost is performed with the modified version of computer code ORCOST, and the modified POWERCO-50 is used to evaluate the cost components. Most of economic parameters are treated as statistical variables, each being given with a certain range. Through a random sampling procedures. the probability histograms on unit plant construction costs and power generating costs are obtained. The power cost probability histograms of the PWR and the PHWR plants overlap considerably, and the power costs of two systems appear to be almost same with the PHWR power cost being 0.4mil1/kwh lower compared with 39.4 mills/kwh for the PWR plant (July 1986 US-dollars). When a construction period of PHWR plant is longer by one year than that of PWR plant, there is no difference in the unit power cost of two plants. This comparison leads to no definite conclusion on the cost advantage of the PWR plant versus the PHWR plant. We conclude that the selection issue of nuclear power plants in Korea still remains an open question and that future effort to solve this question should be made toward economic quantification of those factors such as technology transfer and localization.

• Journal of the Korea Society for Simulation
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• v.13 no.2
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• pp.35-43
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• 2004

The purpose of this study is an economic analysis of power plant utilities by comparing electricity generating cost including environmental costs. Considering the enormous role of electricity in the national economy, it is very important to study the effect of environmental regulation on the electricity sector. Because power utilities need for large investment during construction, operation and maintenance, and also require much construction lead time. Economic analysis is the important process in the electric system expansion planning. This paper compares the costs of electricity generation including environmental costs between a coal-fired power plant and an LNG combined cycle power plants. With the simulation, this study surveys the sensitivity of fuel prices, interest rate and carbon tax. In each case, this sensitivity can help to decide which utility is economically better in environmental regulation circumstance.

• Nuclear Engineering and Technology
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• v.55 no.3
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• pp.1167-1180
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• 2023

Due to the tightened regulatory environment since the Fukushima accident, the capacity factor of Korean nuclear power plants has been declining since 2011. To overcome this circumstance, a shift from 18-month to 24-month cycle operation is being considered in Korea. Therefore, in this study, loading patterns(LPs) for 24-month cycle operation of the Korean standard nuclear power plant(OPR-1000) are suggested and economic evaluations are performed. A single-zone LP with 89 fresh fuels was evaluated to be optimal for 24-month operation of OPR-1000 in terms of economic gain. The 24-month operation of OPR-1000 with this LP gives a profit of 7.073 million dollars per year compared to 18-month operation.

• Economic and Environmental Geology
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• v.30 no.6
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• pp.587-601
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• 1997

This study had three purposes: (1) to investigate the enrichment levels and dispersion patterns of potentially toxic elements in the rock-soil-plant system; (2) to evaluate the uptake ratios of heavy metals from soils into plants and (3) to assess the chemical speciation of heavy metals in soils. Rock, surface soil and plant samples were collected in the Boeun area underlain by black shales of the Okchon Zone. These samples were analyzed for multi-elements using INAA, ICP-AES and AAS. The maximum abundance of U in black shales is 16 mg/kg and radioactivity counts up to 300 cpm. In particular, Mo, V, Ba, Cd, Pb and U are enriched in black shales. Most of soils derived from black shales show high concentrations of U, As, Mo, Ba, Cu, Cd, Pb, Zn and mean concentrations of As and Mo in soils (20 mg/kg of As and 6.6 mg/kg of Mo) are higher than the permissible level suggested by Kloke (1979). Enrichment index values of soils are calculated and higher than 1.0 in the black shale area with the highest value of 6.4. Mean concentration of Cd in plants is higher than those of Cu, Pb and Zn. The concentration of Cd in plant species decreases in the order of Chinese cabbage > red pepper > soybean=sesame > rice stalk > com > rice grain. The biological absorption coefficients (BAC) in plants are in the order of Cd > Zn=Cu > Pb, which suggests that Cd is more bioavailable to plants than Cu, Pb and Zn. From the results of sequential extraction analysis of soils, relatively high proportion of Cu, Pb and Zn are present as residual fractions whereas that of Cd as non-residual fractions. Cadmuim occurs predominantly as exchangeable/water-acid soluble phase in soils, and Cd is more mobile and bioavailable than Cu, Pb and Zn.