• Journal of Energy Engineering
• /
• v.18 no.4
• /
• pp.230-238
• /
• 2009

We study about small gas engine and fuel cell CHP (Combined Heat and Power) as the technologies for energy conservation and $CO_2$ emissions reduction. Korea government plans to use them in near future. This study quantitatively analyzed energy consumption and $CO_2$ emissions reduction potential of small CHP instead of existing electric power plant (coal steam, combined cycle and oil steam) using LEAP (Long-range Energy Alternative Planning system) as energy-economic model. Three future scenarios are discussed. In every scenario similar condition for each CHP is used. Alternative scenario I: about 6.34% reduction in $CO_2$ emissions is observed in 2019 due to increase in amount of gas engine CHP and fuel cell CHP while coal use in thermoelectric power plant is almost stagnant. In alternative scenario II: a small 0.8% increase in $CO_2$ emission is observed in 2019 keeping conditions similar to alternative scenario I but using natural gas in combined cycle power plant instead of coal. During alternative scenario II overall $CO_2$ emission reduction is observed in 2019 due to added heat production from CHP. Alternative scenario III: about 0.8% reduction in $CO_2$ emissions is observed in 2019 using similar CHP as AS I and AS II. Here coal and oil are used in thermoelectric power plant but the quantity of oil and coal is almost constant for next decade.

• Nuclear Engineering and Technology
• /
• v.52 no.7
• /
• pp.1367-1379
• /
• 2020

The small modular sodium-cooled fast reactor (SMSFR) is an important component of Generation-IV reactors. The objective of this work is to improve the reactivity control in SMSFR by using innovative systems, including burnable poisons and optimized control rods. SMSFR with MOX fuel usually exhibits high burnup reactivity loss that leads to high excess reactivity and potential fuel melting in control rod withdrawal (CRW) accidents, which becomes an important constraint on the safety and economic efficiency of SMSFR. This work applies two types of burnable poisons in a SMSFR to reduce the excess reactivity. The first one homogenously loads minor actinides in the fuel. The second one combines absorber and moderators in specific assemblies. The influence of burnable poisons on the core characteristics is discussed and integrated into the analysis of CRW accidents. The results show that burnable poisons improve the safety performance of the core in a significant way. Burnable poisons also lessen the demand for the number, absorption ability, and insertion depth of control rods. Two optimized control rod designs with rare earth oxides (Eu₂O₃ and Gd₂O₃) and moderators are compared to the conventional design with natural boron carbide (B₄C). The optimized designs show improved neutronic and safety performance.

• Nuclear Engineering and Technology
• /
• v.54 no.2
• /
• pp.741-748
• /
• 2022

Policy literacy plays a critical role in enhancing deliberative communication among the public, policymakers, and experts. It also helps develop a positive view of policy by the public, which facilitates public acceptance. Despite its importance, however, policy literacy has received little attention in energy policy practice. Therefore, this study explores factors affecting the public's understanding and knowledge (i.e., policy literacy) of nuclear and new-renewable energy policies. Accordingly, we analyzed data from an online survey of 790 laypeople in Korea. Specifically, we examined the effects of trust, transparency, and policy public relations (PR) on the policy literacy of the public regarding the two alternative energy sources. The analysis revealed that people showed higher policy literacy about the alternative sources when provided with more transparent information and exposed to more policy PR activities. However, we found that trust in energy plant operators played a negligible role in improving policy literacy for both energy sources. Based on these findings, we developed some policy suggestions to secure the energy policy literacy of the public.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
• /
• 2004.11a
• /
• pp.303-309
• /
• 2004

• Proceedings of the Korea Society for Energy Engineering kosee Conference
• /
• 2004.11a
• /
• pp.165-170
• /
• 2004

• Journal of the Korean housing association
• /
• v.15 no.3
• /
• pp.83-91
• /
• 2004

In a planning stage, the assessment system is required to select the proper alternative, reflected the environmental affects such as energy, $CO_2$ and $SO_x$. Unit of energy consumption, $CO_2$ emission and $SO_x$ emission among various assessment systems could be effectively utilized to select the better alternative among various building types. But researches for these areas has not been conducted systematically, but limitedly and sporadically. In this paper, it aimed at providing the unit of energy consumption, $CO_2$ emission and $SO_x$ emission to evaluate the environmental affects between the steel-structured apartment building and wall-typed apartment building. For this, the input-output analysis could be utilized in the construction stage with two-type apartment housing. This approach can be utilized to compare the various alternatives in aspect of the energy consumption and the environment affect, and to select the relatively better alternative. This study found that the unit of energy, $CO_2$ and $SO_x$ of the steel-structured apartment building is lower than that of the wall-typed building

• Journal of Energy Engineering
• /
• v.17 no.1
• /
• pp.15-22
• /
• 2008

This study was carried out to investigate physical and chemical characteristics of the distillates and residue of Athabasca oilsand bitumen obtained from Canada, using a vacuum distillation unit. The distillates and residue produced from the vacuum distillation were characterized through atomic analysis, SARA analysis, and measurement of boiling point distribution, molecular weight, and API gravity. The vacuum distillation equipment consisted of a 6-litter volume vessel, a glass-packed column, a condenser, a reflux device, a flask fer collecting distillates, and a temperature controller. The cutting of distillates was performed with four steps under the condition of full vacuum and maximum temperature of $320^{\circ}C$. The results showed that the sulfur amount and average molecular weight of the distillates were significantly reduced compared to those of oilsand bitumen. As the cutting temperature increased, the hydrogen amount decreased but the sulfur amount and average molecular weight increased in the distillates.

• Journal of The Korean Association For Science Education
• /
• v.32 no.8
• /
• pp.1295-1317
• /
• 2012

There has been disagreement on the importance of definitions in science education. Yager (1983) believes that one crisis in science education was due to the considerable emphasis upon the learning of definitions. Hobson (2004) disagrees with physics textbooks that do not provide general definition on energy. Some textbooks explain that "there is no completely satisfactory definition of energy" or they can only "struggle to define it." In general, imprecise definitions in textbooks (Bauman, 1992) and inaccuracies in definition provided by teachers (Galili & Lehavi, 2006) may cause alternative conceptions. Besides, there are at least four challenges in defining physical concepts: precision, circularity, context and completeness in knowledge. These definitional problems that have been discussed in The Feynman Lectures, may impede the learning of physical concepts. A meta-study approach is employed to examine about five hundreds journal papers that may discuss definitions in physics, problems in defining physical concepts and how they may result in alternative conceptions. These journal papers are mainly selected from journals such as American Journal of Physics, International Journal of Science Education, Journal of Research in Science Teaching, Physics Education, The Physics Teachers, and so on. There are also comparisons of definitions with definitions from textbooks, Dictionaries of Physics, and English Dictionaries. To understand the nature of alternative conception, Lee et al. (2010) have suggested a theoretical framework to describe the learning issues by synthesizing cognitive psychology and science education approaches. Taking it a step further, this study incorporates the challenges in semantics and epistemology, proposes that there are at least four variants of alternative conceptions. We may coin the term, 'alternative definitions', to refer to the commonly available definitions, which have these four problems in defining physics concepts. Based on this study, alternative definitions may result in at least four variants of alternative conceptions. Note that these four definitional problems or challenges in definitions cannot be easily resolved. Educators should be cognizant of the four variants of alternative conceptions which can arise from alternative definitions. The concepts of alternative definitions can be useful and possibly generalized to science education and beyond.

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2018.11a
• /
• pp.137-138
• /
• 2018

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2018.11a
• /
• pp.201-202
• /
• 2018