• Journal of the Korea Organic Resources Recycling Association
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• v.22 no.1
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• pp.11-19
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• 2014

A study on combustion characteristic and evaluation of cost benefit were carried out using dried sewage sludge to evaluate co-combustion with coal in a coal-fired power plant. In the result of proximate analysis, sewage sludge has 78.09%, 79.65% of moisture content in A STP(Sewage Treatment Plant) and B STP, respectively. The dried sewage sludges show 0.12, 0.14 of fuel ratio value, respectively and over 30,000kcal/kg of combustible index. It means that the dried sewage sludges needs to reform from the results of fuel ratio and combustible index. As a results of the economical benefit evaluation of dried sewage sludge, about 73.4 million won through using the dried sewage sludges instead of coal and 56.4 million won through REC(Renewable Energy Certificate) cost were saved, respectively. On the other hand, it occurs 4.2 million won of additional cost related to ash disposal and 2.6 million won of investment/operation cost for co-combustion facility. In conclusion, co-combustion of dried sewage sludges with coal in a coal-fired power plant saves about 123 million won. However, it needs to consider for power supply to produce dried sewage sludges and opportunity cost for environmental pollution and so on to evaluate more reasonable benefit of co-combustion.

• Journal of Plant Biotechnology
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• v.30 no.1
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• pp.19-25
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• 2003

Radiation technique in agriculture was initiated to develop mutant rice. Seeds of Daechungbyeo rice were irradiated with 250 Gy gamma ray for the purpose of inducing and selecting rice variants. Some quantitative traits of the variants in M$_{8}$ generation were evaluated and RAPD analysis was carried out. Variants showed a wider range of agronomic characteristics in both a positive and a negative direction compared with their original variety. The new mutants were characterized by an increased or decreased in plant height, lodging resistance and shorter panicle. RAPD analysis showed that polymorphic bands were presented in most of the primers. In comparison with the original variety, variants were classified into four groups through UPGMA analysis. Among mutants no. 91, 139, 140 and 141 was ranked as salt tolerance and the proline content of these mutants was more increased than that of original variety. The lines of 139, 140 and 141 had the highest genetic distance as compared to original variety in the dendrogram. It is expected that such variants will be useful not only for studying molecular genetics but also for breeding research and genetic analysis.s.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.14 no.2
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• pp.113-122
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• 2016

In this study, the dispersion process of pollutant substances in a port under wave and current environments was evaluated by a hydraulic experiment. Once the contaminants washed ashore into the port of Wolseong nuclear power plant, transport processes of pollutants were investigated by tracking the tracer according to the variations of experimental condition through a hydraulic experiment. Several hydraulic experiments were performed to analyze the pollutant discharge rate of the surface coming from the different coastal environments. From the hydraulic experiment results, the tracer concentration decreased exponentially. These results suggested that, after the tracer was transported to the open sea, a different gradient was shown under different conditions. For the case of a diluted condition, the half-life of flow rate was 2.70, 10.40, and 26.39 days for 30, 20 and 10 rpm in the left-side, respectively. The decrease of the tracer concentration under conditions of 30 rpm was much faster than that under conditions of 10 rpm. For the wave condition, the half-life of flow rate was 4.59 and 15.35 days for the right and left side of the port in a hydraulic scale prototype, respectively.

• Applied Chemistry for Engineering
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• v.7 no.6
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• pp.1164-1173
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• 1996

Treating methods and characteristics of waste from a nuclear fuel powder conversion plant were studied. To recovery or treat a trace uranium in liquid waste, the ammonium uranyl carbonate(AUC) filtrate must be heated for $CO_2$ expelling, essentially. Uranium content of final treated waste solution from fuel powder processes for a heavy water reactor(HWR) could be lowered to 1 ppm by the lime treatment after the ammonium di-uranate(ADU) precipitation by simple heating. Otherwise, in case of the waste from fuel powder processes for a pressurized light water reactor(PWR), it is result in 0.8 ppm as a form of uranium peroxide such as $UO_4{\cdot}2NH_4F$ compounds. Optimum condition was found at $101^{\circ}C$ by the simple heating method in case of HWR powder process waste. And in case of PWR powder process waste, optimum condition could be obtained by precipitating with adding hydrogen peroxide and adjusting at pH 9.5 with ammonia gas at $60^{\circ}C$ after heating the waste In order to expelling $CO_2$. As the characteristics of recovered uranium compounds, median particle size of ADU was increased with pH increasing in case of HWP waste. Also, in case of uranium proxide compound recovered from PWR waste, the property of $U_3O_8$ power obtained after thermal treatment in air atmosphere was similar to that of the powder prepared from AUC conversion plant.

• Archives of design research
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• v.17 no.4
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• pp.233-240
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• 2004

Living in the modern age with well-developed scientific technologies, all of us are enjoying convenient lives because of 'energy'. Korea, poor in resources, is importing a large portion of its energy sources from abroad but energy consumption shows an upward tendency due to the continuing economic growth and the improvement of living conditions. The atomic energy is considered a self-reliant, alternative energy source like our country. However, it is necessary to educate the people on and publicize atomic power generation in the face of the widespread negative recognition that the atomic power plant is a hazardous facility. The study approaches to these matters with a human-friendly and environment-friendly coloring plan in the perspective of environment coloring plan. The study aims to minimize negative images of the atomic power, while highlighting its friendly and positive images so as to enhance the confidence of the people on the atomic power and to create a clean image for the atomic power. For this goal, the study examined and analyzed cases of Japanese nuclear power plants and domestic nuclear power plants, and also carried out an on-site survey in the sites in which nuclear power plants would be constructed to extract concrete colors through the analyses of their natural environment and actual conditions. The study also carried out a survey of residents in the regions to induce their participation, and reflected the survey results to the coloring plan. The study is expected to create a stable and friendly image of the nuclear power plant through materializing its environment-friendly image and remove negative recognition that the people have on the nuclear power plant. It also attempted an external environment-coloring plan a s a strategic means for positive publicity and through this, is expected to ultimately contribute to the creation of the new images of nuclear ower plants.

• Journal of Radiation Protection and Research
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• v.23 no.2
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• pp.109-114
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• 1998

Radiological safety for the conventional operation of Demonstration-Scale Incineration Plant (DSIP) was assessed on the basis of the results of trial burns using the simulated and real radioactive wastes. Radiation dose assessments for routine releases on an annual basis as well a several severe accidental releases on a short-term basis (2h) revealed that there would be no significant environmental impact when low-level waste Is incinerated in DSIP. For semivolatile radioactive cesium species, expected emission concentrations slightly exceeded 10% of maximum permissible concentration. Removal characteristics of the bag filter for condensed-phase cesium species was investigated by the trial burns of simulated waste with inactive cesium tracer. In the off-gas before passing through bag filter, distributions of condensed cesium species in the transition size ranging between the diffusional and inertial region are less than 5%. The overall collection efficiency of the bag filter for cesium species was higher than 99.9%, showing enough decontamination capability as a primary filter for the low-temperature dry off-gas system in radwaste incineration plant.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1996.10b
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• pp.59-65
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• 1996

중국은 향후 2020년까지 1000MW급 경수로를 중점적으로 35기이상을 건설할 것으로 예상되는 최대 잠재시장이다. 따라서 현재 1000MW급 원전기술자립을 95% 확보한 한국은 중국 및 인근 아시아지역 원전건설 시장에서 외국과의 경쟁력 확보를 위하여 주도적인 참여방안을 모색해야 한다. 이러한 관점에서 원자력기반기술이 우수한 중국과 한국은 한국형표준원전(KSNP)을 기본모델로 하여 중국 및 아시아의 원전건설에 적용할 표준원전(CSNP, ASNP)을 공동개발 하기 위한 협력체계 구성방안을 제안하였다. 또한 한국이 원자력기술 수출국으로 위치를 확고히 하고, WTO 출범에 따른 원자력시장 개방화에 경쟁력을 갖추기 위해서는 원자력 선진기술을 보유하고, 건설자금조달 및 사업관리 능력과 함께 폭넓은 해외협력 관계를 갖춘 세계적인 원전공급자(Nuclear Vendor)를 육성해야 한다.

• Journal of Energy Engineering
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• v.14 no.2 s.42
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• pp.147-152
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• 2005

Calculation equations of fired fuel comsumption rating at boiler can lead from combustion anal-ysis and boiler heat balance using mass & energy conservations. By comparing calculation equation results with those of measurement, we can confirm the deviation of fuel consumption rate, and correction rate, and correction degree, and can also establish the proven technology to apply the equation at the site. We applied fuel rate equation to the operating power plant and recorded $2.4\%\;&\;1.5\%$ of deviation at each coal and oil fired boilers. This range of deviation is regarded as trustable to apply the fuel consumption equation to the actual site.

• Journal of Korean Society of Water and Wastewater
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• v.21 no.5
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• pp.539-549
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• 2007

To establish effective and prompt measures for energy conservation in public wastewater treatment plants in Korea, energy consumption rates in 233 utilities in 9 provinces and 7 metropolitan cities are investigated and compared to the rest of the world. Mean load factor for wastewater treatment utilities is 74.9% and those for influent pumps and aeration blowers are 56.2% and 61.0%, respectively. Mean electrical energy usages as the key performance indicators are $0.243kWh/m^3$ for overall sewage treatments and 2.07 kWh per unit kg BOD removal. Digester gas as one of major byproducts in the process amounts to $382,000m^3/day$ nationwide. While major part of the digester gas is used for sludge heating, only 7.3% of the gas is utilized for electricity generation. Both efficiencies for BOD removal and digestion gas generation are considerably lower than those in USA and EU utilities due to low concentration of organic material in influent wastewater. Such low energy regeneration, in turn, results in significantly higher energy consumption in Korean plants, compared to that in USA and EU ones.

• Asian Journal for Public Opinion Research
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• v.2 no.3
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• pp.172-195
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• 2015

Multiple nationwide opinion surveys, carried out by the government (cabinet office), major media (national newspapers and NHK), the National Institute for Environmental Studies, and the Atomic Energy Society of Japan, have revealed that the Fukushima nuclear accident has heightened people's perception of disaster risks, fear of nuclear accidents, and increased recognition of pollution issues, and has changed public opinion on nuclear energy policy. The opinion gap on nuclear energy policy between specialists and lay people has widened since the disaster. The results of the Japanese General Social Survey data show that objections to the promotion of nuclear energy are strong among females, and weaker among young males and the supporters of the LDP. These findings are similar to the data collected after the Chernobyl accident. People who live in a 70km radius of nuclear plants tend to evaluate nuclear disaster risks higher. Distance from nuclear plants and the perception of earthquake risk interactively correlate with opinions on nuclear issues. Among people whose evaluation of earthquake risk is low, those who live nearer to the plants are more likely to object to the abolishment of nuclear plants. It was also found that the nuclear disaster has changed people's behavior; they now try to save electricity. The level of commitment to energy saving is found to relate to opinions on nuclear issues.