A lot of CANDU Spent Fuels (CSFs) have been stored in spent nuclear fuel pools and dry storage facilities. In accordance with the enhanced nuclear regulations, the initial characteristics of CSF should be inspected to ensure the integrity of CSF and the reliable operation of storage system before loading it into a cask for long-term dry storage. For the inspections, an initial characteristics measurement equipment was designed, which is used for Pool-Side Examination (PSE) in the spent fuel pool of the pressurized heavy water reactor nuclear power plant. Measurements using the equipment consist of non-contact inspections and contact inspections. The non-contact inspections do not affect CSF integrity, whereas the integrity of CSF can be reduced during the contact inspections under abnormal operating conditions because the probe of equipment may apply specific loads to the CSF. Therefore, the structural integrity evaluations of equipment and CSF are performed using Finite Element (FE) analyses for four combinations based on two abnormal conditions and two probe positions. The used abnormal conditions are the pressing load condition and the scratching load condition, and two probe positions are the center and bottom of the fuel rod in the longitudinal direction, respectively. In this evaluation, the bottoms of the fuel rod or CSF are defined as the regions facing the bottom surface of equipment. The analysis of the pressing load condition is performed by pressing the probe of the equipment in radial direction of the CSF fuel rod. That of the scratching load condition is carried out by applying a specific radial load to the CSF fuel rod using the probe and then applying the load to the surface of the fuel rod while moving axially along the surface. All combinations are analyzed considering geometric, boundary and material non-linearity under the dynamic load, which is dependent on the equipment operating velocity. The stresses of CSF and equipment components were obtained from these analyses. The maximum stress of each component was generated at the combination on the scratching load condition for the bottom position among the four combinations. The obtained maximum stresses are lower than the yield stress for each component material. Also, the CSF is not overturned due to the support plate of the equipment in all analyses. Therefore, the structural integrity and safety of the equipment and the CSF are maintained under abnormal operating conditions during the inspection using the initial characteristic measurement equipment.

Recently, air pollution from fossil fuels is at a serious level, and the IMO proposes to reduce greenhouse gas emissions by about 70% by 2050, and controls greenhouse gas emissions by applying the energy efficiency disign index(EEDI) to each ship type. In this study, the marine fuel oil viscosity of MGO, MDO, HFO and CGO according to the temperature change was compared and measured and the difference was analyzed. As a result, the viscosity of CGO was 3.32mPa·s, which was almost similar to MGO(3.40mPa·s) and MDO(3.51mPa·s) so it was judged that it could be used as a marine fuel, and it was found that there was a significant difference with HFO at P<0.01 there was.

전 세계적으로 에너지원 다양화 및 온실가스 저감을 위한 다양한 신재생에너지 보급활성화 정책이 추진되고 있다. 국내에서도 500MW 이상의 발전설비를 보유한 발전사업자에게 신재생에너지 공급 의무화제도(Renewable Portfolio Standard(RPS))를 시행중이다. 발전사업자들은 의무공급량 이행을 위해 발전용 바이오중유를 사용하고 있다. 발전용 바이오중유란 동 식물성 유지, 지방산에스테르 및 그들의 혼합물로서 동점도, 유동점, 전산가 등의 품질특성을 만족해야 한다. 발전용 바이오중유는 원료물질에 의해 품질특성이 결정되었고, 중유와의 혼합비율이 증가할수록 유동점, 밀도, 황분 및 동점도는 감소하고 전산가, 요오드가, 산소함량은 증가하였다. 본 연구에서는 중유 대체연료로서의 발전용 바이오중유의 품질특성과 C 중유에 혼합 시, 혼합비율에 따른 물성 변화에 대해 검토하였다.

본 연구에서는 360˚C 물 및 360˚C, 70ppm LiOH 수용액 분위기의 static autoclave를 이용하여 새롭게 개발한 Zr 신합금 (Zr-0.4Nb-0.8Sn-xFeCrMn, Zr-0.2Nb-1.1Sn-xFeCrMn, Zr-1.0Nb-xFeCu) 의 부식 특성을 평가하였다. 합금의 미세구조를 광학현미경과 TEM을 이용하여 관찰하였고, 부식시험 중에 생성된 산화막은 SEM과 XRD를 이용하여 단면 및 결정구조를 조사하였다. 부식시험 결과, 3종의 합금 모두 360˚C 물 분위기보다 360˚C, 70ppm LiOH 수용액 분위기에서의 부식저항성이 감소하였으며 특히, High Nb 합금의 경우 급격한 가속 부식현상을 나타내었다. 합금원소 첨가량과 관련하여 Nb의 함량을 고용도 이내로 줄이고 Sn을 적절히 첨가한 조성의 합금이 Sn을 첨가하지 않고 고용도 이상의 Nb을 가진 합금보다 우수한 부식저항성을 나타내었다. 또한 최종열처리가 부식에 미치는 영향의 경우에, 완전재결정 조직의 합금이 부분재결정 조직을 가진 합금보다 부식저항성이 감소되었는데 이는 기지조직에서 석출하늘 제 2상의 크기 및 분포에 의한 영향으로 사료된다.

Fossil fuel combustion generates large amount of green house gas and it was considered major emission source causingglobal warming. For reducing green house gas, renewable energy resources have been emerged as an alternative energy.Among those resources, waste has been considered major resource as one of renewable energy, but it has been not utilizedsufficiently. In Korea, there are lots of efforts to utilize sewage sludge as one of renewable energy resources due to wasteto energy project of government. In this paper, sewage sludge was utilized as main fuel in order to recover heat energysource using oxy-fuel combustion in 30KWth circulating fluidized bed (CFB) pilot plant. Firstly, basic characteristics ofsewage sludge were analyzed and fuel feed rate was calculated by stoichiometry oxygen demand. For producing 30kwthermal energy in pilot plant, the feeding rate of sewage sludge was calculated as 13kg/hr. In oxy-fuel combustion, oxygeninjection rate was ranged from 21% to 40%. Fluidized material was more suitably circulated in which the rate of U/Umfwas calculated as 8 at 800oC. Secondly, Temperature and pressure gradients in circulation fluidized bed were comparedin case of oxy and air combustion. Temperature gradients was more uniformly depicted in case of 25% oxygen injectionwhen the value of excess oxygen was injected as 1.37. Combustion efficiency was greatest at the condition of 25% oxygeninjection rate. Also, the flue gas temperature was the highest at the condition of 25% oxygen injection rate. Lastly,combustion efficiency was presented in case of oxy and air combustion. Combustion efficiency was increased to 99.39%in case of 25% oxygen injection rate. In flue-gas composition from oxy-fuel combustion, nitrogen oxide was ranged from47ppm to 73ppm, and sulfur dioxide was ranged from 460ppm to 645ppm.

Renewable energy has been focused issue in terms of green house gas (GHG) prevention as well as the sustainable development. One of the most feasible and economical ways to enhance the renewable energy production would be the biomass energy production, which is renewable in terms of carbon neutral. At present, many developed country discovered the biomass resources that will be fitted to their purpose. In Malaysia and Indonesia, palm kernel shell (PKS) was only the waste to dumping on the ground around 5 years ago, but they are exported to all over the countries as a biomass resources. The woody biomass has been the most traditional biomass resources, and their price is so high and quantity is so limited that the electric generation can’t obtain enough quantities to fulfill their renewable energy obligation quarter. Within near future, many types of biomass like rice husk pellet, coconut shell, and empty fruit bunch (EFB) pellet, will be traded commercially and imported to Korea after all. The Korean power plant company using coal try to discover the biomass resources in south. east Asia. In this study, 7 types of biomass was tested for fuel quality as well as the combustion behavior, and compared to each other. It can be found that the fuel property of biomass can be varied with the types and the combustion pattern may not be identical with respect to the types of the biomass. PKS was the very good fuel with high calorific value, but contains some chloride. Wood chips also were a good fuel property cleaner than coal in terms of emission gas. The rice straw, however was not good enough to use as a fuel.

Sediment works as a resource for electric cells. This paper was designed in order to verify how sediment cells work with anodic material such as metal and carbon fiber. As known quite well, sediment under sea, rivers or streams provides a furbished environment for generating electrons via some electron transfer mechanism within specific microbial population or corrosive oxidation on the metal surfaces in the presence of oxygen or water molecules. We experimented with one type of sediment cell using different anodic material so as to attain prolonged, maximum electric power. Iron, Zinc, aluminum, copper, zinc/copper, and graphite felt were tested for anodes. Also, combined type of anodes-metal embedded in the graphite fiber matrix-was experimented for better performances. The results show that the combined type of anodes exhibited sustainable electricity production for ca. 600 h with max. 0.57 W/㎡ Al/Graphite. Meanwhile, graphite-only electrodes produced max. 0.11 W/㎡ along with quite stationary electric output, and for a zinc electrode, in which the electricity generated was not stable with time, therefore resulting in relatively sharp drop in that after 100 h or so, the maximum power density was 0.64 W/㎡. It was observed that the corrosive reaction rates in the metal electrodes might be varied, so that strength and stability in the electric performances(voltage and current density) could be affected by them. In addition to that, COD(chemical oxygen demand) of the sediment of the cell system was reduced by 17.5∼36.7% in 600 h, which implied that the organic matter in the sediment would be partially converted into non-COD substances, that is, would suggest a way for decontamination of the aged, anaerobic sediment as well. The pH reduction for all electrodes could be a sign of organic acid production due to complicated chemical changes in the sediment.