Republic of Korea is preparing to decommission Kori Unit 1 and Wolsong Unit 1. Decommissioning of a nuclear power plant proceeds in the following stages: shutdown, transition period, decontamination, cutting, waste treatment, and site restoration. When nuclear power plant is decommissioned, It is expected that approximately 80,000 drums of radioactive waste will be generated per nuclear power plant. Therefore, various technologies are being researched and developed to reduce this to approximately 14,500 drums. Technologies for waste volume reduction are largely mechanical and electrical/thermal methods. Representative examples of mechanical volume reduction technologies include super compactors and electrical/thermal volume reduction technologies include induction and plasma torch furnaces. Both technologies are effective reduction technologies, but the reduction ratio varies depending on the type or condition of waste before treatment. For example, as a result of testing waste reduction using a super compactor at NUKEM in Germany, the reduction ratio was found to be between 1.3 and 7 depending on the type or condition of waste such as chips, ash, scrap metal, sand, etc. And according to IAEA-TECDOC-1527, when reducing the volume of metals, aluminum, lead, copper, brass, etc. using induction melting, the waste volume reduction ratio is 5 to 20. In this paper, referring to these results, a melting test was conducted using a previously developed plasma torch with an output of more than 100 kW. And volume reduction characteristics of this plasma torch was considered depending on waste type or condition.

The purpose of this study is to provide technical issues in upgrade and modification of fuel handling equipment at operating nuclear power plants. The improvement for safety function and performance enhancement of fuel handling equipment has been going on for 20 years since the early 2000’s. This improvement is recently focused on the replacement of components through the performance analysis and the operation and maintenance plan based on replacement cycle of its component. Additionally, it is required to secure spare parts so that it can be operated at all times with compatibility and standardization to other domestic nuclear power plants. The fuel handling equipment is consisted of refueling machine, upender and carriage of fuel transfer system, spent fuel handling machine, new fuel elevator and various tools, and the equipment are linked in systematic interlocks. Fuel handling is a critical task during a nuclear power plant refueling outage. Even minor component defects may stop operation of the whole system and have a significant impact on the overall system process. To achieve this goal, major components that are expected to be replaced for reliable operation are summarized as follows; 1) motor assembly with AC servomotors and driver for bridge, trolley and hoist of refueling machine and spent fuel handling machine, 2) winch motor and drive for upender and carriage of fuel transfer system, 3) operator control console with a HMI PC base PLC (Programmable Logic Controller) control system, 4) positioning and load weighing sensors such as an encoder and a load cell with its support for periodic calibration and maintenance, 5) main power drapped style festoon cable assembly for bridge of refueling machine, 6) pneumatic control assembly for gripper operation of refueling machine, 7) active components (e. g., air motor, hydraulic cylinder and limit switch) to be removable and reinstallable without requiring the water level to be lowered. It is advisable to utilize such various information as it can help to improve reliability of fuel handling as a critical path in upgrade and modification of fuel handling equipment at operating nuclear power plants.

The purpose of this study is to provide lessons learned in the experience of improvement work of fuel handling equipment at operating nuclear power plants. The upgrade of fuel handling equipment for safety enhancement and performance improvement has been going on for 15 years since the early 2000’s. The main goal is to increase fuel loading/unloading capability of the equipment from about 2.5 fuel assemblies per hour to more than six (6). It is achieved with sequential operations of three (3) fuel handling equipment, which consists of the refueling machine, the fuel transfer system and the spent fuel handling machine. The scope of the upgrade for fuel handling equipment is summarized as follows. The PC data control system based on PLC for interlocks and high speed motor drive system is introduced for better operating efficiency. The motors and drives for bridge, trolley, and hoist are replaced with AC servomotors and drivers, respectively. The fuel transfer system has an auto-initiation feature operating from the refueling machine or the spent fuel handling machine. The winch motor and drive for the carriage of fuel transfer system is also replaced with AC servomotors and drivers. And some of HPU (hydraulic power units) equipment for each building (reactor containment building and fuel handling building) are replaced to improve their function. The considerations for improvement of fuel handling equipment are as belows. 1) Fuel handling should be consistent with the instructions provided by the fuel designer and/or manufacturer, which are for Standard type fuel and Westinghouse type fuel, used in domestic nuclear power plants. Each fuel has unique design characteristics, which are PLC setpoints for overload and underload, slow speed zones for a bridge, trolley and hoist, allowable acceleration/deceleration value in handling, hoist elevation and manual speed in off-index operation at reactor. 2) The interlock system should be designed in accordance with design criteria specified by the utilities of nuclear power plant. 3) Performance should be improved according to the operating characteristics of the fuel handling equipment. High-speed and optimization of FTS upender and carriage are essential for operating performance so that its modification should be considered first. And the low speed and range in the operation mechanism of the hoist should be designed to comply with guidelines. 4) The accident analysis through self-diagnosis function and operation history in modification at domestic operating nuclear power plants would be good lessons learned. It is advisable to utilize such various information as it can help to improve reliability of nuclear fuel handling operation and power plant operation rate.

This paper proposes a method to reduce the pose error and to solve the dead reckoning issue which occurs when the mobile robot with continuous-tracks travels in the unstructured environments. When the continuous-track type mobile platform travels on terrain such as sand, gravel, stairs and etc., slippage occurs and thus the driving state of the mobile robot cannot be recognized normally. To compensate for this pose error, the proposed method utilizes optical flow estimation detected by camera. This method is tested through experiment. Finally, This method reduces the pose error detected on inertia measurement unit within some limit, while the pose error of without compensation increases without limit during robot move.

Pseudolymphoma or benign lymphoid hyperplasia is an uncommon benign lymphoproliferative lesion that occurs very ralely in the oral mucosa, most commonly in the hard palate. It is important to differentiate between malignant lymphoma and pseudolymphoma with similar clinical and morphological symptoms. Clinically, pseudolymphoma is a firm, painless, nonulcerated, nonfluctuant, slowly growing mass or swelling on the one side of the palate. However, lymphoma at hard palate is unilateral, and some are hard, painful, or show evidence of bone destruction. The treatment of pseudolymphoma is local excision.

Recently, Social Commerce that provides customer with cheap deals is under the spotlight. The purpose of this study is to propose how to use social commerce on small restaurant business, which encompass almost a half of entire deals. We analyzed each elem

에너지원으로서 수소를 생산하기 위하여 하니컴 구조를 갖는 모노리스에 10 wt% Ni/CeO2-ZrO2 촉매를 담지한 후 메탄의 수증기 개질 실험을 수행하였다. 다른 CeO2/ZrO2 몰비를 갖는 촉매들 중에서, Ni/CeO2-ZrO2(CeO2/ZrO2=4/1)촉매가 700-800℃에서 높은 메탄의 전환율을 보여 주었다. 10wt% Ni/CeO2-ZrO2 촉매가 담지된 금속 모노리스 촉매체는 높은 열전도도와 비표면적들로 인하여 좋은 촉매 특성을 보여줌을 확인할 수 있었다. 또한, 금속모노리스 촉매체는 반응물에서 과다의 수증기에 의한 수소 수율에서 크게 영향을 받지 않음을 알 수 있었다. GHSV=30,000h-1, 반응물 비(H2O/CH4=3.0) 반응온도 800℃에서 금속모노리스 촉매체는 98%이상의 메탄의 전환율을 보여주었다. 생성물 가스에서 CO2/CO의 비는 수증기/메탄의 반응물비가 증가할수록 수성가스화 반응에 의하여 증가됨을 알 수 있었다.

Environmentally inflicted stress (abiotic stress) such as high drought stress could be limiting the plant productivity. The mechanism of drought stress signaling in plant related with anti-apoptosis has not yet been full described. Understanding drought stress signaling is key to producing drought-tolerant plant. In this study we recently have identified Oryza sativa genes related abiotic stress water deficit. Abiotic stress related genes were screened from Oryza sativa cDNA library and identified gene by yeast functional screening. The yeast expression showed that they east cell grow well on SD-galactose-Leu-Ura-. The screening of over than 7000 clones from Oryza sativa cDNA libraries has been identified. 28 clones that survived following BAX-expression on inducible galactose medium. R12H780 clones confirmed protein prediction like putative senescence-associated-protein. This gene contains an open reading frame (ORF) of 108 amino acids. Transcription of R12H780 was induced in response to drought stresses, RT-PCR analysis showed transcript level in plant strongly detected in earliest time of drought stress treatment. Yeast transformed with R12H780 gene displayed markedly improved tolerance to PEG treatment, and high salinity in comparison to the control yeast (vector only). The results indicate R12H780 expression represents a new type of drought stress related gene with anti-apoptotic in Oryza sativa and endows tolerance to several types abiotic stress.

The significance of genetic stability and bio-safety environment has been recently recognized by many GM plants. This study was to evaluate the GM stability of transgenic rice and to identify the environment variance. The GM rice of vitamin A　-enriched rice and four check cultivars were analyzed the data on agronomic characters and principal component for 2009-2011 in large-GM crop field. Cultivation environment was conducted in the large-GM field and greenhouse to determine grain characters. In this experiment, there was no significant difference in agronomic characters between GM rice of vitamin A-enriched rice and a donor plant, Nagdong. Related to grain characters, grain appearance and physicochemical characteristics were similar to GM rice of vitamin A-enriched rice and a donor plant, Nagdong. However, grain appearance in GM rice of vitamin A-enriched rice showed to white core and white belly when GM rice of vitamin A-enriched rice was planted in greenhouse. The type and distribution of dominant weed species also were not different from GM rice of vitamin A-enriched rice and a donor plant, Nagdong. Additionally that of gene flow was not detected in dominant weed species by PCR analysis.