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        검색결과 18

        1.
        2023.11 구독 인증기관·개인회원 무료
        The PRIDE scale mechanical decladder is decladding apparatus for separating and recovering fuel material and cladding hull by horizontally slitting rod-cut. In order to enhance mechanical decladdng efficiency, the main requirements were considered as follows. Decladding of the fuel rods may be performed by rotation of three circular cutting blades inserted among the rollers arranged at 120° portion. In a mechanical decladder, a slitting assembly as a unit for slitting the cladding tube may include cutting blades for slitting and rollers for guiding extrusion of the cladding tube. Rotation of the cutting blades may be caused by the fuel rods being extruded from a plurality of rollers. Slitting intervals of rod-cuts having different diameters may be controlled by adding or removing a spacing plate between the cutting blade and a ranch bolt for fixing the slitting blade to the slitting assembly. An extrusion velocity with respect to the fuel rods may be controlled by a hydraulic pressure applied to the fuel rods. A force for cutting the fuel rods may be adjusted by controlling steel plates. Forces applied to a plurality of rollers may be generated by the hydraulic cylinder. The hydraulic pressure may be controlled by hydraulic pressure controller. The PRIDE scale mechanical decladder mainly consists of auto feeding module, hydraulic cylinder module and blade module. A load cell was installed between the hydraulic cylinder and the extrusion pin to measure the decladding force and slitting velocity, and a data acquisition system capable of obtaining data by using the RSC 232 was constructed. Also, the control panel can control the forward and backward movement of the extrusion pin, the hydraulic flow rate, and the hydraulic velocity. In the mechanical decladding test, 40 pieces of simulated rod-cuts were loaded in two auto feeding basket and slit by utilizing the 3-CUT blade modules in the housing, and hulls and simulated pellets were collected in the collection container. As a result, 80 pieces of simulated rodcut (brass pellets + Zry4 tube) were slit continuously without any problem. About 35 min was required to slit 80 rod-cuts and average decladding force was 260 kg. The decladding force of the ceramic simulated rod-cuts (castable) requires 25 kg less force than the brass pellets. Therefore, it is estimated that the spent fuel rod-cut can be fully split into three pieces using the mechanical decladder.
        3.
        2023.05 구독 인증기관·개인회원 무료
        An important goal of dismantling process is the disassembling of a spent nuclear fuel assembly for the subsequent extraction process. In order to design the rod extractor and cutter, the major requirements were considered, and the modularization design was carried out considering remote operation and maintenance. In order to design the rod extractor and cutter, these systems were analyzed and designed, also the concept on the rod extraction and cutting were considered by using the solid works tool. The main module consists of five sub-modules, and the function of each is as follows. The clamping module is an assembly fixing module using a cylinder so that the nuclear fuel assembly can be fixed after being placed. The Pusher module pushes the fuel rods by 2 inches out of the assembly to grip the fuel rods. The extraction module extracts the fuel rods of the nuclear fuel assembly and moves them to the consolidation module. The consolidation module collects and consolidates the extracted fuel rods before moving them to the cutting device. And the support module is a base platform on which the modules of the main device can be placed. The modules of level 2 can be disassembled or assembled freely without mutual interference. For the design of fuel rods cutter, the following main requirements were considered. The fuel rod cut section should not be deformed for subsequent processing, and the horizontally mounted fuel rods must be cut at regular intervals. The cutter should have the provision for aligning with the fuel rod, and the feeder and transport clamp should be designed to transfer the fuel rods to the cutting area. The main module consists of 6 sub-modules, and function of each is as follows. The cutting module is a device that cuts the fuel rods to the appropriate depth for notching. The impacting module is a device that impacts the fuel rods and moves them to the collection module. The transfer module is a device that moves the fuel rods to the cutting module when the aligned fuel rods enter the clamp module. The clamping module is a device to clamp the fuel rods before moving them to the cutting module. The collection module is a container where the rod-cuts are collected, and the support module is a base platform on which the modules of the main device can be placed. The module of level 3 can be disassembled or assembled after the cutting module of level 2 is installed, and the modules of level 2 can be disassembled or assembled freely without mutual interference.
        4.
        2022.10 구독 인증기관·개인회원 무료
        Dry head end process is developing for pyro-processing at KAERI (Korea Atomic Energy Research Institute). Dry processes, which include disassembling, mechanical decladding, vol-oxidation, blending, compaction, and sintering shall be performed in advance as the head-end process of pyro-processing. Also, for the operation of the head-end process, the design of the connecting systems between the down ender and the dismantling process is required. The disassembling process includes apparatus for down ender, dismantling of the SF (Spent Fuel) assembly (16×16 PWR), rod extraction, and cutting of extracted spent fuel rods. The disassembling process has four-unit apparatus, which comprises of a down ender that brings the assembly from a vertical position to a horizontal position, a dismantler to remove the upper and bottom nozzles of the spent fuel assembly, an extractor to extract the spent fuel rods from the assembly, and a cutter to cut the extracted spent fuel rods as a final step to transfer the rod-cuts to the mechanical decladding process. An important goal of dismantling process is the disassembling of a spent nuclear fuel assembly for the subsequent extraction process. In order to design the down ender and dismantler, these systems were analyzed and designed, also concept on the interference tools between down ender and dismantler were considered by using the solid works tool.
        5.
        2022.05 구독 인증기관·개인회원 무료
        Dry head end process is developing for pyro-processing at KAERI (Korea Atomic Energy Research Institute). Dry processes, which include disassembly, mechanical decladding, vol-oxidation, blending, compaction, and sintering shall be performed in advance as the head-end process of pyroprocessing. An important goal of the head-end process is the fabrication of a proper feed material for the subsequent electrolytic reduction process. In the vol-oxidation process, the pellet type-SFs are pulverized by an oxidation under an air-blowing condition, and some volatile fission products are removed from the produced powders by using an air flow. After blending, the U3O8 powders are moved to a compactor of compaction process to obtain U3O8 porous pellets. In the fine powders removal system connected with compactor, for the improved performance of oxide reduction process coupled to dry head-end process, the removal/recovery system for fine powders potentially attached to the surface of oxide reduction raw material was developed and applied to the removal of fine powders from green pellets fabricated in dry head-end process. The removal efficiency of fine powders was also verified using porous U3O8 pellets in the fine powders removal system.
        13.
        2018.01 구독 인증기관 무료, 개인회원 유료
        2015년 미국 오바마 대통령은 ‘정밀의학창시 (Precision Medicine Initiative)’를 공표하였다. 오바마가 추진하고자 하는 정밀의학은 지금까지의 맞춤의학을 더욱 고차원적으로 발전시킨 것으로써, 수많은 사람들의 건강 및 의료와 관련된 빅 데이터를 이용하여 질병의 병태생리학과 관련된 모든 변수들 간의 복합적인 관계망을 최대한 담는 알고리듬을 개발한 다음, 개별 환자의 총체적인 신체조건을 고려하여 의학적인 예측과 추천을 해 보려는 시도이다. ‘블랙박스 의학(Black-Box Medicine)’이라고 불리는 이 의학은 진단, 치료, 예방 등의 면에서 의학적인 성과와 함께 의료 활동의 효율성을 높여 의료비 절감의 효과도 기대된다. 본 연구에서는 블랙박스 의학을 선도하고 있는 미국을 중심으로, 맞춤의학을 위해 개발된 체 외진단법들을 살펴보고, 맞춤의학 개발과 관련된 지식재산 제도 및 판매 규제를 분석한 다음, 블랙박스 의학 발전을 위한 인센티브 시스템과 안전성 및 향상된 의료적 결과를 보장할 수 있는 제도적 방안에 대하여 고찰해 본다. 블랙박스 의학을 실현하여 광범위한 의료혜택을 얻기 위해서는 블랙박스 의학의 구성요소별로 효과적인 기술혁신 정책을 세우는 것이 우선이다. 또한 블랙박스 의학을 실현하기 위하여 어느 때보다 대중의 참여와 지원이 필요하다. 블랙박스 의학은 과학자들과 의사들의 노력만으로 절대 실현될 수 없다. 블랙박스 의학의 세 가지 필수요소 중 하나인 데이터세트를 갖추기 위해서는 많은 사람 들의 양질의 건강 및 의료데이터를 오랜 기간 동안 수집하여야 하는데 여기엔 상당한 공적 투자뿐 만 아니라 많은 사람들의 깊은 관심과 적극적인 참여가 꼭 필요하다. 블랙박스 의학 시대의 중요 한 과제는 대규모의 데이터가 수집된 다음 이를 많은 사람들이 최대한 이용할 수 있도록 하는 것이다. 여기에는 접근 허용에 관한 정책, 데이터뱅 크의 운영방식, 하류 기술혁신에 대한 지식재산 전략 등이 관련될 수 있다. 한편 지식재산 제도의 인센티브 보완과 특허권들의 통합 및 공유를 도모 하기 위한 방안 마련과 함께, 차세대 기술 적합성과 성능 보장을 위한 새로운 판매 규제책도 요구 된다.
        6,100원
        15.
        2007.06 구독 인증기관 무료, 개인회원 유료
        As to the unexpected future and rapid changes of technologies, world famous scholars and experts have deliberated an ideal model of future society and suggested a way to overcome future challenges. APEC Future Education Consortium seek to develop a community model of future education, embodying a 'Total-supporting System, ' and advancing research activities to meet the challenges of the IT-based future society while emphasizing a value oriented society and considering the harmony between technologies and human beings through implementing the EduPark.
        4,000원
        16.
        2007.06 구독 인증기관·개인회원 무료
        18.
        2019.03 KCI 등재 서비스 종료(열람 제한)
        철근의 대체보강재로서 섬유보강근에 대한 적용연구가 증가하고 있으며, 단기거동에 대한 많은 연구가 진행되어 왔다. 본 연구에서는 동결융해와 알칼리 환경하에서의 바살트와 유리섬유보강근의 미세구조와 인장거동 변화를 실험적으로 평가하였다. 100회까지의 동결융해에서 5% 내외의 강도와 탄성계수 저하가 발생하였다. 20일까지의 초기 미세구조변화의 경우 알칼리용액의 온도가 낮은 경우에는 손상이 거의 발생하지 않았으나, 60℃에서는 20일 경과시에도 수지 용해와 섬유 손상이 관찰되었으며, 수지계면의 섬유분리가 발견되었다. 알칼리 환경에서는 20℃환경에서 100일까지는 10% 내외의 강도저하 현상이 발생하였으며, 500일 노출시 최대50%의 강도 저하가 발생하는 것으로 관찰되었다. 40℃와 60℃ 환경에서는 50일과 100일에서 급격한 강도저하가 관찰되었으며, 바살트섬유보강근의 경우에는 알칼리에서 섬유부풀음에 의한 손상으로 강도저하가 더 크게 나타났다. 따라서 블레이디드된 섬유보강근의 장기성능을 향상시키기 위해서는 내알칼리성 확보를 위한 표면처리가 필요한 것으로 분석되었다.