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[en] Technology standard for shipping containers of radioactive materials becomes strict by IAEA Regulation 'regulations for the safe transport of radioactive material ST-1' and the domestic regulations. Development of the RI shielding casks having high efficiency is needed. To design a mold for casting the shielding cask, computer simulation was introduced. Purpose of this study is to investigate optimum casting conditions for manufacturing a sound shipping container without defects by the melt filling and solidification analysis using computer code Z-cast. As a result of analysis, although two molds have the same temperature gradient, the mold having higher temperature could reduce the shrinkage defects of a product. When there is no temperature gradient in mold whose riser size is 60mm or 70mm respectively, the shrinkage defects existed in the casting. The temperature gradient of a mold is needed to make a sound product without shrinkage defects. When we are going to reduce the shrinkage defects, the riser size and temperature gradient of the mold is more effective factor than the melting temperature
[en] The structure and incidental facilities of the research reactor fuel fabrication facility, outline of construction, design content, required criteria, and method of construction were described. The main content is as follows. Reinforced concrete structure that is categorized as seismic class II with a total size of 3,618m2 is composed of 1 floor under the ground and 3 floors on the ground. Nuclear fuel fabrication facility is capable of fabricating both 420 kgs of LEU fuel powder and 45 sets of driver fuel assembly. Radioactivity management : the air ventilation in the managed area will be transferred into chimney through HEPA filter. The soild and liquid waste will be treated according to the regulation set up by institute. Supply electricily of 6.6 KV(60 Hz) to necessary fields from a transformer substation located in KAERI and emergency electricity supply system(250 KW) and utility supply system
[en] Since 1994, most of the major steel industries in Taiwan have installed portal monitor to detect the abnormal radiation in metal scrap feed. As a result, the discovery of NORM (Naturally Occurring Radioactive Material) has increased in recent years. In order to save the natural resources and promote radiation protection, an experimental melting process for the NORM contaminated steel scraps was carried out by the Institute of Nuclear Energy Research (INER) Taiwan, ROC. The experimental melting process has a pretreatment step that includes a series of cutting and removal of scales, sludge, as well as combustible and volatile materials on/in the steel scraps. After pretreatment the surface of the steel scraps are relatively clean. Then the scraps are melted by a pilot-type induction furnace. This experiment finally produced seven ingots with a total weight of 2,849 kg and 96.8% recovery. All of the surface dose rates are of the background values. The activity concentrations of these ingots are also below the regulatory criteria. Thus, these NORM-bearing steel scraps are ready for recycling. This study has been granted by the regulatory authority
[en] The water for the secondary cooling system of HANARO research reactor removes heat generated from the reactor core and other facilities using heat exchangers and cooling towers. The quality of the coolant effects the lifetime of the components and the efficiency of heat removal by resulting corrosion, slime, and fouling in the system. So to maintain the quality of the coolant as a optimal condition the periodic sampling and analysis are performed on the several parameter. According to the analysis results countermeasures are implemented. This report describes activities and analysis results during first half of the year 2009.
[en] We describe a technique for generating tunable narrow-band terahertz radiation via optical rectification in periodically-poled lithium niobate. Frequency tuning is accomplished by spatially chirping the domain width laterally to the beam propagation direction, and adjusting the temperature of the sample. We demonstrate tuning over a continuous range from 0.8 to 2.5 THz. The bandwidth of the terahertz waveforms is as narrow as 0.02 THz. [copyright] 2001 American Institute of Physics
[en] Recent neutron-scattering measurements on the La2-xSrxCuO4 system have revealed a drastic change of the incommensurate static-spin correlations from diagonal in the insulating region to parallel in the superconducting region. We report the doping dependence of the ordered magnetic moment for the hole concentration region 0.03≤x≤0.12, focusing on the relationship between the static magnetism and the superconductivity. The elastic magnetic cross-section decreases monotonically with increasing x for 0.03≤x≤0.07. We find that the ordered magnetic moment μ varies from ∼0.18μB/Cu(x=0.03) to ∼0.06μB/Cu(x=0.07). No significant anomaly is observed at the insulator-superconductor boundary (x∼0.055). The elastic magnetic cross-section is enhanced in the vicinity of x=0.12 where resolution-limited width peaks are observed in neutron-scattering measurements and where the apparent magnetic and superconducting transitions coincide
[en] Degradation of critical components of nuclear power plants has become important as the operating years of plants increase. The necessity of degradation study including detection and monitoring technology has raised its head. Because the feeder pipes and the fuel channels are particularly one of the critical components in CANDU nuclear plant, they are treated as a major research target in order to counteract the possible problems and establish the counterplan for the improvement of CANDU reactor safety. To ensure the integrity of feeder pipes and fuel channels in CANDU nuclear plant, the following 3 research tasks were performed in the first stage. - Development of a model for prediction of feeder wall thinning - Development of RFEC detection technology - Development of ICFD noise signal analysis. The technologies developed in this study could contribute to the nuclear safety and estimation of the remaining life of operating CANDU nuclear power plants
[en] □ Completion of post irradiation examination for high-temperature and high power KOMO-4 irradiated fuel rods □ Development of surface treatment technology on the centrifugal atomized U-Mo powder □ Design and fabrication of the fuel rods for KOMO-5 irradiation test □ Irradiation test of high U density (5∼6 gU/cc) full-length U-Mo fuel □ Characteristic evaluation of the surface treated centrifugal atomized U-Mo powder □ Completion of post irradiation examination for KOMO-5 irradiated fuel rods □ Generation of fuel qualification document for the reactor core conversion of HANARO □ Supply centrifugal atomized U-Mo powder to international development and commercialization of high U density U-Mo dispersion fuel plate (8∼9 gU/cc)
[en] Even though Korea has supplied the rod-type fuel based on U-Si alloy to the HANARO research reactor of KAERI and has the centrifugal atomization technology which is the core technology of fuel fabrication, there is little experience for the plate-type fuel. If we accomplish the technology independence of plate-type fuel, we will be the one of the world’s top competitors in fabrication of research reactor fuels with the atomization technology of the fuel powder. The “Know-how” and “Know-why” accumulated by the experience of localization development of HANARO fuel was the important foundation to reduce the development period of the plate-type fuel in Korea. From the operation and management of the advanced fuel science building, the infrastructure for treating a nuclear materials is supported to the fabrication of HANARO fuel and the development of plate-type fuel stably. Through the successful execution of this project, we have accomplished both of the development of fabrication technologies and the establishment of infrastructure for the plate-type fuel as well as the stable supply of HANARO fuel.
[en] The response of the point defect and antistructure systems to ion beam irradiation is investigated using methods of linear response on thin single crystals of ordered Cu3Au grown by molecular beam epitaxy. We demonstrate that antisite evolution, as measured by electrical resistance, quantitatively determines both the defect populations and diffusion in the irradiation field, and we explore new linear and nonlinear response processes as the antistructure system is driven from equilibrium. (c) 2000 The American Physical Society