[en] PRE-WELD program, which generates automatically the input file for the finite element analysis on the 2D butt welding at the dissimilar metal weld part, was developed. This program is pre-process program of the FEM code for analyzing the residual stress at the welding parts. Even if the users have not the detail knowledge for the FEM modelling, the users can make the ABAQUS INPUT easily by inputting the shape data of welding part, the weld current and voltage of welding parameters. By using PRE-WELD program, we can save the time and the effort greatly for preparing the ABAQUS INPUT for the residual stress analysis at the welding parts, and make the exact input without the human error

[en] We analyze the existence of the exotic Θ⁺ from the perspective of instanton induced quark dynamics. The 't Hooft interaction gives strong attraction in specific channels of the triquark uds-bar and diquark ud configurations. In particular it leads to a light uds-bar triquark cluster, with the mass around 750 MeV, in the I=0, S=1/2 and color 3 configuration, and a light ud-diquark configuration, with mass 440 MeV, in the I=0, S=0 and color 3-bar configuration. If we consider the pentaquark as a bound state of such triquark and diquark configurations in a relative L=1 state we obtain good agreement with the data. The small width of Θ⁺ has a natural explanation in this model

[en] Inelastic electron tunneling spectroscopy and microscopy with a scanning tunneling microscope revealed two vibrational modes showing a decrease in conductance at ±82.0 and ±38.3 mV sample bias for single oxygen molecules chemisorbed on the fourfold hollow sites of Ag(110) surface at 13 K. The spatial distribution of the vibrational intensities exhibited π_g -orbital (perpendicular to surface) symmetry of O₂ with the molecular axis along the [001] direction. These results are attributed to resonant inelastic electron tunneling. (c) 2000 The American Physical Society

[en] We measured the suppression of the superconductivity in a mesoscopic Al wire in proximity contact with an overlaid ferromagnetic Co wire. We estimated the resultant spin diffusion length of spin-polarized quasiparticles in the superconductor, which appeared to be related to the pair condensation of quasiparticles through opposite spin channels

[en] The ion sources for induction linac driven heavy ion fusion were fabricated and their emittance characteristics were investigated. For two kinds of ion sources, i. e. a carbon vacuum arc ion source and a cusp field rf ion source, the emittance was measured with a double slit beam scanner. The required normalized emittance of an ion source for heavy ion fusion is 10^-7 - 5x10^-7 πm-rad, and the measured emittances of the ion beams from carbon vacuum arc ion source and cusp field rf ion source (Ne⁺) were 2x10^-6 πm-rad and 4x10^-7 πm-rad, respectively. (author)

[en] The metal vapor vacuum arc (MEVVA) ion source was developed and its operational characteristics were investigated. The new trigger generator based on transistor and small transformer ratio was developed also. At high arc current, the ion beam currents obey the Child-Langmuir rule that is proportional to V^3/2. The maximum ion beam current obtained was 130mA at the condition of 200A arc current and 50kV extraction voltage. With new trigger generator the improved lifetime was achieved and the MEVVA ion source can be operated over 20,000 shots without failure. (author)

[en] Development of fabrication process of functional ceramic materials, evaluation of characteristics and experiments for understanding of irradiation behavior of ceramics were carried out for application of ceramics to the nuclear industry. The developed processes were the SiC surface coating technology with large area for improvement of wear resistance and corrosion resistance, the fabrication technology of SiC composites for excellent irradiation resistance, performance improvement technology of SiC fiber and nano-sized powder processing by combustion ignition and spray. Typical results were CVD SiC coating with diameter of 25cm and thickness of 100μm, highly dense SiC composite by F-CVI, heat-treating technology of SiC fiber using B4C power, and nano-sized powders of ODS-Cu, Li-based breeding materials, Ni-based metal powders with primary particle diameter of 20∼50nm. Furthermore, test equipment, data productions and damage evaluations were performed to understand corrosion resistance and wear resistance of alumina, silicon carbide and silicon nitride under PWR or PHWR operation conditions. Experimental procedures and basic technologies for evaluation of irradiation behavior were also established. Additionally, highly reactive precursor powders were developed by various technologies and the powders were applied to the fabrication of 100 m long Ag/Bi-2223 multi-filamentary wires. High Tc magnets and fly wheel for energy storage were developed, as well

[en] Reactor pressure boundary components including pressure vessel and piping are facing a severe aging condition that can degrade the physical-mechanical properties under neutron irradiation, high temperature, high pressure, and corrosive environments. In order to increase the safety of nuclear power plants, it is inevitable to improve the credibility and capability of evaluation technology based on the quantitative fracture mechanics for aging assessment of reactor components. Irradiation embrittlement is the primary aging mechanism of reactor pressure vessel and various techniques have been developed to predict the aging characteristics by using only small volume of irradiated materials. Material database of the domestic structural steels for KSNP's under reactor environments must be very important to play a role in developing an advanced material, in improving the safety of nuclear components, and also in expanding the nuclear industry abroad. This research project has been focused on developing an advanced technology of testing and analysis in the fracture mechanical point of view as well as acquiring test data and improving the performance of nuclear structural steels

[en] The final purpose of this study is to establish an specific enhancement scheme of the regulatory system for decommissioning of nuclear facilities, including nuclear power plants. In this report, decommissioning status and regulatory systems of Europe countries, such as Germany, the United Kingdom and France, are surveyed and analysed into laws, licensing procedure, safety documents, and regulatory requirements. In addition, contents of the OECD/NEA technical reports are analysed

[en] The final purpose of this study is to establish an specific enhancement scheme of the regulatory system for decommissioning of nuclear facilities, including nuclear power plants. In this report, decommissioning status and regulatory systems of the United States of America and Japan are surveyed and analysed into laws, licensing procedure, safety documents, and regulatory requirements