[en] The proper welding process for Zircaloy-4 endplate of PHWR and DUPIC fuel bundle assembly is considered important in respect to the soundness of weldment and the improvement of the performance of nuclear fuel bundle during the operation in reactor. The Zircaloy-4 endplate of PHWR and DUPIC fuel bundles are welded by the projection joint type, connecting the endcaps of fuel elements. Therefore, the purpose of this projection joint is to improve the welding quality of torque strength and welding deformation and to apply the commercial productions for the endplate welding of PHWR and DUPIC nuclear fuel bundle assembly

[en] Manufacturing process for the basket of dish washer is one of the key technology to be required to make the factory automation. In this technical supports, fundamental data for manufacturing technology was proposed to apply for the basket of dish washers. And, insert device for the rollers of basket and semi-automatic supporter for basket pin-welding was developed by fulfilling the performance tests. This manufacturing technology for the basket of dish washer is closely related to advanced industry. It is expected that the automation processing technology will be adopted to various applications in the industry

[en] The new technology of welding process for fuel bundle of CANDU nuclear fuels is considered important in respect to the soundness of weldments and the improvement of the performance of nuclear fuels during the operation in reactor. The probability of leakage of the fission products is mostly apt to occur at the weldments of fuel bundles, and it is connected directly with the safety and life prediction of the nuclear reactor in operation. The fuel bundles of CANDU nuclear fuels are welded by the electrical resistance method, connecting the endplates and endcaps with fuel rods. Therefore, the purpose of this study of the 2nd year is to select the proper welding parameters and to investigate the characteristics of the full-sized samples using the projection endplates and make some prototype samples for the endplate welding of CANDU nuclear fuels. This study will be also provide the fundamental data for the new design and fabrications of CANDU nuclear fuel bundles

[en] This study is to investigate the welding characteristics of Zr-4 end plug of fuel element in the cases of GTAW and LBW. The welding parameters which affect the bead width and the penetration depth have been also compared. The effect of joint geometry of end plugging for GTAW and LBW has been studied and optimum conditions of Zr-4 end-plug welding have been found. Furthermore, microstructures and micro-hardness of GTA and LB welded specimens have been also compared

[en] ● After figuring out the status of soon to be retired R&D personnel, and appointed researchers who are working as contracted researchers after the retirement of Korea Atomic Energy Research Institute(KAERI), and these highly experienced researchers have been appointed as technical mentors, and they have been carrying out roles such as technical support, technical consultation and technical consultation for KAERI-Family companies and SMEs nationwide, and identified how the performance of these companies has played a role. ● Continuing technology mentoring of visiting service.● Company visiting service of highly experienced researchers group for diagnosis of enterprise technology status. ● Developing efficient enterprise support plan and information sharing though the workshop of excellent support cases presentation.● Provided new business opportunities and resolved technical difficulties though 55 technology consultations for approximately 31 companies ● 2 cases related to the on-site technology difficulty support project

[en] To establish the fabrication process, and for satisfying the requirements of the irradiation test, an TIG(Tungsten Inert Gas) welding machine for the dual cooled rods specimens was developed, and the preliminary welding experiments were performed to optimize the welding process conditions. Cladding tubes of 15.9 and 9 mm for the outer and inner diameters, respectively with a 0.57 mm thickness and end caps were used for the specimens. This paper describes the experimental results of the TIG welds and the micrograph examinations of the TIG welded specimens corresponding to various welding conditions for the dual cooled fuel irradiation test. The investigations revealed that the present TIG process satisfied the requirements for the fuel irradiation test in the HANARO research reactor

[en] The proper welding method for appendage of bearing pads and spacers of PHWR nuclear fuel elements is considered important in respect to the soundness of weldments and the improvement of the performance of nuclear fuels during the operation in reactor. The probability of welding defects of the appendage parts is mostly apt to occur and it is connected directly with the safty and life prediction of the nuclear reactor in operation. Recently there has been studied all over the world to develope welding technology by laser in nuclear fuel processing, and the appendage of bearing pads and spacers of PHWR nuclear fuel elements. Therefore, the purpose of this study is to investigate the characteristics of the laser welded specimens and make some samples for the appendage of bearing pads of PHWR nuclear fuel elements. This study will be also provide the basic data for the fabrications of the appendage of bearing pads and spacers. Especially the laser welding is supposed to be used in the practical application such as precise materials manufacturing fields. In this respect this technology is not only a basic advanced technology with wide applications but also likely to be used for the development of directly applicable technologies for industries, with high potential benefits derived in the view point of economy and industry

[en] The proper welding method for appendage of bearing pads and spacers of PHWR nuclear fuel elements is considered important in respect to the soundness of weldments and the improvement of the performance of nuclear fuels during the operation in reactor. The probability of welding defects of the appendage parts is mostly apt to occur and it is connected directly with the safty and life prediction of the nuclear reactor in operation. Recently there has been studied all over the world to develope welding technology by laser in nuclear fuel processing, and the appendage of bearing pads and spacers of PHWR nuclear fuel elements. Therefore, the purpose of this study is to investigate the characteristics of the laser welded specimens and make some samples for the appendage of bearing pads of PHWR nuclear fuel elements. This study will be also provide the basic data for the fabrications of the appendage of bearing pads and spacers. Especially the laser welding is supposed to be used in the practical application such as precise materials manufacturing fields. In this respect this technology is not only a basic advanced technology with wide applications but also likely to be used for the development of directly applicable technologies for industries, with high potential benefits derived in the view point of economy and industry

[en] An irradiation test of a nuclear fuel rod having external and internal tube structure was planned for a performance. To establish fabrication process satisfying the requirements of irradiation test, micro-TIG welding system for fuel rods was developed, and preliminary welding experiments for optimizing process conditions of fuel rod was performed. Fuel rods with 15.9mm diameter and 0.57mm wall thickness of cladding tubes and end caps have been used and optimum conditions of endcap welding have been selected. In this experiment, the qualification test was performed by tensile tests, helium leak inspections, and metallography examinations to qualify the endcap welding procedure. The soundness of the welds quality of a dual cooled fuel rods has been confirmed by mechanical tests and microstructural examinations

[en] This study is to investigate the optimum conditions of a RW for a Zr-4 endplate welding. RW parameters which affect the weld nugget and the penetration depth were experimentally examined. Also, a joint geometry and an effect of torque strength by using Zr-4 endplate specimens were investigated. It was found that the weld current was 3800 A, the pressure of main electrode was 4 BAR and the weld cycle was 3 cycle. In the strength test of the welded specimens by using Zr-4 endplate specimens, both the outer rods and the inner rods of fuel bundle were found to have greater torque values than that of the production specimens by using the used specimens(commercial products), and further to have low fluctuations in the endplate welds by using the projection typed specimens.