[en] The planning, design, and operation of electric power system require engineering studies to assist in the evaluation of the system performance, reliability, safety and economics. The Class III power of HANARO supplies power for not only HANARO but also RIPF and IMEF. The starting current of most ac motors is five to ten times normal full load current. The loads of the Class III power are connected in consecutive orders at an interval for 10 seconds to avoid excessive voltage drop. This technical report deals with the load flow study and motor starting study for the Class III power of HANARO using ETAP(Electrical Transient Analyzer Program) to verify the capacity of the diesel generator. Short-circuit studies are done to determine the magnitude of the prospective currents flowing throughout the power system at various time intervals after a fault occurs. Short-circuit studies can be performed at the planning stage in order to help finalize the system layout, determine voltage levels, and size cables, transformers, and conductors. From this study, we verify the short circuit current capacity of air circuit breaker(ACB) and automatic transfer switch(ATS) of the Class III power

[en] KNGR adopted independent four train safety injection system which injects water into the downcomer directly through the DVI line in order to enhance safety, economics, and operability. By the adoption of DVI, more complicate phenomena, compared to current cold leg injection plant, can be occurred in the downcomer during LBLOCA. Therefore, in this paper, the effect of ECC bypass and steam condensation during LBLOCA is evaluated. As the results, KNGR DVI design has sufficient margin although ECC bypass and steam condensation make some negative effect to core reflood

[en] The analysis of load flow is for searching the optimal operation condition by computer simulation. The analyzed items are as follows. Active and reactive power from KAERI substation. Voltage drop on Tus. Analysis of load flow of active power and reactive power on Bus The motor starting current of most ac motors is several times normal full load current. Motor starting torque varies directly as square of the applied voltage. If the terminal voltage drop is excessive, the motor may not have enough starting torque to accelerate up to running speed. Running motors may stall from excessive voltage drops. Short-circuit studies are done to determine the magnitude of the prospective currents flowing throughout the power system at various time intervals after a fault occurs. Short-circuit studies can be performed at the planning stage in order to help finalize the system layout, determine voltage levels, and size cables, transformers, and conductors. For existing systems, fault studies are necessary in the cases of installation of extra rotating loads, system layout modifications, rearrangement of protection equipment, verification of the adequacy of existing breakers. This technical report deals with the load flow study, motor starting study and short circuit study for CNS(Cold Neutron Source) power system using ETAP(Electrical Transient Analyzer Program) to determine the optimal operating condition

[en] Since necessity of assessing unsettled problem like pressure tube sag, pressure tube creep, aging mechanism of some equipments in Wolsong 1 and carrying out PSR for PHWR in Korea has been insisted, development of general and independent safety technology system for PHWR should be developed. And 'development of Thermal-hydraulic Assessment Technology for Degradation of CANDU Reactors' is required to perform this process. In this research, after we grasp the general process of the aging mechanism for PHWR(particularly about CANDU), analysis of existing report about Wolsong 1(CATHENA Plant Model for Wolsong 1 with multiple-Average Channels and Ageing Effects for 1999) is performed. And statistical methodology that can be used to analysis of degradation will be considered for the basis of next research. In conclusion, This research has an object to product degradation data of main system and each equipment. Consequently study of aging mechanism for PHWR and analysis of main system, equipments is performed and it results in main 7 factors affecting thermal-hydraulic analysis for PHWR as follows

[en] The analog seismic monitoring system for HANARO has been improved into a new digital Seismic Monitoring Analysis System(SMAS). For this purpose, the digital type hardware for the SMAS was newly developed. And the seismic monitoring and analysis programs that can provide a rapid and precise information for an earthquake were developed. In order to confirm the functional capability of the developed SMAS, the Site Acceptance Test(SAT) was performed. The results of the SAT satisfy the requirements of the fabrication technical specifications. In addition, the structural integrity and seismic characteristics of the newly developed SMAS were evaluated. The evaluated results demonstrate that the SMAS has adequate structural integrity and it can withstand the seismic loads and remain functional. The developed SMAS is successfully operating in the HANARO instrument room for monitoring and analyzing the signal of an earthquake at the HANARO site. The Seismic Evaluation System(SES) that can perform rapid evaluations of the seismic safety of the reactor building has been developed. After an earthquake, using the seismic signal obtained from the field sensors, the developed SES can perform a detail 3-D seismic analysis of the reactor building and some local analyses of the safety related system required for the assessment of the seismic safety of the HANARO building. In addition, the developed seismic evaluation system equipped with the post processing capability to display analysis results graphically or in report form. It is expected that the SES can be utilized for the evaluation of the seismic safety of the HANARO reactor building and the safety related seismic category structures after an earthquake

[en] Since the Fukushima nuclear accident, the importance of education and training for workers has been emphasized for the sustainable use of nuclear technology. It is necessary that Korea, which is a donor country for education and exports nuclear power plants, brings about standardization and internationalization of domestic education and training in radiation protection training. EDTA mission that is the pre-project phase for hosting P GEC has been concluded to be successful. It secured the favorable conditions to host P GEC and reaffirmed domestic infrastructure for radiation education and training was excellent internationally. This study has modified the curriculum of existing P GEC into Korean P GEC appropriate for domestic circumstances by using infrastructure for domestic radiation protection and safety. All of modifications has been made on the basis of the Sat methodology. With the modified curriculum for Korean P GEC, operation model has been developed for the tracks of certification and master's degree. The short-term pilot P GEC was carried out for checking developed lecture materials, lecturers, equipment, evaluation procedures and operation abilities. It was also confirmed the teaching methods were effective. Therefore, it might be said that infrastructure for the future P GEC operation has been established

[en] A spacer grid in a LWR fuel assembly is a key structural component to support fuel rods and to enhance the heat transfer from the fuel rod to the coolant. In this research, the main research items are the development of inherent and high performance spacer grid shapes, the establishment of mechanical/structural analysis and test technology, and the set-up of basic test facilities for the spacer grid. The main research areas and results are as follows. 1. 14 different spacer grid candidates have been invented and applied for domestic and US patents. Among the candidates six are chosen from the patent. 2. Two kinds of spacer grids are finally selected for the advanced LWR fuel after detailed performance tests on the candidates and commercial spacer grids from a mechanical/structural point of view. According to the test results the features of the selected spacer grids are better than those of the commercial spacer grids. 3. Four kinds of basic test facilities are set up and the relevant test technologies are established. 4. Mechanical/structural analysis models and technology for spacer grid performance are developed and the analysis results are compared with the test results to enhance the reliability of the models

[en] The effect of Cu addition on the corrosion of Zr-based alloys that developed for nuclear fuel cladding in KAERI was investigated. The corrosion tests of the alloys having different Cu content were performed in distilled water at 360 .deg. C, steam environment at 400 .deg. C and 70 ppm Li conditions. The alloys were also examined for their microstructures using the optical microscope and the TEM equipped EDS and the oxide property was characterized by using low-angle X-ray diffraction. In different environment of corrosion test more than 390 days, the transition of corrosion rate of the Zr-based alloys was differently observed with Cu addition. The corrosion resistance were gradually increased with the increase of Cu content and the tetragonal ZrO₂ layer was stabilized on the Cu-containing alloys

[en] Space grid in LWR fuel assembly is a key structural component to support fuel rods and to enhance heat transfer from fuel rod to the coolant. Therefore, the original spacer grid has been developed. In addition, new phenomena in fuel behavior occurs at the high burnup, so that models to analyze those new phenomena were developed. Results of this project can be summarized as follows. - Seven different spacer grid candidates have been invented and submitted for domestic and US patents. Spacer grid test specimen(3x3 array and 5x5 array) were fabricated for each candidate and the mechanical tests were performed. - Basic technologies in the mechanical and thermal hydraulic behavior in the spacer grid development are studied and relevant test facilities were established - Fuel performance analysis models and programs were developed for the high burnup pellet and cladding, and fuel performance data base were compiled - Procedures of fuel characterization and in-/out of-pile tests were prepared - Conceptual design of fuel rod for integral PWR was carried out. (author)

[en] At the stage of giving technology, we should provide the high quality education more strategically as a means of confrontation to ensure proliferation and expert of the technical strengths. This study established the mid/long term policy to cope actively with the changing international circumstances in nuclear education and provide competitive education contents. Accordingly, we can have the initiative providing differentiated nuclear education programme. As a prerequisite to advancement of systematic education and training, this study presents a course design system reflecting requirements from all steps of SAT. To play an important role in exchange and spread the nuclear knowledge, we loaded the education contents developed in this study to 'ANENT' local learning system. And this study developed 6 education programme of the KAERI's technical strengths involved in 'Global Nuclear R and D Academy'. The methodology of demand and supply of nuclear workforce studied in this year expected to be applied to the entire manpower planning of the institute in 2015. According to the institute's own duty, the result of education should be connected directly to the management performance to realize the key policy of administration, 'creative economy'. As a result, we should secure the virtuous circle of manpower training and guidance technology development and also serve the country by promoting R and D result diffusion and raising brand awareness of institute by educating in technical strengths.