• Nuclear Engineering and Technology
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• v.31 no.6
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• pp.66-82
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• 1999

The national long-term R&D program, updated in 1997, requires Korea Atomic Energy Research Institute(KAERI) to complete by the year 2006 the basic design of Korea Advanced Liquid Metal Reactor(KALIMER), along with supporting R&D work, with the capability of resolving the issue of spent fuel storage as well as with significantly enhanced safety. KALIMER is a 150 MWe pool-type sodium cooled prototype reactor that uses metallic fuel. The conceptual design is currently under way to establish a self-consistent design meeting a set of major safety design requirements for accident prevention. Some of the current emphasis includes those for inherent and passive means of negative reactivity insertion and decay heat removal, high shutdown reliability, prevention of and protection from sodium chemical reaction, and high seismic margin, among others. All of these requirements affect the reactor design significantly and involve extensive supporting R&D programs. This paper summarizes some of the results of conceptual engineering and design analyses performed for the safety of HAMMER in the area of inherent safety, passive decay heat removal, sodium water reaction, and seismic isolation.

• Nuclear Engineering and Technology
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• v.38 no.6
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• pp.489-504
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• 2006

A review has been made for the previous studies on safety of a geologic repository for high-level radioactive wastes (HLW) related to autocatalytic criticality phenomena with positive reactivity feedback. Neutronic studies on geometric and materials configuration consisting of rock, water and thermally fissile materials and the radionuclide migration and accumulation studies were performed previously for the Yucca Mountain Repository and a hypothetical water-saturated repository for vitrified HLW. In either case, it was concluded that it would be highly unlikely for an autocatalytic criticality event to happen at a geologic repository. Remaining scenarios can be avoided by careful selection of a repository site, engineered-barrier design and conditioning of solidified HLW. Thus, criticality safety should be properly addressed in regulations and site selection criteria. The models developed for radiological safety assessment to obtain conservatively overestimated exposure dose rates to the public may not be used directly for the criticality safety assessment, where accumulated fissile materials mass needs to be conservatively overestimated. The models for criticality safety also require more careful treatment of geometry and heterogeneity in transport paths because a minimum critical mass is sensitive to geometry of fissile materials accumulation.

• Journal of the Korean Society of Safety
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• v.15 no.2
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• pp.92-96
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• 2000

In this experiment, we studied about concentration characteristics of $NO_x$ and generation of ozone in the reactor of corona discharge type by using mixed gas of $NO/N_2$ and $N_2/O_2$. In the case of the initial NO concentration increased, decrease rate of NO concentration was weakened and discharge input power of minimum NO concentration became high. When NO concentration was high, NO decomposition limit was appeared. And NO reduction rate was decreased, when initial NO concentration and discharge input power increased. When discharge input power was 5W, we could know the most proper energy value for treatment of NO. When the concentration of initial NO increased, generation of ozone decreased and in the case of same concentration of NO, according to discharge input power increase, generation of ozone increased.

• Proceedings of the KSR Conference
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• 2001.05a
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• pp.319-326
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• 2001

Railway signaling safety system organizes equipments and facilities of railway, increases transport efficiency and assures safe operation of railway. In the early days of signaling system railway managers made sure of safety by using relay logic technology based on fail-safe concept. But the development result of computer and science having been introduced to railway industry, railway signaling equipments begin to be operated through micro electronic control system. Accordingly high speed and high density operation of train became possible. Software reliability and safety technology that controls important systems of railway was highlighted. In the middle of 1990s the standard or guideline of railway reliability and safety were studied and established, and are being reviewing in Europe, Japan etc. Our reliability and safety technology have depended largely on foreign countries. In this study we performed a basic study about the reliability of software that controls the railway signaling system.

• Journal of the Korean Society of Safety
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• v.35 no.3
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• pp.32-42
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• 2020

In this study, in order to secure the necessity of introducing the safety certification system for the assembled temporary equipment and materials, the feasibility of the introduction was analyzed through literature review, structural analysis, and actual experiments and surveys related to the assembled temporary equipment and materials. In the previous studies, it was found that the research on the assembled temporary equipment and materials was insufficient, and it was possible to grasp the necessity of introducing the safety certification system for the assembled temporary equipment and materials. In addition, in the results of the serious accident analysis, it was found that the soundness of the temporary equipment and materials is determined by the structural characteristics after it was assembled. As a result of the feasibility analysis of the introduction of the safety certification of the assembled temporary equipment and materials through structural analysis, it is possible to effectively and rationally reflect the main geometrical influence factors, and to introduce the safety certification system that can test the procedures and procedures of the assembled temporary equipment and materials and based on it. It was found that there is a need. As a result of feasibility analysis on the necessity of introducing the safety certification system for assembled temporary equipment and materials through actual experiments, the existing single member performance evaluation has limitations in evaluating the structural performance of the assembled temporary equipment and materials. It was found that there is a need to introduce a safety certification system. As a result of gathering opinions on the feasibility of introducing the safety certification system for assembled temporary equipment and materials of manufacturers and users through the survey, it was found that the overall positive response result was high and the effectiveness was high.

• Journal of Home Health Care Nursing
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• v.27 no.3
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• pp.250-258
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• 2020

Purpose: This study aimed to investigate the relationship between nursing work environment, patient safety culture, and patient safety nursing activities in hemodialysis units at primary care centers. Methods: In this cross-sectional descriptive study, 116 nurses working in hemodialysis units at 22 primary care centers were enrolled as participants. They were selected them by the convenience sampling method. Data were collected using structured questionnaires that included questions on general characteristics, nursing work environment, patient safety culture, and patient safety nursing activities. Results: The nursing work environment was relatively good; however, the patient safety culture and patient safety nursing activities were poor. A positive correlation was found between nursing work environment, patient safety culture, and patient safety nursing activities. Factors that affect patient safety culture were rated high in the order of nursing work environment and patient safety nursing activities, and factors affecting patient safety nursing activities were rated high in the order of patient safety culture and age. Conclusion: This study showed that the development of tailored patient safety training for nurses in hemodialysis units working in primary care and administrative support from those institutions are needed. In particular, strategies accounting for nurses' characteristics such as age are required to strengthen patient safety nursing activities.

• Nuclear Engineering and Technology
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• v.54 no.5
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• pp.1825-1834
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• 2022

Performing high-fidelity computational fluid dynamics (HF-CFD) to predict the flow and heat transfer state of the coolant in the reactor core is expensive, especially in scenarios that require extensive parameter search, such as uncertainty analysis and design optimization. This work investigated the performance of utilizing a multi-fidelity reduced-order model (MF-ROM) in PWR rod bundles simulation. Firstly, basis vectors and basis vector coefficients of high-fidelity and low-fidelity CFD results are extracted separately by the proper orthogonal decomposition (POD) approach. Secondly, a surrogate model is trained to map the relationship between the extracted coefficients from different fidelity results. In the prediction stage, the coefficients of the low-fidelity data under the new operating conditions are extracted by using the obtained POD basis vectors. Then, the trained surrogate model uses the low-fidelity coefficients to regress the high-fidelity coefficients. The predicted high-fidelity data is reconstructed from the product of extracted basis vectors and the regression coefficients. The effectiveness of the MF-ROM is evaluated on a flow and heat transfer problem in PWR fuel rod bundles. Two data-driven algorithms, the Kriging and artificial neural network (ANN), are trained as surrogate models for the MF-ROM to reconstruct the complex flow and heat transfer field downstream of the mixing vanes. The results show good agreements between the data reconstructed with the trained MF-ROM and the high-fidelity CFD simulation result, while the former only requires to taken the computational burden of low-fidelity simulation. The results also show that the performance of the ANN model is slightly better than the Kriging model when using a high number of POD basis vectors for regression. Moreover, the result presented in this paper demonstrates the suitability of the proposed MF-ROM for high-fidelity fixed value initialization to accelerate complex simulation.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.37-40
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• 2008

We have concentrated on the performance improvement of each part for durability, safety and cost of high pressure storage system for fuel cell vehicle so far. But for the mass production of fuel cell vehicle, it is necessary to evaluate durability and safety in system module. We built the standard to evaluate and collision safety of high pressure storage system for fuel cell vehicle, and could verify reliability of high pressure storage system.

• Journal of Radiation Protection and Research
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• v.40 no.3
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• pp.132-146
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• 2015

To develop tailored elementary, middle, and high school textbooks suitable for understanding the nuclear energy and radiation, quantitative and qualitative research was carried out in parallel, which included nine steps to ensure the validity of content and structure. The elementary, middle, and high school students wanted to acquire information used in their daily lives, including the definition of nuclear energy and radiation, principles and status of nuclear power generation, and information about irradiated food, medical radiation, and radiation in life. In the evaluation of the effects of textbook contents according to the educational requirements of each school level, high suitability frequencies (>80%) were shown for the human character, education goals, curriculum goals, evaluation method, and education time. At some levels, the high suitability frequencies (>70%) were shown for the education grade, education type, and textbook type.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.467-472
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• 2005

The characteristics of dynamic vibration are generally analyzed by an acceleration of a car body of high speed train and the acceleration can be applied to evaluation of running safety. The test of process and the analysis method about it are well explained on UIC Code 518 OR which is the spacial international standard about running safety and dynamic behavior on the line test for railway vehicle. Korean High Speed Train designed to operate at speed 350km/h has been tested on high speed line since it was developed in 2002 and it recorded the highest speed 352.4km/h at the 16th Dec. 2004 in Korea. This paper includes the analysis of running behavior of this train at speed 350km/h and also the analysis of dynamic safety is presented in it, extending to the range of high speed while the UIC 518 limit the speed below 200km/h.