• Nuclear Engineering and Technology
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• v.54 no.11
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• pp.4373-4391
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• 2022

Marine reactor systems experience platform movement, and therefore, the system thermal-hydraulic analysis code needs to reflect the motion effect on the fluid to evaluate reactor safety. A moving reactor model for MARS-KS was developed to simulate the hydrodynamic phenomena in the reactor under motion conditions; however, its applicability does not cover the MULTID component used in multidimensional flow analyses. In this study, a moving reactor model is implemented for the MULTID component to address the importance of multidimensional flow effects under dynamic motion. The concept of the volume connection is generalized to facilitate the handling of the junction of MULTID. Further, the accuracy in calculating the pressure head between volumes is enhanced to precisely evaluate the additional body force. Finally, the Coriolis force is modeled in the momentum equations in an acceleration form. The improvements are verified with conceptual problems; the modified model shows good agreement with the analytical solutions and the computational fluid dynamic (CFD) simulation results. Moreover, a simplified gravity-driven injection is simulated, and the model is validated against a ship flooding experiment. Throughout the verifications and validations, the model showed that the modification was well implemented to determine the capability of multidimensional flow analysis under ocean conditions.

• KSBB Journal
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• v.20 no.2 s.91
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• pp.100-105
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• 2005

Removal of nitrogen compound from waste water is essential and often accomplished by biological process. Denitrification bacterium, Paracoccus denitrificans (KCTC 2350) is employed to estimate the denitrification ability and the characteristics. In the immobilized biological reactor system, the measurement of absolute amount of active strain in the reactor is comparatively difficult or impossible. In this. study, a reactor was designed with the unwoven texture wrapped peep holed plastic tube to calculate the absolute amount of active strain by comparing the activity of the permeabilized and or immobilized reactor and the free cell reactor The reactor system was continuous stirred tank reactor and the reaction rate of substrate consumption was assumed to satisfy the Michaelis-Menten equation. The effluent concentration of nitrate and nitrite was measured to estimate the apparent parameter of Michaelis-Menten equation. As a result, we found that the amount of immobilized active strain was figured out to be half of the total active strain in the reactor and the time required to be reached in the equilibrium state in the permeabilized and or immobilized reactor system was figured out to be shorter than that of the free cell reactor system.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.34 no.4
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• pp.49-56
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• 2011

The Project of Jordan Research and Training Reactor (JRTR) officially launched in Aug. 2010. JRTR is the first made-in-Korea nuclear system to be built abroad by year 2015, and Korea Atomic Energy Research Institute (KAERI) is responsible for the design of major systems including the reactor core. While the PDCS (Project Document Control System) being operated by EPC company controls all the documents of the whole Project, KAERI is supposed to have its own system for KAERI documents. Meeting such a need; KAERI has implemented a document control for the JRTR Project into already existing ANSIM (KAERI Advanced Nuclear Safety Information Management) system. The documents of JRTR project to be controlled are defined in the PPM (Project Procedures Manual), QAP (Quality Assurance Procedure) and PEP (Project Execution Program). The ANSIM consists of the document management holder, document container holder and organization management holder. The document management holder, which is the most important part of ANSIM-JRTR, consists of the DDA (Document Distribution for Agreement), IOC (Inter-office Correspondence), PM Memo. (Project Manager Memorandum) and cover sheets of design documents. Other materials such as meeting minutes, sub-department materials and design information materials are stored in an independent COP (Community of Practice). This established computerized document control system, ANSIM, could lessen a burden for project management team and enhance the productivity as well.

• Journal of Microbiology and Biotechnology
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• v.9 no.6
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• pp.773-777
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• 1999

Scale-up experiments for hydrolysis of beef tallow, fat, and palm kernel with lipase derived from Candida cylindracea were carried out in 1-1, 100-1, and 10,000-1 reactors. The optimum agitation speed for the hydrolysis of the 1-1 reactor was investigated and found to be 350rpm, and this was a basis for the scale-up of agitation speed. The hydrolysis system in this work was the oil-water system in which the hydrolysis seems to process a heterogeneous reaction. An emulsion condition was the most important factor for determining the reaction rate of hydrolysis. Therefore, the scale-up of agitation speed was performed by using the power n = 1/3 in an equation of the rules of thumb method. The geometrical similarity for scaling-up turned out to be unsatisfactory in this study. Thus, the working volume per one agitator was used for the scale-up. In the case of scale-up from a 1-1 reactor to a 100-1 reactor, the hydrolysis of palm kernel was very much scaled-up by initiating the rules of thumb method. However, the hydrolysis of fat and beef tallow in a 100-1 reactor was a little higher than that of the 1-1 reactor because of the difference of geometrical similarity. The scale-up of hydrolysis from the 100-1 reactor to the 10,000-1 reactor was improved compared to that of the 1-1 to 100-1 reactor. The present results indicated that the scale-up of hydrolysis in the oil-water system by the rules of thumb method was more satisfactory under the condition of geometrical similarity. Even in the case where geometrical similarity was not satisfactory, the working volume per one agitator could be used for the scale-up of a heterogeneous enzyme reaction.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.288-288
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• 2000

Reactor vessel is one of the most important equipment with regard to the safety of nuclear power plant. Thus nuclear regulation requires its periodical examination by certified inspection experts. Conventional reactor inspection machines are obsolete, hard to handle, and very expensive. To solve these problems we developed robotic reactor vessel inspection system which are small, easy to use for inspection, cost effective, and convenient in operation. This paper describes the main features of Main Control System which is one part of robotic inspection equipment we developed.

• Nuclear Engineering and Technology
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• v.56 no.3
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• pp.949-958
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• 2024

In contrast to all-time flooded small modular reactor (SMR) systems, an in-kind flooding safety system (FSS) has been proposed as a passive safety system applicable to small modular reactors (SMRs) that adopt a metal containment vessel (MCV). Under transient conditions, the FSS can provide emergency cooling to dry reactor cavities and sustain long-term coolability using re-acquired evaporated steam in the reactor building on demand. When designing an FSS, the effect of the flooding flow area is vital as it affects the overall accident sequence and safety. Therefore, in this study, a MELCOR model of a reference SMR is developed and numerical analysis is performed under postulated accident scenarios. Without flooding, the MCV pressure of the reactor module exceeds the design pressure before core damage. To prevent core damage, an emergency flooding strategy is devised using various flow path parameters and requirements to ensure an adequate emergency coolant supply before the core damage is investigated. The results indicate that a flow area exceeding 0.02 m2 is required in the FSS to prevent MCV overpressure and core damage. This study is the first to report a strategic analysis for appropriately sizing an FSS flooding valve applicable to innovative SMRs.

• Journal of the Korean Society of Safety
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• v.23 no.6
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• pp.91-99
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• 2008

The identification of thermal hazards associated with a process such as heats of reaction and understanding of thermodynamics before any large scale operations are undertaken. The evaluation of thermal behavior with operating conditions such as a reaction temperature, stirrer speed and reactants concentration in neutralization process of pigment plant are described. The experiments were performed by a sort of calorimetry with multimax reactor system The aim of the study was to evaluate the results of heat of reaction in terms of safety reliability to be practical applications. It suggested that we be proposed safe operating conditions and securities for accident prevention on reactor explosion through this study.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.3
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• pp.367-372
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• 2008

This study configured the conventional $A^2O$ (Anaerobic-Anoxic-Aerobic bioreactor) system which the fixed media immersed into the anoxic reactor(Named PFR system : Plug Flow Reactor) for evaluating the removal efficiency of nitrogen in the wastewater. The experimental equipment was a cylinder which was consist of 4 pleated PE Pipes(Length 330M, Diameter 100mm) including 2 rope shape media. As a result, the average effluent T-N removal efficiency of the conventional $A^2O$ system was 17.9, 40.3, 50.6, 44.6% in each mode, but the average effluent T-N removal efficiency of the PFR system could achieve 38.8, 57.1, 71.8, 65.4% in each mode. It indicated that the PFR system caused to the increasing of C/N ratio that effected to the increasing of the denitrification efficiency. Not only the effective T-N removal efficiency but also the controllable install space will give advantages for retrofitting of the wastewater treatment plant with the conventional treatment system to the PFR system.

• International Journal of Safety
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• v.7 no.2
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• pp.7-11
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• 2008

In this paper, a Magnetic Core Reactor (MCR) which forms a part of the DC reactor type three-phase high-Tc superconducting fault current limiter (SFCL) has been developed. This SFCL is more economical than other types with three coils since it uses only one high-Tc superconducting (HTS) coil. When DC reactor type three-phase high-Tc SFCL is developed using just one coil, fewer power electronic devices and shorter HTS wire are needed. The SFCL proposed in this paper needs a power-linking device to connect the SFCL to the power system. The design concept for this device was sprang from the fact that the magnetic energy could be changed into the electrical energy and vice versa. Ferromagnetic material is used as a path of magnetic flux. When high-Tc superconducting DC reactor is separated from the power system by using SCRs, this device also limits fault current until the circuit breaker is opened. The device mentioned above was named Magnetic Core Reactor (MCR). MCR was designed to minimize the voltage drop and total losses. Majority of the design parameters was tuned through experiments with the design prototype. In the experiment, the current density of winding conductor was found to be $1.3\;A/mm^2$, voltage drop across MCR was 20 V and total losses on normal state was 1.3 kW.

• 한국전산유체공학회:학술대회논문집
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• 2005.10a
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• pp.39-44
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• 2005

In HANARO, a multi-purpose research reactor of 30 MWth, the emergency water supply system consists essentially of an emergency water storage tank located in the level of about thirteen meter (13 m) above the reactor core, a three inch ('3\%') diameter water injection pipe line including injection valves from the tank to the reactor cooling inlet pipe and a test loop to do periodic system performance test. When the water level of the reactor pool comes down to the extremely low due to a loss of reactor pool water accident the emergency water stored in the tank should be fed to the core by the gravity force and at that time the design flow rate is eleven point four kilogram per second (11.4 kg/s). But it is impossible periodically to measure the injection flow rate under the emergency condition because the normal water level should be maintained during the reactor operation. This paper describes a flow network analysis to simulate the flow rate under the emergency condition. As results, it was confirmed through the analysis results that the calculated flow rate agrees with the design requirement under the emergency condition.