• 한국안전학회지
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• 제20권2호
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• pp.32-37
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• 2005

The purpose of this study is for the sensitivity study f9r a Steam Generator Tube Rupture (SGTR) of the System-integrated Modular Advanced ReacTor for a Pilot (SMART-P) plant. The thermal hydraulic analysis of a SGIR for the Limiting Conditions for Operation (LCO) is performed using TASS/SMR code. The TASS/SMR code can calculate the core power, pressure, flow, temperature and other values of the primary and secondary system for the various initiating conditions. The major concern of this sensitivity study is not the minimum Critical Heat Flux Ratio(CHFR) but the maximum leakage amount from the primary to secondary sides at the steam generator. Therefore the break area causing the maximum accumulated break flow is researched for this reason. In the case of a SGIR for the SMART-p, the total integrated break flow is 11,740kg in the worst case scenario, the minimum CHFR is maintained at Over 1.3 and the hottest fuel rod temperature is below 606"I during the transient. It means that the integrity of the fuel rod is guaranteed. The reactor coolant system and the secondary system pressures are maintained below 18.7MPa, which is system design pressure.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1997년도 추계학술발표회논문집(1)
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• pp.475-480
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• 1997

In order to conduct the effective integration of computer-aided conceptual design for integrated nuclear power reactor, not only is a smooth information flow required, but also decision making fur both conceptual design and construction process design must be synthesized. In addition to the aboves, the relations between the one step and another step and the methodologies to optimize the decision variables are verified, in this paper especially, that is, scaling laws and scaling criteria. In the respect with the running of the system, the integrated optimization process is proposed in which decisions concerning both conceptual design are simultaneously made. According to the proposed reactor types and power levels, an integrated optimization problems are formulated. This optimization is expressed as a multi-objective optimization problem. The algorithm for solving the problem is also presented. The proposed method is applied to designing a integrated sub-critical reactors.

• 한국대기환경학회지
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• 제23권2호
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• pp.203-213
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• 2007

Numerical analysis has been performed to understand flow characteristics in the reactor with bag filters in an integrated adsorption/catalytic process which can treat dioxin and $NO_{x}$ together. Computational fluid dynamics technique was employed with Euler-Lagrangian model to consider flue gas and activated carbon particles simultaneously, so that residence time of flue gas and activated carbon particle could be obtained from the numerical analysis directly. The numerical analysis has been performed with different three particle sizes and compared each flow characteristics with particle's size. Fundamental flow patterns of flue gas and activated carbon particles, pressure distribution, residence time of flue gas and activated carbon particles, and distribution of activated carbon have been obtained from the numerical analysis. Flow patterns of flue gas and activated carbon particles in the reactor were very complicated and they moved along very various paths. Therefore, their residence time in the reactor was also various. The results obtained would be effectively used to estimate the removal efficiency in the reactor once the residence time is combined with the reaction equation.

• 대한기계학회논문집B
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• 제35권6호
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• pp.641-648
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• 2011

고온 발전용 연료전지인 MCFC의 연료극에서 방출되는 미반응 가스를 촉매연소의 열원으로 사용하고, 촉매연소 반응에 의해 발생한 열을 개질 반응에 필요한 공급열로 이용하는 통합형 촉매연소-개질 반응기에 있어서 MCFC의 운전 조건 변경에 따른 반응기의 열적 거동과 반응 특성을 실험적으로 연구하였다. 특히, 연료극에서 연료 이용률을 변동될 때 슬립가스의 조성이 바뀌는 것을 고려하여 촉매연소측에 공급해줄 혼합가스의 조성을 실험조건으로 설정하였다. 또한 개질측에서는 S/C(수증기/탄소)의 비를 운전조건의 변동 조건으로 설정하였다. 실험적으로 얻어진 데이터는 보다 현실적인 통합형 촉매연소-개질반응기를 설계하고 제작하는데 필요한 기본 자료로 활용될 수 있을 것이다.

• Korean Chemical Engineering Research
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• 제60권1호
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• pp.116-124
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• 2022

교대로 운전되는 광촉매반응기 공정, 및 바이오필터 공정(전통적 바이오필터(L 반응기)와 두 개의 유닛(unit)을 가지는 개선된 바이오필터시스템(R 반응기))로 구성된 통합처리시스템에서, 에탄올과 황화수소를 동시 함유한 폐가스 처리를 수행하는데 발생하는 공정 당 압력강하(△p)와 바이오필터 공정의 미생물 population 분포를 관찰하였다. 교대로 운전되는 광촉매 반응기의 △p는, 바이오필터의 △p와 비교할 때에 무시할 정도로 작게 관찰되었다. L 반응기의 △p는, 통합처리시스템의 운전 중에 계속 증가하여 4.0~5.0 mmH₂O (i.e., 5.0~6.25 mmH₂O/m)로 증가하였다. 한편 R 반응기의 경우에서는 L 반응기의 △p의 약 16~20% 이하인 작은 △p를 나타내었다. 본 연구에서 적용한 공극율이 큰 폐타이어 담체 등의 바이오필터 담체 및 R 반응기 설계의 적용이, 목재 칩(wood chip)과 목재 바크(wood bark)의 50 대 50인 혼합물을 바이오필터 담체로 사용한 전통적 바이오필터의 보고된 압력강하 값의 각각 37~50%와 40~53% 만큼 압력강하 저감에 공헌하였다고 분석되었다. 또한 본 연구의 R 반응기 운전에서 압력강하 값이, 공극율이 큰 화산석(scoria)과 compost를 75 대 25로 혼합한 복합 담체를 충전한 전통적 바이오필터의 보고된 압력강하 값보다 약 80%만큼 저감된 결과는 주로 R 반응기 설계의 적용에 기인하였다고 해석되었다. 한편, 통합처리시스템에서 바이오필터 담체의 microbial population 분포로서 L 반응기 및 R 반응기의 담체 내 미생물 콜로니 수 비교에서는 L 반응기가 제일 밑단에서 다른 윗 단의 콜로니 수보다 거의 두 배로 증가하였으나; R 반응기의 경우는 R_dn 반응기와 R_up 반응기 각각의 상단과 하단에서 고르게 분포하였고 L 반응기보다 콜로니 수가 평균적으로 약 50% 정도 더 컸다. 이러한 현상은 R 반응기의 상단과 하단의 함수율이 50-55%의 고른 분포를 보인 것에 기인하였다. 따라서 개선된 바이오필터시스템이 전통적 바이오필터보다 △p와 미생물 population 분포에서 더욱 우수한 특성을 보였다.

• Nuclear Engineering and Technology
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• 제40권7호
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• pp.615-624
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• 2008

In this paper, the contribution of task types and error types involved in the human-related unplanned reactor trip events that have occurred between 1986 and 2006 in Korean nuclear power plants are analysed in order to establish a strategy for reducing the human-related unplanned reactor trips. Classification systems for the task types, error modes, and cognitive functions are developed or adopted from the currently available taxonomies, and the relevant information is extracted from the event reports or judged on the basis of an event description. According to the analyses from this study, the contributions of the task types are as follows: corrective maintenance (25.7%), planned maintenance (22.8%), planned operation (19.8%), periodic preventive maintenance (14.9%), response to a transient (9.9%), and design/manufacturing/installation (6.9%). According to the analysis of the error modes, error modes such as control failure (22.2%), wrong object (18.5%), omission (14.8%), wrong action (11.1 %), and inadequate (8.3%) take up about 75% of the total unplanned trip events. The analysis of the cognitive functions involved in the events indicated that the planning function had the highest contribution (46.7%) to the human actions leading to unplanned reactor trips. This analysis concludes that in order to significantly reduce human-induced or human-related unplanned reactor trips, an aide system (in support of maintenance personnel) for evaluating possible (negative) impacts of planned actions or erroneous actions as well as an appropriate human error prediction technique, should be developed.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집D
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• pp.921-926
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• 2001

The reliability and accuracy of the information on control rod position are very important to the reactor safety and the design of the core protection system. In this study, a thorough investigation on the RSPT(Reed Switch Position Transmitter) type control rod position indication system and its actual implementation in the exiting nuclear power plants in Korea was performed first. A design of the control rod position indication system using reed switch for the CEDM on the system-integrated reactor SMART was developed based on the position indicator technology identified through the investigation. The feasibility of the design was evaluated by test of manufactured control rod position indicator using reed switch for SMART.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1998년도 춘계학술발표회논문집(1)
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• pp.660-665
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• 1998

The feasibility study on conceptual design methodology for accelerator-driven sodium-cooled sub-critical transmutation reactors has been conducted to optimize the design parameters from the scale laws and validates reactor performance with the integrated code system. A 1000 MWth sodium-cooled sub-critical transmutation reactor has been scale and verified through the methodology in this paper, which is referred to advanced Liquid Metal Reactor (ALMR). a Pb-Bi target material and a partitioned fuel are the liquid phases, and they are cooled by the circulation of secondary Pb-Bi coolant and by primary sodium coolant, respectively. Overall key design parameters are generated from the scale laws and they are improved and validated by the intergrated code system. Intergrated Code System (ICS) consist of LAHET, HMCNP, ORIGEN2, and COMMIX codes and some files. Through ICS the target region, the core region, and thermal-hydraulic related are analyzed once-through. Results of conceptual design are attached in this paper.

• 대한전기학회논문지:전력기술부문A
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• 제52권4호
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• pp.147-147
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• 2003

This paper describes the finite element analysis(FEA) for the design of electromagnet for Control Element Drive Mechanism(CEDM) in System-integrated Modular Advanced Reactor(SMART) and compared with the lifting power characteristics of prototype electromagnet. A thermal analysis was performed for the electromagnet. A model for the thermal analysis of the electromagnet was developed and theoretical bases for the model were established. It is important that the temperature of the electromagnet windings be maintained within the allowable limit of the insulation. since the electromagnet of CEDM is always supplied with current during the reactor operation. So the thermal analysis of the winding insulation which is composed of polyimide and air were performed by finite element method. As a result, it is shown that the characteristics of prototype electromagnet have a good agreement with the results of FEA. The thermal properties obtained here will be used as input for the optimization analysis of the electromagnet.

• Structural Engineering and Mechanics
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• 제76권3호
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• pp.367-378
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• 2020

This paper presents a new design concept for ocean nuclear power plants (ONPPs) using a tension leg platform (TLP). The system-integrated modular advanced reactor, which is one of the successful small modular reactors, is mounted for demonstration. The authors define the design requirements and parameters, modularize and rearrange the nuclear and other facilities, and propose a new total general arrangement. The most fundamental level of design results for the platform and tendon system are provided, and the construction procedure and safety features are discussed. The integrated passive safety system developed for the gravity based structure-type ONPP is also available in the TLP-type ONPP with minor modifications. The safety system fully utilizes the benefits of the ocean environment, and enhances the safety features of the proposed concept. For the verification of the design concept, hydrodynamic analyses are performed using the commercial software ANSYS AQWA with the Pierson-Moskowitz and JONSWAP wave spectra that represent various ocean environments and the results are discussed.