• Proceedings of the Korean Nuclear Society Conference
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• 1998.05a
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• pp.707-712
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• 1998

이종 코드에 의한 CE형 발전소의 대형 냉각재 상실 사고 해석이 수행되었다. 이 연구는 상대적으로 최근에 개발된 웨스팅하우스 대형 냉각재 상실 사고 해석 코드를 사용하여 영광 3&4호기의 대형 냉각재 상실 사고를 계산해 봄으로써 CE 대형 냉각재 상실 사고 해석 코드의 개선 방향을 고찰하는 것을 목적으로 하였다. 계산은 가장 제한적인 대형 냉각재 상실 사고의 Blowdown 및 Refill 기간 동안 수행하였다. 이 기간 동안의 RCS내 열수력적 거동 및 연료봉 온도 변화는 CE 대형 냉각재 상실 사고 해석 코드를 사용하여 계산한 경우와 크게 다르지 않음을 확인하였다. 따라서 향후 CE 대형 냉각재 상실 사고 해석 코드의 성능 개설은 Reflood 해석용 코드의 개선 및 개발을 중심으로 이루어져야 한다는 결론을 얻었다.

• Proceedings of the Korea Society for Simulation Conference
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• 2000.04a
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• pp.168-173
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• 2000

지금까지 국내에서 설치되어 있는 원전 시뮬레이터용 노심 (Neutronics) 모델 프로그램은 주로 전산기 성능이 오늘날 비해 낮은 환경에서 실시간으로 노물리 계산을 위해 중성자 확산(Diffusion)현상을 미리 반영한 곡선을 사용하는 등 빠른 계산을 위해 많은 가정과 간략화가 있었다. 본 논문에서는 중성자 물리 계산을 2 Group 3-D로 계산이 가능한 최신의 노심코드(REMARK)를 이용하여, WH사가 공급한 900Mw의 3 Loop PWR인 영광 1호기 12주기를 기준으로 한 시뮬레이터의 노심모델 개발하기 위한 핵설계 전산체계인 APA(ALPHA-PHOENIX-ANC) 시스템의 출력으로부터 자동으로 REMAR 입력데이타를 생성하기 위한 GUI툴 개발과 개발된 노심모델의 자체 검증 및 원자력발전소 사고해석에 쓰이는 최적평가코드(RETRAN)를 기반으로 하는 최신 실시간 열수력 시뷸레이션(ARTS) 모델과 결합(Integration)되어 원자로 냉각재 펌프 1대 정지 및 터빈정지 시험등 과도시험한 결과를 기술하였으며 개발된 노심 모델은 원자력 교육원 2호기 시뮤레이터에 적용될 예정이다.

• The KSFM Journal of Fluid Machinery
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• v.9 no.4 s.37
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• pp.20-26
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• 2006

A cryogenic test facility has been developed to perform inducer and pump tests using liquid nitrogen. Performance tests of a turbopump in the maximum 50ton-thrust class can be performed with cryogenic fluid in the facility which operates at a temperature around -196oC with the rotational speed up to 30,000rpm To verify the reliability of the cryogenic pump test facility, hydraulic performance tests of an inducer were accomplished, and their results were compared with the result from a water test. The results confirm the reliability of the cryogenic test facility, and it is expected to contribute for on-going development of a turbopump for liquid rocket engines.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.687-689
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• 2005

Francis turbine of commercial small hydro -power plants under 10kw which is investigate a flow characterist and an efficiency in the research which it sees, the problem and an improvement is investigate. In the research which it is simply model with casing, guide-vane, runner, draft tube for simulation numerical analysis of small-sized Francis turbine. model uses the Gambit and it composes with approximately 800,000 nonuniform lattices. Solutions are investigate the hydraulic characteristics against an outward angle of guide vane, the number of guide vane, head(inlet velocity) by using FLUENT which is a commercial business code.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.495-498
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• 2006

The Kaplan turbine model has been tested and analyzed. The blade angle and the guide vane opening of the turbine model were designed to be varied according to the best combination of guide vane and runner blade opening. When the changes in head and output were comparatively large, the efficiency drop were small, so the efficiency characteristics and stability of the entire operating condition were maintained in good condition. These results showed that the developed model in this study will be suitable for small hydropower stations with large changes In head and load such as agricultural reservoir.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.16 no.2
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• pp.10-17
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• 2020

Securing the integrity of steam generator tubes is an essential requirement for safe operation of nuclear power plants. Therefore, tubes that do not satisfy integrity requirements are no longer usable and must be repaired according to the related requirements. In general, the repair criterion is that the damage depth is more than 40% of the tube wall thickness. However, the plugging limit can be changed and be applied, provided a technical proof is given that integrity can be secured against specific degradation at a specific plants and that approval can be obtained from a regulatory agency. A typical example is alternative repair criteria for defects within the tube sheet or tube support plates. In this paper, a background of establishing the plugging limit for steam generator tubes and changes in maintenance criteria are reviewed as examples.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.1
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• pp.9-15
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• 2011

In this study, we investigated the hydrodynamic and thermal performance of constructal architectures on the basis of the mass flow rates for a given pressure drop, and we determined the thermal resistance and flow uniformity. The five flow configuration used in this study were the first construct with optimized hydraulic diameter, the second construct with optimized hydraulic diameter, the first construct with non-optimized hydraulic diameter, second construct with non-optimized hydraulic diameter, and a serpentine configuration. The results of our study suggest that the best fluid-flow structure is the second constructal structure with optimized constructal configurations. We also found that in the case of the optimized structure of cooling plates, the heat transfer was remarkably higher and the pumping power was significantly lower than those of traditional channels.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.11
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• pp.74-79
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• 2005

Computational studies on the hydrodynamic behavior of the forward-sweep inducers for the rocket-engine turbopump are presented in comparison with the conventional backward- sweep inducers. In the present study, two kinds of forward-sweep inducers are designed and numerically investigated. Forward-sweep inducers have bigger tip solidity compared to backward-sweep inducers even with shorter axial length due to their forward-sweep leading edge profiles. It is shown that back flows at the inlet decreases dramatically for forward- sweep inducers. And the low pressure region at the back flow are also decreased, which is assumed to promote the suction performance of the inducers. It seems that the hub located upstream of the tip at the leading edge induces pre whirl at the inlet blade tip for the backward sweep inducer. And this pre whirl leads to the big back flow.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.7
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• pp.120-128
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• 2019

It is very important to verify the seismic performance and stability of the power plant fixture in the domestic power plant, because earthquakes have increased in frequency around the world which resulted in the frequent occurrence of power plant damage caused by the failure of electric power facilities. In this study, through the on-site inspection of power plant fixation unit installed in domestic power plants, we carried out structural performance evaluation of the fixation unit anchor bolts installed on the concrete slabs. The field survey showed M12 J hook anchor bolts were used. Anchor bolt pullout and shear performance evaluation were performed based on ASTM E 488-96 standard. Moreover, artificial crack with the width of 0.5 mm was applied during the experiment based on ATM355.4 and ETAG 001. The comparison of M12 J hook anchor bolt pullout and shear test result to design value required in domestic and international design standard, show a satisfactory result. M12 J hook anchor pullout and shear performance was found to be about 35% and 7%, respectively, higher than the required design value.

• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.2
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• pp.65-72
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• 2015

Performance tests of a turbopump for the developing 7-tonf liquid rocket engine were conducted. The performance of turbopump components and their power matching were measured and examined firstly under the LN2 and water environment. In the real propellant(LOX and kerosene) environment tests, design and off-design performances of turbopump were fully verified. During the off-design tests, turbopump running time was set the same as engine operating time and pump inlet pressure were set lower than nominal operating value in order to investigate pump suction capability. It have been verified that subject turbopump satisfies required performance - flow rate, head, suction performance and operational time - in the operating regime of developing liquid rocket engine.