• Proceedings of the Korean Nuclear Society Conference
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• 1995.05a
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• pp.596-601
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• 1995

신뢰도 분석 방법을 이용하여 습식 사용후핵연료 중간저장시설의 냉각계통에 대한 최적 설계조건을 도출하기 위한 연구를 수행하였다. 먼저 고장수목 분석을 통한 설계 취약점을 평가하여 21개의 설계대안을 도출하였고, 최종적으로 설계대안에 대한 건설비 용, 계통신뢰도 분석 및 확률론적 안전기준을 고려한 비용효과 분석을 실시하였다. 설계 대안들 중에서 100% 루프 다중설계, 루프당 한 개의 펌프 사용, 안전등급 부여 및 주 루프에서 정화계통이 분리된 경우가 최적설계안으로 나타났다. 여기서 적용된 방법론은 유사시설의 최적설계에 유용하게 응용될 수 있을 것으로 사료된다.

• Proceedings of the Korean Nuclear Society Conference
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• 2001.05a
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• pp.112.1-112
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• 2001

• Proceedings of the KSME Conference
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• 2005.11a
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• pp.106.1-106.1
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• 2005

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.11
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• pp.991-998
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• 2010

The effect of increasing the elevation of an IHX (intermediate heat exchanger) on the transient performance of the KALIMER-600 reactor pool during the early phase of a loss of normal heat sink accident was investigated. Three reactors equipped with IHXs that were elevated to different heights were designed, and the thermal-hydraulic analyses were carried out for the steady and transient state by using the COMMIX-1AR/P code. In order to analyze the effects of the elevation of an IHX between reactors, various thermal-hydraulic properties such as mass flow rate, core peak temperature, RmfQ (ratio of mass flow over Q) and initiation time of decay heat removal via DHX (decay heat exchanger) were evaluated. It was found that with an increase in the IHX elevation, the circulation flow rate increases and a steep rise in the core peak temperature under the same coastdown flow condition is prevented without a delay in the initiation of the second stage of cooling. The available coastdown flow range in the reactor could be increased by increasing the elevation of the IHX.

• Aerospace Engineering and Technology
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• v.7 no.1
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• pp.129-135
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• 2008

The 30 tonf-class liquid rocket combustor currently being developed is designed to connect the fuel feeding line at a middle position of the supersonic nozzle in order to reduce both pressure loss in the regenerative cooling passage and overall envelope of the thrust chamber in spite of increase in design complexity. To verify the design of cooling passages including fuel ring, connecting holes, two-directional cooling channels and collectors, numerical analysis has been performed.

• 한국기계연구소 소보
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• s.11
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• pp.69-76
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• 1984

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05d
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• pp.247-252
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• 1996

사용후핵연료 건식 중간저장시설은 설계수명기간 동안 방사능 차폐, 냉각, 보호 등과 같은 주요 기능이 확실히 보장되도록 설계 및 유지·관리되어야 한다. 이러한 주요 기능은 여러가지 설계하중 하에서 구조물의 거동을 정확히 파악한 결과를 설계에 반영함으로써 보장된다. 본 연구에서는 구조물의 건전성을 보장할 수 있는 기능적 측면과 구조적 측면에서 고려되어야 할 항목 및 내용을 국외에서 적용되고 있는 기술기준을 토대로 하고 풍하중, 홍수방호, 내진설계, 열하중해석, 철근콘크리트 및 강구조물, 기초지반과 같은 세부항목에 대한 해석 및 설계의 연구결과를 추가하여 국내 원자력법령과 시행령에 부합되는 사용후핵연료 건식중간저장시설의 구조 및 설비기준을 개발하였다.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.7
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• pp.86-93
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• 1999

Turbocharger has been used to increase the performance of diesel engine, especially ship engine , for years. Recently, the turbocharger is being adopted not only for an agricultural engine but also for an automobile engine. To improve the performance of diesel engine , the problem of the reduction of A/F ratio in high speed should be solved. Turbocharger is well known for its cost effectiveness, reliability and duration . In this study, an experiment was conducted to verify simulation program . The results for natural aspiration engine and turbocharged engine were compared. In order to estimate the characteristics of exhaust gas, D-13 mode was selected. Power, torque and BSFC of turbocharged engine were increased than those of natural aspiration engine by about 48%, 46% and 5%, respectively . The components in exhaust gas except NOx from turbocharger engine were less than the amount set up for 2000-year regulation.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2001.02a
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• pp.155-158
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• 2001

An intermediate cooling is indispensible to reduce the refrigeration power at superconducting system that is cooled conductively by a cryocooler without liquid cryogens. The cooling load at the intermediate stage is caused by the mechanical supports, the radiation shield and the current lead. From the cooling load calculation, a thermodynamic analysis that take into account the temperature-dependent properties of the materials and the actual performance of the cryocooler is developed. For any given physical dimensions of the various components, it is shown that there exist a unique optimum for the intermediate temperature to minimize the overall refrigeration power. The results of this study can be usefully applied to the selection of the cryocooler as well as the design of the conduction-cooled cryostat.

• The Journal of the Petrological Society of Korea
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• v.13 no.2
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• pp.103-118
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• 2004

In Cheongsong area, very rare spherulitic rhyolites both in Korea and foreign countries occur as dykes showing various types. The spherulites in them represent an undercooling caused by very fast cooling of the dykes in a shallow depth near to the surface and the variety of types were resulted from the difference of relative cooling rate. Cheongsong spherulitic rhyolites can be classified into five types; radiated simple spherulite, layered simple spherulite, layered multiple spherulite, radiated-layered multiple spherulite, radiating layered multiple spherulite. Radiated simple and radiating layered multiple spherulites formed by diffusion current caused by undercooling related to very fast cooling. On the other hand, layered multiple spherulites formed by relatively slow diffusion as a Liesegang ring during relatively slow cooling. If the cooling rate is between the two cases, layered simple spherulites formed. This interpretation indicates that Chrysanthemum, Dandelion, Dahlia and Sunflower types which are included in radiated simple or radiating layered multiple spherulites formed in the dykes with the fastest cooling rate in Cheongsong area while Peony, Rose and Innominate types classified as layered multiple spherulite formed in the dykes with the relatively slowest cooling rate. At the cooling rate between them, Apricot type spherulite formed. The K-Ar age-dating for Cheongsong spherulitic rhyolites indicate them to be formed between 48 and 50 Ma. The Cheongsong rhyolites are very valuable for research and preservation because of their rarity, beauty and diversity.