• 기술혁신연구
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• 제12권1호
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• pp.219-240
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• 2004

As Shapiro and Varian argue the open approach generates bandwagon effects and facilitates the diffusion of a standard thanks to network externalities. However, the open approach is not linked automatically to economic benefits as suggested by some famous cases as the IBM PC history. On the contrary, the closed approach enables a tight control over a technology and its development, and insures the appropriation of economic benefits. As Shapiro and Varian suggest, a firm can also decide to mix an open approach with tight control over improvement or extentions. Patent pool is to offer fair, reasonable, nondiscriminatory access under a single license to patents that are essential for the use of standards-based or other platform technologies. patent pool offers only one license to everyone, Since each patent is essential, the royalty rate and thus the value is the same whether a licensee uses one or more patents.

• 한국멀티미디어학회논문지
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• 제19권3호
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• pp.650-658
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• 2016

This study proposes web-based authoring system for the lecturers who published textbooks by inserting external open resource. When lecturer publishes textbooks, the system makes it easier to utilize external resources by providing an open resource pool that the lecturer can search not only his own resources but external resources. In addition, we designed an open resource pool based on Original Contents Tracing Model to check whether the scrapped resource is changed or not in the future. Open Resource Pool allows inserting text, images and videos by searching multimedia, and stores metadata for the follow-up management. We made the system to determine the change of the resource using the metadata stored in the tracking system. Through this research, we confirmed that it is possible to publish textbooks by utilizing a variety of open resources on the web and revise the book by tracing the scrapped resources.

• 한국방재안전학회논문집
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• 제9권2호
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• pp.33-42
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• 2016

항만 옥외저장소는 포장위험물의 수출입을 위해 컨테이너 터미널 특정 공간에 마련된 장소로, 옥외저장소 간 보유공지 기준을 완화하여 사고발생 시 피해확대 우려가 가중되고 있다. 본 연구에서는 탱크 컨테이너로부터 인화성 액체 누출로 인한 액면화재를 모사함으로써 복사열에 대한 피해영향을 분석하였다. 그 결과 임계손상기준에 따른 복사열 도달거리가 현행 보유공지 기준을 상회하는 것으로 분석되었으며, 인접 컨테이너가 early pool fire에 지속적으로 노출될 경우 단시간 내 구조적 손상 가능성이 있는 것으로 평가되었다. 본 연구는 컨테이너 터미널에서의 적절한 옥외저장소 간 보유공지 기준을 마련하는데 도움이 될 수 있을 것으로 판단된다.

• 대한기계학회논문집 C: 기술과 교육
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• 제5권2호
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• pp.135-143
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• 2017

국내 유일의 연구용원자로인 하나로(Hi-flux Advanced Neutron Application ReactOr)는 다목적으로 중성자를 이용하기 위해 개방형 수조 내 노심이 존재하는 구조이며, 노심에서 발생되는 핵분열 열을 제거하기 위한 일차 냉각계통, 그리고 연결된 유체계통이 구비되어 있다. 원자로 수조 상부 근방에서 진행되는 방사성 작업 시 작업자의 방사능 피폭을 최소화하기 위해 수조고온층계통에 의해 상부에 고온층이 형성되어 있으며, 다소 저온 영역에 있는 방사능 가스 및 이물질이 상부로 올라오는 것을 방지하기 위해 수조수 온도를 $50^{\circ}C$이하로 제한하고 있으며 이를 위해 수조수관리계통이 연결되어 있다. 수조수관리계통의 구비된 판형열교환기의 열용량을 정상운전 조건에서 260 kW가 되도록 설계하여 각 수조에서 발생되는 열원을 제거하는지에 대해 평가하였고, 원자로 운전 모드와 관계없이 정상적으로 유체계통이 운전된다면 각 수조의 수조수 온도는 제한치 이하를 유지하고 있음을 확인하였다.

• 태양에너지
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• 제11권1호
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• pp.87-91
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• 1991

Pool cover를 이용한 수영장에서의 열손실에 관하여 실험적 연구를 수행하였다. 그 결과 본 연구의 실험조건에서 pool cover 를 이용할 경우, 전체열손실이 50% 이상 줄어 듬을 알 수 있었다.

• 한국유체기계학회 논문집
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• 제13권5호
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• pp.5-10
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• 2010

5MW, open pool type research reactor, is commonly used to education and experimental purpose. It is necessary to prepare a standardization of system designs for considering a demand. HANARO has prepared the standardization of 5MW research reactor system designs based on the design, installation, commissioning and operating experiences of HANARO. For maintaining an open pool type reactor safety, a primary cooling system (after below, PCS) should remove the heat generated by the reactor under a reactor normal operation condition and a reactor shutdown condition. For removing the heat generated by the reactor, the PCS should maintain a required coolant flow rate. For a verification of the required flow rate, a flow network analysis of the PCS was carried under a normal operating condition. Based on the flow network analysis result, this paper describes the PCS flow characteristics of a 5MW open pool type research reactor. Through the result, it was confirmed that the PCS met design requirements including design flow rate without cavitation.

• 에너지공학
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• 제12권2호
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• pp.74-83
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• 2003

APR1400과 같은 차세대 원자력발전소에서는 원자로 안전성을 증진시키기 위하여 SDVS와 같은 계통을 도입하고 있다. 완전급수상실사고와 같은 경우는 POSRV가 개방되어 수조내 Sparger를 통하여 증기가 방출·응축되게 된다 증기가 응축함에 있어서 설계에서 고려해야 될 사항은 하중과 수조 혼합이며 증기제트 응축의 물리적 현상 이해를 통하여 적절한 대처를 마련할 수 있다. 수조내 Sparger를 통하여 분사되는 증기 응축에 대하여 하중과 수조 혼합 검토에 도움이 될 수 있도록 증기제트 응축의 물리적 현상 이해에 대한 검토와 평가를 수행하였다.

• Nuclear Engineering and Technology
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• 제55권5호
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• pp.1604-1615
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• 2023

In an open-pool type research reactor with a downward forced flow in the core, pipes can be under sub-atmospheric pressure because of the large pressure drop at the reactor core in the atmospheric pool. Sub-atmospheric pressure can result in air inflow into the pipe from the pressure difference between the atmosphere and the inside of the pipe, which in a postulated pipe break scenario can lead to the breakdown of the cooling pump. In this study, a plant-scale experiment was conducted to study air inflow in large piping systems by considering the actual operational conditions of an advanced research reactor. The air inflow rate was measured, and the entrained air was visualized to investigate the behavior of air inflow and flow regime depending on the pipe break size. In addition, the developed drift-flux model for a large vertical pipe with a diameter of 600 mm was compared with other correlations. The flow regime transition in a large vertical pipe under downward flow was also studied using the newly developed drift-flux model. Consequently, the characteristics of two-phase flow in a large vertical pipe were found to differ from those in small vertical pipes where liquid recirculation was not dominant.

• Nuclear Engineering and Technology
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• 제52권10호
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• pp.2204-2220
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• 2020

An open-pool type research reactor is designed and operated considering the accessibility around the pool top area to enhance the reactor utilization. The reactor structure assembly is placed at the bottom of the pool and filled with water as a primary coolant for the core cooling and radiation shielding. Most radioactive materials are generated from the fuel assemblies in the reactor core and circulated with the primary coolant. If the primary coolant goes up to the pool surface, the radiation level increases around the working area near the top of the pool. Hence, the hot water layer is designed and formed at the upper part of the pool to suppress the rising of the primary coolant to the pool surface. The temperature gradient is established from the hot water layer to the primary coolant. As this temperature gradient suppresses the circulation of the primary coolant at the upper region of the pool, the radioactive primary coolant rising up directly to the pool surface is minimized. Water mixing between these layers is reduced because the hot water layer is formed above the primary coolant with a higher temperature. The radiation level above the pool surface area is maintained as low as reasonably achievable since the radioactive materials in the primary coolant are trapped under the hot water layer. The key to maintaining the stable hot water layer and keeping the radiation level low on the pool surface is to have a stable flow of the primary coolant. In the research reactor with a downward core flow, the primary coolant is dumped into the reactor pool and goes to the reactor core through the flow guide structure. Flow fields of the primary coolant at the lower region of the reactor pool are largely affected by the dumped primary coolant. Simple, circular, and duct type discharge headers are designed to control the flow fields and make the primary coolant flow stable in the reactor pool. In this research, flow fields of the primary coolant and hot water layer are numerically simulated in the reactor pool. The heat transfer rate, temperature, and velocity fields are taken into consideration to determine the formation of the stable hot water layer and primary coolant flow. The bulk Richardson number is used to evaluate the stability of the flow field. A duct type discharge header is finally chosen to dump the primary coolant into the reactor pool. The bulk Richardson number should be higher than 2.7 and the temperature of the hot water layer should be 1 ℃ higher than the temperature of the primary coolant to maintain the stability of the stratified thermal layer.

• Nuclear Engineering and Technology
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• 제42권1호
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• pp.125-130
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• 2010

Sipping measurements were implemented at the Open Pool Australian Light water reactor (OPAL) to test for failure in reactor fuel elements. Fission product released by the fuel element into the pool water was measured using both High Purity Germanium (HPGe) detection via samples and a NaI(Tl) detection in-situ with the sipping device. Results from two fuel elements are presented.