• 설비공학논문집
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• 제17권6호
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• pp.596-604
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• 2005

This paper presents the work on evaluating the LCC (Life-Cycle Cost) of a heat pump system as unutilized energy system. The river water as an unutilized energy source was used for the heat source of heat pump system. LCC analysis is a concrete method for evaluating the economical efficiency of energy facilities of building. The present case study shows an example of adequate use of the LCC analysis on a heat pump system and conventional gas boiler and refrigerator for building heat supply. A life cycle of 20 years was used to calculated net present value of energy cost. Over a 20 year life cycle, the energy cost could be reduced by 612 million won if a heat pump system were used instead of a conventional boiler and an absorption refrigerator.

• Nuclear Engineering and Technology
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• 제43권2호
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• pp.141-148
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• 2011

This paper presents the quantitative analysis results of research on the burnup effect on the nuclear fuel cycle cost of BeO-$UO_2$ fuel. As a result of this analysis, if the burnup is 60 MWD/kg, which is the limit under South Korean regulations, the nuclear fuel cycle cost is 4.47 mills/kWh at 4.8wt% of Be content for the BeO-$UO_2$ fuel. It is, however, reduced to 3.70 mills/kWh at 5.4wt% of Be content if the burnup is 75MWD/kg. Therefore, it seems very advantageous, in terms of the economic aspect, to develop BeO-$UO_2$ fuel, which does not have any technical problem with its safety and is a high burnup & long life cycle nuclear fuel.

• Nuclear Engineering and Technology
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• 제49권3호
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• pp.621-631
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• 2017

Many developing countries considering the introduction of nuclear power find that large-scale reactor plants in the range of 1,000 MWe to 1,600 MWe are not grid appropriate for their current circumstance. By contrast, small modular reactors are generally too small to make significant contributions toward rapidly growing electricity demand and to date have not been demonstrated. This paper proposes a radically simplified re-design for the nuclear steam cycle for a medium-sized reactor plant in the range of 600 MWe. Historically, balance of plant designs for units of this size have emphasized reliability and efficiency. It will be demonstrated here that advances over the past 50 years in component design, materials, and fabrication techniques allow both of these goals to be met with a less complex design. A disciplined approach to reduce component count will result in substantial benefits in the life cycle cost of the units. Specifically, fabrication, transportation, construction, operations, and maintenance costs and expenses can all see significant reductions. In addition, the design described here can also be expected to significantly reduce both construction duration and operational requirements for maintenance and inspections.

• Nuclear Engineering and Technology
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• 제54권3호
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• pp.877-887
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• 2022

A new reactor concept is described that directly couples a supercritical CO₂ (sCO₂) power cycle with a CO₂-cooled, heavy water moderated pressure tube core. This configuration attains the simplification and economic potential of past direct-cycle sCO₂ concepts, while also providing safety and power density benefits by using the moderator as a heat sink for decay heat removal. A 200 MWe design is described that heavily leverages existing commercial nuclear technologies, including reactor and moderator systems from Canadian CANDU reactors and fuels and materials from UK Advanced Gas-cooled Reactors (AGRs). Descriptions are provided of the power cycle, nuclear island systems, reactor core, and safety systems, and the results of safety analyses are shown illustrating the ability of the design to withstand large-break loss of coolant accidents. The resulting design attains high efficiency while employing considerably fewer systems than current light water reactors and advanced reactor technologies, illustrating its economic promise. Prospects for the design are discussed, including the ability to demonstrate its technologies in a small (~20 MWe) initial system, and avenues for further improvement of the design using advanced technologies.

• 자원환경지질
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• 제54권6호
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• pp.733-741
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• 2021

전세계적으로 2015년 파리기후협약에서 정한 목표에 따라 2050년까지 탄소중립을 위하여 각 국가는 감축목표를 수립 및 선언하고, "장기 저탄소 발전전략" (Long-term low greenhouse gas Emission Development Strategies, LEDS)을 수립, 감축 목표 설정을 위한 로드맵 등을 발표하고 있다. 국제사회의 탄소중립사회 전환 가속화에 따라 2020년말까지 128개국이 탄소중립을 선언하였으며, G20 회원국을 중심으로 지속적으로 탄소중립선언이 확대되고 있다. 우리나라도 2020년 12월 탄소중립의 능동적 대응을 통해 탄소중립과 경제성장, 국민 삶의 질 향상을 동시 달성하는 기반 마련을 위한 "2050 탄소중립 추진전략"을 발표하였고, 이를 위한 정책과제를 단계적으로 추진하고 있다. 우리나라에서 온실가스 감축을 위하여 시행되고 있는 온실가스에너지 목표관리제 및 온실가스 배출권거래제 상쇄제도 등 의무감축제도의 영역에서 벗어나 있어 종합적인 탄소관리는 미흡하며, 현재 광해방지사업으로 인한 이산화탄소배출량을 정량화한 사례는 없다. 따라서, 본 연구에서는 전세계적인 탄소중립의 관심과 정부 정책 기조에 따라 탄소 중립 실현을 위해서 한국광해광업공단의 주 업무인 광해방지사업에 대하여 국내외 탄소배출량 산정 방법으로 제시된 표준방법을 검토하고, 광해방지사업에 적합한 탄소배출량 산정 방법을 제시하고자 하였다.

• 대한기계학회논문집B
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• 제40권10호
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• pp.673-679
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• 2016

초임계 이산화탄소 사이클은 소형화 및 효율 향상에 대한 잠재력 때문에 최근 관심이 증가하고 있으며, 원자력, 태양열(CSP) 및 화력 발전 분야에서 활발히 연구되고 있다. 이와 관련하여, 본 논문에서는 한국에너지기술연구원(KIER)의 초임계 이산화탄소 동력 사이클 연구 내용과 현황을 소개하였다. 1 단계 연구에서는 단순 초임계 브레이튼 사이클 실험 루프를 제작 및 시운전 하였으며, 현재 진행중인 2 단계 연구에서는 두개의 터빈과 두개의 재생기를 갖는 초임계 이중(dual) 브레이튼 사이클을 설계 및 제작하고 있다. 최적 설계를 위한 초임계 이중 브레이튼 사이클 모델링 및 시뮬레이션 결과, 본 연구에서 고려한 조건하에서, 사이클의 순출력을 극대화시키는 설계 변수가 존재함을 확인하였다.

• Nuclear Engineering and Technology
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• 제52권5호
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• pp.869-877
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• 2020

A 24-month Advanced Power Reactor 1400 (APR1400) core with a very-low-boron (VLB) concentration has been investigated for an inherently safe and high-performance PWR in this work. To develop a high-performance APR1400 which is able to do the passive frequency control operation, VLB feature is essential. In this paper, the centrally-shielded burnable absorber (CSBA) is utilized for an efficient VLB operation in the 24-month cycle APR1400 core. This innovative design of the VLB APR1400 core includes the optimization of burnable absorber and loading pattern as well as axial cutback for a 24-month cycle operation. In addition to CSBA, an Er-doped guide thimble is also introduced for partial management of the excess reactivity and local peaking factor. To improve the neutron economy of the core, two alternative radial reflectors are adopted in this study, which are SS-304 and ZrO₂. The core reactivity and power distributions for a 2-batch equilibrium cycle are analyzed and compared for each reflector design. Numerical results show that a VLB core can be successfully designed with 24-month cycle and the cycle length is improved significantly with the alternative reflectors. The neutronic analyses are performed using the Monte Carlo Serpent code and 3-D diffusion code COREDAX-2 with the ENDF/B-VII.1.

• 한국환경과학회지
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• 제16권2호
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• pp.233-239
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• 2007

In the coastal wetland the mud is consist of fine particles, which means that it is characterized by small gap, and heat transfer is obstructed since moisture is found between the gaps. The relationship between net radiation ($R_N$) and soil heat flux($H_G$) shows a counterclockwise hysteresis cycle, which refer to a time lag behind in the maximal soil heat fluxes. The albedo is independent of seasonal variation of the vegetation canopy which plays very important roles to store and control the heat in the atmospheric surface layer.

• 수산해양기술연구
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• 제26권4호
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• pp.380-386
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• 1990

The high stress, low cycle fatigue test were carried out on HT80 plates with artificial part-through notch. The LBB conditions by the net section stress approach was examined in detail. Finite element methods for the state of deformation were also applied and the results were compared with the results from experiments. From the test results, it was noted that the LBB condition in fatigue test was dependent upon the maximun load change before and after the crack penetration. The LBB criterion By the net section stress approach were slightly dependent on initial crack size. It was shown that the state of deformation can be used to predict whether the component is likely to show LBB condition or they will be broken rapidly.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2004년도 춘계공동학술대회 논문집
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• pp.39-43
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• 2004

A research shows that a new category of software, Collaborative Product Commerce (CPC), is now emerging, allowing discrete manufacturers to once again distinguish themselves on their products and innovations. CPC permits discrete manufacturers to significantly improve the core processes around the management functions associated with the complete product life cycle that are the basis of their existence. As a way to develop computing tools of CPC to support a design process of product, a web-based design supporting system was constructed in the paper. The system consists of C-Product system and Net Meeting Communication system to improve communications between designers and persons for verification of design. The product data files of C-Product system were designed by Pro/Engineer and converted to 3D Viewer format for being used in the web browser. Also, Net Meeting Communication system and Database were developed using ASP and Microsoft SQL 2000 Server to share diverse files that can be utilized to design on the web in real time.