• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.109.1-109.1
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• 2011

KEPCO was operating power plants with diesel generators in 49 islands including Baekryeong-Do, and the generation capacity was about 66 MW in 2008. The cost of fuel is increasing by the international oil price inflation and continuous rise of oil price is predicted. For the stabilizing of electric power supply to the separate islands, renewable energy and fuel cell systems were considered. Hydrogen is made using renewable energy such as wind power and solar energy, and then a fuel cell system generates electricity with the stored hydrogen. Though the system efficiency is low, it is treated as the only way to secure the stable electric supply using renewable energy at this present. The analytic hierarchy process was used to select suitable candidate island for the system installation and 5 islands including Ulleung-Do were selected. Economic evaluation for the system composed of a kerosene generator, a wind power, an electrolysis, and a fuel cell system was conducted with levelized generation cost based on present value methode. As the result, the necessity of renewable energy combined generation system and micro grid composition in the candidated islands was confirmed. Henceforth, the development of an integration technology which connects micro grid to the total power grid will be needed.

• Bulletin of the Korean Chemical Society
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• 제27권2호
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• pp.281-285
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• 2006

Microbial fuel cells (MFC) stacked with bipolar plates have been constructed and their performance was tested. In this design, single fuel cell unit was connected in series by bipolar plates where an anode and a cathode were made in one graphite block. Two types of bipolar plate stacked MFCs were constructed. Both utilized the same glucose oxidation reaction catalyzed by Gram negative bacteria, Proteus vulgaris as a biocatalyst in an anodic compartment, but two different cathodic reactions were employed: One with ferricyanide reduction and the other with oxygen reduction reactions. In both cases, the total voltage was the mathematical sum of individual fuel cells and no degradation in performance was found. Electricity from these MFCs was stored in a supercapacitor to drive external loads such as a motor and electric bulb.

• 방사선산업학회지
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• 제17권4호
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• pp.519-532
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• 2023

Spent nuclear fuel(SNF) is stored in nuclear power plants for a certain period of time and then transported to an interim storage facility. After that, SNF is finally repackaged in a disposal canister at an encapsulation plant for final disposal. Finland and Sweden, leading countries in SNF disposal technology, have already completed designing of spent fuel encapsulation plant. In particular, the encapsulation plant construction in Finland is near completion. When it comes to South Korea, as the amount of SNF production and disposal plan is different from those in Finland and Sweden, it is difficult to apply the concepts of these contries as is. Therefore, it is necessary to establish the spent fuel repackaging concept and to derive each operating and repackaging procedures by considering annual disposal plan of South Korea. The results of this study is expected to be used to establish the concept of optimized encapsulation plant through further research.

• Nuclear Engineering and Technology
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• 제54권7호
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• pp.2395-2407
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• 2022

The sodium-cooled fast reactor is among the innovative nuclear technologies selected in the framework of the development of Generation IV concepts, allowing the irradiation of uranium-plutonium mixed oxide fuels (MOX). A fundamental step for the safety assessment of MOX-fuelled pins for fast reactor applications is the evaluation, by means of fuel performance codes, of the integral thermal-mechanical behaviour under irradiation, involving the fission gas behaviour and release in the fuel-cladding gap. This work is dedicated to the performance analysis of an inner-core fuel pin representative of the ASTRID sodium-cooled concept design, selected as case study for the benchmark between the GERMINAL and TRANSURANUS fuel performance codes. The focus is on fission gas-related mechanisms and integral outcomes as predicted by means of the SCIANTIX module (allowing the physics-based treatment of inert gas behaviour and release) coupled to both fuel performance codes. The benchmark activity involves the application of both GERMINAL and TRANSURANUS in their "pre-INSPYRE" versions, i.e., adopting the state-of-the-art recommended correlations available in the codes, compared with the "post-INSPYRE" code results, obtained by implementing novel models for MOX fuel properties and phenomena (SCIANTIX included) developed in the framework of the INSPYRE H2020 Project. The SCIANTIX modelling includes the consideration of burst releases of the fission gas stored at the grain boundaries occurring during power transients of shutdown and start-up, whose effect on a fast reactor fuel concept is analysed. A clear need to further extend and validate the SCIANTIX module for application to fast reactor MOX emerges from this work; nevertheless, the GERMINAL-TRANSURANUS benchmark on the ASTRID case study highlights the achieved code capabilities for fast reactor conditions and paves the way towards the proper application of fuel performance codes to safety evaluations on Generation IV reactor concepts.

• Preventive Nutrition and Food Science
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• 제9권1호
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• pp.39-44
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• 2004

This study investigated the effect of allium vegetable intake on the storage and utilization of energy substrates before, during, and after exercise in tissues of rats. Ninety rats were fed either a control diet or a diet with added Allium sativum (AS, garlic), Allium cepa (AC, onion), Allium fistulosum (AF, spring onion), or Allium tuberosum (AT, Chinese chives) for 4 weeks and were then subdivided into 3 groups: before-exercise (BE); during-exercise (DE); after-exercise (AE). The DE group was exercised on treadmill for 1 hour just before being sacrificed at the end of 4th week of the dietary treatment rats in the AE group were allowed to recuperate for 2 hours after being exercised like the DE group. The levels of glycogen (GLY), triglyceride (TG) and protein (PRO) were compared in liver and skeletal muscle. In the AS diet animals, the level of liver GLY was significantly higher than those of control animals in the BE, DE and AE groups. The level of muscle TG also tended to be higher in BE, but lower in AE than in control animals. In AC animals, the level of muscle GLY was significantly lower than those of control animals in BE, DE and AE. The level of muscle TG also tended to be higher than those of control animals in BE and DE but tended to be lower in AE. In AF animals, the level of muscle GLY was significantly lower than those of control animals in BE, DE and AE. The level of muscle TG was also significantly lower than those of control animals in BE, DE and AE groups. In AT animals, the level of muscle GLY was significantly lower than those of control animals in BE, DE and AE. These results suggest that Allium sativum diets enhance the capacity to store fuel before as well as during exercise and increases the potential to utilize the stored fuel during exercise.

• 한국수소및신에너지학회논문집
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• 제28권2호
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• pp.156-165
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• 2017

This study quantitatively assessed the environmental impacts of fuel cell (FC) systems by performing life cycle assessment (LCA) and analyzed their energy efficiencies based on energy return on investment (EROI) and electrical energy stored on investment (ESOI). Molten carbonate fuel cell (MCFC) system and polymer electrolyte membrane fuel cell (PEMFC) system were selected as the fuel cell systems. Five different paths to produce hydrogen ($H_2$) as fuel such as natural gas steam reforming (NGSR), centralized naptha SR (NSR(C)), NSR station (NSR(S)), liquified petroleum gas SR (LPGSR), water electrolysis (WE) were each applied to the FCs. The environmental impacts and the energy efficiencies of the FCs were compared with rechargeable batteries such as $LiFePO_4$ (LFP) and Nickel-metal hydride (Ni-MH). The LCA results show that MCFC_NSR(C) and PEMFC_NSR(C) have the lowest global warming potential (GWP) with 6.23E-02 kg $CO_2$ eq./MJ electricity and 6.84E-02 kg $CO_2$ eq./MJ electricity, respectively. For the impact category of abiotic resource depletion potential (ADP), MCFC_NGSR(S) and PEMFC_NGSR(S) show the lowest impacts of 7.42E-01 g Sb eq./MJ electricity and 7.19E-01 g Sb eq./MJ electricity, respectively. And, the energy efficiencies of the FCs are higher than those of the rechargeable batteries except for the case of hydrogen produced by WE.

• 마이크로전자및패키징학회지
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• 제13권1호통권38호
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• pp.57-61
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• 2006

연료전지는 연료(수소)의 화학적 반응에 의해 축적된 화학에너지를 전기에너지로 변환하여 직류 전기를 발생시키는 에너지원이다. 연료전지는 질소나 유황산화물 등의 유해한 물질을 방출하지 않으며 기계적 동력부가 없고 거의 무소음으로 운전되는 이점을 가진다. 수소연료에 의한 연료전지는 그들의 부산물로써 열과 물을 방출한다. 연료전지를 이용한 응용분야의 확대로 인해 화석연료나 수입 석유의 의존도를 현저히 감소시킬 수 있다. 본 논문에서는 이러한 연료전지 (PEMFC, Proton Exchange Membrane Fuel Cell)의 출력을 치대한 활용하고 발전시스템의 안전운전을 위한 전력변환기(PCS, Power Conditioning System)에 대해 연구하였다. 본 논문에서는 고효율로 운전하는 새로운 전력변환 회로토폴로지를 설계하고, 발전시스템에 적용하여 각종 실험을 통하여 그 타당성을 입증하였다. 그 결과 연료전지 발전시스템은 고성능으로 동작되는 전력변환기에 의해 발전시스템의 효율과 성능을 향상시키게 된다.

• Nuclear Engineering and Technology
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• 제25권1호
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• pp.166-177
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• 1993

사용후 핵연료 건식 저장 캐니스터의 핵연료 바스켓 안에 있는 CANDU 37소자 핵연료 다발의 최대 온도를 계산하기 위한 단순화된 열해석 방법과 함께 대기 조건 인자들이 캐니스터 내부의 최대 핵연료 온도에 미치는 영향을 조사하기 위해 수행한 표본 해석 결과를 제시하였다. 3가지 모우드(mode)의 열전달이 공존하는 캐니스터 내부핵연료 다발의 복잡한 기하학적 구조에 대한 다차원열전달 문제를 풀기 위하여 건식저장 캐니스터에 저장된 CANDU 사용후 핵연료 다발들을 등가 및 동심의 핵연료 실린더(cylinder)로 대치하였다. 추가적인 입력 자료 및 열전달 상관식을 이용하여 등가 핵연료 실린더의 단순화된 축대칭, 2차원, 복수 모우드(multi-mode)의 열전달 문제를 기존의 컴퓨터 코드인 HEATING5로 해석하였다. 예측한 온도 분포와 식물 모형 실험 결과의 비교는 만족스러울 정도로 일치함을 보여주고 있다.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2018년도 추계학술논문요약집
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• pp.104-104
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• 2018

Kori Unit 1 is the first permanent shutdown nuclear power plant in Korea and it is on June 18th, 2017. Spent fuel assemblies began to be discharged from the reactor core to the spent fuel pool(SFP) within one week after shutdown of Kori unit 1 and the campaign was completed on June 27th, 2017. The total number of spent nuclear fuel assemblies in SFP of Kori Unit-1 is 485 and their discharging date is different respectively. So, decay heat was evaluated considering the actual enrichment, operation history and cooling time of the spent fuel assemblies stored in SFP of the Kori Unit-1. The code used in the evaluation is the ORIGEN-based CAREPOOL system developed by KHNP. Decay heat calculation of PWR fuel is based on ANSI/ANS 5.1-2005, "Decay heat power in light water reactors" and ISO-10645, "Nuclear energy - Light water reactors - Calculation of the decay heat power in nuclear fuels. Also, we considered the contribution of fission products, actinide nuclides, neutron capture and radioactive material in decay heat calculation. CAREPOOL system calculates the individual and total decay heat of all of the spent fuel assemblies in SFP of Kori Unit-1. As a result, the total decay heat generated in SFP on June 28th, 2017 when the spent fuel assemblies were discharged from the reactor core, is estimated to be about 4,185.8 kw and to be about 609.5 kw on September 1st, 2018. It was also estimated that 119.6 kw is generated in 2050 when it is 32 years after the permanent shutdown. Figure 1 shows the trend of total decay heat in SFP of Kori Unit-1.

• Nuclear Engineering and Technology
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• 제39권2호
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• pp.143-148
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• 2007

Spent nuclear fuel generated at nuclear power plants must be safely stored during interim storage periods. A dry storage cask to safely store the spent nuclear fuel should be able to adequately emit the decay heat from the spent nuclear fuel. Therefore, heat removal tests using a half scale dry storage cask have been performed to estimate the heat transfer characteristics of a dry storage cask under normal, off-normal, and accident conditions. In the normal condition, the heat transfer rate to an ambient atmosphere by convective air through a passive heat removal system reached 83%. Accordingly, the passive heat removal system is designed well and works adequately. In the off-normal condition, the influence of a half blockage in the inlet on the temperature appears minimal. In the accident condition, the temperature rose for 12 hours after the accident, but the temperature rise steadied after 36 hours.