• 한국산학기술학회논문지
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• 제20권5호
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• pp.13-19
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• 2019

후쿠시마 원전사고 이후 비상 배터리 시설에 대한 안전성 강화가 요구되면서 리튬 폴리머 배터리를 적용한 새로운 전원 공급장치가 국내에서 세계 최초로 제안되었다. 그러나 제안된 기술을 현장에 적용하기 위해서는 배터리 장치가 설치되는 랙 시스템의 내진 안전성이 요구된다. 본 연구에서는 세계 최초로 72시간 용량 확보를 위해 개발 된 리튬폴리머 배터리 장치를 대상으로 지진 발생 시 전원장치의 안전성을 확보하기 위해 설계 된 전원장치 스트링 및 랙 프레임에 대한 내진성능을 평가하고자 하였다. 실험 결과 1) 단위 랙 시스템의 공진대역은 9 Hz로서 지진하중 전 후의 고유진동수가 변하지 않음에 따라 설계지진하중에 대한 부재 및 부재간의 연결부에 대한 안전성을 확인할 수 있었다. 원전 설계기준 OBE와 SSE에서의 가속도 응답 결과 2) 스트링 제작에 의한 진동 저감 효과가 약 20%정도 보였으며, 3) OBE, SSE 조건에서의 내진시험 결과 랙 프레임 시스템은 설계지진에 대해 안전한 것으로 나타났다. 따라서 본 연구에서 제시한 랙 시스템은 요구 지진력에 대한 구조적 건전성이 입증되었으므로 원전 시설에 적용이 가능한 것으로 나타났다.

• 방사선산업학회지
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• 제9권4호
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• pp.167-170
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• 2015

Radioisotope (Nuclear) battery using $^{63}Ni$ was prepared as beta cell. The electroplated $^{63}Ni$ on Ni foil is fabricated, and beta cell and photovoltaic hybrid battery was designed to use at both day and night in space project. A Ni-plating solution is prepared by dissolving metal particles including $^{62}Ni$ and $^{63}Ni$ from neutron irradiation of ($n,{\gamma}$). Electroplating solution of a chloride bath consists on nickel ions in HCl, $H_3BO_3$, and KOH. The deposition was carried out at current density of $10mA\;cm^{-2}$. The prepared beta source was attached on a PN junction and measured I-V properties. The power output at activity of 0.07 mCi and 0.45 mCi were 0.55 pW and 2.69 nW, respectively.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1996년도 춘계학술발표회논문집(1)
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• pp.419-424
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• 1996

안전등급 Ni-Cd 축전지는 품질수명이 15-25년으로 환경시험 등을 통하여 입증되었지만, 설치후 7년이 경과한 한국 원자력 연구소 방사성 폐기물 처리시설의 안전등급 Ni-Cd 축전지는 1992년에 실시한 최초의 용량시험 결과 기준용량에 미달하였다. 안전등급 Ni-Cd 축전지와 관련된 각종 유지보수 기술을 조사하고, 용량복구를 위한 증류수와 전해질 성분의 적절한 보충, 충전과 방전 특성의 적용, 활성제 보충, 전극의 청소를 통하여 매년 성능이 회복되어서 1995년도 용량시험시에는 기준용량을 초과하였으므로 안전등급 Ni-Cd 축전지의 용량 문제해결 사례로 소개한다.

• Nuclear Engineering and Technology
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• 제54권9호
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• pp.3299-3309
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• 2022

Nuclear energy has the potential to play an influential role in energy transition efforts than is now anticipated by many countries. Realizing sustainable human development and reducing global climate crises will become more difficult without significantly increasing nuclear power. This paper aims to probe the role of nuclear energy, external debt, and financial globalization in sustaining human development and environmental conditions simultaneously in BRICS (Brazil, Russia, India, China, and South Africa) countries. This study applied a battery of second-generation estimation approaches over the period from 1990 to 2019. These methods are useful and robust to cross-countries dependencies, slope heterogeneity, parameters endogeneity, and serial correlation that are ignored in conventional approaches to generate more comprehensive and reliable estimates. The empirical findings indicate that nuclear energy and financial globalization contribute to human development, whereas external debt inhibits it. Similarly, financial globalization accelerates ecological deterioration, but nuclear energy and external debt promote environmental sustainability. Moreover, the study reveals bidirectional feedback causalities between human development, carbon emissions and nuclear energy consumption. The study offers useful policy guidance on accomplishing sustainable and inclusive development in BRICS countries.

• Nuclear Engineering and Technology
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• 제51권3호
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• pp.676-682
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• 2019

After the Fukushima Daiichi accident, there has been an increasing preference for passive safety features in the nuclear power industry. Some passive safety systems require limited active components to trigger subsequent passive operation. Under very serious accident conditions, passive safety features could be rendered inoperable or damaged. This study evaluates (i) the performance and effectiveness of the passive safety features of iPOWER (innovative Power Reactor), and (ii) whether a severe accident condition could be reached if the passive safety systems are damaged, namely the case of heat exchanger tube rupture. Analysis results show that the reactor coolant system remains in the hot shutdown condition without operator actions or electricity for over 72 h when the passive auxiliary feedwater systems (PAFSs) are operable without damage. However, heat exchanger tube rupture in the PAFS leads to core damage after about 18 h. Such results demonstrate that, to enhance the safety of iPOWER, maintaining the integrity of the PAFS is critical, and therefore additional protections for PAFS are necessary. To improve the reliability of iPOWER, additional battery sets are necessary for the passive safety systems using limited active components for accident mitigation under such extreme circumstances.

• 한국자기공명학회논문지
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• 제18권2호
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• pp.63-68
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• 2014

$^7Li$ nuclear magnetic resonance (NMR) spectra have been observed for $LiMPO_4$ (M = Fe, Mn) samples, as a promising cathode material of lithium ion battery. Observed $^7Li$ shifts of $LiFe_{1-x}Mn_xPO_4$ (x = 0, 0.6, 0.8, and 1) synthesized with solid-state reaction are compared with calculated $^7Li$ shift ranges based on the supertranferred hyperfine interaction of Li-O-M. Ex situ $^7Li$ NMR study of $LiFe_{0.4}Mn_{0.6}PO_4$ in different cut-off voltage for the first charge process is also performed to understand the relationship between $^7Li$ chemical shift and oxidation state of metals affected by delithiation process. The increment of oxidation state for metals makes to downfield shift of $^7Li$ by influencing the supertranferred hyperfine interaction.

• 산업기술연구
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• 제40권1호
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• pp.13-18
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• 2020

Lithium-ion batteries have a small volume, light weight and high energy density, maximizing the utilization of mobile devices. It is widely used for various purposes such as electric bicycles and scooters (e-Mobility), mass energy storage (ESS), and electric and hybrid vehicles. To date, lithium-ion batteries have grown to focus on increasing energy density and reducing production costs in line with the required capacity. However, the research and development level of lithium-ion batteries seems to have reached the limit in terms of energy density. In addition, the charging time is an important factor for using lithium-ion batteries. Therefore, it was urgent to develop a high-speed charger to shorten the charging time. In this thesis, a discharger was fabricated to evaluate the capacity and characteristics of Li-ion battery pack which can be used for e-mobility. To achieve this, a smart discharger is designed with a combination of active load, current sensor, and temperature sensor. To carry out this thesis, an active load switching using sensor control circuit, signal processing circuit, and FET was designed and manufactured as hardware with the characteristics of active discharger. And as software for controlling the hardware of the active discharger, a Raspberry Pi control device and a touch screen program were designed. The developed discharger is designed to change the 600W capacity battery in the form of active load.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2011년도 추계학술대회
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• pp.38-39
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• 2011

본 논문에서는 계통연계형 배터리 에너지 저장장치의 실험에 대하여 서술한다. 배터리 에너지 저장장치는 배터리 뱅크와 계통연계형 인버터로 이루어져 있다. 배터리 뱅크는 납축전지로 구성되고, DC Link에 병렬로 연결된다. 인버터의 동작모드는 충전과 방전 두 가지로 나뉘며, 충전모드에서는 배터리의 수명을 고려하여 CC-CV 제어를 수행하고, 방전모드에서는 유효/무효 전력제어를 수행한다.

• Nuclear Engineering and Technology
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• 제55권6호
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• pp.2158-2165
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• 2023

Marine radioactivity monitoring is critical for taking immediate action in case of unexpected nuclear accidents at nuclear facilities located near coastal areas. Especially when the level of contamination is not predictable, mobile monitoring systems will be useful for wide-area ocean radiation survey and for determination of the level of radioactivity. Here, we used a silicon photomultiplier and a high-efficiency GAGG crystal to fabricate a compact, battery-powered gamma spectroscopy that can be used in an ocean environment. The developed spectroscopy has compact dimensions of 6.5 × 6.5× 8 cm³ and weighs 560 g. We used LoRa, a low-power wireless protocol for communication. Successful data transmission was achieved within 1.4 m water depth. The developed gamma spectroscopy was able to detect radioactivity from a ¹³⁷Cs point source (3.7 kBq) at a distance of 20 cm in water. Moreover, we demonstrated an unmanned radioactivity monitoring system in a real sea by combining unmanned surface vehicle with the developed gamma spectroscopy. A hidden ¹³⁷Cs source (3.07 MBq) was detected by the unmanned system at a distance of 3 m. After successfully testing the developed mobile spectroscopy in an ocean environment, we believe that our proposed system will be an effective solution for mobile real-time marine radioactivity monitoring.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2019년도 추계학술대회
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• pp.178-179
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• 2019

최근 다양한 어플리케이션에서 리튬 이온 배터리가 사용됨에 따라 이에 대한 연구가 활발히 이루어지고 있다. 전기 자동차(Electric Vehicles; EVs) 및 에너지저장장치(Energy Storage Systems; ESSs) 등의 개발로 대형 배터리 시스템이 요구되고 있으며, 이의 해석이 요구되고 있다. 본 논문에서는 18650 원통형 셀로 구성된 14S20P 배터리 모듈의 노화에 따른 전기적 특성 및 열 거동 변화를 분석하였다.