• Title/Summary/Keyword: Nuclear Emergency

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A Study on the Emergency and Recovery AC/DC Combination Lamps in the Electric Substations (변전소의 AC/DC 겸용 비상 및 복구 등에 관한 연구)

  • Park, Joon-Yeol;An, Youn-Ki;Kim, Jong-Soo;Shin, Hye-Young
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.24 no.6
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    • pp.27-34
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    • 2010
  • This study is for the improvement in the equipment environment of the emergency and recovery lamps in electric substations. To solve problem about the weak illuminance of existing emergency lamps, the AC/DC combination lamps and switches are reviewed. And the improved illuminance standards that are divided each room's purpose are suggested. It is based on a nuclear power plant's Illuminance Standards and a safety lamp's Illuminance Standards of Illuminance Standards Korean Industrial Standards - KS A 3011 -, not just 5~10[%] in according with normal lamp's illuminance. Lastly, The experiments are conducted to prove the suggested contents on this study. Consequently, a battery capacity is not increased, but illuminance of emergency and recovery lamps can be increased.

Optimization of In-vivo Monitoring Program for Radiation Emergency Response

  • Ha, Wi-Ho;Kim, Jong Kyung
    • Journal of Radiation Protection and Research
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    • v.41 no.4
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    • pp.333-338
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    • 2016
  • Background: In case of radiation emergencies, internal exposure monitoring for the members of public will be required to confirm internal contamination of each individual. In-vivo monitoring technique using portable gamma spectrometer can be easily applied for internal exposure monitoring in the vicinity of the on-site area. Materials and Methods: In this study, minimum detectable doses (MDDs) for $^{134}Cs$, $^{137}Cs$, and $^{131}I$ were calculated adjusting minimum detectable activities (MDAs) from 50 to 1,000 Bq to find out the optimal in-vivo counting condition. DCAL software was used to derive retention fraction of Cs and I isotopes in the whole body and thyroid, respectively. A minimum detect-able level was determined to set committed effective dose of 0.1 mSv for emergency response. Results and Discussion: We found that MDDs at each MDA increased along with the elapsed time. 1,000 Bq for $^{134}Cs$ and $^{137}Cs$, and 100 Bq for $^{131}I$ were suggested as optimal MDAs to provide in-vivo monitoring service in case of radiation emergencies. Conclusion: In-vivo monitoring program for emergency response should be designed to achieve the optimal MDA suggested from the present work. We expect that a reduction of counting time compared with routine monitoring program can achieve the high throughput system in case of radiation emergencies.

Design of a Control System for the Emergency Diesel Generator (비상용 디젤발전기 제어시스템 설계)

  • Kim, Jin-ae;Joo, Jae-hun;Baek, Pan-Geun;Kim, Byeong-Jun;Choi, Jung-Keyng
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2009.05a
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    • pp.849-853
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    • 2009
  • A generator is in use for a moving vehicle like car, aircraft, ship as well as key industry including a thermal power plant, a water power plant, a nuclear power plant, and so on. Such the AC generator plays an important role in vehicle, ship, aircraft, and so forth, at the point of generating electric power. Especially in the matter of the ship, the emergency generator system is mounted to provide against malfunction of main generator on a voyage. So, it is ordered that the system can monitor the main generator and operate the emergency generator when the emergency happens. This study is about controller for the emergency diesel engine generator and design of a various software.

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Evaluation of Antioxidant Activity and Cytotoxicity in Mixture Extract of Artemisia asiatica Nakai and Moringa oleifera Lam

  • Lee, Yoon-Ji;Kim, Jang-Oh;Jeon, Chan-Hee;Lee, Ji-Eun;Shin, Ji-Hye;Min, Byung-In
    • Biomedical Science Letters
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    • v.26 no.4
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    • pp.296-301
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    • 2020
  • The purpose of this study was performed to evaluate antioxidant activity of the Artemisia asiatica Nakai and Moringa oleifera Lam mixture extract. Mixture extracts were manufactured by concentration and compared with a single extract (only the Artemisia asiatica Nakai mixture and only the Moringa oleifera Lam mixture). The experiments conducted Total polyphenol measurements, Total flavonoid measurements, DPPH radical scavenging activty, ABTS radical scavenging activty and LDH assay. The LDH assay assessment shows that all extracts are cells compared to controls. The toxicity was weak. Finally, The antioxidant capacity was rated higher than mixture extract of a single extract. Also, the optimized mixture was determined AM5 (Artemisia asiatica Nakai mixture: Moringa oleifera Lam mixture = 3:1). For extracts of AM5, Total phenol and flavonoid contents were 271.769±18.087 mg/g and 45.384±5.026 mg/g. and DPPH and ABTS scavenging activity were 70.8±6.496% and 77.1±9.634%. Therefore, it is expected that the value of the extract will increase as it increases its antioxidant activity if it is manufactured according to the appropriate ratio.

An accident diagnosis algorithm using long short-term memory

  • Yang, Jaemin;Kim, Jonghyun
    • Nuclear Engineering and Technology
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    • v.50 no.4
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    • pp.582-588
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    • 2018
  • Accident diagnosis is one of the complex tasks for nuclear power plant (NPP) operators. In abnormal or emergency situations, the diagnostic activity of the NPP states is burdensome though necessary. Numerous computer-based methods and operator support systems have been suggested to address this problem. Among them, the recurrent neural network (RNN) has performed well at analyzing time series data. This study proposes an algorithm for accident diagnosis using long short-term memory (LSTM), which is a kind of RNN, which improves the limitation for time reflection. The algorithm consists of preprocessing, the LSTM network, and postprocessing. In the LSTM-based algorithm, preprocessed input variables are calculated to output the accident diagnosis results. The outputs are also postprocessed using softmax to determine the ranking of accident diagnosis results with probabilities. This algorithm was trained using a compact nuclear simulator for several accidents: a loss of coolant accident, a steam generator tube rupture, and a main steam line break. The trained algorithm was also tested to demonstrate the feasibility of diagnosing NPP accidents.

On-site water level measurement method based on wavelength division multiplexing for harsh environments in nuclear power plants

  • Lee, Hoon-Keun;Choo, Jaeyul;Shin, Gangsig;Kim, Sung-Man
    • Nuclear Engineering and Technology
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    • v.52 no.12
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    • pp.2847-2851
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    • 2020
  • A simple water level measurement method based on wavelength division multiplexing (WDM) is proposed and demonstrated. The measurement principle is based on the change of Fresnel reflection occurring at the end facet of the optical fiber tip (OFT). To increase the spatial resolution of water level sensing, a broadband light source (BLS) and an arrayed waveguide grating (AWG) are employed. The OFTs are multiplexed with the dedicated wavelength channels of AWG. By measuring all of the reflection powers reflected at the OFTs with a proposed on-site reflectometer, the water level can be monitored continuously for a fast emergency response. Moreover, it can be implemented easily with the commercially available optical components and devices with the simple configuration.

Derivation of Intervention levels for Protection of the Public in a Radiological Emergency in Korea (주민보호조치를 위한 국내 방사선비상 개입준위 산출)

  • Lee, Jong-Tai;Lee, Goan-Yup;Khang, Byung-Oui;Oh, Ki-Hoon;Kim, Chang-Kyu
    • Journal of Radiation Protection and Research
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    • v.26 no.4
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    • pp.357-365
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    • 2001
  • Intervention levels for protection of the public in a radiological emergency are theoretically derived by the cost-benefit approach with the concept of justification and optimization. Intervention levels on the sheltering, evacuation, temporary relocation and permanent resettlement for protection of the public are estimated with the cost to protective countermeasures and the value from dose averted which are the site specific parameters. As a result, it is confirmed that IAEA guidelines for intervention levels are applicable to the radiological emergency in Korea. Optimum ranges of 5 - 10 mSv/2days for sheltering, 25 - 130 mSv/week for evacuation, 15 - 90 mSv/month lot temporary relocation and 600 - 3,500 mSv/lifetime for permanent resettlement for intervention levels are also provided. The result can be applied as useful data to update intervention levels under the theoretical background in Korea.

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Design of Class and Causality Model for Diagnosis System of an Emergency Generator in Nuclear Plant (원전 비상 발전기의 고장진단시스템을 위한 클래스 및 인과관계 모형 설계)

  • Ha, Chang-Seung;Part, Jong-Il
    • Journal of the Korea Society of Computer and Information
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    • v.11 no.3
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    • pp.125-132
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    • 2006
  • The construction of an emergency generator's diagnosis system for the preparation of emergency in nuclear plant is vital. To construct a knowledge base of the diagnosis system, the classes and a causality model should be designed. In order to design those elements, at first. object of the diagnosis system should be defined. After the investigation of normal and abnormal states. the external knowledge such as entities and activities is extracted, that the operational principle of the system. For the conversion of the extracted external knowledge to the internal one, the entities are defined as classes and the activities converted into the causality. Through the recursive configuration of the causality and proper examination, the diagnosis knowledge applicable to the knowledge base is completed. In this paper, it is possible to construct a knowledge base with high portability since the independence of design model is considered through the decision table.

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AN AXIOMATIC DESIGN APPROACH OF NANOFLUID-ENGINEERED NUCLEAR SAFETY FEATURES FOR GENERATION III+ REACTORS

  • Bang, In-Cheol;Heo, Gyun-Young;Jeong, Yong-Hoon;Heo, Sun
    • Nuclear Engineering and Technology
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    • v.41 no.9
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    • pp.1157-1170
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    • 2009
  • A variety of Generation III/III+ reactor designs featuring enhanced safety and improved economics are being proposed by nuclear power industries around the world to solve the future energy supply shortfall. Nanofluid coolants showing an improved thermal performance are being considered as a new key technology to secure nuclear safety and economics. However, it should be noted that there is a lack of comprehensible design works to apply nanofluids to Generation III+ reactor designs. In this work, the review of accident scenarios that consider expected nanofluid mechanisms is carried out to seek detailed application spots. The Axiomatic Design (AD) theory is then applied to systemize the design of nanofluid-engineered nuclear safety systems such as Emergency Core Cooling System (ECCS) and External Reactor Vessel Cooling System (ERVCS). The various couplings between Gen-III/III+ nuclear safety features and nanofluids are investigated and they try to be reduced from the perspective of the AD in terms of prevention/mitigation of severe accidents. This study contributes to the establishment of a standard communication protocol in the design of nanofluid-engineered nuclear safety systems.

Appropriateness of Location of Nuclear Accident Evacuation Shelters based on Population Characteristics and Accessibility -The Case of Busan Gijang-gun, Geumjeong-gu and Haeundae-gu in Korea- (인구특성과 접근성을 고려한 방사능재난 대피시설 입지 적정성 분석 -부산광역시 기장군, 금정구, 해운대구를 대상으로-)

  • DONG, Ah-Hyeon;LEE, Sang-Hyeok;KANG, Jung-Eun
    • Journal of the Korean Association of Geographic Information Studies
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    • v.22 no.4
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    • pp.131-145
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    • 2019
  • Korea has set up a radiation emergency planning zone based on the 「Act on Physical Protection and Radiological Emergency」 to protect residents living near nuclear power plants in the event of nuclear disasters. Little research has been conducted on the appropriateness of existing nuclear evacuation facilities because of a general lack of interest in nuclear accidents. This research addresses this gap by analyzing the location adequacy of evacuation facilities in Busan's emergency protection planning area based on vulnerable populations and accessibility analyses. The Gijang-gun which has the greatest risk, shows that only 4.05% of the total urban area was included in the evacuation service area within 5 minutes while only 36.93% of Geumjeong-gu and 37.23% of Haeundae-gu were included in the evacuation-enabled area. In addition, evaluation facilities in the elderly population hotspots were lacking, and there was a wide gap between dongs within the same Gu. Thus, additional evacuation facilities need to be designated and installed considering the spatial equity between areas and safety of both the public and vulnerable populations.