• Title/Summary/Keyword: Nuclear accidents

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Three-dimensional porous graphene materials for environmental applications

  • Rethinasabapathy, Muruganantham;Kang, Sung-Min;Jang, Sung-Chan;Huh, Yun Suk
    • Carbon letters
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    • v.22
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    • pp.1-13
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    • 2017
  • Porous materials play a vital role in science and technology. The ability to control their pore structures at the atomic, molecular, and nanometer scales enable interactions with atoms, ions and molecules to occur throughout the bulk of the material, for practical applications. Three-dimensional (3D) porous carbon-based materials (e.g., graphene aerogels/hydrogels, sponges and foams) made of graphene or graphene oxide-based networks have attracted considerable attention because they offer low density, high porosity, large surface area, excellent electrical conductivity and stable mechanical properties. Water pollution and associated environmental issues have become a hot topic in recent years. Rapid industrialization has led to a massive increase in the amount of wastewater that industries discharge into the environment. Water pollution is caused by oil spills, heavy metals, dyes, and organic compounds released by industry, as well as via unpredictable accidents. In addition, water pollution is also caused by radionuclides released by nuclear disasters or leakage. This review presents an overview of the state-of-the-art synthesis methodologies of 3D porous graphene materials and highlights their synthesis for environmental applications. The various synthetic methods used to prepare these 3D materials are discussed, particularly template-free self-assembly methods, and template-directed methods. Some key results are summarized, where 3D graphene materials have been used for the adsorption of dyes, heavy metals, and radioactive materials from polluted environments.

The Research for Cyber Security Experts (사이버보안 전문가 양성을 위한 연구)

  • Kim, Seul-gi;Park, Dea-woo
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.21 no.6
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    • pp.1137-1142
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    • 2017
  • Cyber hacking attacks and cyber terrorism are damaging to the lives of the people, and in the end, national security is threatened. Cyber-hacking attacks leaked nuclear power cooling system design drawings, cyber accidents such as hacking of Cheongwadae's homepage and hacking of KBS stations occurred. The Act on Information and Communication Infrastructure Protection, Promotion of Information and Communication Network Utilization and Information Protection, and the Personal Information Protection Act remove the responsibility for cyber attacks, but it is difficult to prevent attacks by hackers armed with new technologies. This paper studies the development of cyber security experts for cyber security. Build a Knowledge Data Base for cyber security professionals. Web hacking, System hacking, and Network hacking technologies and evaluation. Through researches on the operation and acquisition of cyber security expert certification, we hope to help nurture cyber security experts for national cyber security.

Influence of Physicochemical Properties on Cesium Adsorption onto Soil (토양의 물리화학적 특성이 세슘 흡착에 미치는 영향)

  • Park, Sang-Min;Lee, Jeshin;Kim, Young-Hun;Lee, Jeung-Sun;Baek, Kitae
    • Journal of Soil and Groundwater Environment
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    • v.22 no.1
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    • pp.27-32
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    • 2017
  • Cesium (Cs) generated by nuclear accidents is one of the most hazardous radionuclides because of its gamma radiation and long half-life. Especially, when Cs is exposed on the soil environments, Cs is mainly adsorbed on the topsoil and is strongly combined with tiny soil particle including clay minerals. The adsorption of Cs onto soil can vary depending on various physicochemical properties of soil. In this study, the adsorption characteristics between soil and Cs were investigated according to various physicochemical properties of soil including organic matter contents, cation exchange capacity (CEC), soil particle size, and the types of clay minerals. Soil organic matter inhibited the adsorption of Cs onto the soil because organic matter was blocking the soil surface. In addition, it was estimated that the CEC of the soil influenced the adsorption of Cs onto the soil. Moreover, more Cs was adsorbed as the soil particles size decreased. It was estimated that Cs was mostly adsorbed onto the topsoil, this is related to the clay mineral. Therefore, soil organic matter, CEC, soil particle size, and clay minerals are considered the key factors that can influence the adsorption characteristics between soil and Cs.

Cracking Behavior of Containment Wall of Nuclear Power Plant Reactor (원자력 발전소 격납건물 벽체의 균열거동)

  • Cho, Jae-Yeol;Kim, Nam-Sik;Cho, Nam-So;Choi, In-Kil
    • Journal of the Korea Concrete Institute
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    • v.15 no.1
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    • pp.60-68
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    • 2003
  • Tension tests of six half-thickness concrete containment wall elements were conducted as a part of Korea Atomic Energy Research Institute (KAERI) program. The aim of the KAERI test program is to provide a test-verified analytical method for estimating capacities of concrete reactor containment buildings under internal overpressurization from postulated degraded core accidents. The data from the tests reported herein should be useful for benchmarking analytical method that require modeling of material behavior including concrete cracking behavior and reinforcement/concrete interaction exhibited by the test. Major test variable is compressive strength of concrete, and its effect on the behavior of prestressed concrete panel subjected to biaxial tension is investigated.

A Study on Analysis of Requirements in the Smart Societal Security Wireless Network (스마트 사회안전무선통신망 요구사항 분석에 관한 연구)

  • Choi, Jae-Myeong;Woo, Byung-Hoon;Kang, Heau-Jo
    • Journal of Advanced Navigation Technology
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    • v.18 no.5
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    • pp.518-523
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    • 2014
  • The development of Societal and Scientific technologies have increased risk of dysfunction caused by new technologies such as nuclear power, information technology. Also, urbanization and population density is increasing risk to high-rise building fires, traffic accidents, crime and etc. Implementation of wireless communication network on the societal security is very necessary for prevention, preparation and response against these risks. It always consists maintenance, management and the network must be maintained in an emergency. In this paper, we studied the societal security wireless communication network for prevention, preparation and response against complex disasters, and analyzed requirements(essential function, add-ons) for implementation network in the societal security wireless network.

Radiation Protective Effect of Selenium and Folic Acid Mixtures in the Development of Congenital Anomalies Following Radiation Exposure to the Fetus of Perinatal Female White Rats (주산기 암컷 백서의 태아에 방사선피폭에 따른 선천성기형 발생 시 셀레늄과 엽산 혼합물의 방사선 방호효과)

  • Jung, Do-Young;Choi, Hyung-Seok;Kim, Jang-Oh;Shin, Ji-Hye;Kim, Joo-Hee;Park, Gyeong-Jin;Min, Byung-In
    • Journal of radiological science and technology
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    • v.41 no.2
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    • pp.157-162
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    • 2018
  • This study is a search for radiation protection effects of radiation exposure on the organogenic period during the prenatal period, which is known to be the most likely to have congenital malformations by radiation exposure. To study the radiation protection for the mixture of selenium that is strong antioxidant and folic acid that is essential vitamin for DNA synthesis, 2 Gy of radiation was irradiated to pregnant female rats. then, after 14 days of fetal birth, observing blood components, SOD(Superoxide Dismutase), histological changes and external malformations. There was a significant protective effect to reduce blood cell damage(p<0.05) in the irradiation group after selenium and folic acid mixture were administered than irradiation group, and the activation of SOD which is antioxidant enzymes was increased. In addition, confirmed the effect of suppressing the expression of apoptosis of small intestinal cells and the reduction of cerebral cortex layer reduction by radiation. thus, it was confirmed that the congenital malformations were reduced as a result of these protective effects. Based on these results, selenium and folic acid mixture may reduce the incidence of congenital malformations, and it will reduce the damage of the fetus caused by the exposure of the organogenic period due to accidents.

Plant Extracts and Plant-Derived Compounds: Promising Players in Countermeasure Strategy Against Radiological Exposure: A Review

  • Kma, Lakhan
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.6
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    • pp.2405-2425
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    • 2014
  • Radiation exposure leads to several pathophysiological conditions, including oxidative damage, inflammation and fibrosis, thereby affecting the survival of organisms. This review explores the radiation countermeasure properties of fourteen (14) plant extracts or plant-derived compounds against these cellular manifestations. It was aimed at evaluating the possible role of plants or its constituents in radiation countermeasure strategy. All the 14 plant extracts or compounds derived from it and considered in this review have shown some radioprotection in different in vivo, ex-vivo and or in vitro models of radiological injury. However, few have demonstrated advantages over the others. C. majus possessing antioxidant, anti-inflammatory and immunomodulatory effects appears to be promising in radioprotection. Its crude extracts as well as various alkaloids and flavonoids derived from it, have shown to enhance survival rate in irradiated mice. Similarly, curcumin with its antioxidant and the ability to ameliorate late effect of radiation exposure, combined with improvement in survival in experimental animal following irradiation, makes it another probable candidate against radiological injury. Furthermore, the extracts of P. hexandrum and P. kurroa in combine treatment regime, M. piperita, E. officinalis, A. sinensis, nutmeg, genistein and ginsan warrants further studies on their radioprotective potentials. However, one that has received a lot of attention is the dietary flaxseed. The scavenging ability against radiation-induced free radicals, prevention of radiation-induced lipid peroxidation, reduction in radiation cachexia, level of inflammatory cytokines and fibrosis, are some of the remarkable characteristics of flaxseed in animal models of radiation injury. While countering the harmful effects of radiation exposure, it has shown its ability to enhance survival rate in experimental animals. Further, flaxseed has been tested and found to be equally effective when administered before or after irradiation, and against low doses (${\leq}5Gy$) to the whole body or high doses (12-13.5 Gy) to the whole thorax. This is particularly relevant since apart from the possibility of using it in pre-conditioning regime in radiotherapy, it could also be used during nuclear plant leakage/accidents and radiological terrorism, which are not pre-determined scenarios. However, considering the infancy of the field of plant-based radioprotectors, all the above-mentioned plant extracts/plant-derived compounds deserves further stringent study in different models of radiation injury.

Output Signal Analysis for Variation of Resistance Passive Element in the R-L-C Equivalent Circuit Modeling under Temperature Accident Conditions in NPPs (원전 온도 사고 조건에서 R-L-C회로 모델링 등가 회로의 저항 수동 소자 변화에 대한 출력 신호 분석)

  • Koo, Kil-Mo;Kim, Sang-Baik;Kim, Hee-Dong;Cho, Young-Ro
    • Proceedings of the KIEE Conference
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    • 2006.10c
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    • pp.600-602
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    • 2006
  • Some abnormal signals diagnostics and analysis through an important equivalent circuits modeling for passive elements under severe accident conditions have been performed. Unlike the design basis accidents, there are inherently some uncertainties in the instrumentation capabilities under the accident conditions. So, the circuit simulation analysis and diagnosis methods are used to assess instruments in detail when they give apparently abnormal readings as an accident alternative method. The simulations can be useful to investigate what the signal and circuit characteristics would be when similar to a variety of symptoms that can result from the environmental conditions such as high temperature, humidity, and pressure condition. In this paper, a new simulator through an analysis of the important equivalent circuits modeling under temperature accident conditions has been designed, the designed simulator is composed of the LabVIEW code as a main tool and the out-put file of the Multi-SIM code as an engine tool is exported to in-put file of the LabVIEW code. The procedure for the simulator design was divided into two design steps, of which the first step was the diagnosis method, the second step was the circuit simulator for the signal processing tool. It has three main functions which are a signal processing tool, an accident management tool, and an additional guide from the initial screen. This simulator should be possible that it could be applied a output signal analysis to some transient signal by variation of the resistance passive elements in the R-L-C equivalent circuit modeling under various degraded conditions in NPPs.

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Design and Implementation of Prototype Anti-disaster Remote Control Robot Model using Smart Phone (스마트폰을 이용한 방재용 원격 조정 로봇의 프로토 타입 모델 설계 및 구현)

  • Choi, Sung-Jai
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.14 no.6
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    • pp.221-227
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    • 2014
  • This paper presented a design which was a minimized remote control robot. This remote control robot was created for preventing life damage from conflagrations, nuclear events and HF gas accidents. This robot's system based smart phone that had camera and GPS systems. When fire came out, The robot figured out that how big fire was, where the fire was started and various aspects of situations. And The robot broadcasted the informations to smart phone using mobile application and wi-fi camera. By doing these, the fire mans could more accurate and be easier to plan a strategy for saving life. The body of robot are 2 parts. One is a car and the other one is a remote controller. By the power, 1step to 10steps, of grabbing remote controller could change the car's speed to move. Also, The prototype robot was already confirmed its utility itself.

Design Concept of Hybrid SIT (복합안전주입탱크(Hybrid SIT) 설계개념)

  • Kwon, Tae-Soon;Euh, Dong-Jin;Kim, Ki-Hwan
    • The KSFM Journal of Fluid Machinery
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    • v.17 no.6
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    • pp.104-108
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    • 2014
  • The recent Fukushima nuclear power plant accidents shows that the core make up at high RCS pressure condition is very important to prevent core melting. The core make up flow at high pressure condition should be driven by gravity force or passive forces because the AC-powered safety features are not available during a Station Black Out (SBO) accident. The reactor Coolant System (RCS) mass inventory is continuously decreased by releasing steam through the pressurizer safety valves after reactor trip during a SBO accident. The core will be melted down within 2~3 hours without core make up action by active or passive mode. In the new design concept of a Hybrid Safety Injection Tank (Hybrid SIT) both for low and high RCS pressure conditions, the low pressure nitrogen gas serves as a charging pressure for a LBLOCA injection mode, while the PZR high pressure steam provides an equalizing pressure for a high pressure injection mode such as a SBO accident. After the pressure equalizing process by battery driven initiation valve at a high pressure SBO condition, the Hybrid SIT injection water will be passively injected into the reactor downcomer by gravity head. The SBO simulation by MARS code show that the core makeup injection flow through the Hybrid SIT continued up to the SIT empty condition, and the core heatup is delayed as much.