• Title/Summary/Keyword: high safety

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Mitigation of high energy arcing faults in nuclear power plant medium voltage switchgear

  • Chang, Choong-koo
    • Nuclear Engineering and Technology
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    • v.51 no.1
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    • pp.317-324
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    • 2019
  • A high energy arcing fault event occurred in the medium-voltage (13.8 kV and 4.16 kV) metalclad switchgears in a nuclear power plant not only affecting switchgear but also connected equipment due to the arc energy. The high energy arcing fault also causes a fire that influences the safety function of the unit. Therefore, from the safety point of view, it is necessary to evaluate the influences of high energy arcing fault events on the safety functions of nuclear power plants. The purpose of this paper is to elaborate the characteristics of high energy arcing faults and propose a high energy arcing fault mitigation scheme for medium voltage networks in nuclear power plants.

A Study on the Development of the Measuring Scale of Safety Consciousness (안전의식 측정 척도 개발 연구 : 서울시 일부 중학생을 중심으로)

  • 김혜원;이명선
    • Korean Journal of Health Education and Promotion
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    • v.19 no.1
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    • pp.87-107
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    • 2002
  • Recently, the industrialized world is suffering from accidents referring from the lack of safety consciousness. According to Korean Safety Regulation Department(1996), students at junior high schools are mostly involved in safety accidents, and this is due to lack of safety consciousness. To prevent these accidents, we need to have safety consciousness and attitude. To make junior high school students who are mostly affected in these accidents act safely, they need to know their level of safety consciousness. The purpose of this study is to develop a guideline of measuring the scale of safety consciousness and analyze the relationship between safety education, accident experiences and safety consciousness. This study is based on a survey of 708 junior high students in Seoul, which was carried out from 12 November, 2001 to 21 November, 2001. 1. The main fields of safety consciousness are home safety, school safety, fire safety, emergency management based on documents. Home safety is again divided into facility safety and livelihood safety, school safety is divided into facility safety, livelihood safety and laboratory safety, traffic safety is divided into pedestrian safety, bicycling safety and public transportation safety, fire safety divided into prevention and escaping during fire breakouts, emergency management safety is divided into general principles and escaping during emergency situations. 2. The primary safety consciousness scale was made according to every field of safety consciousness. A preliminary examination based on the scale and a study of reliance and the factors was held. Based on these results, 27 questions which were concerned to be impairing reliability or lacking in factor were deleted on the secondary safety consciousness scale development The secondary safety consciousness scale which constituted of 73 questions was put into another preliminary study and after analyzing reliability and the factors, 12 questions of low reliabilities were deleted and with these results, the third scale were made consisting of 61 questions. 3. A study based on the third safety scale which is made of 61 questions, were held and with a analysis of the reliability and factors made, the relationship between safety education, accident experience and safety mind were examined. (1) The study of reliability and factors show that Cronbach's coefficient in home safety fields is .7598, in school safety .7924, in traffic safety .8306, in emergency treatment .7775, in fire safety .7247. The questions indicating low reliability were deleted. The factor analysis revealed that home safety is converged on facility safety and livelihood safety. But one question was deleted because it showed incongruence of validity. School safety was converged on facility safety, livelihood safety and laboratory safety. But 2 questions showed incongruence of validity and these were deleted. Traffic safety fields were converged on pedestrian safety, bicycle safety and public transportation safety. One question showing incongruence of validity was deleted. Emergency treatment fields converged on general principles and acting in emergency situations and three questions showing incongruence of validity were deleted. Fire safety was converged on prevention and acting in fire breakouts. Totally, eight questions were removed and the final scale were consisted of 53 questions (2) The 3/sup rd/ grade students scored higher average safety mind scales than 1st graders(p〈.05). And students who had high scores at school tend to have a higher scale than those who do not(p〈.001). (3) Average scale of students who had experience in safety education were higher(p〈.001). Students who had previously been involved in home safety accidents had a low score(p〈.001). This was same to students with experience in school safety accidents(p〈.001). Students with traffic safety accidents and fire safety accidents tend to have a lower scale too(p〈.05, p〈.001).

OVERVIEW OF RECENT EFFORTS THROUGH ROSA/LSTF EXPERIMENTS

  • Nakamura, Hideo;Watanabe, Tadashi;Takeda, Takeshi;Maruyama, Yu;Suzuki, Mitsuhiro
    • Nuclear Engineering and Technology
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    • v.41 no.6
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    • pp.753-764
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    • 2009
  • JAEA started the LSTF experiments in 1985 for the fourth stage of the ROSA Program (ROSA-IV) for the LWR thermal-hydraulic safety research to identify and investigate the thermal-hydraulic phenomena and to confirm the effectiveness of ECCS during small-break LOCAs and operational transients. The LSTF experiments are underway for the ROSA-V Program and the OECD/NEA ROSA Project that intends to resolve issues in thermal-hydraulic analyses relevant to LWR safety. Six types of the LSTF experiments have been done for both the system integral and separate-effect experiments among international members from 14 countries. Results of four experiments for the ROSA Project are briefly presented with analysis by a best-estimate (BE) code and a computational fluid dynamics (CFD) code to illustrate the capability of the LSTF and codes to simulate the thermal-hydraulic phenomena that may appear during SBLOCAs and transients. The thermal-hydraulic phenomena dealt with are coolant mixing and temperature stratification, water hammer up to high system pressure, natural circulation under high core power condition, and non-condensable gas effect during asymmetric SG depressurization as an AM action.

Effects of Adolescents' Perception of the Need for Safety Education on Fire Safety Awareness: The Control Effect of Personality Factors (청소년의 안전교육 필요성에 대한 인식이 소방안전의식에 미치는 영향: 성격요인의 조절효과)

  • JinKyoung, Lee;Jai Young, Lee;Sook-hee, Im
    • Journal of the Korea Safety Management & Science
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    • v.24 no.4
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    • pp.109-116
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    • 2022
  • This study attempted to explore how the perception of the necessity of safety education for adolescents affects fire safety consciousness and whether personality factors control the relationship. To this end, a survey was conducted at a high school in region C, and data of 1,049 people who agreed to the survey and responded faithfully were used for analysis. Hayes' macro was used to analyze the moderating effect, and as a result of the analysis, adolescents' awareness of the need for safety education increased, and their relationship was significantly regulated by extroversion, openness, and conscientiousness among the five personality factors. A simple regression line analysis was conducted to find out the specific direction, and it was found that the higher the need for safety education in both the group with high extroversion, openness, and conscientiousness, the higher the awareness of safety education. These results suggest that changes in educational methods and contents are needed to raise awareness of the necessity of education in fire safety education and to improve educational motivation, and that it may be helpful to actively utilize students' personality strengths in education.

A Study on The Safety Awareness of Technical High School Student in Chemistry Major (화학전공 특성화 고등학생의 안전의식에 관한 연구)

  • Hong, Young-Ho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.9
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    • pp.617-625
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    • 2020
  • The purpose of this study was to elucidate the safety consciousness of high school students in chemistry-related departments in terms of disaster safety education, degree of safety education knowledge, and the relationship between safety consciousness and safety education knowledge. The subjects were 469 students attending technical high schools in Gyeonggi and Chungcheongnam-do. For the results, students responded that their level of safety consciousness (3.44) was better than that of others (2.85). In addition, safety regulations were considered in relation to others. Safety education at school was cited as necessary, but respondents were not interested in the education contents. Students had been receiving safety education at school, but they cited that the use of protective equipment in class was not performed well. Disaster awareness was positively (+) correlated, and safety and fire safety awareness were found to be significant. The results of this study can be used as basic data for safety education to improve disaster safety education. It is necessary to develop an education program to raise safety awareness and to develop an education manual. Based on this study, future studies should be conducted.

Development of Standard Checklist for Safety Management of Toxic Gas facility in Domestic University Laboratory (국내 대학 실험실 독성가스 시설의 안전관리를 위한 표준 체크리스트 개발)

  • Lee, Sungjin;Kim, Byung-Duk;Ha, Dong-Myeong
    • Journal of the Korean Institute of Gas
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    • v.19 no.6
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    • pp.92-98
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    • 2015
  • Toxic gases are managed by High Pressure Gas Safety Control Act. Toxic Gases are "31 designated species and each gas of which the permissible concentration($LC_{50}$) is equal to or less than 5000 ppm as defined in High Pressure Gas Safety Control Act.". Korean toxic gas usage in accordance with the growth of the electronic industry has increased explosively. The demand of toxic gas research in domestic university laboratories has grown together. But the research associated with toxic gas safety management in the domestic laboratory is nonexistent state. In this study, we identified weak points of toxic gas safety management through a survey of domestic university laboratory facilities. This paper presented toxic gas safety measures in order to overcome those weak points. Also this paper developed a standard checklist to improve and ensure safe management of toxic gas facility in accordance with the proposed measures. This research is to enforce safety management of toxic gas facilities in domestic university laboratory and it will provide safety guidelines for every laboratory.

Multiclass Method for the Determination of Anthelmintic and Antiprotozoal Drugs in Livestock Products by Ultra-High-Performance Liquid Chromatography-Tandem Mass Spectrometry

  • Hyunjin Park;Eunjung Kim;Tae Ho Lee;Sihyun Park;Jang-Duck Choi;Guiim Moon
    • Food Science of Animal Resources
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    • v.43 no.5
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    • pp.914-937
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    • 2023
  • The objective of this study was to establish a multi-residue quantitative method for the analysis of anthelmintic and antiprotozoal drugs in various livestock products (beef, pork, and chicken) using ultra-high-performance liquid chromatography-tandem mass spectrometry. Each compound performed validation at three different levels i.e., 0.5, 1, and 2× the maximum residue limit according to the CODEX guidelines (CAC/GL 71-2009). This study was conducted according to the modified quick, easy, cheap, effective, rugged, and safe procedure. The matrix-matched calibrations gave correlation coefficients >0.98, and the obtained recoveries were in the range of 60.2%-119.9%, with coefficients of variation ≤32.0%. Furthermore, the detection and quantification limits of the method were in the ranges of 0.03-3.2 and 0.1-9.7 ㎍/kg, respectively. Moreover, a survey of residual anthelmintic and antiprotozoal drugs was also carried out in 30 samples of beef, pork, and chicken collected in Korea. Toltrazuril sulfone was detected in all three samples. Thus, our results indicated that the developed method is suitable for determining the anthelmintic and antiprotozoal drug contents in livestock products.

The Functional Safety Assessment of WIG Craft in Design Stage (위그선 설계단계에서의 안전성 평가)

  • Lee, Soon-Sup;Park, Beom-Jin;Lee, Jong-Kap
    • Journal of Ocean Engineering and Technology
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    • v.24 no.6
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    • pp.103-108
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    • 2010
  • WIG crafts are high speed vessels with the features of a dynamic supported craft. These crafts, which are predominantly lightweight and operate at substantially greater speeds than conventional craft, could not be accommodated under traditional maritime safety instruments. WIG crafts inherently possess more hazard factors than conventional ships because of their relatively high speed, lightweight, and navigational characteristics, and an accident is likely to cause damage to the ship and a high loss of life. Because WIG crafts are composed of many systems and subsystems, the safety assessment of a WIG must use a commercial software system in the design stage. This paper reviews a safety assessment process and methodology proposed by the IMO interim guideline, which were developed in view of the configuration of WIG crafts. This safety assessment system was developed to fit the WIG's safety assessment process using a reliability analysis system widely used in commercial systems. The FHA was performed on the functional hazards of systems in the conceptual design stage.

A study of jet dispersion and jet-fire characteristics for safety distance of the hydrogen refueling station (수소충전소 안전거리 설정을 위한 수소제트 및 화염 특성 분석)

  • Kang, Seung-Kyu
    • Journal of the Korean Institute of Gas
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    • v.23 no.6
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    • pp.74-80
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    • 2019
  • Hydrogen refueling stations that use compressed hydrogen at high pressure provide safety distances between facilities in order to ensure safety. Most accidents occurring in hydrogen stations are accidental leaks. When a leak occurs, various types of ignition sources generate a jet flame. Therefore, the analysis of leaked gas diffusion and jet flame due to high pressure hydrogen leakage is one of the most important factor for setting the safety distance. In this study, the leakage accidents that occur in the hydrogen refueling station operated in high pressure environment are simulated for various leakage source sizes. The results of this study will be used as a reference for the future safety standards.

Preparation and Properties of Polymer Blends Type Humidity Sensor for Process Safety (공정안전용 Polymer Blend형 습도센서의 특성 연구)

  • Kang Young-Goo;Cho Myoung-Ho
    • Journal of the Korean Society of Safety
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    • v.19 no.3 s.67
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    • pp.51-56
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    • 2004
  • Conductive polymer blends and composites are widely used for different safety application such as electrostatic charge dissipation(ESD), electromagnetic interference(EMI) shielding, electrostatic prevention and safety chemical sensor. In order to prepare a impedance-type humidity sensor that is durable at high humidities and high temperature, electically conductive polymer blends based on diallyldimethylammonium chloride(DADMAC) and epoxy were prepared in this study. The polymer blends type conductive ionomer exhibits reaction each other DADMAC and epoxy in FT-IR and DSC analysis. The blends material was traced by new peak at 1600cm-1 and appeard improvement of thermal resistance by melting point shift. Alumina substrate was deposited a pair of gold electrodes by screen printing. The blend material were spin-coated with a thin film type on the surface of alumina substrate. The polymer bleld type sensor exhibits a linear impedance increasing better than DADMAC coated humidity sensor. Also it shows good sensitivity, low hysteresis and durability against high humidity.