• Title/Summary/Keyword: Major accidents

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A Large Dry PWR Containment Response Analysis for Postulated Severe Accidents (가상적 중대사고에 대한 대형건식 가압경수로 격납용기의 반응해석)

  • Chun, Moon-Hyun
    • Nuclear Engineering and Technology
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    • v.19 no.4
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    • pp.292-309
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    • 1987
  • A large dry PWR containment response analysis for postulated severe accidents was performed as part of the Zion Risk Rebaselining study for input to the U.S. NRC's "Reactor Risk Reference Document," NUREG-1150. The Methodologies used in the present work were developed as part of the Severe Accident Risk Reduction Program (SARRP) at Sandia National Laboratory specifically for the Surry Plant, but they were extrapolated to Zion. Major steps of the quantification of risk from a nuclear power plant are first outlined. Then, the methodologies of containment response analysis for severe accidents used for Zion are described in detail: major features of the containment event tree (CET) analysis codes and CET quantification procedures are summarized. In addition, plant specific features important to containment response analysis are presented along with the containment loading and performance issues included in the present uncertainty analysis. Finally, a brief summary of the results of deterministic and statistical containment event tree analysis is presented to provide a perspective on the large dry PWR containment response for postulated severe accidents.accidents.

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Accident research II for the college students happened during Dental Laboratory Technology-major classes (치기공과 실습 중 안전사고 실태조사 II)

  • Park, Jong-Hee
    • Journal of Technologic Dentistry
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    • v.27 no.1
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    • pp.131-153
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    • 2005
  • The purpose of this study was to identify the accidents happened in the college dental laboratory technique classes and to realize the level of safety education for the dental laboratory technique major students. The research data were collected from a self-administered survey distributed to the conveniently selected college students whose majors were dental laboratory technology in Suwon, Daejeon, Daegu, Kimcheon, and Icsan. The study participants were 422 freshmen, sophomore and junior students in the selected cities. All collected survey responses were encoded and analyzed in SPSS 12.0. The findings were as follows. 1. The students who had any accidents in their laboratory classes were 36% and the other 64% answered 'no.' 2. Most injuries which the participants had were not significant. 3. The medical treatment periods of most injury cases were less than one week; however, approximately 20% of the self-reported injury cases reported that their treatment periods were longer than one week. 4. The body parts frequently injured from accidents were hands with 84.7% and arms, eyes, face, head, and legs in order. 5. Concerning the materials involved in the laboratory classes, most accidents happened when working with wax in 59.9%, with plaster in 52.3%, with wire in 39.8%, with alcohol in 34.6%, and casting iron in 22.2% in order. 6. The accident-prone laboratory methods were polishing with 53.5%, pickling or sanding with 17.4%, and casting or burning with 5.8% in order. 7. Most students wore their laboratory gowns well; however, few students wore mask before dust-involved jobs. Furthermore, only 57.1% students answered their laboratory fans worked during the polishing job. 8. Approximately 54% participant students answered that they took laboratory safety education when necessary only from the class instructors. 9. The 76.1% students responded that they needed laboratory safety education at least 1-2 times every semester. 10. The survey participants answered that the primary factors for injury prevention in their laboratory were taking safety education, wearing safety equipments, and providing safety-focused facilities. Concludingly, comprehensive evaluation and monitoring for potential risk factors from both the human side and the environment side should be continually provided to minimize the college laboratory accidents.

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A Study on The Life Tablefor Specific Causes of Death in Korea (사망원인과 특정사인생명표에 관한 연구)

  • 한동준
    • Korea journal of population studies
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    • v.6 no.1
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    • pp.43-69
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    • 1983
  • This study was conducted to make the life tables from specific causes of death in Korea. Both "Life tables of Korea in l978-79" and "the statistics on causes of death statistics in 1980" issued by Economic Planning Board were used as source of data for this study. Among the 58, 187 death certificates reported to the concerned authorities, 39, 801 causes were drawn for the purpose of this study. As a result, it is revealed that two thirds of men in Korea died from these 10 major causes of death. The summarized results are as follows: 1. According to recent statistics, 10 major causes of death in 1980 were shown in the order of 1) malignant neoplasms, 2) cerebrovascular disease, 3) accidents and adverse effects, 4)hypertensive disease, 5) ischaemic heart disease and heart attack, 6) chronic liver disease and cirrhosis, 7) tuberculosis, 8) pneumonia, bronchitis, emphysema and asthma, 9) suicide, 10) diabetes mellitis. 2. The major causes of death in Korea were very similar to those of developed countries such as West Germany, Denmark and Japan. This means that our pattern of death causes is almost approaching to that of developed countries. 3. Our crude death rate in 1980 was on the line of 6.6 per 1, 000 people. This is very low level, compared with 12.1 in West Germany and 10.0 in Denmark, however, our age sepcific death rate was on the verge of doubled level in each age category as to that of West Germany, Denmark and Japan. The fact tells us that our death rate is very high yet, especially in young and prime adult age, and the proportion of the aged is quite low. 4. Average ages of people died from malignant neoplasms, cerebro vascular diseases and hypertensive diseases were 63.1, 66.6, 67.3 respectively, however, that of accidents and adverse effect was only 42.5. This shows that accidents occur indifferently from age. 5. In the curve of eventual death probability, the curve of malignant neoplasms was the highest of all curves before 60 in age. However, the probability curve of eventually dying from accidents and adverse effects tends to decline with age. 6. In this study five life tables from major causes of death (four leading causes of death and of tuberculosis) were constructed for 1979. These life tables are reflecting accurately the effects of age distribution on the specific cause of death. In the surviving curje of these tables we can see that the curve of accidents is adversely related to age. While curves of neoplasms, hypertension and tuberculosis are not diminishing before 40 in age, they are going sharply downward after 50 in age.ard after 50 in age.

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Analysis of Structural Relation between the Shipyard Workers' Ego-state, Safe and Unsafe Behaviors, and Industrial Accidents (조선업 작업자의 자아상태, 안전 및 불안전행동, 산업재해 간의 구조관계 분석)

  • Jeong, Inseok;Jeong, Daekyum
    • Journal of the Korean Society of Safety
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    • v.33 no.5
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    • pp.101-108
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    • 2018
  • This study was carried out to obtain baseline data on the causes of industrial accidents and their prevention by investigating structural models between the Shipyard workers' egogram ego-states (CP: Critical Parent, NP: Nurturing Parent, A: Adult, FC: Free Child, AC: Adapted Child), safe and unsafe behaviors, and industrial accidents (frequency/severity). In order to achieve this goal, 378 workers from 3 locations of major corporations in Geojedo Island and Ulsan took a questionnaire, which was then analyzed with a structural equation model using the SPSS 23.0 and AMOS 24 statistics package, and the main results of the study are as follows. First, NP and A's ego-states had a positive influence on safe behavior, AC's ego-state had a negative influence on safe behavior, and A's ego-state had the largest influence on safe behavior. Second, CP and AC's ego-states had a positive influence on unsafe behavior, and A's ego-state had a negative influence on unsafe behavior. AC's ego-state had the largest influence on unsafe behavior. Third, safe behavior did not have a significant influence on industrial accidents. However, unsafe behavior had a positive influence on industrial accident frequency and industrial accident severity, both sub-factors of industrial accidents. This study, despite its limitations, such as sampling limitations, has the following significance. First, this study verified that ego-state, a psychological characteristic, is an important factor for predicting unsafe behavior that induces industrial accidents. Second, in order to reduce industrial accidents, there is a need to stimulate the A ego-states, and promote continuous safety management and safety education to neutralize the AC ego-state. Third, previous studies were limited in the area of practical methods for reducing unsafe behaviors, but this study presents practical methods for reducing unsafe behaviors by verifying the structural relationship between safe/unsafe behaviors and industrial accidents by selecting ego-gram ego-states, variable personality theory, as an independent variable.

A Study on safety enhancement of Medium and small boilers (중소형 보일러의 안전성 향상에 관한 연구)

  • Kim, Dae-Ryong;Lee, Keun-Oh
    • Journal of Energy Engineering
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    • v.22 no.3
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    • pp.294-301
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    • 2013
  • The accidents related to boilers are caused by defects with high risk which can lead to the explosion of the equipment. The number of boiler accidents from 1979 to 2006 is 100 andthe casualties totaled 379, and the scale of accidents has been growing larger every year. The analysis has found that the number of accidents caused by carelessness in management is 59, 72% of total 82 cases and 18by low level of water. The analysis of accidents in foreign countries showed a similar result. From the past till today most of the accidents have been resulted from bad handlingand maintenance. The analysis of accidents for the inspected boilers also showed that the major cause of the accidents was bad handling and maintenance of automatic controllers, safety devices, etc. And in the large-scale explosive accidents, the number one cause of them was the low level of water.

Analysis of Occupational Injury and Feature Importance of Fall Accidents on the Construction Sites using Adaboost (에이다 부스트를 활용한 건설현장 추락재해의 강도 예측과 영향요인 분석)

  • Choi, Jaehyun;Ryu, HanGuk
    • Journal of the Architectural Institute of Korea Structure & Construction
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    • v.35 no.11
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    • pp.155-162
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    • 2019
  • The construction industry is the highest safety accident causing industry as 28.55% portion of all industries' accidents in Korea. In particular, falling is the highest accidents type composed of 60.16% among the construction field accidents. Therefore, we analyzed the factors of major disaster affecting the fall accident and then derived feature importances by considering various variables. We used data collected from Korea Occupational Safety & Health Agency (KOSHA) for learning and predicting in the proposed model. We have an effort to predict the degree of occupational fall accidents by using the machine learning model, i.e., Adaboost, short for Adaptive Boosting. Adaboost is a machine learning meta-algorithm which can be used in conjunction with many other types of learning algorithms to improve performance. Decision trees were combined with AdaBoost in this model to predict and classify the degree of occupational fall accidents. HyOperpt was also used to optimize hyperparameters and to combine k-fold cross validation by hierarchy. We extracted and analyzed feature importances and affecting fall disaster by permutation technique. In this study, we verified the degree of fall accidents with predictive accuracy. The machine learning model was also confirmed to be applicable to the safety accident analysis in construction site. In the future, if the safety accident data is accumulated automatically in the network system using IoT(Internet of things) technology in real time in the construction site, it will be possible to analyze the factors and types of accidents according to the site conditions from the real time data.

RELAP5 Simulation of the Small Inlet Header Break Test B8604 Conducted in the RD-14 Test Facility

  • Lee, Sukho;Kim, Manwoong
    • Nuclear Engineering and Technology
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    • v.32 no.1
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    • pp.57-66
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    • 2000
  • The RELAP5 code has been developed for best-estimate simulation of transients and accidents for pressurized water reactors and their associated systems, but it has not been fully assessed for those of CANDU reactors. However, a previous study suggested that the RELAP5 code could be applicable to simulate the transients and accidents for CANDU reactors. Nevertheless, it is indicated that there are some works to be resolved, such as modeling of headers and multi-channel simulation for the reactor core, etc. Therefore, this study has been initiated with an aim to identify the code applicability for all the postulated transients and accidents in CANDU reactors. In the present study, the small inlet header break experiment (B8604) in the RD-14 test facility was simulated with RELAP5/MOD3.2 code. The RELAP5 results were also compared with both experimental data and those of CATHENA analyses performed by AECL and the analyses demonstrated the code's capability to predict major . phenomena occurring in the transient with sufficient accuracy for both Qualitative and quantitative viewpoint However, some discrepancies in the depressurization of the primary heat transport system after the break and the consequent time delay of the major phenomena were also observed.

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Empirical Study of Smart Safety System to Increase Construction Disaster Prevention Effect - Centered on Construction Machinery (건설 재해 예방효과 증대를 위한 스마트 안전 시스템 실증연구 - 건설기계 중심)

  • Seung-Yong Choi
    • Journal of the Society of Disaster Information
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    • v.19 no.2
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    • pp.421-431
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    • 2023
  • Purpose: The purpose of this study is to analyze the safety and disaster prevention effects of the Smart Safety System used to prevent safety accidents in construction machinery and demonstrate its safety. Method: Among construction machines, the behavioral patterns of workers according to the presence or absence of a smart safety system were analyzed for excavators with high risk and frequent accidents. Result: When the smart safety system was installed in the construction machine, the safety of workers from accidents caused by constriction and collision with the construction machine was secured. Conclusion: It is judged that the smart safety system installed in construction machinery can increase the effectiveness of disaster reduction and major disaster prevention related to construction machinery.

A Study on the Effects of Factors of Traffic Accidents Caused by Frozen Urban Road Surfaces in the Winter (겨울철 도시부 노면결빙사고 발생에 미치는 요소에 관한 연구)

  • Kim, Sangyoup;Jang, Youngsoo;Kim, Sungkyu;Min, Dongchan;Na, Hohyuk;Choi, Jaisung
    • International Journal of Highway Engineering
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    • v.17 no.2
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    • pp.79-87
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    • 2015
  • PURPOSES: According to accident statistics for road built in 2004, the ratio of accidents on frozen roads to normal roads is 0.9%, whereas the fatality ratio is 2.7%. The risk of accidents on frozen roads is very high. Measures taken every year to prevent traffic accidents of frozen roads in the winter season are still insufficient. Additionally, measures have been established mainly on rural roads. Therefore, for urban roads, analyses and measures to prevent accidents are lacking. In this study, data on accidents on frozen roads was used to search for the causes behind these accidents and measures to reduce accidents have been recommended. METHODS: In this study, collected data from the TAMS (Traffic Accident Management System), which were collected by the Seoul National Police Agency was used. The data were divided into vehicle, people, and condition of road. The analytical model used here was the Logistic Regression Model, which is frequently used for traffic safety and accident analysis. This study uses the odds ratio analysis to search for variables related to frozen road traffic accidents in each category. A total of 18 out of 47 variables were found to be the causes of accidents. RESULTS: From the results of the comparative analysis of 18 variables, the category of the condition of the road was found to be the most critical. Contrary to expectations, more accidents occurred in clear weather than in other conditions. Accidents on bridges occurred frequently, and its odds ratio was the highest compared with other road types. When BPT is operated, the probability of accidents on frozen roads is lower than in general conditions, and accidents occurred frequently on roads with less than four lanes. CONCLUSIONS : Based on the results of this study, suggestions for reducing the risk of future domestic road accidents in freezing conditions are indicated as follows. First, it is necessary to perform a technical review of the urban road traffic accidents caused by frozen roads. Second, it is necessary to establish criteria for the study of the road environment based on the major causes of road accidents on frozen roads. Third, improvements in urban road environmental factors should be made.

A Study on the Occurrences and Policy Development for Accident Prevention (한국의 사고발생 실태와 사고예방을 위한 정책 연구)

  • 이경자;이정렬;강규숙;한정석
    • Journal of Korean Academy of Nursing
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    • v.25 no.2
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    • pp.362-371
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    • 1995
  • There is no national system to manage, evaluate, and analyse the information about accidents, even though it is necessary for accident prevention policies and health promotion of the general public. The existing studies are, also limited as they focus only on particular group(for example : inpatients, emergency room patients) or on particular geographic areas. Thus the results of the studies cannot be ap-plied to the general public. In order to overcome these limitations, this research focuses on data collection and analysis from accident information for the general population. By providing the analysis on types and causes af accidents, this research aims to produce the basic data necessary for accident prevention policy development. The specific aims of this research are to : 1. Analyse the actual occurrences and characteristics of accidents. 2. Suggest for the accident prevention policies and safety education. Accident report form three major newspaper printed in Korea between January 1, 1989 and December 31, 1993 were collected, and the cause, place, time, and personal injury related to the accidents were classified and then analyzed by de-scriptive statistics. The results of this research conclude : 1. The number of accidents reported by the three newspapers were 2155. 2. The highest proportion of accidents were as follows ; occurred during the June-August(31.2%), Sunday(24.8%), and 5 p.m. (7.6%) of the day. 3. The highest proportion of the accident occurred in Seoul(33. l%), Kyunggi province(14.5%), Kangwon province (7.8%), and Kyungnam prov-ince(6.7%) were next highest. 4. The main causes include car accidents(32.4%), drowning(10.9%), falls(8.8%), explosion(7.1%), and poisoning(5.8%). 5. Slightly more than half of injuries(50.5%) and about two fifths of deaths(40.3%) were caused by car accidents. Therefore, the most serious type of accidents were car accidents. 6. The number of males in accidents were almost three times higher than that of females(males 72.3%, females : 27.7%). 7. The age group from 10 to 19 years old represents the highest proportion(21%) of accidents. 8. The number of the accidents in Korea, based on the information collected from the newspapers, is estimated to be 14, 367 per year. The number of in-juries is estimated to be 88, 480 persons, and the number of deaths 29, 007 respectively. It is said that ninety percent of accidents can be prevented. Several accidents prevention policies are suggested here. 1. Safety education should be done more actively throughtout life, with special emphasis on safety education for children. 2. Safety measures for children(halmets for cycling, children car seats, seats belts, and so on) should be emphasized. 3. An injury surveillance system should be initiated. The initiation of injury reporting system in each factory and school could contribute considerably to the reduction of accidents.

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