최근 원자력 지진 PSA(Probabilistic Safety Assessment)를 토대로 산업시설물의 지진 PSA를 수행하는 연구가 진행되었다. 해당 연 구는 원자력 발전소와 산업시설물의 차이를 파악하고, 최종적으로 운영정지를 목표로 하는 고장수목(Fault Tree)를 구축한 후 시각적 확률도구인 베이지안 네트워크(Bayesian Network, BN)으로 변환하였다. 본 연구는 선행연구를 기반으로 지진으로 유발된 구조손상 으로 인해 발생 가능한 화재･폭발에 대해 PSA를 수행하고자 하였다. 이를 위해 화재･폭발을 사건수목(Event Tree)으로 표현하고, BN 으로 변환하였다. 변환된 BN은 화재･폭발 모듈로서 선행연구에서 제시된 고장수목 기반 BN과 연계되어 최종적으로 지진 유발 화재･ 폭발 PSA를 수행할 수 있는 BN 기반 방법론이 개발되었다. 개발된 BN을 검증하기위해 수치예제로서 가상의 가스플랜트 Plot Plan을 생성하였고, 가스플랜트의 설비 종류가 구체적으로 반영된 대규모 BN을 구축하였다. 해당 BN을 이용하여 지진 규모에 따른 전체시 스템의 운영정지 확률 및 하위시스템들의 고장확률 산정과 더불어 역으로 전체시스템이 운영 정지되었을 때 하위시스템들의 영향도 분석과 화재･폭발 가능성을 산정하여 다양한 의사결정을 수행할 수 있음을 제시함으로써 그 우수성을 확인하였다.

Executive safety leadership is essential to prevent accidents in the workplace. However, will safety be secured by emphasizing only executive safety leadership to workers? In this study, the impact of executive safety leadership on the workplace hazard level was analyzed by adding the supervisor's safety role as a mediating variable. This paper shows that executive safety leadership has no direct effect on workplace hazard levels. However, executive safety leadership was found to have a significant impact on the supervisor safety role, and the supervisor safety role was found to lower the hazard levels in the workplace. In summary, executive safety leadership was found to reduce the hazard levels in the workplace through the full mediating effect of the supervisor safety role. Based on these research results, this study seeks to present the following recommendations to the government and management: The government should ensure that a workplace safety and health system is established by strengthening the effects of other mediating factors, such as strengthening the role of supervisors who are actually responsible for workplace safety and health. Executives must grant supervisors actual authority and responsibility to properly perform their safety roles and establish personnel and performance evaluation systems.

PURPOSES : Recently, air pollution due to fine particulate matter has been increasing in Korea. Nitrogen oxides (NOx) are particulate matter precursors significantly contributing to air pollution. Increasing efforts have been dedicated to NOx removal from air, since it is particularly harmful. Application of titanium dioxide (TiO2) for concrete road structures is a suitable alternative to remove NOx. As the photocatalytic reaction of TiO2 is the mechanism that eliminates NOx, the ultraviolet rays in sunlight and TiO2 in existing concrete structures need to be contacted for the reaction process. For the application of vertical concrete road structures such as retaining walls, side ditches, and barriers, a pressurized TiO2 fixation method has been developed considering the pressure and pressurization time. In this study, longterm serviceability and repeatability were investigated on concrete specimens applying the dynamic pressurized TiO2 fixation method. Additionally, the environmental hazards of nitrate adsorbed on TiO2 particles were evaluated. METHODS : Concrete specimens to simulate roadside vertical concrete structures were manufactured and used to evaluate the long-term serviceability and repeatability of the dynamic pressurized TiO2 fixation method. The NOx removal efficiency was measured using NOx evaluation equipment based on ISO 22197-1. In addition, the nitrate concentration was measured using a comprehensive water quality analyzer for evaluating environmental hazards. RESULTS : As the experiment to evaluate the NOx removal efficiency of the dynamic pressurized TiO2 fixation method progressed from one to seven cycles, the nitrate concentration increased from 2.35 mg/L to 3.06 mg/L, and the NOx removal efficiency decreased from 53% to 25%. After seven cycles of NOx removal efficiency evaluation, the average nitrate concentration was 3.06 mg/L. The nitrate concentration collected immediately after the NOx removal efficiency test for each cycle was in the range of 2.51 to 2.57 mg/L. By contrast, it was confirmed that the nitrate concentration was lowered to approximately 2.1 mg/L when the surface was washed with water. CONCLUSIONS : The NOx removal efficiency was maintained at over 25% even after seven cycles of NOx removal efficiency evaluation, securing long-term serviceability. In addition, the harmful effects on the environment and human health are insignificant, since the nitrate concentration was less than 10 mg/L, in accordance with domestic and foreign standards. Practical applicability of the pressurized TiO2 fixation method was established by evaluating the long-term serviceability, repeatability, and environmental hazards.

국제해사기구의 온실가스 감축 노력으로, 해운 산업에서는 저탄소 연료로서 액화천연가스와 메탄올, 그리고 무탄소 연료로서 수소와 암모니아가 대두되고 있으며, 환경 친화적인 연료로 평가되고 있다. 특히 암모니아의 경우 화물로써 운반선을 통한 상당 기간의 운항 경험을 보유하고 있으며, 24년 하반기에는 암모니아 선박 엔진이 공급 예정으로, 상용화가 상대적으로 용이한 연료 중 하나로 간주 되고 있다. 그러나 암모니아를 연료로 사용하기 위해서는 독성의 문제점을 극복해야할 필요가 있다. 5ppm 수준의 농도에서 후각으로 판 단이 가능하며, 300ppm 이상을 30분 이상 흡입할 경우 회복이 불가능한 상태에 이를 수 있는 독성물질이다. 화학물질안전원에서 제공하는 KORA 프로그램을 사용하여 암모니아 벙커링시 누설시 발생할 수 있는 위험성에 대하여 평가하였으며, 1분간의 누설로 인해서 반경 약 7.5km에서 5ppm의 영향이 있을 수 있으며 이는 부산시 주요지역에 해당하며, 인체에 치명적일 수 있는 300ppm의 경우 벙커링 인근 인구 밀집지역 및 학교등에 심각한 영향을 미칠 수 있음을 확인할 수 있었다. 따라서 암모니아 벙커링 관련 법제도가 부재한 상태로 작은 누설 에도 광범위한 지역에 독성의 영향이 미칠 수 있기 때문에 지자체, 소방, 환경관서 등과의 유기적인 체계 구축이 마련될 수 있도록 법제 도 개발이 필요하다.

This study proposes a methodology for assessing seismic liquefaction hazard by implementing high-resolution three-dimensional (3D) ground models with high-density/high-precision site investigation data acquired in an area of interest, which would be linked to geotechnical numerical analysis tools. It is possible to estimate the vulnerability of earthquake-induced geotechnical phenomena (ground motion amplification, liquefaction, landslide, etc.) and their triggering complex disasters across an area for urban development with several stages of high-density datasets. In this study, the spatial-ground models for city development were built with a 3D high-precision grid of 5 m x 5 m x 1 m by applying geostatistic methods. Finally, after comparing each prediction error, the geotechnical model from the Gaussian sequential simulation is selected to assess earthquake-induced geotechnical hazards. In particular, with seven independent input earthquake motions, liquefaction analysis with finite element analyses and hazard mappings with LPI and LSN are performed reliably based on the spatial geotechnical models in the study area. Furthermore, various phenomena and parameters, including settlement in the city planning area, are assessed in terms of geotechnical vulnerability also based on the high-resolution spatial-ground modeling. This case study on the high-precision 3D ground model-based zonations in the area of interest verifies the usefulness in assessing spatially earthquake-induced hazards and geotechnical vulnerability and their decision-making support.

Radioactive materials depositied after nuclear accident or radiological emergency result in radiation exposure to individuals living in long-term contaminated territories. Therefore, the remedial actions should be taken on affected areas for the evacuated residents to return to their homes and normal lifestyle. Meanwhile, radiation exposure occurs through various pathways by work types during the site clean-up. Therefore, dose assessment is crucial to protect emergency workers and helpers from the potential radiological risk. This study estimated the exposure dose to individuals decontaminating the areas contaminated with 60Co, 63Ni, 90Sr, 134Cs, 137Cs, and then calculated the maximum workable soil concentration to comply with the reference level of 20 mSv/y for transition to existing exposure situations. For the realistic assessment, the detailed exposure scenarios depending on the types of work (excavation, collection, transportation, disposal, landfill), and the relevant exposure pathways were used. In addition, with the LHS (Latin Hypercube Sampling) - PRCC (Partial Rank Correlation Coefficient) method, sensitivity analysis was performed to identify the influence of the input parameters and their variation on the model outcomes. As a result, the most severe exposure-induced type was identified as the excavator operation with an annual individual dose of 4.75E-01 mSv at the unit soil concentration (1 Bq/g), from which the derived maximum workable soil concentration was 4.21E+01 Bq/g. Dose contribution by isotopes were found to be 60Co (55.63%), 134Cs (32.01%), and 137Cs (12.28%), and the impact of 63Ni and 90Sr were found to be negligible. Dose contribution by exposure pathways decreased in the following order: ground-shine, soil ingestion, dust inhalation, and skin contamination. Furthermore, the most high sensitive input parameters and their PRCC were found to be as the dilution factor (0.75) and as the exposure time (0.63). In conclusion, the results are expected to contribute to optimize radiation protection strategeis for recovery workers and to establish appropriate response procedures to be applicable in areas with high deposition density after a radiological or nuclear emergency.

This study investigated the hazard factors based on imported food non-compliance and global food hazard information for the last 4 years to suggest imported food safety management. Food safety management on utensils or packaging containers is appropriately managed for the compounds derived from them. Food safety management on health-functional foods, processed foods, and agricultural products is concentrated on ingredient contents, food additives, and pesticide residuals. Additional hazards are illegal compounds, mycotoxins & pesticide residuals, hygieneindicator microorganisms and food-borne pathogens in health-functional foods, processed foods, and agricultural products, respectively. The continuous increase in hazards related to safety and hygiene in global food hazard information needs additional attention. To reduce the hazard factors, this study proposes that imported food be limited to products certified by HACCP or an equivalent food safety management system because registering foreign food facilities for processed and health-functional foods is mandatory. Additionally, the customs clearance inspections should focus on the hazard factors derived from the global food hazard information system. This study suggests a global food hazard information system that could derive frequently issued hazard factors at a given period and newly issued hazard factors in aspects, such as food items, subcategories, and exporting countries.

Most of the drinking water dams managed by the local governments in Korea are earthfill dams, and these dams have almost no geotechnical property information necessary for seismic performance evaluation. Nevertheless, in the rough planning stage for improving seismic safety for these dams, it is necessary to classify their relative seismic hazard against earthquakes and conduct an additional ground investigation. The zero seismic failure probability curve is a curve suggested in this study in which the probability of failure due to an earthquake becomes ‘0’ regardless of the geotechnical properties of the earthfill dam. By examining the method and procedure for calculating failure probability due to an earthquake suggested in previous researches, the zero seismic failure probability curves for an earthquake in 1,000-year and 2,400-year return periods in Korea were presented in the form of a hyperbola on the plane of the dam height versus freeboard ratio (ratio of freeboard to dam height), respectively. The distribution characteristics of the dam height and the freeboard ratio of 81 Korean earthfill dams were presented. The two proposed zero seismic failure probability curves are shown on the plane of the dam height versus freeboard ratio, and the relative seismic hazard of 81 dams can be classified into three groups using these curves as boundaries. This study presented the method of classifying the relative seismic hazard and the classification result.

Despite the recent increase in the consumption level of the processed meat-byproducts, the health and safety issue has consistently been raised in the processes of production, distribution and consumption. The purpose of this study is to analyze and evaluate the microbiological hazard elements in the Korean sausage, “Sundae,” to present not only the safety standard of meat by-product vendors based on HACCP (Hazard Analysis Critical Control Point), but also the quality control criteria and sanitary arrangements of small manufacturers. For the study, the microbiological hazards in 24 raw materials, 7 manufacturing processes, 40 facilities and tools, 17 workplace environment, and 12 workers were analyzed. The analysis revealed the hazardous elements in the initial stages with 6.28 and 4.07 log CFU/g of total aerobic count and coliforms, respectively, detected from the porcine blood and 3.23 log CFU/g of coliforms from the porcine small intestines. The result also showed that the total aerobic counts and coliforms in the process of mixing and filling process exceeds the standards in the hygiene guidelines by Natick with the total aerobic counts of 5.23, 5.45 log CFU/g, and the coliforms of 3.25, and 3.31 log CFU/g, respectively. Although the detected total aerobic count and the coliforms in the filling and washing rooms exceeded the standards, it was found that the total aerobic count was significantly reduced by 98% after cleaning and disinfecting and no coliforms was detected in any process thereafter. In order to achieve high level of safety in the manufacturing processes of Sundae, the separation of washing and disinfection room from the other sections and the sanitation control of the workers must be preceded, along with strict monitoring in the storage and distribution processes. The study raises necessity for additional studies for the safety evaluation of the processed meat-byproducts and further researches on the validity of the critical limits.

본 연구는 지난 12년간의 우주위험 관련 언론기사의 토픽모델링 분석을 통해 우주위험별 언론 보도 현황을 알 아보기 위한 목적으로 수행되었다. 빅카인즈(BIGKinds)의 뉴스 플랫폼에서 2010년부터 2021년까지의 태양폭풍, 인공우 주물체, 자연우주물체에 대한 우주위험 기사를 각각 1200여건 이상 수집하였으며, 키워드 분석, 잠재적 디리클레 할당 모형(LDA) 분석을 수행하였다. 그 결과 태양폭풍 관련 기사는 3개의 토픽인 태양폭발이 인공위성에 미치는 영향, 우주 전파센터를 중심으로 태양폭발이 우리나라 전파 통신에 미치는 영향, 항공종사자와 우주방사선의 관계로 요약되었다. 인공우주물체 관련 기사의 경우 3개의 토픽으로 인공위성과 우주정거장이 우주쓰레기로부터 위협을 받거나 그 자체가 우주쓰레기가 될 수 있다는 토픽, 영화를 통한 우주쓰레기와 인류의 관계에 대한 토픽, 우주쓰레기 추적·감시 및 처리 를 위한 우주강국들의 노력이라는 토픽으로 요약되었다. 자연우주물체 관련 기사는 2개의 토픽으로 국제 우주기관의 근 지구소행성에 대한 추적·감시와 충돌 대책과 소행성과 혜성 충돌을 중심으로 공룡과 포유류의 진화 및 멸종 원인으로 요약되었다. 이로부터 2010년부터 현재까지 국내 언론은 우주위험을 사회, 문화 등 다양한 영역에서 총 8개의 주제로 대중들에게 그 위험성과 경각심을 전하는 역할을 하고 있음을 확인하였으며, 이러한 결과를 기반으로 우주위험에 대한 교육방법과 교육정책의 필요성을 제언하였다.

최근 들어 한반도에 중규모의 지진이 연속해서 발생함에 따라 중앙정부와 지방자치단체에서는 지진방재 대책을 새로이 마련하고 있다. 지진재해 분석에서 가장 핵심적인 정보는 지질과 지반정보로 여러 관계기관에서 관련자료를 수 집하고 DB를 구축하고 있다. 하지만, 실제 이러한 정보들을 지자체의 지진방재 대책 수립에 이용하고자 할 때는 여러 문제점이 발생하고 있다. 지질정보의 경우, 소축척 지질도는 개략적으로 표현이 되어 세부적인 특징을 보여주기가 어렵 고, 대축척 지질도는 도폭 간의 경계에서 암상이 불일치하거나 구조선의 연장이 불분명하다. 지반정보의 경우, 디지털화 가 이루어지지 않고 사장된 정보들이 다수 존재한다. 이러한 문제를 해결하기 위해 지진방재 대책의 기초단위인 지방자 치단체 단계에서의 지질·지반정보관리 정책방안을 제시하였다. 첫째, 이미 생산되었거나 생산될 지질정보와 지반정보를 보다 효율적이고 전문적으로 이용하기 위하여 산학연 기술연계 방안이 필요하다. 둘째, 많은 지질과 지반정보가 축적될 수 있도록 자치법규 제정 및 개정이 요구된다. 셋째, 지질·지반정보의 질적 향상을 위하여 전문가시스템 도입방안이 마 련되어야 한다. 넷째, 효율적인 정보의 관리를 위하여 전담부서 신설과 예산지원 확대가 필요하다.

This study aimed at elementary, middle, and high school dietitians who purchase ingredients for school meals. Therefore, for the study, the awareness and usage of nutritional information by 108 teachers and dieticians on 5 hazard-free meals using multivariate analysis of variance were investigated during May 18~21, 2021. Among the five questions that asked the general perceptions of school meal dietitians of 5 hazard-free meals, the perception that the “5 hazard-free foods can be easily distinguished” was the lowest. Problems were associated with using the 5 hazard-free meals such as “expensive price,” “no variety in items,” “disruption in the supply and demand,” “inconsistent quality,” and “lack of taste,” in that order. Therefore, to improve 5 hazard-free school meal service, it is necessary to not only lower the price burden by providing subsidies to schools but also improve the development and distribution structure of various 5 hazard-free foods.

The water supply facilities of Korea have achieved a rapid growth, along with the other social infrastructures consisting a city, due to the phenomenon of urbanization according to economic development. Meanwhile, the level of water supply service demanded by consumer is also steadily getting higher in keeping with economic growth. However, as an adverse effect of rapid growth, the quantity of aged water supply pipes are increasing rapidly, Bursts caused by pipe aging brought about an enormous economic loss of about 6,161 billion won as of 2019. These problems are not only worsening water supply management, also increasing the regional gap in water supply services. The purpose of this study is to classify hazard evaluation indicators and to rank the water distribution network hazard by cluster using the TOPSIS method. In conclusion, in this study, the entropy-based multi-criteria decision-making methods was applied to rank the hazard management of the water distribution network, and the hazard management ranking for each cluster according to the water supply conditions of the county-level municipalities was determined according to the evaluation indicators of water outage, water leakage, and pipe aging. As such, the hazard ranking method proposed in this study can consider various factors that can impede the tap water supply service in the water distribution network from a macroscopic point of view, and it can be reflected in evaluating the degree of hazard management of the water distribution network from a preventive point of view. Also, it can be utilized in the implementation of the maintenance plan and water distribution network management project considering the equity of water supply service and the stability of service supply.

Contemporary safety literature recognizes that error reporting - reporting of hazards, near-misses and incidents is important in the development of safety in high risk industries such as shipping - where the success of such reporting programs has been limited. Reporting is integral to the concept of “continuous improvement” as envisaged by the International Safety Management Code. However, shipping - like other industries - suffers from considerable under-reporting. At the same time, many Safety managers find positive correlation between numbers of such reports and shipboard safety, and to encourage reporting, many follow a mandatory reporting system. This study attempted to understand whether increasing numbers of submitted error reports does result in a consequent decrease in incidents/accidents, thereby validating this premise. The study was limited to the fleet of only one shipping company, and to the quantitative analysis of the error reports; not the content or quality of such reports. To achieve this, annual compiled error reports from across all fleet vessels of one shipping company were collected. This company had made a significant increase in the numbers of reports to be submitted by vessels in its fleet thereby presenting this opportunity. These reports were analyzed using Pearson correlation to determine any statistically significant correlations between numbers of hazards and near-misses reported, and recorded incidents/accidents. Analysis of the data showed that, from a quantitative point of view, the mandated increase in the number of reports did not result in a decrease in the numbers of near misses or incidents/accidents. It was concluded that merely increasing the number of reports may not improve safety performance, but may lead to the submission of reports just to meet requirements thereby devaluing the entire process. Companies should look at more effective ways through which the safety culture can be enhanced and improve on-board safety performance.