PURPOSES : This study investigates the effects of three different three-color arrow traffic light operations on right-turn vehicles at intersections in Busan Metropolitan City. METHODS : Intersections in this study were categorized as general intersections (Type 1), intersections with right-turn pockets (Type 2), and intersections with scramble crosswalks (Type 3), and were investigated in terms of the efficiency (i.e., control delay) and safety (i.e., number of conflicts) of right-turn vehicles by employing VISSIM 2023 and SSAM3. RESULTS : From a mobility perspective (i.e., control delay), the protected/permitted operation outperformed the other two methods at the three types of intersections. The protected operation, similar to the results of the protected/permitted operation, was also superior to the permitted operation in terms of safety (i.e., number of conflicts). CONCLUSIONS : Protected/permitted operation has been proven to be a more efficient and safer measure than other operation methods for alleviating the problems of protected right-turn operation, which is currently implemented without three-color arrow traffic lights.

곧 다가올 미래에는 자율운항선박, 육상 원격제어센터에서 제어되는 선박, 그리고 항해사가 탑승하여 운항하는 선박이 함 께 공존하며 해상을 운항할 것이며, 이러한 상황이 도래했을 때 해상 교통 환경의 안전을 평가할 수 있는 방법이 필요할 것으로 사료 된다. 이에 본 연구에서는 자율운항기술을 사용하여 항해사가 직접 조종하는 선박과 자율운항선박이 공존하는 해상환경 하에서 선박 조종시뮬레이션을 통해 통항 안전성을 평가하기 위한 방안을 제시하였다. 자선은 6-자유도 운동 기반의 MMG 모델을 심층 강화학습 기법 중 하나인 PPO 알고리즘으로 학습하여 자율운항 기능을 갖출 수 있도록 설계하였다. 타선은 평가 대상 해역의 해상 교통 모델 링 자료로부터 선박이 생성되도록 하였고, 기 학습된 선박모델을 기반으로 자율운항 기능을 구현되도록 하였다. 그리고 해양기상 자 료 데이터베이스로부터 조위, 파랑, 조류, 바람에 대한 자료를 수집하여 수치 모델을 수립하고 이를 기반으로 해양기상 모델을 생성하 여 시뮬레이터 상에서 해양 기상이 재현되도록 설계하였다. 마지막으로 안전성 평가는 기존의 평가 방법을 그대로 유지하되, 선박조 종시뮬레이션에서 해상교통류 시뮬레이션을 통한 충돌 위험성 평가가 가능하도록 하는 시스템을 제안하였다.

The aim of this study is to ensure the structural integrity of a canister to be used in a dry storage system currently being developed in Korea. Based on burnup and cooling periods, the canister is designed with 24 bundles of spent nuclear fuel stored inside it. It is a cylindrical structure with a height of 4,890 mm, an internal diameter of 1,708 mm, and an inner length of 4,590 mm. The canister lid is fixed with multiple seals and welds to maintain its confinement boundary to prevent the leakage of radioactive waste. The canister is evaluated under different loads that may be generated under normal, off-normal, and accident conditions, and combinations of these loads are compared against the allowable stress thresholds to assess its structural integrity in accordance with NUREG-2215. The evaluation result shows that the stress intensities applied on the canister under normal, off-normal, and accident conditions are below the allowable stress thresholds, thus confirming its structural integrity.

A transfer cask serves as the container for transporting and handling canisters loaded with spent nuclear fuels from light water reactors. This study focuses on a cylindrical transfer cask, standing at 5,300 mm with an external diameter of 2,170 mm, featuring impact limiters on the top and bottom sides. The base of the cask body has an openable/closable lid for loading canisters with storage modules. The transfer cask houses a canister containing spent nuclear fuels from lightweight reactors, serving as the confinement boundary while the cask itself lacks the confinement structure. The objective of this study was to conduct a structural analysis evaluation of the transfer cask, currently under development in Korea, ensuring its safety. This evaluation encompasses analyses of loads under normal, off-normal, and accident conditions, adhering to NUREG-2215. Structural integrity was assessed by comparing combined results for each load against stress limits. The results confirm that the transfer cask meets stress limits across normal, off-normal, and accident conditions, establishing its structural safety.

PURPOSES : This study evaluates the effectiveness of traffic flow optimization when giving safety strategy guidance to a connected autonomous vehicle (CAV) based on information received through infrastructure cooperation in a V2X environment for non-signal intersection. METHODS : To evaluate the effectiveness of safety strategy guidance based on developed traffic flow control algorithm at a non-signalized intersection, it was implemented on simulation. A scenario based on the Level of Service (LOS) and the market penetration rate(MPR) of autonomous vehicles was established. The simulation results were divided into safety, operation, and environment to evaluate the effect, and the effect of optimizing traffic flow was finally derived through the integrated evaluation score. RESULTS : As a result, when safety strategy guidance was provided, the number of conflicts and CO emissions decreased by about 29% and about 15%, improving safety and environmental performance. In the case of operation, the mean of delay time was increased overall by 1%, but in the case of MPR 50 and above, the delay time was reduced by about 38%, thereby increasing operation. Finally, the aspect of traffic flow optimization, effectiveness of safety strategy guidance was derived through the integrated evaluation score, and the average integrated evaluation score improved from MPR 20 or higher. CONCLUSIONS : Providing guidance had the effect of optimizing traffic flow at a non-signal intersection. In the future, V2X communications will provide CAV with algorithm-based guidance developed in this study to control driving behavior. it will support safe and efficient driving at non-signal intersections.

Human and material damage can be reduced if the risk is evaluated by engineering analysis of fire combustion products, smoke concentration, and smoke movement speed in the event of a fire in apartment houses and officetels. In this study, a lot of research on related safety evaluation in the basement needs to be studied and reflected in design, so experimental research was conducted to analyze the flow of smoke through computer simulation and provide analysis data through evacuation safety evaluation. First of all, the five-story underground parking lot subject to simulation has a large floor area, which is advantageous for improving evacuation safety performance, but it uses temperature detectors to increase detection time and fire spread speed. Second, it was analyzed that the evacuation time at all evacuation ports did not exceed the evacuation time, and as the time from the start of evacuation to the evacuation time was 216.9% compared to the travel time, it was evaluated that the safety performance of the evacuation was secured. Third, the above simulation results are a comprehensive safety evaluation based on the non-operation of fire extinguishing facilities in the fire room to increase safety, which means that smoother evacuation safety performance can be secured by linking fire extinguishing facilities.

The operation time of a disposal repository is generally more than one hundred years except for the institutional control phase. The structural integrity of a repository can be regarded as one of the most important research issues from the perspective of a long-term performance assessment, which is closely related to the public acceptance with regard to the nuclear safety. The objective of this study is to suggest the methodology for quantitative evaluation of structural integrity in a nuclear waste repository based on the adaptive artificial intelligence (AI), fractal theory, and acoustic emission (AE) monitoring. Here, adaptive AI means that the advanced AI model trained additionally based on the expert’s decision, engineering & field scale tests, numerical studies etc. in addition to the lab. test. In the process of a methodology development, AE source location, wave attenuation, the maximum AE energy and crack type classification were subsequently studied from the various lab. tests and Mazars damage model. The developed methodology for structural integrity was also applied to engineering scale concrete block (1.3 m × 1.3 m × 1.3 m) by artificial crack generation using a plate jacking method (up to 30 MPa) in KURT (KAERI Underground Research Tunnel). The concrete recipe used in engineering scale test was same as that of Gyeongju low & intermediate level waste repository. From this study, the reliability for AE crack source location, crack type classification, and damage assessment increased and all the processes for the technology development were verified from the Korea Testing Laboratory (KTL) in 2022.

본 연구에서는 첫째, 국제표준에서 규정한 형광직물과 재귀반사 소재에, 아동들이 선호하는 동물의 문양을 재귀반 사 필름과 검정색 직물로 디자인하여 부착한, 2벌의 안전의복과 안전조끼를 제작하였다. 둘째, 야간에 주변광원이 없어도 원거리에서 생체를 인지할 수 있도록 안전의복에 스마트 포토닉 디바이스를 장착함으로써, 어린이들이 어두 운 때 버튼 원터치만으로 상황에 따라 3가지 발광이 가능하도록 구현하였다. 제작한 스마트 안전의복을 마네킹에 착용시켜 주야간의 시인성을 비교한 결과, 시인성의 차이가 야간에 확연히 나타났는데, 기존의 안전의복 착용 시에 는 주변광원 없이는 착용자가 표출되지 않은 반면, 스마트 안전의복 착용 시는 약 70m의 원거리에서도 표출됨을 확인하였다. 따라서 야간이나 기상악화 시에 주행하는 운전자가 원거리에서 생체를 인지할 수 있어 교통사고나 도로상의 안전사고 예방에 기여할 것으로 기대된다. 셋째, 광섬유의 발광기능 안정성 유지와 발광시간의 연장을 위하여 에너지 소진 시 태양전지로 수확한 전기에너지를 사용함으로써, 장시간 안정되게 광섬유 발광이 가능하여 시인성의 안정성을 확인할 수 있었다. 이로써 스마트 포토닉 안전의복은 야간 작업자용으로도 활용 가능함이 증명되었다. 그 러므로 광섬유 안전의복은 태양전지에 의한 에너지 하베스팅 적용으로 안정적인 충전에 의해 실생활뿐만 아니라 어 두운 산업현장에서도 착용 가능성이 높을 것으로 기대된다.

본 연구는 광주 내 대형마트와 온라인 마켓에서 영유아 를 대상으로 판매하는 과자류 80건 및 음료류 40건의 식 품첨가물(타르색소, 인공감미료), 곰팡이독소 및 영양성분 (자당, 무기질)을 분석하였다. 유아용 표시 식품의 기준 및 규격이 불검출로 설정된 타르색소와 사카린나트륨은 모든 시료에서 검출되지 않았다. 과자류(기타가공품) 1건에서 인공감미료인 아세설팜 칼륨이 0.07 g/kg 검출되었으나 이 는 식품첨가물의 기준 및 규격에서 정한 허용 기준치 이 하였다. 곰팡이독소는 아플라톡신 및 오크라톡신 A는 검 출되지 않았으며, 푸모니신 B1, B2 및 제랄레논이 각각 과자류에서 14건(9.78-78.94 μg/kg), 6건(5.58-11.73 μg/kg) 및 9건(2.96-8.83 μg/kg) 검출되었다. 푸모니신에 대한 기 준·규격은 따로 설정되어 있지 않았으나 타 연구 결과와 비교했을 때 비슷한 수준이었으며, 제랄레논은 식품 일반 에 대한 공통 기준·규격 이내로 확인되었다. 자당은 과자 류에서 65건(0.02-40.94 g/내용량(g)), 음료류에서 24건(0.12- 27.60 g/내용량(g)) 검출되었으나 식품유형간 유의적인 차 이는 없었으며, 타 연구 결과와 비교했을 때 그 함량도 적 은 편이었다. 다만, 검출 시료 89건 중 1건을 제외하고는 모두 1일 영양성분 기준치를 성인 기준으로 표시하고 있 었기 때문에 제품 구입 시 영유아 기준으로 오인될 우려 가 있다. 무기질은 대부분의 시료에서 검출되었으며 과자 류 중 4건의 시료에서 내용량 당 아연 함량이 상한섭취량 (1-2세: 6 mg/일, 3-5세: 9 mg/일)을 초과하는 수준이었다. 아연 강화식품이나 보충제의 과다 섭취가 인체의 유해성 을 보인다는 다수의 보고가 있으므로 섭취시 유의할 필요 가 있다. 나트륨은 과자류 80건 중 16건이 영유아용 표시 식품의 기준을 초과하였으나 모두 품목제조보고서상 영유 아 섭취 대상 식품으로 표시하지 않아 해당 기준을 적용 할 수 없었다. 따라서 영유아용 표시 식품의 기준·규격을 설정과 함께 현재 시행되는 기준·규격이 알맞게 적용될 수 있도록 표시 기준 강화 등의 제도적 개선이 필요할 것으 로 보인다.

This study aimed to verify the validity of the evaluation items and weight determination of the indoor environmental safety area, which has the most frequent accidents, among the safety certification evaluations of educational facilities by the Ministry of Education of the Republic of Korea, which has been conducted since May 2021. As a preceding study, the evaluation items of the school safety evaluation checklist being implemented in the US state of Vermont were compared, and the causes of accidents judged by teachers in the accident experiences written by 200 Korean teachers were compared with the safety certification evaluation items belonged to the Ministry of Education. In addition, research literature using the AHP analysis technique on safety risks of elementary and secondary schools in China and safety evaluation index study cases of 539 elementary school children in Indonesia were analyzed. Through these preceding studies, measures to add and adjust evaluation items were derived and the validity and importance rankings of evaluation items were calculated through AHP questionnaires to teachers and safety experts. In addition, a survey was conducted on 104 ordinary people to verify the results of expert analysis. As a result of expert AHP analysis, 'safety education and disaster response training (.396)' was the highest priority for the relative importance of the first layer, followed by 'safety measures (.387)' and 'building materials'. Safety (.216)' was found to be the highest priority. In the overall importance ranking of the 13 second-tier screening items, safety accident prevention education had the highest priority and disaster preparedness training ranked second, proving that the Ministry of Education's review weight was underestimated. In addition, slip and collision accident countermeasures, which were not in the existing Ministry of Education review items, ranked 4th, laboratory practice room safety measures ranked 6th, and sanitation, cleanliness, hazardous substance management, and cafeteria/cooking room safety measures ranked 9th, indicating a significant level of importance. Referring to the importance ranking, which is the result of this study, it is suggested that it is necessary to review the weight of each review item again.

Decommissioning plan of nuclear facilities require the radiological characterizations and the establishment of a decommissioning process that can ensure the safety and efficiency of the decommissioning workers. By utilizing the rapidly developed ICT technology, we have developed a technology that can acquire, analyze, and deliver information from the decommissioning work area to ensure the safety of decommissioning workers, optimize the decommissioning process, and actively respond to various decommissioning situations. The established a surveillance system that monitors nuclide inventory and radiation dose distribution at dismantling work area in real time and wireless transmits data for evaluation. Developed an evaluation program based on an evaluation model for optimizing the dismantling process by linking real-time measurement information. We developed a technology that can detect the location of dismantling workers in real time using stereovision cameras and artificial intelligence technology. The developed technology can be used for safety evaluation of dismantling workers and process optimization evaluation by linking the radionuclides inventory and dose distribution in dismantling work space of decommissioning nuclear power plant in the future.

Fault activity acts as the greatest risk factor in relation to the stability of the radioactive waste disposal facilities and nuclear power plant site, and for this reason, geological studies on areas with past fault activity history must precede site evaluation studies. This study aims to trace the fault activity history of large fault zones, including the Yangsan fault in the southeastern part of the Korean Peninsula, where two major earthquakes occurred, and to obtain fault activity direction information that is the basis for stability evaluation. The 3D-Shape Preferred Orientation (SPO) of particles in the fault rock created by the earthquake was investigated to analyze the direction of fault plane activity, and the age of fault activity was estimated through Illite Age Analysis (IAA) analysis. It is expected that the large-scale fault activity information in the southeastern part of the Korean Peninsula obtained through the SPO and IAA analysis can be used as basic data for safety evaluation of existing or future nuclear power plants and radioactive waste facilities.