• Journal of Korean Society of Disaster and Security
• /
• v.16 no.4
• /
• pp.137-145
• /
• 2023

Accidents involving deaths of children and pedestrians continue to occur in child protection zones, also known as school zones. Over the three years from 2019 to 2021, 11 child deaths occurred in school zones in Korea. In December 2022, a fatal accident occurred among an elementary school student in a school zone near an elementary school in Gangnam-gu, Seoul. In April 2023, an accident occurred in which an elementary school student died in a school zone near Seo-gu Middle School in Daejeon and an elementary school in Yeongdo-gu, Busan. Until recently, child deaths continued to occur on sidewalks in child protection zones. It is time to closely review the status of safety facilities installed in school zones and related regulations. We investigated and analyzed the current status of safety facilities and related regulations installed on sidewalks in child protection zones in Korea, and identified matters necessary for institutional improvement regarding safety facilities for sidewalks in child protection zones.

• Nuclear Engineering and Technology
• /
• v.38 no.6
• /
• pp.489-504
• /
• 2006

A review has been made for the previous studies on safety of a geologic repository for high-level radioactive wastes (HLW) related to autocatalytic criticality phenomena with positive reactivity feedback. Neutronic studies on geometric and materials configuration consisting of rock, water and thermally fissile materials and the radionuclide migration and accumulation studies were performed previously for the Yucca Mountain Repository and a hypothetical water-saturated repository for vitrified HLW. In either case, it was concluded that it would be highly unlikely for an autocatalytic criticality event to happen at a geologic repository. Remaining scenarios can be avoided by careful selection of a repository site, engineered-barrier design and conditioning of solidified HLW. Thus, criticality safety should be properly addressed in regulations and site selection criteria. The models developed for radiological safety assessment to obtain conservatively overestimated exposure dose rates to the public may not be used directly for the criticality safety assessment, where accumulated fissile materials mass needs to be conservatively overestimated. The models for criticality safety also require more careful treatment of geometry and heterogeneity in transport paths because a minimum critical mass is sensitive to geometry of fissile materials accumulation.

• Journal of the Korean Society of Safety
• /
• v.20 no.2 s.70
• /
• pp.1-5
• /
• 2005

An experimental study was conducted to develop an understanding of failure of ceramic coating when subjected to a thermal cycling. Number of cycles to failure were decreased as the coating thickness and the oxide of bond coat were increased. Using the finite element method, an analysis of stress distribution in ceramic coatings was performed. Radial compressive stress was increased in the top/bond coat interface with increasing coating thickness and oxide of bond coat.

• Proceedings of the Korean Institute of Industrial Safety Conference
• /
• 1998.11a
• /
• pp.47-52
• /
• 1998

최근에 세라믹-금속 접합, 열차폐코팅(Thermal Barrier Coating), 마모저항코팅등 이종재료접합의 이용이 급증하고 있다. 열차폐코팅의 경우, 고온환경쪽에 세라믹을 배치하여 내열성을 부여하고, 냉각환경쪽은 금속재료를 사용하여 열전도성과 기계적 강도를 부여한다. 이 때 두 재료의 경계부에서는 열적, 기계적 특성 차이로 인하여 제조과정이나 사용중에 열적, 기계적 부하에 의하여 내부잔류응력이 생기게 되며, 이는 재료의 강도, 파괴특성에 많은 영향을 미치기 때문에 잔류응력의 감소기술이 중요시되고 있다. (중략)

• Journal of Auto-vehicle Safety Association
• /
• v.8 no.2
• /
• pp.11-16
• /
• 2016

The objective of this study was to construct the spring-mass models for the car-to-car offset frontal impact crash. The SISAME software was utilized to extract the spring-mass models using the data from the offset frontal crash test. The spring-mass model of the passenger car could effectively approximate the crash characteristics for the offset frontal barrier impact and the car-to-car offset frontal impact scenarios.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.13 no.1
• /
• pp.73-86
• /
• 2015

The use of complimentary indicators, other than radiation dose and risk, to assess the safety of radioactive waste disposal has been discussed in a number of publications for providing the reasonable assurance of disposal safety and convincing the public audience. In this study, the radionuclide flux was selected as performance indicator to appraise the performance of engineered barriers and natural barrier in the Wolsong low- and intermediate-level waste disposal facility. Radionuclide flux showing the retention capability by each compartment of the disposal system is independent of assumptions in biosphere model and exposure pathways. The scenario considered as the normal scenario of disposal facility has been divided into intact or degraded silo concrete conditions. In the intact silo concrete, the radionuclide flux has been assessed with respect to the radionuclide retardation performance of each engineered barrier. In the degraded silo concrete, the radionuclide flux has been explored based on the performance degradation of engineered barriers and the relative significance of natural barrier quantitatively. The results can be used to optimally design the near-surface disposal facility being planned as the second project phase. In the future, additional complimentary indicators will be employed for strengthening the safety case for improving the public acceptance of low- and intermediate-level waste disposal facility.

• Tunnel and Underground Space
• /
• v.17 no.6
• /
• pp.464-474
• /
• 2007

An enhancement in the performance and safety of a high-level waste repository requires a validation of its engineered barrier. An engineering-scale test (named "KENTEX") has been conducted to investigate the thermal-hydro-mechanical behaviors in the engineered barrier of the Korean reference disposal system The validation test started on May 31, 2005 and is still under operation. The experimental data obtained allowed a preliminary and qualitative interpretation of the thermal-hydro-mechanical behaviors in the bentonite blocks. The temperature was higher as it became closer to the heater, while it became lower as it was farther away from the heater. The water content had a higher value in the part close to the hydration surface than that in the heater part. The relative humidity data suggested that a hydration of the bentonite blocks might occur by different drying-wetting processes, depending on their position. The total pressure was continuously increased by the evolution of the saturation front in the bentonite blocks and thereby the swelling pressure. Near the heater region, there was also a significant contribution of the thermal expansion of bentonite and the vapor pressure in the pores of the bentonite blocks.

• Journal of the Korean Society of Industry Convergence
• /
• v.27 no.1
• /
• pp.207-212
• /
• 2024

Recently, with the strengthening of environmental regulations, there has been an increasing interest in eco-friendly energy sources, leading to a trend of the increasing scale of Cargo Containment Systems (CCS) for Liquefied Natural Gas (LNG) carriers. Among these systems, membrane tanks have gained popularity in LNG transport vessels due to their superior spatial utilization and competitiveness. However, due to high initial investment costs and the difficulty in repair in case of damage, a safety layer, the secondary barrier, must be installed without fail. In this study, in order to apply a new secondary barrier to the existing membrane-type LNG CCS, tests were conducted on the fiberglass layer previously used in the Triplex-Flexible Secondary Barrier (FSB), substituting it with basalt fiber. Tensile and vertical tensile tests were performed to assess the newly applied material. Environmental tests were conducted at room temperature (25℃) and extremely low temperatures (-170℃), considering the temperatures to which substances may be exposed during LNG vessel operations. The basalt-FSB produced in this study demonstrated superior results compared to the specifications of the existing product, confirming its potential applicability for implementation.

• 한국도로학회:학술대회논문집
• /
• 2009.11a
• /
• pp.441-446
• /
• 2009

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2000.11a
• /
• pp.563-566
• /
• 2000

Recently vehicle development trend puts emphasis on cost reduction and performance improvement through weight reduction, and safety security to protect passenger and chassis against external impact. Primary factors effected on vehicle safety are chassis structure, chassis system, and safety equipment like bumper. Research in part of weight reduction is proceeding actively about prohibition of over-design and material through optimal design method. Bumper in these factors is demanded two of all factors, safety security and weight reduction. It is the part that prohibits or reduces a physical impact in low speed crash. Bumper is composed of a few parts but this study exhibits the shape of bumper rail has a role on energy absorption of safety security and weight reduction from structure analysis of bumper rail's variable shape surface.