• Ecology and Resilient Infrastructure
• /
• v.7 no.4
• /
• pp.294-299
• /
• 2020

Based on the combined results of field surveys and analyses of the road structure and traffic flow, we propose a new plan for reducing roadside non-point pollution in the Paldang Water Source Protection Zone. The results show that the soil surrounding the roads in Paldang is highly permeable, which mitigates the need for filtration facilities. Roads flanked by steep slopes are found to facilitate the reduction of non-point roadside pollution through vegetation and soils along road slopes without the need for pollution reduction facilities. These results highlight the need for a flexible roadside non-point pollution reduction plan for roadside non-point pollution, which can be tailored to compliment relevant regulations and design standards after analyzing the characteristics of the target road.

• Journal of Radiation Protection and Research
• /
• v.46 no.1
• /
• pp.1-7
• /
• 2021

Background: The use of computed tomography (CT) device has increased in the past few decades in Japan. Dose optimization is strongly required in pediatric CT examinations, since there is concern that an unreasonably excessive medical radiation exposure might increase the risk of brain cancer and leukemia. To accelerate the process of dose optimization, continual assessment of the dose levels in actual hospitals and medical facilities is necessary. This study presents organ dose estimation using pediatric cerebral CT scans in the Kyushu region, Japan in 2012 and the web-based calculator, WAZA-ARI (https://waza-ari.nirs.qst.go.jp). Materials and Methods: We collected actual patient information and CT scan parameters from hospitals and medical facilities with more than 200 beds that perform pediatric CT in the Kyushu region, Japan through a questionnaire survey. To estimate the actual organ dose (brain dose, bone marrow dose, thyroid dose, lens dose), we divided the pediatric population into five age groups (0, 1, 5, 10, 15) based on body size, and inputted CT scan parameters into WAZA-ARI. Results and Discussion: Organ doses for each age group were obtained using WAZA-ARI. The brain dose, thyroid dose, and lens dose were the highest in the Age 0 group among the age groups, and the bone marrow and thyroid doses tended to decrease with increasing age groups. All organ doses showed differences among facilities, and this tendency was remarkable in the young group, especially in the Age 0 group. This study confirmed a difference of more than 10-fold in organ doses depending on the facility and CT scan parameters, even when the same CT device was used in the same age group. Conclusion: This study indicated that organ doses varied widely by age group, and also suggested that CT scan parameters are not optimized for children in some hospitals and medical facilities.

• Fire Science and Engineering
• /
• v.33 no.6
• /
• pp.63-71
• /
• 2019

This study quantitatively analyzed the fire risk of buildings by use nationwide, fire occurrence, and the statistical data of buildings by use. Fire incidents and buildings' statistics from the past 10 years (2008-2017) were used and classified as "Building Laws" and "Enforcement Decree of the Act on the Installation, Maintenance, and Safety of Fire Facilities" to be used for the relative assessment under the Natural Breaks as a risk matrix. In addition, after conducting risk assessment using 2018 fire occurrence data, we compared and analyzed the same with past 10 years' data. The results showed that most facilities had similar risk grades, except for the results of reduced risk levels from IV to II in recreational facilities, confirming the past and present data correlations as valid. Hence, the classification method is deemed appropriate. Through the results, the fire risk assessment of buildings by use nationwide are presented as a reference for fire safety.

• Journal of Radiation Protection and Research
• /
• v.41 no.4
• /
• pp.409-417
• /
• 2016

Background: Airborne radioactive particulate in many important nuclear facilities (particularly nuclear power plants) will have a strong impact on the relative public dose if they are released into the corresponding environment traversing the stack or vents. The radiation protection researchers have regarded the relative environment assessing and estimation of public doses. And the model of assessing impact of discharges radioactive substance to the environment have been recommended by many international organizations (e.g. IAEA) with the nuclear energy safety and radiation protection. Materials and Methods: This paper introduced the generic models that were suggested by International Atomic Energy Agency (IAEA), for use in assessing the impact of discharges of radioactive substances to the environment (e.g. IAEA Safety Report Series No.19). Results and Discussion: The writers of this paper, based on the recommend methods, assessed the discharge limits in some airborne radioactive substances discharging standards. The reasons that IAEA method are introduced are mainly the following considerations: IAEA is one of international organizations with some authorities in the nuclear energy safety and radiation protection; and, more important, the recommend modes are operational methods rather than the methods having little operations such as that have used by some researchers. Conclusion: It is wish that the introduced methods in this paper can be referenced in draft or revise of the standards related to discharges of radioactive substances to the environment.

• Journal of Korean Society for Geospatial Information Science
• /
• v.24 no.1
• /
• pp.43-50
• /
• 2016

Urbanization in Korea has increased significantly and subsequently, various facilities have been concentrated in urban areas at high speed in accordance with a growing urban population. Accordingly, damages have occurred due to a variety of disasters. In particular, fire damage among the social disasters caused the most severe damage in urban areas along with traffic accidents. 44,432 cases of fire occurred in 2015 in Korea. Due to these accidents, 253 were killed and property damage of 4,50 billion won was generated. However, despite the efforts to reduce a variety of damage, fire danger still remains high. In this regard, this study collected fire data, generated from 2007 to 2014 through the Jinju Fire Department and the National Fire Data System(NFDS) and calculated fire risk by analyzing the clustering of fire cases and facilities in Jinju-si based on the current DB of facilities, offered by the Ministry of Government Administration and Home Affairs. As a result, the risk ratings of fire occurrence were classified as four stages under the standards of the US Society of Fire Protection Engineers(SEPE). Business facilities, entertainment facilities, and automobile facilities were classified as the highest A grade, detached houses, Apartment houses, education facilities, sales facilities, accommodation, set of facilities, medical facilities, industrial facilities, and life service facilities were classified as U grade, and other facilities were classified as EU grade. Finally, hazardous production facilities were classified as BEU grade, the lowest grade. In addition, in the case of setting the standard with loss of life, the highest risk facility was the hazardous production facilities, while in the case of setting the standard with property damage, a set of facilities and industrial facilities showed the highest risk. In this regard, this study is expected to be effectively utilized to establish the fire reduction measures against facilities, distributed in urban space by calculating risk grades regarding the generation frequency, casualties, and property damage, through the classification of fire, occurred in the city, according to the facilities.

• Journal of Advanced Marine Engineering and Technology
• /
• v.33 no.8
• /
• pp.1232-1238
• /
• 2009

As power facilities are getting higher at capacity, the monitoring and diagnosis of generators for fault detection and protection has attracted intensive interest. In case of an after-fault in high capacity rotating machines, the recovering cost is usually very expensive and additional time is necessary for returning in a normal situation. In this paper, we developed the protection program for the generator fault protection system and each module of the digital protective relay H/W for loading the protection program. The protective relay H/W was designed to have EMC characteristics for prohibiting from fault operation in bad power systems.

• Nuclear Engineering and Technology
• /
• v.52 no.8
• /
• pp.1661-1668
• /
• 2020

A physical protection system (PPS) is used for the protection of critical facilities. This paper proposes a structure analytic hierarchy approach (SAHA) for the hierarchical evaluation of the PPS effectiveness in critical infrastructure. SAHA is based on the traditional analysis methods "estimate of adversary sequence interruption, EASI". A community algorithm is used in the building of the SAHA model. SAHA is applied to cluster the associated protection elements for the topological design of complicated PPS with graphical vertexes equivalent to protection elements.

• Nuclear Engineering and Technology
• /
• v.34 no.3
• /
• pp.259-267
• /
• 2002

NFPA-803 has been referred as the Fire Protection Standard at the Nuclear Power Plants of Pressurized Water Reactor. This Standard has been used as the fire protection regulation, containing prescriptive requirements with deterministic methodology. Recently, with cumulative efforts by the U.S. Nuclear Regulatory Commission and Utilities in America to establish a new Standard, including a quantitative evaluation methodology, NFPA-805, the Performance-Based Standard for FIRE Protection for Light Water Reactor Electric Generating Plants was issued and approved by the American National Standards Institute as an American National Standard with an effective date of February 9, 2001. This paper presents an analysis result from the computer modeling for the fire simulation In addition, it proposes the idea that this kind of analytic method can be available for the facilities design of fire prevention and protection fields, as well as an evaluation for the fire suppression system with a quantitative analysis for the thermal phenomena in fire compartments in Nuclear Power Plants.

• Fire Science and Engineering
• /
• v.34 no.2
• /
• pp.22-29
• /
• 2020

In this study, the fire patterns, heat emissions, and smoke generated by means of fire tests developed for representative combustibles in residential facilities were analyzed from among seven fire types. These combustibles were selected in a previous study to simulate real-world situations and professionalism required while dealing with these types of fires and develop the field commander training content. Consequently, the maximum heat dissipation was recorded as 728.6 kW, followed by the dissipation measured from the combination of a mattress and electric blanket, desk and chair, and TV and mattress. The total heat emission of sofas (226.2 MJ) and the combination of mattress and electric blanket (2,259.5 ㎡) was recorded. In this study, the scope of the tests was limited to the fire characteristics and characteristics of the combustibles, and it is expected that a simulation using various data acquisition methods and FDS would be performed and evaluated at a later stage.

• Journal of the Korea Safety Management & Science
• /
• v.25 no.4
• /
• pp.95-104
• /
• 2023

The purpose of this study is to propose measures to increase evacuation safety by calculating the habitable time using a fire and evacuation simulation program for the Room-escape cafe currently in operation, and comparing and analyzing it with the evacuation required time. Assuming a fire due to overheating of electric heaters in use in front of the warehouse, the habitable time was calculated through fire simulation, and the occupant's evacuation time calculated through evacuation simulation according installation of safety facilities, etc. was compared and analyzed with the habitable time. In the case of escape room cafes with safety facilities installed, evacuation safety was satisfied, but in escape room cafes without safety facilities, the evacuation safety was not secure. As a result of analyzing evacuation safety for each scenario based on the ASET analyzed in the fire simulation, it was found that in scenario 1, evacuation safety was secured and everyone successfully evacuated, while in scenario 2, no one succeeded in evacuation. These results can be said to confirm that the installation of safety facilities is very important in business establishments such as escape room cafes, which become enclosed structures when games are started.