• Fire Science and Engineering
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• v.20 no.4 s.64
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• pp.98-104
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• 2006

The Fire Protection Regulatory documents require the fire-resistive rating of fire barrier penetration seals be same as that of fire barriers. Pilot application of penetration seal evaluation for K nuclear plant, built before penetration seal requirements were made, was done. In this evaluation, visual inspection and estimating fire rating by comparing installed configuration with tested configuration of penetration seals, called bounding approach method, were applied. Further improvements for retrofit and maintenance are recommended with penetration seal evaluation results also. The practical use of the methodology adopted in this study and the evaluation result of K nuclear plant will be anticipated for other plant's penetration seal evaluation.

• Journal of radiological science and technology
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• v.30 no.3
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• pp.213-219
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• 2007

The purpose of this study is to evaluate shielding effect of radiation protector for interventional radiologists in procedures by measuring inside and outside of radiation protector. In this study, we measured the radiation dose of 4 interventional radiologists during TACE and PTBD procedure for 4 month(2005.05-2005.09). Absorbed dose were measured by TLD placed underneath and over radiation protector such as Goggle, Thyroid protector, Apron and placed on the 4th finger of Hand. In addition, we measured background radiation dose in the control room using TLD. During TACE procedure, using 0.07 mmPb Goggle decreased average 53.8% of radiation dose rate in continuous fluoroscopic mode and decreased average 77.6% of radiation dose rate in pulse fluoroscopic mode. Using 0.5 mmPb Thyroid protector decreased average 88.9% of radiation dose rate in continuous fluoroscopic mode and decreased average 92.8% in pulse fluoroscopic mode. During PTBD procedure, using 0.07 mmPb Goggle decreased radiation dose rate average 62.7%, 87.9% by 0.5 mmPb Thyroid protector, 90.5% by 0.5 mmPb Apron. The average fluoroscopic time of PTBD was 6.14 min. shorter than TACE procedure, but radiation exposure dose rate of PTBD was 3 times higher in total body dose, and 40 times higher in hand dose rate than TACE. Interventional radiologists must wear thicker protector recommended over 0.5 mmPb. Also, they must use lead Goggle during interventional procedure. Abdomen dose decreased average 38.4% by drawing a lead curtain under the patient's table, therefore, they must draw a lead curtain to shield scattering ray. Radiation exposure dose decreased average 59.0% by using pulse fluoroscopic mode. So radiologists would better use pulse fluoroscopic mode than continuous fluoroscopic mode to decrease exposure dose.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.8
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• pp.1623-1631
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• 2016

There are many researches which analyze vulnerability for combat systems, have been progressing, and apply the analyzed result to reflect on design phase. Recently, there have been requirements for integrating the previous module based researches which conducted independently. In this paper, we propose an integrated vulnerability analysis method for the combat system considering characteristics of threats and protection performance of armors through an analysis of the advanced research. In addition, by applying the proposed method improves the existing hit probability analysis program and we are verified based on scenarios for improving survivability of PKM (Petrol Killer Medium) for vulnerability analysis confirmed the results. The proposed method improves reliability of vulnerability analysis by considering threats and defense ability. Also it able to satisfied with the integration requirements. Furthermore, we became buildup for the development of applied system and the method and integrated vulnerability analysis method for combat systems.

• Journal of Radiation Protection and Research
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• v.38 no.1
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• pp.1-9
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• 2013

Education and training is an important means of promoting safety culture and enhancing the level of competence of radiation worker in radiation protection. The existing international nuclear education and training of short duration has been carried out on the high-level officials and focussed on the classroom based training. The developing countries has been asking for support to cultivate their own technical experts to Korea which is a donor country exporting nuclear power plants. This paper summarizes the results of developing and operating the international education and training course to froster technical experts in radiation protection that emphasized practical training sessions and technical visits using the excellent domestic radiation facilities and infrastructure of education and training. It mentions the procedures of assessment and feedback as well. In an effort to maximize teaching-learning effects and to maintain consistency of the learning objectives, methods and assessment, SAT methodology has been applied on the processes of developing and operating the course. In the comparative and final assessment which were conducted at the beginning or at the end of training course, participants' average score increased around 2 points. The questionnaire of participants showed a high level of satisfaction of 4.0 points or above for the most of the questions. These imply teaching-learning methods applied to it might be effective. The teaching-learning methodologies may provide the opportunity to develop the customized training course for bringing up international technical experts and to shift educational paradigm from theory-oriented to on-site practice-based education.

• Journal of radiological science and technology
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• v.40 no.3
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• pp.453-460
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• 2017

This study proposes effective quality control and maintenance method by developing a new qualitative evaluation method of apron for medical radiation protection. As an experimental material, one of 0.45 mm lead and 100 of 0.45 mm Pb aprons were used and irradiated under the conditions of a tube voltage of 75 kVp and a tube current of 12.5 mAs to obtain an image. and using the Image J program, PSNR values were compared and analyzed. The results showed that there were 40 aprons (less than 11dB), 55 aprons (less than 11dB, less than 30dB), and 5 aprons (30dB or more). In addition, the dose showed a normal distribution for the apron, and 5 aprons with PSNR less than 11dB and 30dB or more were selected and divided into 8 zones, and these groups were statistically significant.

• Fire Science and Engineering
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• v.33 no.6
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• pp.43-52
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• 2019

A walk-down procedure for fire modeling of nuclear power plants, based on deterministic fire protection requirements, was developed. The walk-down procedure includes checking the locations of safety shutdown equipment and cables that are not correctly indicated on drawings and identifying the existence and location of combustibles and ignition sources. In order to verify the performance of the walk-down procedure developed in this study, a sample of important equipment and cables were selected for hypothetical multiple spurious operation (MSO) scenarios. In addition, the hypothetical fire modeling scenarios were derived from the selected safe shutdown equipment and cables and an actual walk-down was conducted. The plant information collected through the walk-down was compared to the information obtained from the drawings, so that the collected information may be used as input values for the fire modeling.

• Fire Science and Engineering
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• v.16 no.2
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• pp.59-69
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• 2002

The conventional fire extinguishing gas-agent system has a configuration in which the gas-agent comes out of a cylindrical container having vertically settled shape. However, in this study a horizontally installed container of a piping shape having a cylinder of the same shape with a cylinder valve and a discharge nozzle was used, and the relationship between orifice size of nozzle and discharge rate of gas-agent was investigated through various experiments including the measurement of discharge rate under different ambient-temperature conditions. In such experiments, HCFC Blend A was used without super-pressurization by nitrogen. From this research, it was observed that statutory discharge duration of 10 seconds can be met if the relatively large size of the valve and the nozzle orifice were properly selected.

• Journal of the Society of Disaster Information
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• v.11 no.2
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• pp.263-267
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• 2015

This study shows the result of the security assessment of the nationwide key energy facilities and suggests the ways of improving the security level. According to the study, most of the energy facilities are adequately equipped with physical security factors such as security personnel, security systems, fences, and guard posts, but lack of awareness is pervasive among those concerned, so the security operation is inefficient. In other words, inefficient deployment of security personnel, lack of the fundamental knowledge of the security systems, excessive dependence on surveillance cameras' functions such as Pan/Tilt/Zoom, misplaced cameras, low efficiency of monitoring, and irrelevant security plans. To solve these problems, above all, the authority concerned need to develop professional training programs to secure certified security mangers, and need to standardize security process to ensure consistency and to harness the standardization as a source of self assessment to improve security level.

• Journal of the Korea Society for Simulation
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• v.24 no.4
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• pp.59-68
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• 2015

In this paper, we proposed a methodology of vulnerability analysis for armored fighting vehicle based on modeling and simulation. The SES/MB framework serves hierarchical representation of the structure for a complex systems and is easy to conduct modeling for the armored fighting vehicle which consists of various components. When the armored fighting vehicle is hit by the shots from threat, the vulnerability of the armored fighting vehicle is decreased by damaged or penetrated level of armors and components. The penetration is determined by the result of comparing a penetration energy through penetration analysis equation and defence ability of armor and components. And the defence ability is determined in accordance with type and defined property of normal component and armor component, all components have a weighted values for the degree of importance. We developed a simulation program for verification proposed methodology. Thus, the program analyzes vulnerability for armored fighting vehicle SES/MB framework using importance.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.5
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• pp.102-113
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• 2021

The deterioration environments caused by de-icing salt and airborne chlorides in the seashore, evaluated in the "Detailed guideline for safety and management practice of facilities (performance evaluation)", were reviewed in terms of penetrated chlorides into concrete on various road facilities. Target concrete structures, in this study, were 4 concrete barriers in Gangwon area, 3 concrete barriers and 1 retaining wall in Busan area, and 4 bridges in Gangwon-do, Seoul, Gyeonggi-do, and Busan. The deterioration environments were classified into three categories: direct and indirect de-icing salt attack, and airborne salt attack depending on the distance to seashore and the height of pier, and the penetrated chlorides in to concrete were analyzed. The results showed that (1) the regional deterioration environments were clearly classified by de-icing salt sprayed days (snowfall days), (2) the penetrated chlorides increased significantly when leakage occurred through slabs or expansion joints, and (3) the airborne chlorides affected to a height of 20 m concrete in the seashore, Busan. From these, it could be confirmed that the chloride ion penetration properties depend on the exposed aging environment, member location and height, and deterioration status, even on the same structure, so the selection of target members and location is very important in the inspection and maintenance. If the database of penetrated chlorides properties in various deterioration environments is constructed, it is expected that the proactive durability management on concrete structures will be possible in the field.