• Journal of Radiation Protection and Research
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• v.36 no.3
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• pp.154-159
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• 2011

To evaluate the radiation exposure of workers participating in task where high radiation exposure is expected, two-dosimeter is typically provided radiation workers, one on the chest and the other on the back, at Korean nuclear power plants (NPPs). In a previous study, the NCRP (55:50) algorithm was selected as the optimal two-dosimeter algorithm (TDA) with various field tests and this TDA has been applied to all Korean NPPs since 2006. In 2007, the International Commission on Radiological Protection (ICRP) published the new ICRP recommendation, ICRP 103, which provides the revised weighting factors for both radiation and tissues and the new reference phantom. In this study, the applicability of current NCRP (55:50) algorithm at Korean NPPs for ICRP 103 was analyzed. As a result, it was found that the NCRP (55:50) algorithm is still effective to estimate the effective dose of workers under ICRP 103.

• Journal of the Society of Disaster Information
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• v.10 no.1
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• pp.91-97
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• 2014

purpose of this study was to conduct status survey on existing shelter facilities for residents and use it as basic material to plan and design improved shelter facilities in the future. As the result, first, although existing shelter facilities are judged to have been designed in consideration only of the protection from high explosive shells, actual protection capability is significantly low against high explosive shells when exit direction and protection capabilities of main entrances were investigated. Second, all the 7 facilities did not have air purifier with filters installed for the air that flows into the inside from outside and since the height of air exhausts and intake pipes in the outside are also close to the earth, there are possibilities that heavy contaminated air can flow into the inside. Third, although some facilities have anti-explosion doors installed, it is impossible to use them as chemical, biological and radiological (CBR) shelter because of improper installation of openings and anti-explosion valves as well as poor plumbing that cannot ensure air-tightness and poor finish of piping penetration.

• Journal of the Korean Society of Radiology
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• v.11 no.7
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• pp.555-564
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• 2017

The current radiation risk assessment for occupational exposure is based on the measured exposure dose and health checkups of workers. This people-centered risk assessment may occur errors because absence of using personal dosimeter or unrelated health symptoms of individuals lead to difficulties in obtaining accurate data from workers. In addition, although the established legal upper dose limit was used as a reference for the assessment, it does not imply that this limit is the optimal dose of radiation workers should get; ALARA principle should always be appreciated. Therefore, a new risk assessment model that can take account of all the important factors and implement optimization of radiation protection is required at the national level. In this paper, based on the KOSHA Risk Assessment, we studied on the workplace-centered risk assessment model for radiation field rather than the people-centered. The result of the study derived a right model for radiation field through the analysis of the risk assessment methods in various fields and also found data acquisition methods and procedures for applying to the model. Multidimensional model centering on the workplace will enables more accurate radiation risk assessment by using a risk index and radar plot, and consequently contribute to the efficient worker management, preemptive worker protection and implementation of optimization of radiation protection.

• 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.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.7
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• pp.417-422
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• 2017

One of the most frightening aspects of weapons of mass destruction (WMD) is their ability to cause death in very small quantities without being visible to the public. The military authorities are making considerable effort to ensure the survivability of the combatants in the event of NBC(Nuclear, Biological and Chemical) contamination. Therefore, in this study, modules were developed for the measurement of the positive pressure and for the detection of the chemicals used for the control of the various shut-off valves used in an NBC shelter. In addition, a high performance gas tight shut-off valve was developed that can overcome the disadvantages associated with manual manufacturing, such as the occurrence of defective products and high manufacturing cost. By applying the positive pressure measurement and chemical detection modules, this valve was able to be used to control the facility. The developed gas-tight shut-off valve maintained airtight characteristics at a pressure loss of 28[Pa] at the prescribed wind velocity and an internal pressure of 30[kPa]. It is expected to be possible to control the gas-tight shut-off valve through the remote measurement of the positive pressure, thereby ensuring the foreign independence of import substitution and defense related technology in the future. In addition, by installing these valves in all of the intake ports or exhaust ports connected to the outside of the NBC shelter, it is possible to prevent the damage resulting from the rapid inflow of the storm pressure caused by conventional weapons and nuclear explosions, thereby protecting the people and equipment in the shelter.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.6
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• pp.895-906
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• 2018

The improvement project for school zone in Korea is occurring mostly in kindergartens and elementary schools in which children are mainly active, and is being promoted as part of measures to prevent children's traffic accidents. However, since the study on the essential installation facilities and proper level of safety facilities for School zone is lacking, this study relatively evaluated the efficiency of safety facility installation using DEA (Data Envelope Analysis) and suggested improvement plan. We built the facilities and incident data for 28 school zones in Hwaseong City. Six major facilities (Raised intersection, Raised crosswalk, Protective fence, Skid Proof, Speed hump, Speed cameras) that have proven to be effective in the preceding research were analyzed as input factors. As a result of the analysis, only 12 out of 28 showed efficiency and 16 out of efficiency. Effective groups of school zones were found to have fewer installed Protective fences, Skid Proof, and Speed cameras installations than school zones classified as ineffective groups. Protective fences were found to be efficient even if only 47% of the total extension of the school zone was installed, and the number of slip prevention facilities was 8.7 per square km. The number of subjects to be compared is 28, so this study is limited to use as a relative efficiency evaluation index, and it can be grouped into nationwide units and efficiency evaluation can be done for each group.

• Nuclear industry
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• v.35 no.9
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• pp.46-52
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• 2015

1975년 우라늄협회로 출발한 세계원자력협회(WNA)는 원자력을 평화적으로 이용하는 것을 적극 지원하고, 원자력 발전과 핵연료주기 전반에 걸친 원자력 산업 발전을 위하고자 설립한 세계적 민간 기구로, 우라늄 채광부터 변환, 농축, 핵연료 제조, 원자력발전 운영, 기자재(설비) 제작 및 사용후핵연료 처분에 이르기까지 원자력발전의 전 주기 산업을 촉진하고 관련 정보를 지원하고 있다. 2001년 지금의 명칭으로 변경한 WNA는 전 세계 원자력산업체와 원자력 관련 기관, 대학 등 175개 회원사를 두고 상호 협력과 전문 인력 교육 기반 강화, 국제화에 적극 나서고 있으며, 원자력산업 정보 제공과 교환을 위해 관련 보고서와 자료도 수시로 발행하고 있다. 2013년부터 WNA를 이끌고 있는 아그네타 라이징 사무총장은 지난 11월 영국 런던 소재 WNA를 방문한 <원자력신문>과의 인터뷰를 통해, 원전과 주변지역 주민의 갑상선암 발병에 대한 인과 관계에 대하여 "갑상선암 발병이 원전과 연관성 있다는 주장은 과학적 근거가 없다"고 단호히 말하고, "한국과 유사한 사례가 해외 원자력계(과학계)와 의학계에 보고된 적이 있냐"는 질문에 "해외에서 정상 운영되고 있는 원전 시설은 국제방사선방호위원회(ICRP)의 엄격한 기준(ICRP-60)이 적용하고 있으며, 방사선 방호와 관련된 연구보고서(논문)를 꾸준히 내고 있지만 원전 주변 주민에 대한 여러 역학 조사에서도 갑상선암이 증가했다는 사례는 보고된 바 없다"고 말했다. 또한 "실제로 일본 원폭 생존자 연구와 체르노빌 원전 주변 주민 연구에 의하면 20세 이상의 성인에서 방사선 노출에 의해 갑상선암이 증가한다는 증거는 없었다."면서 "체르노빌 사고와 후쿠시마 원전 사고 이후 방사선 누출로 인해 방사선이 갑상선암의 발생률을 증가시키는 것으로 알려졌지만 실제로 원전에서 발생하는 방사능은 갑상선암을 유발시킬 수 있는 양에 비해 아주 적다. 그럼에도 원전 시설에서 나오는 방사능 수치에 대해 제대로 밝히는 기관이 없기 때문에 원전 주변에 살아도 영향을 받는 것으로 오해할 수 있다."고 덧붙였다. 아그네타 라이징 사무총장은 스웨덴 출신의 방사선 방호 전문가로, 스웨덴 국영기업 Vattenfall AB 그룹에서 원자력 에너지 환경 분야 최고 전문가로 활동했으며, 스웨덴원자력학회, 유럽원자력학회, 세계여성원자력전문인회(WiN-Global) 회장 등을 역임했다. 인터뷰 전문을 게재한다.

• Fire Science and Engineering
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• v.27 no.3
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• pp.8-13
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• 2013

In case of fire in a high-rise building fire can be easily spread along the building external walls dramatically if the flame comes out through broken windows. There are a few effective methods to prevent the fire spread at the moment. One is using a fire resistance window, and the other is using a window sprinkler that discharges water to resist flame in case of fire. In this study a window sprinkler which is installed on top of windows and prevents fire by discharging water when its heat-responsive element opens was tested using a large scale furnace in accordance with the standard temperature-time graph. Test result showed that one window sprinkler was able to protect a 2,400 mm wide window from fire for 2 hours and the window backside's temperature locally increased up to $126^{\circ}C$ but kept stable around $100^{\circ}C$ for the test duration.

• Journal of radiological science and technology
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• v.28 no.4
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• pp.333-340
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• 2005

In this study, the radioprotective effects of Grifola umbellata hot water extracts (Gu-extract) on mice were investigated. Single pre-administration of Gu-extract increased the 40-day survival ratio of irradiated mice from 65.5％ to 78.6％. The growth of 3 week old male mice in the irradiated group was slightly retarded as compared to those of the control and Gu-extract treated mice. The average spleen and thymus weights of the irradiated mice were lower than those of the control and Gu-extract treated mice. The weight reduction of testis in the irradiated mice was significant. While it was relatively slight in the Gu-extract treated mice as compared to that of control mice. No significant difference in the weight was observed in heart, kidney or liver among three groups. The leukocytes of the Gu-extract treated mice did not decrease dramatically as in the irradiated group, but recovery patterns were similar in both groups. Reduction of erythrocytes were similar in both groups but its recovery occurred more rapidly in the extract treated group. The glucose level of the Gu-extract treated group did not change during the period examined, while it was still higher in the irradiated group than the level in the control group in two weeks. The cholesterol levels in the irradiated and the Gu-extract treated groups were higher than that of control group on day 7, but decreased to the level of the control group on day 14. No difference was observed in total protein amount of the serum among the three groups. SDS-polyacrylamide gel electrophoresis of the soluble proteins extracted from various organs did not reveal differences to any extent in all groups except in the livers of the irradiated and extract treated groups, in which some proteins were missing or less present.

• 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.