• 한국안전학회지
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• 제37권5호
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• pp.80-88
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• 2022

The Korean nuclear industry had developed the SPACE (Safety and Performance Analysis Code for nuclear power plants) code, which adopts a two-fluid, three-field model that is comprised of gas, continuous liquid and droplet fields and has the capability to simulate three-dimensional models. According to the revised law by the Nuclear Safety and Security Commission (NSSC) in Korea, the multiple failure accidents that must be considered for the accident management plan of a nuclear power plant was determined based on the lessons learned from the Fukushima accident. Generally, to improve the reliability of the calculation results of a safety analysis code, verification is required for the separate and integral effect experiments. Therefore, the goal of this work is to verify the calculation capability of the SPACE code for multiple failure accidents. For this purpose, an experiment was conducted to simulate a Control Element Drive Mechanism (CEDM) break with a safety injection failure using the ATLAS test facility, which is operated by Korea Atomic Energy Research Institute (KAERI). This experiment focused on the comparison between the experiment results and code calculation results to verify the performance of the SPACE code. The results of the overall system transient response using the SPACE code showed similar trends with the experimental results for parameters such as the system pressure, mass flow rate, and collapsed water level in component. In conclusion, it can be concluded that the SPACE code has sufficient capability to simulate a CEDM break with a safety injection failure accident.

• Nuclear Engineering and Technology
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• 제47권1호
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• pp.59-65
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• 2015

Background: After the Fukushima accident, the importance of hazard analysis for extreme external events was raised. Methods: To analyze typhoon-induced hazards, which are one of the significant disasters of East Asian countries, a statistical analysis using the extreme value theory, which is a method for estimating the annual exceedance frequency of a rare event, was conducted for an estimation of the occurrence intervals or hazard levels. For the four meteorological variables, maximum wind speed, instantaneous wind speed, hourly precipitation, and daily precipitation, the parameters of the predictive extreme value theory models were estimated. Results: The 100-year return levels for each variable were predicted using the developed models and compared with previously reported values. It was also found that there exist significant long-term climate changes of wind speed and precipitation. Conclusion: A fragility analysis should be conducted to ensure the safety levels of a nuclear power plant for high levels of wind speed and precipitation, which exceed the results of a previous analysis.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2013년도 춘계학술발표대회
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• pp.311-314
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• 2013

본 논문에서는 일본의 (주) 동경전력이 공개한 후쿠시마 제 1 원자력발전소 2 호기 원자로건물 지하에 위치한 S/C (Suppression Chamber) 주변의 Vent 관 조사 동영상들을 분석하였다. S/C 는 donut (환형) 모양의 구조물로 PCV (격납용기) 와 연결된 8 개의 Vent 관을 통해 원자로의 압력을 억제한다. 후쿠시마 사고 원자로의 용융 핵연료를 인출하기 위해서는 원자로 압력용기 및 PCV에 물을 채워서 방사선 선량율을 떨어뜨려야 한다. 물을 채운 후에 누설이 되면 안되기 때문에, PCV 와 S/C 사이에 연결된 Vent 관에 대한 방사능 오염수의 누설지점을 찾는 것이 중요하다. 이를 위한 사전공정으로 (주) 도시바의 4 족보행 로봇 탑재 카메라를 이용하여 8 개 Vent 관 모두를 육안 검사하였다. (주) 동경전력이 공개한 영상을 분석한 결과 고선량 감마선에 의한 Speckle 들이 관측되었다. 본 논문에서는 이러한 Speckle 분포의 특성을 분석하여 S/C 와 PCV 를 연결하는 8개 Vent 관중 방사능 오염물질이 많은 곳을 특정하고자 하였다.

• 한국방사선학회논문지
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• 제6권6호
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• pp.435-440
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• 2012

본 연구는 2011년 일본 후쿠시마 원자력 발전소 방사선 누출사고가 방사능 오염식품과 방사선 조사식품에 관한 유치원 부모의 인식에 미치는 영향을 분석하여 국민건강자료를 제공하는데 의의가 있다. 본 연구는 2012년 8월 J시의 K와 M유치원의 학부모 205명을 대상으로 설문지를 배부하여 회수된 178명의 자료를 분석하였다. 본 연구의 결과, 일본 원전사고는 방사능 오염식품에 대한 학부모의 불안감에 영향을 미쳤으며, 방사선조사 식품에 대한 부모들의 인식은 낮았다. 결론적으로 방사선조사 식품에 대한 유치원 부모들의 인식을 높이고, 방사능 오염식품과의 명확한 구분 및 올바른 인식을 돕는 적극적인 홍보와 부모교육이 이루어져야 할 것이다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.2902-2909
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• 2011

Regional torrential rains in summer this year due to abnormal climate changes compared to last year, have been frequent. Since Typhoon Rusa and Typhoon Maemi resulted in major damage to railroad facilities in 2002 and 2003 consecutively, problems with abnormal climate changes became a global problem including railroad and floods and droughts around the globe, heavy snow and winter warming have been repeated until now. Serious problem of radiation leakage in Fukushima nuclear power plant by the Tsunami due to 9.0-scale earthquake, this year in March, in northeastern Japan happened, and has given an impact on the life of Japanese citizens and industries and has also influenced on Korean. This shows how important to secure and to protect major national facilities including railroad structures to natural disasters such as earthquake. Therefore, we will briefly discuss about technologies for securing and protecting railroad structures to earthquakes, floods and other natural disasters.

• Journal of Contemporary Eastern Asia
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• 제12권2호
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• pp.5-17
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• 2013

This paper discusses the future of journalism, including social-media use. The findings within this paper are based on the results of the "Social Survey on Social Media Use in the Great East Japan Earthquake." The author conducted this Internet-based survey in June 2012, and the results discussed herein are based on a sample size of 1,000 persons. The main findings suggest that social-media use during and immediately following the March 11, 2011 earthquake in Japan has been developing in a mutually complementary manner with traditional media.

• 한국압력기기공학회 논문집
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• 제10권1호
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• pp.25-30
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• 2014

Korea Hydro & Nuclear Power Co.,LTD(KHNP) was strongly interested in promotion of employee's Safety Culture because it is needed to change the recognition of Safety Culture after the Fukushima accident and Kori-1 blackout event. So, KHNP developed the KHNP Safety Culture Definition, Principles and Attributes and shared them with all employees. By using them, Safety Culture Assessment for a site plant employees was carried out. Through the pilot Safety Culture Assessment in 2012, In 2013, it was expanded to 6 plants and various improvements had been obtained from that. KHNP has been developing a variety of training materials, Safety Culture posters, videos which was designed to give lessons about safety culture with a variety of event cases. And keep trying to form Safety Culture Circumstances In this study, statistic methods are used to verify the effectiveness of KHNP Safety Culture Principles and Safety Culture Assessment.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2019년도 추계학술대회
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• pp.211-212
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• 2019

후쿠시마 원전사고 이후, 오염수 방출등에 의한 해양오염문제가 크게 대두되고 있다. 본 논문은 해양환경 모니터링 센서 시스템 개발에 관한 연구에 관한 내용이다. 본 논문에서는 해양환경 모니터링을 위해서 실시간의 해상에서의 여러 가지 해양 오염원을 계측하고 이를 실시간으로 분석하여 관측센터로 전송하는 센서 및 통신 시스템에 관한 연구를 발표하고자 한다.

• Mycobiology
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• 제46권4호
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• pp.388-395
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• 2018

Radionuclides were deposited at forest areas in eastern parts of Japan following the Fukushima Daiichi Nuclear Power Plant incident in March 2011. Ectomycorrhizal (EM) fungi have important effects on radiocaesium dynamics in forest ecosystems. We examined the effect of colonization by the EM fungus Astraeus hygrometricus on the uptake of cesium (Cs) and potassium (K) by Pinus densiflora seedlings. Pine seedlings exhibited enhanced growth after the EM formation due to the colonization by A. hygrometricus. Additionally, the shoot Cs concentration increased after the EM formation when Cs was not added to the medium. This suggests that A. hygrometricus might be able to solubilize Cs fixed to soil particles. Moreover, the shoot K concentration increased significantly after the EM formation when Cs was added. However, there were no significant differences in the root K concentration between EM and non-EM seedlings. These results suggest that different mechanisms control the transfer of Cs and K from the root to the shoot of pine seedlings.

• International Journal of Safety
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• 제11권1호
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• pp.33-36
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• 2012

Examples and experiences of risk management on radiation under prolonged exposure situation are shown. The accident of the Fukushima dai-ichi nuclear power plant after the great east Japan earthquake (11 March, 2011) elevates background level of environmental radiation around the east Japan. For example, ambient dose equivalent rate around Tohkatsu area next to Tokyo located about 200 km-south from the plant, is about 0.1-0.6 micro-Sv $h^{-1}$ mainly due to $^{134}Cs$ and $^{137}Cs$ falling on the ground soil. This level is about double or up to ten times higher than the genuine natural level around the area. International Commission on Radiological Protection (ICRP) recommends how to face the existing exposure situation; that is the prolonged exposure situation. Referring to ICRP's reports and/or related international/domestic documents, we have been discussing and acting to gain public's safety and relief, who have a possibility to be exposed to prolonged lower-dose radiation. Here, we introduce our several experiences on risk management, especially focusing on risk communication, radiation education to public, and stakeholder involvements into making decision in local governments on radiation protection, relating to the accident.