• 센서학회지
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• 제22권1호
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• pp.71-75
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• 2013

Nuclear containment building is used as second blockage to protect us from a radiation leakage caused by the natural disaster or any accidents, so it's safety is important and must be kept with continuous surveillance. In this study, we measured the strain of a nuclear containment building's wall by using FBG sensor and investigated the structural safety of a nuclear containment building. 50 FBG strain sensors and 18 FBG strain sensors were attached on the side wall and upper dome of a nuclear containment building, respectively. We measured the strains of the outside concrete wall during the Structural Integrity Test (SIT) of a nuclear containment building. The strain of an upper dome was larger than that of a side wall, about $200{\mu}{\varepsilon}$. And the very small strain was measured at vertical direction of a side wall. These experimental results were used to evaluate the structural health of nuclear containment building.

• 한국재난정보학회 논문집
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• 제19권3호
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• pp.582-596
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• 2023

연구목적: 본 연구는 원전사고 발생 시 임시 대피시설의 안전성을 강화할 수 있는 방안을 연구하였다. 연구방법: 본 연구에서는 과거의 체르노빌, 후쿠시마, 쓰리마일섬(TMI) 원전사고에 대한 사례연구를 활용하였다. 연구결과: 현재의 방사선 비상 대응 계획은 소개에 중점을 두고 있으며, 실내대피 개념은 단순히 주민 대피를 지원하는 수단으로 활용되고 있다. 그러나 사례연구를 통해 INES-5 이상의 사고의 경우, 소개보다 실내대피를 장려하는 것이 사상자 최소화에 효과적임을 확인하였다. 더 나은 실내대피를 보장하기 위해 아파트를 임시 대피소로 활용할 것을 권장하며, 아파트가 방사선 방호 기술을 갖추도록 개선사항을 제안한다. 결론: 더 나은 실내대피를 보장하기 위해 아파트를 임시 대피소로 활용할 것을 권장하며, 차폐, 양압, 밀폐기술을 이용해서 아파트의 성능을 보완하고자 한다.

• Nuclear Engineering and Technology
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• 제56권1호
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• pp.78-91
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• 2024

Double steel plate concrete composite shear wall (SCSW) has been widely utilized in nuclear power plants and high-rise structures, and its shear connectors have a substantial impact on the seismic performance of SCSW. Therefore, in this study, the mechanical properties of SCSW with angle stiffening ribs as shear connections were parametrically examined for the reactor containment structure of nuclear power plants. The axial compression ratio of the SCSW, the spacing of the angle stiffening rib arrangement and the thickness of the angle stiffening rib steel plate were selected as the study parameters. Four finite element models were constructed by using the finite element program named ABAQUS to verify the experimental results of our team, and 13 finite element models were established to investigate the selected three parameters. Thus, the shear capacity, deformation capacity, ductility and energy dissipation capacity of SCSW were determined. The research results show that: compared with studs, using stiffened ribs as shear connectors can significantly enhance the mechanical properties of SCSW; When the axial compression ratio is 0.3-0.4, the seismic performance of SCSW can be maximized; with the lowering of stiffener gap, the shear bearing capacity is greatly enhanced, and when the gap is lowered to a specific distance, the shear bearing capacity has no major affect; in addition, increasing the thickness of stiffeners can significantly increase the shear capacity, ductility and energy dissipation capacity of SCSW. With the rise in the thickness of angle stiffening ribs, the improvement rate of each mechanical property index slows down. Finally, the shear bearing capacity calculation formula of SCSW with angle stiffening ribs as shear connectors is derived. The average error between the theoretical calculation formula and the finite element calculation results is 8% demonstrating that the theoretical formula is reliable. This study can provide reference for the design of SCSW.

• Nuclear Engineering and Technology
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• 제49권7호
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• pp.1431-1441
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• 2017

The Fukushima accident reveals the vulnerability of existing active nuclear power plant (NPP) design against prolonged loss of external electricity events. The passive safety system is considered an attractive alternative to cope with this kind of disaster. Also, the passive safety system enhances both the safety and the economics of NPPs. The adoption of a passive safety system reduces the number of active components and can minimize the construction cost of NPPs. In this paper, reflecting on the experience during the development of the APR+ design in Korea, we propose the concept of an innovative Power Reactor (iPower), which is a kind of passive NPP, to enhance safety in a revolutionary manner. The ultimate goal of iPower is to confirm the feasibility of practically eliminating radioactive material release to the environment in all accident conditions. The representative safety grade passive system includes a passive emergency core cooling system, a passive containment cooling system, and a passive auxiliary feedwater system. Preliminary analysis results show that these concepts are feasible with respect to preventing and/or mitigating the consequences of design base accidents and severe accidents.

• 대한인간공학회지
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• 제35권2호
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• pp.75-84
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• 2016

Objective: The aim of this study is to suggest some improvement ideas based on the validity and the reliability analyses of the current safety culture measurement method applied to the Korean nuclear power industry. Background: Wrong safety culture is known as one of the major causes of the disasters such as the space shuttle Columbia disaster or the Fukushima Nuclear Power Plant accident. Assessment of safety culture of an organization is important to build a safer organizational environment as well as to identify the risks hidden in the organization. Method: A face validity of the current safety culture measurement method was analyzed by comparison of the key factors of safety culture in the Korean nuclear power industry with those factors reviewed in the previous studies. The current interview method was analyzed to identify the problems which degrade the consistency of evaluation. Results: Most safety culture factors reviewed in the literatures are covered in the list of the Korean nuclear power industry safety culture factors. However the unstructured questions used in the interview may result in inconsistency of safety culture evaluation among interviewers. Conclusion: This study suggests some examples which might improve the consistency of interviewers' evaluation on safety culture such as a post interview evaluation form. Application: An extended post interview evaluation form might help to increase the accuracy of the interviewing method for Korean nuclear industry safety culture evaluation.

• 한국산학기술학회논문지
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• 제19권2호
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• pp.668-675
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• 2018

전 세계적으로 도시화와 산업화의 발달은 많은 양의 전력을 필요로 하였다. 그리하여 연안 지역에 원자력 발전소를 비롯한 주요 사회기반시설의 건설이 가속화되었다. 또한 지구 온난화와 이상 기후 현상에 의해 자연 재해의 강도는 증가하고 있다. 자연 재해는 발생 지점과 규모를 예측하기 어렵고, 인명 피해와 재산 피해에 영향을 주고 있다. 이러한 문제로 인하여 연안 지역의 피해 예측과 재해 규모의 산정은 중요한 문제가 되었다. 그리하여 본 연구에서는 예측 가능한 기상 자료를 바탕으로 풍랑 피해의 피해액을 예측하고 예측한 결과를 바탕으로 풍랑 피해에 대하여 사전 대비 차원의 재난 관리가 가능할 것이라 판단된다. 본 연구에서는 재해 통계 자료가 부족한 시 군 구는 인접한 기상 관측소의 자료를 활용하는 지역은 군집분석을 활용하였다. 예측 가능한 기상자료와 지역 등급을 반영하였고, 재해 통계를 기반으로 남해연안지역의 풍랑 피해 예측함수를 개발 하였고, 검증 작업으로는 NRMSE를 활용하였다. 그 결과 NRMSE는 1.61%에서 21.73%로 분석되었다.

• Journal of Radiation Protection and Research
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• 제46권2호
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• pp.66-79
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• 2021

Background: The Japan Atomic Energy Agency (JAEA) is specified in the Disaster Counter-measures Basic Act as a designated public corporation for dealing with nuclear disasters. Materials and Methods: The Nuclear Emergency Assistance and Training Center (NEAT) was established in 2002 as the activity base providing technical assistance to both national and local governments during nuclear emergencies. The NEAT has a robust structure and utilities and special installations, and it organizes training and exercises. Results and Discussion: Due to an offshore earthquake that caused a devastating tsunami in March 2011, a nuclear accident occurred at the Tokyo Electric Power Company's Fukushima Daiichi Nuclear Power Station. The NEAT responded by conducting off-site environmental radiation monitoring and contamination screening, dispatching special vehicles, offering telephone consultations, and calculating the dispersion of radioactive materials. An examination of the emergency response activities revealed that the organization was prepared for these types of disasters and was able to plan long-term response. Conclusion: As a designated public corporation, the JAEA technically supports the national government, the Fukushima prefectural government, and the Ibaraki prefectural government, all of which responded to the off-site emergencies resulting from the March 2011 Fukushima Daiichi accident

• Nuclear Engineering and Technology
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• 제52권7호
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• pp.1471-1480
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• 2020

This research presents a case study on the remediation of a radioactive waste (uranium: U) utilizing a multi-objective fuzzy optimization in an electrocoagulation process for the iron-stainless steel and aluminum-stainless steel anode/cathode systems. The incorporation of the cumulative uncertainty of result, operational cost and energy consumption are essential key elements in determining the feasibility of the developed model equations in satisfying specific maximum contaminant level (MCL) required by stringent environmental regulations worldwide. Pareto-optimal solutions showed that the iron system (0 ㎍/L U: 492 USD/g-U) outperformed the aluminum system (96 ㎍/L U: 747 USD/g-U) in terms of the retained uranium concentration and energy consumption. Thus, the iron system was further carried out in a multi-objective analysis due to its feasibility in satisfying various uranium standard regulatory limits. Based on the 30 ㎍/L MCL, the decision-making process via fuzzy logic showed an overall satisfaction of 6.1% at a treatment time and current density of 101.6 min and 59.9 mA/㎠, respectively. The fuzzy optimal solution reveals the following: uranium concentration - 5 ㎍/L, cumulative uncertainty - 25 ㎍/L, energy consumption - 461.7 kWh/g-U and operational cost based on electricity cost in the United States - 60.0 USD/g-U, South Korea - 55.4 USD/g-U and Finland - 78.5 USD/g-U.

• 한국안전학회지
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• 제31권1호
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• pp.25-32
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• 2016

A sensitivity analysis of FDS(Fire Dynamics Simulator) results for the input uncertainty of heat release rate (Q) which might be the most influencing parameter to fire behaviors was performed. The calculated results were compared with experimental data obtained by the OECD/NEA PRISME project. The sensitivity of FDS results with the change in Q was also compared with the empirical correlations suggested in previous literature. As a result, the change in the specified Q led to the different dependence of major quantities such as temperature and species concentrations for the over- and under-ventilated fire conditions, respectively. It was also found that the sensitivity of major quantities to uncertain value of Q showed the significant difference in results obtained using the previous empirical correlations.

• 대한토목학회논문집
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• 제40권3호
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• pp.331-336
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• 2020

국내에서는 아직 생소한 CM (Consequence Management; 사후대응관리)에 대한 개념이 현대의 재난 발생 유형과 포괄적 안보 개념 하에서 볼 때, 중요한 것임을 인지하고, 문헌연구를 진행하였다. 재난관리 선진국에서 활용하고 있는 CM 개념을 통합재난관리 측면과 포괄적 안보 개념 측면에서 한국에도 도입할 필요가 있으며, 특히 CBRNE (Chemical, Biological, Radiation, Nuclear and high yield Explosives) 상황 발생 시군이 주도적으로 대응해야 할 필요성을 확인하고, 미군의 CBRNE-CM 대응기관을 모델로 하여 한국군 CM 조직 발전방안을 제시하였다.