• Journal of Radiation Industry
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• v.18 no.1
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• pp.35-42
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• 2024

Demand for RW transportation is expected to increase due to the continuous generation of RW from nuclear power plants and facilities, decommissioning of plants, and saturation of spent fuel temporary storage facilities. The locational aspect of plants and radiation protection optimization for the public have led to an increasing demand for maritime transportation, necessitating to apprehend the overseas and domestic current status. Given the potential long-term radiological impact on the public in the event of a sinking accident, a pre-transportation exposure assessment is necessary. The objective of this study is to investigate the overseas and domestic RW maritime transportation current status and overseas dose assessment cases for the public in sinking accident. Selected countries, including Japan, UK, Sweden, and Korea, were examined for transport cases, Japan and the U.S were chosen for dose assessment case in sinking accidents. As a result of the maritime transportation case analysis, it was performed between nuclear power plants and reprocessing facilities, from plants to disposal or intermediate storage facilities. HLW and MOX fuel were transported using INF 3 shipments, and all transports were performed low speed of 13 kn or less. As a result of the dose assessment for the public in sinking accident, japan conducted an assessment for the sinking of spent fuel and vitrified HLW, and the U.S conducted for the sinking of spent fuel. Both countries considered external exposure through swimming and working at seashore, and internal exposure through seafood ingestion as exposure pathway. Additionally, Japan considered external exposure through working on board and fishing, and the U.S considered internal exposure through spray inhalation and desalinized water and salt ingestion. Internal exposure through seafood ingestion had the largest dose contribution. The average public exposure dose was 20 years after the sinking, 0.04 mSv yr^-1 for spent fuel and 5 years after the sinking, 0.03 mSv yr^-1 for vitrified HLW in Japan. In the U.S, it was 1.81 mSv yr^-1 5 years after the sinking of spent fuel. The results of this study will be used as fundamental data for maritime transportation of domestic RW in the future.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.05a
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• pp.581-586
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• 1997

중대사고시 노심의 손상에 의한 노심용융물이 원자로 용기 하부 반구로 재배치될 때 고온의 노심용융물에 의한 열적 부하로 원자로 용기의 파손을 일으키게 된다. 원자로 용기하부 반구 내에서의 노심용융물의 열적 거동 및 하부 반구에 대한 열적 부하에 대한 분석은 용융물의 성분 및 재배치 과정의 복잡성 등으로 인한 실험적 모사의 한계성 및 현상 분석의 난이함에도 불구하고 기존 원자로의 중대사고에 대한 안전 여유도의 제고와 이에 따른 노내외 사고 관리 전략의 수립을 위하여 연구의 필요성이 제기된다. 본 연구에서는 노심용융물 냉각연구(SONATA-IV)의 예비 실험으로 노심용융물의 상사물로 $Al_2$O$_3$/Fe Thermite 용융물을 이용하여 실제 원자로 용기 하부 반구를 1/8 로 선형 축소한 반구형 실험 용기로 주입하는 실험을 수행하였다. 아울러 원자로 용기 하부 반구로 재배치된 노심용융물에 의한 열적, 기계적 부하에 대한 분석을 수행하기 개발된 유한 요소 프로그램인 CALF (Computer Analysis for Lower Head Failure ) 코드를 이용한 하부 반구의 열적 거동에 대한 해석 결과를 정리하였다. 용융물 주입 실험 결과 용융물 주입과 동시에 하부 반구에 직경 5cm 크기의 하부 반구 파손이 발생하였다. 이는 고온 용융물에 의한 제트류(Jet Impingement)의 효과로 생각된다 동일한 조건에서 CALF 코드로 하부 반구의 열적 거동을 분석하였는데, 실험과는 달리 하부 반구의 파손이 발생하지 않았다 이같은 해석 결과는 용융물의 제트류 효과가 존재하지 않는다면 고온의 용융물이 하부 반구 내로 재배치되더라도 하부 반구의 파손이 발생하지 않는다는 것을 보여준다.>$_3$ 흡착제 제조시 TiO$_2$ 함량에 따른 Co$^{2＋}$ 흡착량과 25$0^{\circ}C$의 고온에서 ZrO$_2$와 $Al_2$O$_3$의 표면에 생성된 코발트 화합물을 XPS와 EPMA로 부터 확인하였다.인을 명시적으로 설명할 수 있다. 둘째, 오류의 시발점을 정확히 포착하여 동기가 분명한 수정대책을 강구할 수 있다. 셋째, 음운 과 정의 분석 모델은 새로운 언어 학습시에 관련된 언어 상호간의 구조적 마찰을 설명해 줄 수 있다. 넷째, 불규칙적이며 종잡기 힘들고 단편적인 것으로만 보이던 중간언어도 일정한 체계 속에서 변화한다는 사실을 알 수 있다. 다섯째, 종전의 오류 분석에서는 지나치게 모국어의 영향만 강조하고 다른 요인들에 대해서는 다분히 추상적인 언급으로 끝났지만 이 분석을 통 해서 배경어, 목표어, 특히 중간규칙의 역할이 괄목할 만한 것임을 가시적으로 관찰할 수 있 다. 이와 같은 오류분석 방법은 학습자의 모국어 및 관련 외국어의 음운규칙만 알면 어느 학습대상 외국어에라도 적용할 수 있는 보편성을 지니는 것으로 사료된다.없다. 그렇다면 겹의문사를 [-wh]의리를 지 닌 의문사의 병렬로 분석할 수 없다. 예를 들어 누구누구를 [주구-이-ν가] [누구누구-이- ν가]로부터 생성되었다고 볼 수 없다. 그러므로 [-wh] 겹의문사는 복수 의미를 지닐 수 없 다. 그러면 단수 의미는 어떻게 생성되는가\ulcorner 본 논문에서는 표면적 형태에도 불구하고 [-wh]의미의 겹의문사는 병렬적 관계의 합성어가 아니라 내부구조를 지니지 않은 단순한 단어(minim

• Journal of Radiation Protection and Research
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• v.28 no.4
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• pp.299-309
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• 2003

In an accidental release of radioactive materials to the environment the contaminative influence of animal products due to the inhalation of air and the ingestion of soil of livestock, both of which are dealt with as minor contaminative pathways in most radioecological models but may not be neglected, was investigated with the improvement of the Korean dynamic food chain model DYNACON Although mathematical models for both contaminative pathways have been established for considering all animal products and incorporated into the model, investigation was limited to milk. As a result, it was found that both pathways are influential in the contamination of milk in the case of an accidental release during the non-grazing period of dairy cows. In the case of an accidental release during the non-grazing period, the inhalation of air was more influential than the ingestion of soil in the early days following an accidental release. While, it was the opposite with the lapse of time. If precipitation is encountered during an accidental release, contaminative influence due to the ingestion of soil was greater compared with the cases of no precipitation, in general, because of a stealer deposition of radionuclides onto the ground. Precipitation during an accidental release was a less influential factor in $^{131}I$ (elemental iodine) contamination compared with the $^{137}Cs\;and\;^{90}Sr$ contaminations. In the case of an accidental release during the grazing period of dairy cows, the contaminative influence due to the inhalation of air was negligible.

• Journal of the Society of Disaster Information
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• v.17 no.2
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• pp.206-217
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• 2021

Purpose: Recently, a series of large social disasters have led to a lot of research to prevent social disasters as well as natural disasters and reduce damage. However, this paper aims to select the types of social disasters that local governments should focus on and create basic data for effective countermeasures and mitigation efforts. Method: Among 43 types of disasters announced by the Ministry of Public Administration and Security, 11 types of disasters were selected and collected to select the main types of disasters, and risk types were derived by region with risk maps. In order to derive the risk map, each detailed index was rescheduled to be 0-1 and weights were determined through entropy technique. Result: As a result, about 41% of the major disasters announced by the Ministry of Public Administration and Security were consistent, and the rest of the major types were disasters that could not be obtained or have not occurred in the past 20 years. Conclusion: Therefore, in order to establish an effective prevention and recovery plan for social disasters through this study, it was intended to present social disaster-focused disasters for each local government.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.8
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• pp.107-112
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• 2016

Safety Critical Instrumentation and Control Systems perform those functions to maintain nuclear power plants' parameters within acceptable limits established for a design basis events and anticipated operating occurrence to ensure safety function. Those digitalized systems shall protect inadvertent and non-malicious behavior to ensure the reliable operation of systems, known as a Secure Development and Operational Environment(SDOE). SDOE would be established through managerial and technical controls. The objective of this paper is to evaluate the effectiveness of Cyclic Redundancy Checksum diagnostic, which is one of technical controls for SDOE, that can confirm the integrity of software of I&C systems to establish the secure environment. The results of this assessment would be the practical implementation of design and safety review of nuclear I&C systems.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.5
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• pp.725-730
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• 2017

The use of general IT resources in the Instrumentation and Control system(I&C) for the safety of Nuclear Power Plants(NPPs) is increasing. As a result, potential security vulnerabilities of existing IT resources may cause cyber attack to NPPs, which may cause serious consequences not only to shutdown of NPPs but also to national disasters. In order to respond to this, domestic nuclear regulatory agencies are developing guidelines for regulating nuclear cyber security regulations and expanding the range of regulatory targets. However, it is necessary to take measures to cope with not only general security problems of NPPs but also attacks specific to NPPs. In this paper, we select 42 items related to the vulnerability inspection in the contents defined in R.G.5.71 and classify it into 5 types. If the vulnerability inspection tool is developed based on the proposed analysis, it will be possible to improve the inspection efficiency of the cyber security vulnerability of the NPPs.

• Journal of the Korean Society of Radiology
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• v.7 no.3
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• pp.221-225
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• 2013

The purpose of this study was to examine the impact of the Fukushima nuclear power plant accident of Japan in 2011 on kindergarten teachers' perception on young children's safety due to radioactive contamination. This study analysed the 134 questionnaire forms out of 197 kindergarten teachers in the region of Chungbuk. The findings of the study indicated that the Japanese unclear power plant accident exerted an influence on anxious of kindergarten teachers on young children's safety due to radioactive contamination. In conclusion, kindergarten teacher education are required to improve the safety knowledge of kindergarten teachers and alternative resolution method for young children's safety due to radioactive contamination.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.5
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• pp.453-460
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• 2015

Since the Fukushima nuclear accident, several researchers are extensively studying the effect of torsion on the piping systems In nuclear power plants. Piping installations in power plants with a circumferential crack can be operated under combined loading conditions such as bending and torsion. ASME Code provides flaw evaluations for fully plastic fractures using limit load criteria for the structural integrity of the cracked pipes. According to the recent version of Code, combined loadings are provided only for the membrane and bending. Even though actual operating conditions have torsion loading, the methodology for evaluating torsion load is not established. This paper provides the results of limit load analyses by using finite element models for circumferentially cracked pipes under pure bending, pure torsion, and combined bending and torsion with tension. Theoretical limit load solutions based on net-section fully plastic criteria are suggested and verified with the results of finite element analyses.

• Journal of the Korean Society for Nondestructive Testing
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• v.29 no.2
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• pp.98-103
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• 2009

The nuclear power plants have been safely operated by plugging the steam generator tubes which have the crack indications. Tube rupture events can occur if analysts fail to detect crack indications during in-service inspection. There are various types of crack indication in steam generator tubes and they have been detected by the eddy current test. The integrity assessment should be performed using the crack-sizing results from eddy current data when the crack indication is detected. However, it is not easy to evaluate the crack-depth precisely and consistently due to the complexity of the methods. The current crack-sizing methods were reviewed in this paper and the suitable ones were selected through the laboratory tests. The retired steam generators of Kori Unit 1 were used for this study. The round robin tests by the domestic qualified analysts were carried out and the statistical models were introduced to establish the appropriate depth-sizing techniques. It is expected that the proposed techniques in this study can be utilized in the Steam Generator Management Program.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2006.05a
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• pp.371-376
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• 2006

서로 갈등적인 관계에 있는 다중 기준 하에서 다양한 국가 전력 시스템을 정량적으로 비교하는 데에는 전력 시스템의 비교 지표가 필요하다. 이러한 비교 지표를 산출하기 위하여 해석적 망형 과정(Analytic Network Process; ANP) 모델 가운데 상호 의존도 수중이 낮은 되먹임 모델 및 상호 의존도가 없는 독립성 모델이 개발되었다. 이러한 ANP 모델은 구성요소로 교점들(nodes)과 상호작용 관계를 표현하는 가지들(arcs)을 포함하고 있다. 의사결정 목표 교점에는 세 가지 유형의 리스크 성향이 포함되었다. 이러한 리스크 성향은 원자력 발전소 같은 위험 설비에 대한 전문가(그룹)의 리스크 성향이며, 더 구체적으로 말하면, 리스크 감수 성향, 리스크 혐오 성향, 리스크 중립 성향 등이다. 여기서 수행된 연구의 주요 목적은 ANP 모델을 구성하는 교점들 가운데 하나인 평가 기준 교점에서의 변화가 전력 시스템의 비교 지표에 미치는 영향을 해석하려는 것이다. 이러한 모델 변이가 비교 지표에 미치는 영향을 알아보기 위한 사례 연구에서 각 발전원의 특성을 비교할 평가 기준은 기준 사례와 비교 사례 각각에 대하여 상이하게 선정되었다: 기준 사례의 경우에는 보건성을 대표하는 생명 단축 [yr/TWh], 환경성을 대표하는 지구 온난화 [$g\;CO_{2}-eq./kWh$], 사회성을 대표하는 지속가능 정도[-], 경제성을 대표하는 발전 단가 [\/kWh] 등이 선정되었다; 반면에, 비교 사례의 경우에서는 보건성을 대표하는 사고 사망 [death/GWh]만이 다르고 나머지는 동일하게 선정되었다. 이러한 보건성을 대표하는 생명 단축 또는 사고 사망의 선정은 다음과 같은 비교 지표에 영향을 미친다는 것이 발견되었다: (1) 되먹임 모델에서는 성향 가중치 및 기준 등급에 영향을 준다. (2) 되먹임 모델과 독립성 모델에서는 시스템 등급에 영향을 준다. 향후에는 더욱 더 다양한 상호의존 모델들이 정량화될 필요성이 있다고 본다.