• 대한인간공학회지
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• 제32권1호
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• pp.117-124
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• 2013

Objective: This paper presents additional considerations related to organization and safety culture extracted from recent human error incidents in Korea, such as station blackout(i.e., SBO) in Kori#1. Background: Safety culture has been already highlighted as a major cause of human errors after 1986 Chernobyl accident. After Fukushima accident in Japan, the public acceptance for nuclear energy has taken its toll. Organizational characteristics and culture became elucidated as a major contributor again. Therefore many nuclear countries are re-evaluating their safety culture, and discussing any preparedness and its improvement. On top of that, there was an SBO in 2012 in the Kori#1. Korean public feels frustrated due to the similar human errors causing to a catastrophe like Fukushima accident. Method: This paper reassesses Japan's incidents, and revisits Korea's recent incidents. It focuses on the analysis of the hazards rather than the causes of human errors, the derivation of countermeasures, and their implementation. The preceding incidents and conclusions from Japanese experience are also re-analyzed. The Fukushima accident was an SBO due to the natural disaster such as earthquakes and a successive tsunami. Unlike the Fukushima accident, the Kori#1 incident itself was simple and restored without any loss and radioactive release. However, the fact that the incident was deliberately concealed led to massive distrust. Moreover, the continued violation of rules and organized concealment of the accident are serious signs of a new distorted type of human errors, blatantly revealing the cultural and fundamental weakness of the current organization. Result: We should learn from Japanese experiences who had taken pride in its safety technology and fairly high confidence in safety culture. Japan's first criticality accident in JCO facility splashed cold water on that confidence. It has turned out to be a typical case revealing the problems in the organization and safety culture. Since Japan has failed to gain lessons and countermeasure, the issue persists to the Fukushima incident. Conclusion: Safety culture is not a specific independent element, which makes it difficult to either evaluate it properly or establish countermeasures from the lessons. It may continue to expose similar human errors such as concealment of incident and manipulation of bad data. Application: Not only will this work establish the course of research for organization and safety culture, but this work will also contribute to the revitalization of Korea's nuclear industry from the disappointment after the export contract to UAE.

• 디지털융복합연구
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• 제14권12호
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• pp.463-470
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• 2016

본 연구는 미디어 효과 연구로서, 후쿠시마 원전 사고에 의해 폭넓게 확산되고 있는 방사능 오염 실태를 취재한 시사 다큐멘터리의 시청이 국내 수용자의 정치적, 사회적 인식에 어떤 영향을 미치는지 실험을 통해 살펴본 연구이다. 그동안의 미디어 효과에 관한 선행 연구들은 TV나 신문 인터넷 등의 뉴스 콘텐츠가 수용자에게 미치는 영향을 살펴보고 있다. 그러나 이들 미디어의 뉴스 콘텐츠 못지않게 다양한 주제를 심층 분석하여 수용자들에게 깊이 있는 정보를 제공하고 있는 TV 시사다큐멘터리를 대상으로 한 수용자 효과 연구는 매우 제한적이며, 특히 지구 환경에 큰 영향을 미치고 있는 방사능 오염을 주제로 한 재난 다큐멘터리가 수용자에 미치는 영향에 관한 연구는 찾아보기 어렵다. 따라서 본 연구에서는 후쿠시마 원전사고에 의한 방사능 오염문제를 집중적으로 보도한 재난 다큐멘터리가 수용자의 정치적, 사회적 인식에 미치는 영향을 살펴보기 위해 실험연구를 수행하였다. 분석결과 시사다큐멘터리를 시청한 피험자들은 시사다큐멘터리를 시청하지 않은 피험자들보다 야당의 지지도가 높았으며, 노후 원전문제를 더 심각하게 인식하여 더 적극적으로 폐기를 주장하는 경향이 있었고, 원전의 추가 건설을 더 적극적으로 반대하는 경향이 있었다.

• Journal of Multimedia Information System
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• 제7권2호
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• pp.147-156
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• 2020

The author Nakajima was involved in the field of disaster communications and emergency medical care as guest research scientist at the Fukushima Nuclear Accident Independent Investigation Commission established by the National Diet of Japan and reviewer of the Commission's report, and Kurokawa was the chairman of this Commission. Looking back over a decade, we are on the liability issue of bureaucrats and telecom operators, so it's becoming clear what was hidden at the time. The battery of NTT DoCoMo's mobile phone repeaters had a capacity of only about 24 hours, and communication failures increased after one day. The Government also failed to issue an announcement of "Vent from reactor" under the Telecommunications Act Article No. 129. This mistake lost the opportunity to use the third-party telecommunications (e.g. taxi radios). Furthermore, as a result of LASCOM (telecommunications satellite network for local governments via GEO) and a variety of unexpected communication failures, the evacuation order "Escape!" could not be notified to the general public well. As a result, the general public was exposed to unnecessary radiation exposure. Such bureaucratic slow action in emergencies is common in the response to the 2020 coronavirus.

• 환경정책연구
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• 제13권4호
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• pp.79-105
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• 2014

Natech위험은 자연적 위해요소(natural hazards)로 인해 발생하는 산업사고 또는 기술재난을 의미한다. 유럽, 미국 등 서구 국가들에서는 1990년대 중반부터 Natech위험에 대한 연구가 활발히 진행되어 왔으며, 특히 2011년 동일본 대지진으로 인한 후쿠시마 원자력발전소 사고 이후, 이와 같은 자연 기술 복합재난에 대한 정책적, 학문적 관심이 높아지고 있다. 초기 Natech위험에 대한 연구가 원인인 자연재해의 유형과 발생확률, 결과로 유출되는 유해물질의 종류 및 위험성 등에 대한 공학적 접근이 주를 이루었던 반면, 최근의 연구는 효과적인 관리방안을 모색하기 위한 접근으로 확대되고 있다. 특히 기존의 재난관리와 비교했을 때 차별화되는 Natech재난의 특징들을 중심으로, 불확실성의 문제, 전문 분야 간 통합적 관리의 문제, 책임 소재의 문제 등이 주요 쟁점으로 부각되고 있다. 우리나라의 경우, Natech위험의 개념조차 제대로 소개되지 않았을 뿐 아니라, 복합재난에 대한 학문적, 정책적 논의 역시 부족한 실정이다. 최근의 후쿠시마 원전사고와 유해화학물질 사고 등으로 인해, 원자력 및 화학물질관리 분야의 안전 제고를 위한 정책적 개선이 이루어지고는 있으나, 자연재해 발생 시의 Natech위험 발생에 대해서는 정책적 방안이 여전히 미흡하며, 향후 다양한 정책적, 학문적 교류와 논의를 통해, Natech위험에 대한 사회적 인식 제고 및 연구 활성화가 필요하다.

• 대한원격탐사학회지
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• 제37권6_3호
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• pp.2027-2034
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• 2021

다중 시기 KOMPSAT-3/3A 고해상도 위성영상을 이용하여 후쿠시마 제1 원자력 발전소 주변 지역에 대한 식생지수를 산출하고 식생 변화의 양상을 분석하였다. 식생지수 산출 시에는 KOMPSAT-3/3A 위성영상의 지표반사도를 사용하였다. 4개 연도의 위성영상을 사용하였으며 이 영상이 중첩되는 지역을 연구의 대상이 되는 관심영역으로 정하였다. 자료 분석 방법으로 주로 식생이 분포하는 지역을 지나가는 측선을 설정하여 연도별 변화 양상을 살펴보았다. 또한, 2차원 공간상의 식생지수의 변화를 정량적으로 나타내기 위하여 관심영역 내에서 랜덤 포인트를 추출하여 상자그림으로 나타내었다. 연구의 주요 결과는 원전 인근 지역에서 2014년 식생지수는 관심영역 내에서 낮은 값으로 나타났지만 이후 2021년까지 지속해서 식생이 발달하고 있는 것으로 나타났다. 이러한 결과는 측선이나 상자그림으로 나타낸 변화 모니터링 결과에서도 확인할 수 있었다. 현장 자료를 수집하기 어려운 후쿠시마 원전 지역과 같이 접근이 제한되는 재난 지역에서는 위성영상을 이용하여 높은 정확도를 갖는 토지 피복 분류 산출물을 얻기가 어렵기 때문에 고해상도 위성영상 정보부터 얻는 식생지수와 같이 기본적인 산출물을 이용하여 분석하는 방식이 적절하다. 한편 국제적으로 공동 활용이 가능한 위성정보 자원의 활용 체계 구축과 함께 우리나라에 영향을 줄 수 있는 주변국의 환경 변화를 주기적으로 모니터링하기 위하여 고해상도 위성영상을 이용한 활용 모델과 시스템을 구축할 필요가 있다.

• 한국안전학회지
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• 제35권5호
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• pp.121-127
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• 2020

Since the Fukushima nuclear accident in 2011, the public were concerned about the safety of Nuclear Power Plants (NPPs) in extreme natural disaster situations, such as earthquakes, flooding, heavy rain and tsunami, have been increasing around the world. Accordingly, the Stress Test was conducted in Europe, Japan, Russia, and other countries by reassessing the safety and response capabilities of NPPs in extreme natural disaster situations that exceed the design basis. The extreme natural disaster can put the NPPs in beyond-design-basis conditions such as the loss of the power system and the ultimate heat sink. The behaviors and capabilities of NPPs with losing their essential safety functions should be measured to find and supplement weak areas in hardware, procedures and coping strategies. The Loss of Ultimate Heat Sink (LUHS) accident assumes impairment of the essential service water system accompanying the failure of the component cooling water system. In such conditions, residual heat removal and cooling of safety-relevant components are not possible for a long period of time. It is therefore very important to establish coping strategies considering all available equipment to mitigate the consequence of the LUHS accident and keep the NPPs safe. In this study, thermal hydraulic behavior of the LUHS event was analyzed using RELAP5/Mod3.3 code. We also performed the sensitivity analysis to identify the effects of the operator recovery actions and operation strategy for charging pumps on the results of the LUHS accident.

• Journal of Radiation Protection and Research
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• 제48권3호
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• pp.131-143
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• 2023

Background: This study examined the detection limit of thyroid screening monitoring conducted at the time of the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident in 2011 using a Monte Carlo simulation. Materials and Methods: We calculated the detection limit of a NaI(Tl) survey meter to measure ¹³¹I accumulation in the thyroid gland of children. Mathematical phantoms of 1- and 5-year-old children were developed in the simulation of the Particle and Heavy Ion Transport code System code. Contamination of the body surface with eight radionuclides found after the FDNPP accident was assumed to have been deposited on the neck and shoulder area. Results and Discussion: The detection limit was calculated as a function of ambient dose rate. In the case of 40 Bq/cm² contamination on the body surface of the neck, the present simulations showed that residual thyroid radioactivity corresponding to thyroid dose of 100 mSv can be detected within 21 days after intake at the ambient dose rate of 0.2 µSv/hr and within 11 days in the case of 2.0 µSv/hr. When a time constant of 10 seconds was used at the dose rate of 0.2 µSv/hr, the estimated survey meter output error was 5%. Evaluation of the effect of individual differences in the location of the thyroid gland confirmed that the measured value would decrease by approximately 6% for a height difference of ±1 cm and increase by approximately 65% for a depth of 1 cm. Conclusion: In the event of a nuclear disaster, simple measurements carried out using a NaI(Tl) scintillation survey meter remain effective for assessing ¹³¹I intake. However, it should be noted that the presence of short-half-life radioactive materials on the body surface affects the detection limit.

• 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.

• 전자공학회논문지
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• 제51권3호
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• pp.10-21
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• 2014

후쿠시마 원전사고는 자연재해에 의한 중대사고 발생 시 전원공급 중단 및 극한 환경으로 인해 발전소 내부 상황을 정확하게 파악하지 못하였고, 대부분의 계측제어시스템이 그 기능을 제대로 발휘하지 못해 비상냉각기능이 상실되어 수소폭발 및 다량의 방사능이 누출된 사고였다. 본 논문에서는 중대사고 발생 시에도 발전소 내부 상황을 감시하고, 적절히 제어할 수 있는 비상대응시스템에 대하여 소개하고, 비상대응시스템에 사용되는 무선통신망의 성능요구사항에 대해서 논의하고, 요구사항을 만족시킬 수 있는 비상통신망의 성능을 마코프 모델을 이용하여 분석하였다.