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Oba, Kyoko; Yoshizawa, Atsufumi*; Kitamura, Masaharu*
Kogaku Kyoiku, 69(3), p.3 - 10, 2021/05
The purpose of engineering ethics education is to understand the effects and impacts of technology on society and nature and the responsibilities that engineers have to fulfill for society. There are many cases used in the educational method so that the students can understand the problems surrounding the engineers. However, most of the cases correspond to event scenarios where engineers have failed to maintain safety. Resilience engineering was born from the criticism of safety measures for the purpose of preventing recurrence by seeking human error and organizational culture as the cause of accidents in the field of ergonomics. Its features are that people are considered as beings that realize safety in dangerous systems, and that they focus on good practices. This paper describes the improvement of engineering ethics education by utilizing resilience engineering concept.
Yoshizawa, Atsufumi*; Oba, Kyoko; Kitamura, Masaharu*
Nihon Genshiryoku Gakkai Wabun Rombunshi, 18(2), p.55 - 68, 2019/06
This study aims to improve the potential of an emergency response by analyzing the workload management during the accident at the Emergency Response Center (ERC) of TEPCO's Fukushima Daiichi Nuclear Power Plant. Specifically, the research focused on the response of the ERC during the time between the discontinuation of Unit 3 core water injection and its recovery. It identified the different types of workload at the ERC had and how they had been managed based on the record of a TV conference. It also deduced the casual factors of the responses, supplementing the interview record of the director of ERC at the time by applying workload management analysis. On the basis of these findings, lessons to enhance the potential of the on-site emergency response have been obtained for ERC and outside organizations.
Yoshizawa, Atsufumi*; Oba, Kyoko; Kitamura, Masaharu*
Ningen Kogaku, 54(3), p.124 - 134, 2018/06
Fukushima Daiichi Nuclear Power Plant caused a severe accident which released a large amount of radioactivity triggered by the Great East Japan Earthquake. The existing investigation reports of the accident prepared by several institutions pay attention only to the process which caused the accident but not much to the accident mitigation or the recovery process. This study focused on Unit 3 of Fukushima Daiichi Nuclear Power Plant, including its recovery process from the accident. Based on the public data, the time sequences for the recovery process between the accident occurrence and the state of cold shutdown were classified. Then, the groups of actions were sorted out in terms of ergonomics viewpoint. The important responses in the recovery process were identified and analyzed referring to the m-SHEL model. As a result, new lessons were learned from the accident case regarding the actions required for recovering from the accident.
Yoshizawa, Atsufumi*; Oba, Kyoko; Kitamura, Masaharu*
Ningen Kogaku, 54(1), p.1 - 13, 2018/02
The two approaches as the concepts to ensure safety of the complicated socio-technical systems have been proposed by Hollnagel. They are the safety concepts called "Safety-I" to reduce risks and "Safety-II" to expand successes. The resilience engineering is suggested as the methodology to achieve Safety-II. The study analyzes the recovery of the water injection of Unit 3 based on the resilience engineering, focusing on the fact that preventing further progress of the accident case in Fukushima Daiichi Nuclear Power Plant which has been evaluated for extracting risk factors. Based on those results, the study has clarified the method of learning to enhance safety which has a different view from existing accident investigation.
Yoshizawa, Atsufumi*; Oba, Kyoko; Kitamura, Masaharu*
Nihon Kikai Gakkai Rombunshu (Internet), 83(856), p.17-00263_1 - 17-00263_17, 2017/12
-tetrafluoroethylene) films using different mediaNuryanthi, N.*; Yamaki, Tetsuya; Kitamura, Akane; Koshikawa, Hiroshi; Yoshimura, Kimio; Sawada, Shinichi; Hasegawa, Shin; Asano, Masaharu; Maekawa, Yasunari; Suzuki, Akihiro*; et al.
Transactions of the Materials Research Society of Japan, 40(4), p.359 - 362, 2015/12
The ion-track grafting of a vinylbenzyl chloride (VBC) into a poly(ethylene-co-tetrafluoroethylene) (ETFE) film is necessary for preparing nanostructured hydroxide-ion-conductive electrolyte membranes. A key for success here is to obtain as high graft levels as possible (for higher conductivity) in a smaller number of tracks (for improving the other membrane properties). To this end, therefore, the effect of the medium for the VBC grafting was investigated as part of our continuing effort to optimize the experimental conditions. A 25 
m-thick ETFE film was irradiated in a vacuum chamber with 560 MeV 
Xe at different fluences, and then the grafting was performed by immersing the irradiated films in a 20vol% VBC monomer at 60
C. A medium was a mixture of water (H
O) and isopropyl alcohol (iPrOH) at different volume ratios. The degree of grafting increased as the HO content became higher, and reached a maximum in pure HO. These results can be explained by considering the well-known Trommsdorff effect, in which poor solubility of the grafted polymer in polar media leads to an increased polymerization rate probably due to a lower termination rate.
Shinohara, Yoshikuni; Kitamura, Masaharu*
JAERI-M 5664, 34 Pages, 1974/04
no abstracts in English
-ray-induced graftingNuryanthi, N.*; Yamaki, Tetsuya; Kitamura, Akane; Koshikawa, Hiroshi; Yoshimura, Kimio; Sawada, Shinichi; Hasegawa, Shin; Asano, Masaharu; Maekawa, Yasunari; Suzuki, Akihiro*; et al.
no journal, ,
The ion-track grafting of a vinylbenzyl chloride (VBC) into a poly(ethylene-co-tetrafluoroethylene) (ETFE) film is necessary for preparing nanostructured hydroxide-ion conductive electrolyte membranes. A key for success here is to obtain as high graft levels as possible (for higher conductivity) in a smaller number of tracks (for improving the other membrane properties). To this end, therefore, the effect of the medium for the VBC grafting was investigated as part of our continuing effort to optimize the experimental conditions. A 25 m-thick ETFE film was irradiated in a vacuum chamber with 560 MeV Xe at different fluences, and then the grafting was performed by immersing the irradiated films in a 20vol% VBC monomer at 60C. A medium was a mixture of water (HO) and isopropyl alcohol (iPrOH) at different volume ratios. The degree of grafting increased as the HO content became higher, and reached a maximum in pure HO.
Oba, Kyoko; Yoshizawa, Atsufumi*; Kitamura, Masaharu*
no journal, ,
no abstracts in English
Yoshizawa, Atsufumi*; Oba, Kyoko; Kitamura, Masaharu*
no journal, ,
no abstracts in English
Oba, Kyoko; Yoshizawa, Atsufumi*; Kitamura, Masaharu*
no journal, ,
Five years have passed since the Fukushima accident, and at first look Fukushima Daiichi Nuclear Power Station appears as an ordinary factory. However, regarding safety education and training, the remains of the accident which bore the brunt of the overwhelming impact of the disaster carry an important meaning in the development of attitude and motivation for safety, and many organizations have already begun working on implementing it for future safety. This article seeks to propose the proper attitude for nuclear industry by utilizing remains of the Fukushima accident focusing on the transportation industry, while considering previous approaches which utilized remains.
Oba, Kyoko; Yoshizawa, Atsufumi*; Kitamura, Masaharu*
no journal, ,
This paper focuses on the Tokai No.2 Nuclear Power Station, which was hit by earthquakes and subsequent tsunami in the Great East Japan Earthquake in 2011 but swiftly achieved cold shutdown. The earthquake struck the power station just before the scheduled completion of engineering work to raise the walls of the room housing a seawater intake pump. The fact that the work had been applied helped continuous operation of the seawater intake pump, a key piece of equipment for achieving cold shutdown. The power station followed its pre-defined procedure to bring its reactors to cold shutdown. Focusing on the background of the engineering work, which was not mentioned in past reports, this paper analyzes multiple organizations (main actors) based on the concept of Resilience Engineering to reveal how the collaboration between these organizations enhanced the power station's resilience, and considers the potential of such collaboration in boosting the resilience of our society.
Matsuda, Yasuhiro*; Okuyama, Katsushi*; Komatsu, Hisanori*; Oki, Saiko*; Hashimoto, Naoki*; Sano, Hidehiko*; Yamamoto, Hiroko*; Iwami, Yukiteru*; Hayashi, Mikako*; Nomachi, Masaharu*; et al.
no journal, ,
no abstracts in English
Oba, Kyoko; Yoshizawa, Atsufumi*; Kitamura, Masaharu*
no journal, ,
no abstracts in English
Oba, Kyoko; Yoshizawa, Atsufumi*; Kitamura, Masaharu*
no journal, ,
At the time of the Great East Japan Earthquake, many socio-technical systems experienced significant damages from the earthquake and tsunami far beyond the preparedness for disasters. Therefore, necessity of Business Continuity Plan (BCP) has been recognized irrespective of domains. Case studies of various on-site responses related to this disaster were analyzed to extract lessons from BCP that is common to various systems. Specifically, in reference to the concept of Resilience Engineering that is focused for enhancing resilience of organizations (i.e. resilience and flexibility) in recent years, analysis was conducted with attention to the cases in which the concerned systems could restore or ensured the safety from disturbance. Lessons useful for disaster prevention and mitigation have been extracted successfully from activities conducted for preparing and responding to the earthquake-driven disturbances.
Yoshizawa, Atsufumi*; Oba, Kyoko; Kitamura, Masaharu*
no journal, ,
The Great East Japan Earthquake caused substantial damage to complex socio-technical systems essential for modern life. This article references Resilience Engineering, which is indicative of the importance of learning from "things that went right", and analyzes things that went right in field responses to the earthquake during the Fukushima accident as well as transport operations, in an attempt to deduce new lessons about emergency responses and preparations against unforeseen contingencies, which are common to socio-technical systems.
Nuryanthi, N.*; Yamaki, Tetsuya; Koshikawa, Hiroshi; Asano, Masaharu; Sawada, Shinichi; Hasegawa, Shin; Kitamura, Akane; Maekawa, Yasunari; Katsumura, Yosuke*
no journal, ,
We prepared ion-track membranes of poly(vinylidene fluoride) by chemical etching in a conductometric cell and then investigated how the applied AC voltage affected etching characteristics using scanning electron microscopy. The high voltage application had some effect on the final pore diameter, which seems inconsistent with the findings of our previous conductometric analysis, while shortening the breakthrough time greatly.
Yoshizawa, Atsufumi*; Oba, Kyoko; Kitamura, Masaharu*
no journal, ,
The accident at the Fukushima Daiichi Nuclear Power Station, which was triggered by the Great East Japan Earthquake, has presented significant issues about in which the safety of massive socio-technical systems is structured. We must derive the greatest number of lessons possible from this accident to ensure the safety of systems in the future, but the lessons learned so far have mainly focused on risks and been deduced from an analysis of failures that led to the accident. This paper references the approach of Resilience Engineering which aims to extend successes in a changing environment, and focuses on the actions that prevented "further catastrophe" through an analysis of the Fukushima accident and derives new lessons to improve the capability to handle "unforeseen contingencies."
Yamaki, Tetsuya; Nuryanthi, N.*; Koshikawa, Hiroshi; Asano, Masaharu*; Sawada, Shinichi; Kitamura, Akane; Maekawa, Yasunari; Kay-Obbe, V.*; Severin, D.*; Seidl, T.*; et al.
no journal, ,
Practically, polyvinylidene fluoride (PVDF) has been said to be the only fluoropolymer in which ion tracks can be developed by chemical etching. We thus investigated the possibility of varying the beam parameters and applying the effect of a pre-etching treatment for PVDF ion-track membranes with the goal of achieving enhanced track etching for effective control of the pore size and shape. Our activities also cover all types of fluoropolymers including PVDF. Compared to PVDF, poly(ethylene-
-tetrafluoroethylene) and a series of perfluoropolymers are known to be very stable in highly-concentrated acid or alkaline solutions or at higher temperatures. Although this property might make their ion-track etching very challenging, the ongoing research is expected to allow one to accumulate know-how on methods of chemical etching, which can be generalized for the chemical structures. These will give feedback to a guiding principle for effective ion-track etching in fluoropolymers.
