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 Fukushima Daiichi Nuclear Power Plant prevented further deterioration of the accident case, rather than the aspect that it has been evaluated for extracting risk factors. Based on those results, the study clarifies the method of learning to enhance safety which has a different view from existing accident investigation.

Approximately 60％ of accidents that happen on railway platforms in Japan resulting in injury or deaths are caused by drunken passengers. This study was designed to identify patterns of falls from platforms experienced by drunken passengers, as well as premonitory behaviors before falls and before making contact with moving train cars. Images collected from security cameras recording such accidents were analyzed. Results indicated （1） patterns of falls experienced by drunken passengers just before accidents could be classified into three types. （2） Premonitory behaviors displayed by drunken passengers on platforms and in concourses before having an accident could be classified into five types, and we calculated the incidence of these behaviors. Furthermore, 90％ of drunken passengers fell, or made contact with moving train cars after a few seconds of commencing to walk. It is suggested that station staff who observes drunken passengers displaying premonitory behaviors should call out to them and ensure their safety.