Emphasis on Human Positive Contributions to Safety

Makoto Takahashi

Department of Quantum Science and Energy Engineering, Tohoku University, Japan

Masaharu Kitamura

Research Institute for Technology Management Strategy (TeMS), Japan

The accident of Fukushima Daiichi Nuclear Power Plant (NPP) after the Great East Japan earthquake has caused huge and tragic influences on the people. Although accident reports already published mainly focuses on finding individual causes, responsible persons root causes, less attentions have been paid on judgments and actions that reduced the disaster level of the accidents after the tsunami hit the plant and lost almost all methods to save the plant. In case of Onagawa NPP (Tohoku Electric Power Co. Inc.), which is the nearest nuclear power plant to the epicenter, three reactor units had been successfully shutdown and had become stable condition while facing severe situation similar to Fukushima Daiichi NPP. In this paper, the focus has been set on the actions less known but contributed to mitigate outcome of damage in the NPP caused by earthquake and tsunami from the view point of Resilience Engineering.

In the framework of Resilience Engineering, the mechanisms of causing failure are considered to be same as the ones leading to success and the cause of the accident cannot be attributed to a single root cause. Resilience Engineering also emphasizes the importance of human positive contributions to enhance overall safety of socio-technical system. In this paper, focus has been set on the human behavior contributing to the mitigation of the disaster when facing extremely severe situation. Actual activities that contributed to attain the cold-shutdown of the reactor units have been clarified in light of Resilience Engineering. This paper concludes by pointing out the need to deal with human as a constituent element contributing to reduce to damage level when facing extremely severe situation.

1. Sulfikar Amir
2. Hyungsub Choi