Shadows spreading to the far north and south - Japan's crisis drawn by the 250-kilometer evacuation line (2011)

Shadows spreading to the far north and south - Japan's crisis drawn by the 250-kilometer evacuation line (2011)

In March 2011, during the Fukushima Daiichi nuclear power plant accident, the worst-case scenario discussed within the government included a shocking 250-kilometer evacuation zone extending from Fukushima. Morioka City in Iwate Prefecture to the north, and Yokohama City in Kanagawa Prefecture to the south were linked as a single evacuation zone, indicating that 35 million people in the Tokyo metropolitan area could lose their livelihoods. This assumption was not fanciful at all, but was based on the complex crisis that was developing in the early stages of the accident: the explosion of Units 1 and 3, the suspected damage to Unit 2, and the unclear status of the pool in Unit 4 all combined to make it impossible to accurately assess the state of the reactor core, and the threat of a prolonged massive release of radioactive materials became a real possibility. The situation was becoming more and more serious.

Furthermore, the direction of the wind around March 15 was biased to the south, and the possibility of radioactive materials reaching the Kanto region could not be ruled out. Trace amounts of radioactive materials were detected in Ibaraki, Chiba, Tokyo, and Kanagawa, which also heightened fears of widespread contamination. The U.S. government recommended evacuation from the 80-kilometer zone, and the international community shared the seriousness of the situation. Under these circumstances, the 250-kilometer evacuation line took on heavy scientific and political significance, and became a symbolic line indicating that the very foundations of Japan's administration, economy, and society were at stake.

This worst-case scenario highlighted the structural flaws in the nuclear administration's failure to envision a chain of serious accidents and visualized the vulnerabilities that Japanese society was facing. The issues of the coexistence of giant technology and society, and the question of how to prepare for a national crisis, remain unanswered even now, more than 10 years after the accident.