FACTS AND LESSONS OF THE FUKUSHIMA NUCLEAR ACCIDENT

摘要

The paper provides detailed facts of the Fukushima accident, and lessons learned from it by comparing the cases at Fukushima Daiichi Nuclear Power Station (1F) and Fukushima Daini Nuclear Power Station (2F). Firstly, how the facilities were damaged by a series of beyond design basis tsunamis is described. All the units at 1F resulted in loss of cooling function and ultimate heat sink for a long period of time. Although 2F also lost cooling function and ultimate heat sink, the off-site power and some of the electric buses were available unlike 1F. And all the units reached cold shut down in 5 days after the recovery of the damages. Secondly, how the accident was successfully stabilized at 2F, how the accident developed at 1F, and how the personnel in the emergency organizations at both 1F and 2F responded to the accident are described. Massive damage by the tsunamis and lack of necessary equipment and resources hampered quick recovery. Lastly, it summarizes technical lessons learned from the accident and key human and organizational factors in managing crisis. This information may be helpful for those in the nuclear community across the world to develop countermeasures and establish a robust emergency response organization.