Japan draws some conclusions

摘要

The report concludes that there were three turning points in the events at Fukushima: inability to supply AC power to the station, inability to remove heat from the reactor, and leakage of hydrogen into the building and hydrogen explosions. It further breaks down the first problem-station blackout-into four subsidiary problems: inability to supply external power, inability to supply power from emergency diesel generators, inability to interchange power sources, and the impossibility of early power recovery. The document analyses each of these issues, lists the reasons why they could not be accomplished, and proposes particular resulting issues to be examined (see box for recommendations). The report concludes, "The essence of the problem is that preparations assuming a contingency brought about by tsunami strike were ineffectual."