1) Why did TEPCO and the Japanese regulator not take action years ago when experts predicted tsunamis larger than the existing sea walls could withstand?
2) The plants' cooling systems were initially reported to have survived the 9.0 earthquake intact, but later TEPCO was forced to change its story; see Atlantic report. The U.S. Navy was in the area and, with its heavy helicopter lifting capacity, could have airlifted in diesel electric generating equipment and the fuel to keep it running. The huge, uncontrolled releases of radioactive materials may have been avoided had the proper emergency cooling contingencies been in place and had the Japanese nuclear regulator swiftly accepted such offers of assistance from the U.S. and others; see report by Japanese nuclear engineer "Fukushima: Probability theory is unsafe".
Did the Japanese government turn down outside offers of assistance during the critical first hours? Why?
Haphazard soil dumping reported
Meltdown: What Really Happened at Fukushima
Concrete enclosures similar to the sarcophagus at Chernobyl are to be constructed over Fukushima's three melted reactors
Plant operator TEPCO and the Japanese nuclear regulator are shown to be unprepared and incompetent in rapidly dealing with power loss crisis. Had they immediately asked for outside assistance in providing mobile diesel generators and fuel, the spent fuel fires and reactor meltdowns could have been averted. The international nuclear power community (IEAE and others) failed miserably during the first day, with the result that the readily apparent crisis turned into a catastrophe.
The magnitude of Fukushima tsunami had a 1923 Kanto earthquake tsunami precedent which was ignored by TEPCO and the Japanese government
NIRS Fukushima factsheet
NIRS Fukushima update page (ongoing)
Detailed retrospective including many images, on the first anniversary
Learning from Japan's Nuclear Disaster
GE "brings good things to life"