I lived in Japan for nearly 3 years during the last decade. The government and high ranking company officals are not good at communicating bad news.
I don't beleive the nuclear plants survived the quakes. It seems apparent that the reactors in question have not been able to hold coolant water since the quakes that started last Friday. This is likley a result of cracked cooling pipes leading into and out of the steel reactor containment structures.
It is a known risk that pipes that carry nuclear material become brittle over time and the quake likely cause these to fall.
Yes, the tittle wave was a factor in several failed coolant systems but it is not the only cause.
One thing is certain; the current designs in Japan and other places worldwide are NOT safe.