Unfortunately, I don't think we have the whole story on this yet, and I don't think we will have it for quite some time. What we certainly know is, if there had been another major aftershock, Japan would be hurting for certain. When Thomas Midgley, an engineer, created CFCs he used Chlorine more by luck than by design. Had he been a chemist and used Bromine, we would all be dead now, and probably none the wiser.
If anything, the fact the Japanese have behaved the way they have towards this issue, and now that TEPCOs mendacity has been exposed regarding the plants when they were working, only compels us to ask serious, serious questions about our maturity as a culture and a species to handle the power of the atom. As we have now seen, having no clue about what to do with the spent fuel may cost Japan dearly, and that is just the tip of our collective irresponsibility.