I think the suggestion is that this represents a pretty 'worst case' scenario-- an old reactor of obsolete design that is dramatically less safe than many modern designs (at least as I understand it)and one of the worst earthquakes on record. If the "no fallout" situation does occur, it seems like a pretty powerful argument on the "pro-nuclear power" side of the debate.

And no, I don't suspect the anti nuclear crowd will buy it at all.