More Japan nuclear problems: from having had to pour sea water into reactors salt buildup on rods may stop water's cooling ability which could cause rods to melt, causing... etc etc etc.
Oh, for the days when a meltdown was "just a meltdown".
Just as in 3 Mile Island and Chernobyl, the events are fluid and unpredictable. Anyone that says they know something is just guessing. The only thing to know is that you can't possibly know.