[topher]

I think the chances are now slim and none to contain the third reactor from uncovering the core and exploding...

Probably safe to say that there is a radioactive cloud headed this way (if winds are West to East).

[BuckeyeTexan]

An exposed core melts. It doesn’t explode. That’s why it’s called a meltdown.

http://www.freerepublic.com/focus/f-news/2688397/posts#10

[BuckeyeTexan]

An exposed core melts. It doesn’t explode. That’s why it’s called a meltdown.

http://www.freerepublic.com/focus/f-news/2688397/posts#10

[palmer]

I think the chances are now slim and none to contain the third reactor from uncovering the core and exploding...

No core has "exploded" nor will any. No core has been uncovered or breached. However, venting of the core has released some radiation. Also venting of the core allowed a hydrogen gas buildup in the two buildings which then exploded. The third building might explode too, but should not, although I didn't expect the second building to explode.

Just so you know the crucial fact: the worst case scenario is the core doesn't stay cooled and melts down through the container. The core has probably melted in at least two reactors, maybe three, but has not melted down. It won't melt down as long as it is being injected with water and boron (which then must be vented releasing some radiation).

The difference between melting and melting down is that melting is subcritical, melting down means the fuel is pooled and goes critical.