I understand that this is a Three Mile Island type of incident so fallout and radioactive contamination will be limited to the containment buildings of the other two reactors at that facility that are in danger.

As for the one that exploded well first we need to realize that it is not a nuclear "explosion" like we get from an atomic bomb. This is what happens or at least happened at TMI:

http://www.threemileisland.org/scien...ong/index.html

It should also be noted that the human operators at TMI ignored multiple alarms, had a faulty indicator, had a vital warning lite covered up and could not get through to the NRC for emergency help. TMI was totally avoidable or so some claim.

If one is to believe the Japanese government and the press then the fallout will not affect a large area like Chernobyl did.

Here is some interesting reading on the subject:

http://www.threemileisland.org/index.html

http://www.csmonitor.com/World/Globa...ey-differences

Here is something that got my attention. The expert on the Bob Brinker show Money Talk on WHP580 am talk radio today was from Lawrence Livermore Labs I think. Regardless he brought up the point of redundancy in the backup systems. He stated that most American plants have at least 4 cooling system backups and that the reason TMI happened was the operators ignored the system warnings. The system worked until the operators intervened. Now he said that the Japanese reactors only have two cooling system back ups. He drove home the points that the quake only damaged the system and it immediately shut down. The tsunami however is the culprit that destroyed the backup diesel generators that were now needed to generate power for the cooling system. His opinion was that the Japanese knew they were building these things in a tsunami zone and therefore should have had an emergency backup plan in place to airlift in via helicopter the new generators along with other repair supplies.

His whole point was that like TMI the human error caused a situation that should have been easily controlled to go out of control. Take his opinion as just that. His opinion.