In Chernobyl, there was a nuclear event and ensuing fires. There probably won't be a nuclear event at Fukushima (although it is theoretically possible, I think

In Chernobyl, there was a nuclear event and ensuing fires. There probably won't be a nuclear event at Fukushima (although it is theoretically possible, I think - the melted fuel rods will no longer be damped, and can run together in a clump that might achieve criticality) but there will be ensuing fires, and hot particles and steam will be distributed over a wide area. Ever seen a volcano? Did you notice that heavier-than-air particles (ash, rocks, dust) were widely dispersed from that volcano? Indeed, the most recent news articles are pointing out that the spent fuel ponds are running dry as well, and might melt and go critical as well. There is five times as much fuel in the spent fuel ponds as in the reactor cores themselves...