As pointed out by others the similarities between Chernobyl and Fukushima units 1,2, and 3 are that both are nuclear reactors. Chernobyl was a carbon pile reactor without any containment and lacking safety systems. The reaction ran away, the carbon pile caught fire, and there was nothing there to keep the escaping radiological mess from leaving. And, no emergency systems in place or readily available way to shut it down, putting out the fire, or contain anything.

The Fukushima units have the core inside a large steel containment, listed as 20cm, ~8", thick, that is itself inside a heavily constructed reinforced concrete shell. Both are air tight and designed to handle pressure. Under the plant is a very thick, specially constructed, concrete slab designed to catch the core in the worse possible meltdown.

So far, as of Sunday, there has been no significant release of radiation. The small amount released would have an effect less than flying cross-country a few times, if that. The ability of the monitoring system to detect these small amounts of radiation is a testament to their extreme sensitivity, not any greatly raised risk.

It is ironic that the earthquake and tidal wave have killed tens of thousands, and made many times that homeless and we are spending time talking about a a situation that has only killed one, killed in the hydrogen explosion, because the word nuclear and the idea of radiation irrationally scares people.