When 3 Is Less Than 1: Fukushima & Chernobyl

Lately I've been battling the claim that Fukushima is worse than Chernobyl in terms of human health effects.

The reasoning has been because Fukushima involved 3 reactors and Chernobyl only one.

But there's more to the issue than that.

All of the Fukushima reactors were shutdown when they melted down (due to loss of cooling water).  They are (or were) GE boiling water reactors which means the cores are within Reactor Pressure Vessels (RPV), which contain them.

Chernobyl was operating and had a power excursion (>100%) in which it blew itself up.  It was an RMBK reactor which has no RPV containment.

The RMBK design includes graphite which caught fire. The fire wafted radioactive particles away from the site.

Finally, the Japanese did better at their evacuation than the Russians did.

Here's a snapshot of related differences.