For years we heard that an exposed core will spread deadly radiation across the world, destroying cities, killing women and children(that’s when I should have known it was a lib plot to get rid of nukes) and decimating eco-systems.
So 3 cores are exposed and what?
Well, that’s what we don’t know. We won’t know for probably years how exposed the cores were.
It took five years after TMI to learn the true extent of what happened inside the reactor. The actual results out of TMI were that a) the core melted significantly, b) it happened while everyone was hopping up and down, wondering what was going on, c) that it appeared to have happened pretty early in the event, d) it never made it through the pressure vessel.