The corium flow stopped itself. Basic nuclear physics.
BTW, I do have a great deal of respect for the men who had to deal with that catastrophe. Same as I do for those dealing with Fukushima. Which is why I can’t stand people who try to sensationalize this event, and blow it far out of proportion.
You have respect for the Fukushima personal, but you deny recognition of actually how difficult the situation is over there for them. One negates the other.