How Hot Is Corium?

The temperature of corium can be as high as 2,400 °C (4,350 °F) in the first hours after the meltdown, potentially reaching over 2,800 °C (5,070 °F). A large amount of heat can be released by reaction of metals (particularly zirconium) in corium with water.

Is corium still hot?

The corium of the Elephant's Foot might not be as active as it was, but it's still generating heat and still melting down into the base of Chernobyl. ... The Elephant's Foot will cool over time, but it will remain radioactive and (if you were able to touch it) warm for centuries to come.

Why is corium so dangerous?

So, why is corium so dangerous? Well, even long after the flow has stopped, that lava will be highly radioactive for decades to centuries (along with the surrounding countryside if radioactive material made it out of the containment vessel) as the various radioactive materials in the lava decay.