[mrsmith]

It depends on the meaning of “melting”.
It’s a vague word and the media love it.

[thackney]

I believe we are also seeing confusion between the term reactor (steel vessel) of the fuel rod assembly inside the reactor.

Even if the fuel rod assembly melts down and puddles in the bottom of the reactor, the reactor is designed to still contain it.

Hydrogen is being generated and released intentionally as they are venting to keep the pressure down.