I’ve seen the vids.
It wasn’t a nuke, the Rebels say Kiev hit the State Chemicals Factory with a Ballistic Missile, likely a Luna-M. Lots of nasty stuff stored underground there, it seems.
It got hit by an SS-21 missile in the fall, and there was a huge explosion then, as well.
Good to know....
I knew it was not a low velocity explosion. A large package and a secondary would explain what we are seeing.