The only conformation to such an event is the readings from the blast which have not been forthcoming, only hints, such as from the harden bunker control room, of course ignoring all the other fallout in the no-go zone, worldwide and the seawater. I think it was Washington State University reported their filters picked up fallout days after the Unit 1 explosion and they analyzed the contaminates after sorting out background noise and Chernobyl signatures and concluded the Unit 1 was in a state of shutdown at the time of the blast...Haven't heard much from them lately. Also, never heard the conclusion why a reactor in Virgina shut itself down, shades of Sweden's sensor alarm going off after the Chernobyl event where the Russian's failed to give notice."Must be a nuclear fission explosion", comparing #1 to #3, not mentioning the different containment etc, comparing the hot, rising gases to a nuke. Facepalm.
That "expert" should go write novels.
We'll just throw that "expert" under the bus.