The question of you asked and which I answered was what if we take
one fuel pellet and disperse it.
I never said Chernobyl wasn't bad (heck, I called it a disaster for a reason!). But that was tons of spent fuel (rather than the few grams being contained in one fuel pellet) being blown out of the reactor building due to the steam explosion, or going up in smoke during the subsequent fires, and even that was far from the end of the world.
In this case, I guess marketing takes pains, because one of the main ideas of this fuel type is to make them even safer, even during severe accident scenarios. Is it absolutely fool proof? Of course not; you shouldn't grind up the spent fuel and inhale the dust, for instance.