The comment spoke about nuclear power accidents; neither Three mile island, Fukishima, nor Chernobyl wiped out all (or even a significant number) of existing lifeforms.

Bikini Atoll was blasted with 23 (or 24, there's an edge case) separate nuclear explosions in the air, at sea level, and underwater, one a thousand times more powerful than either of the Hiroshima and Nagasaki weapons.

Not comparable to a nuclear power station accident.