How powerful is the worlds largest nuclear bomb?
The largest nuclear bomb ever detonated was the Russian RDS-220 “Tsar” with a 50 megaton yield, tested only once in 1961. The design was supposed to be 100 megaton, but it was deliberately curbed down to reduce fallouts. Still, the fireball had a radius of 4.6 km, and would have vaporized everything in that zone, with the heat effect being able to cause 3rd degree burn on unprotected skin up to 100 km away from ground zero. There is not real upper limit to how powerful a fusion bomb can be, the Teller design simply adds stages that are boosting the next one.
