Tsar Bomba's one and only test produced an approximate yield of 50 megatons or 50 million tons of TNT, making it the most powerful man-made explosive in history.
Many of them have cheaper capture cost with the ability to improve the overall economics and kick-start a network that has the ability to scale up to 28 megatons.
All residential buildings inside of the country built after 1978 are mandated by law to contain a nuclear shelter capable of surviving a 12 megaton blast from a distance of 700 meters away.