These atomic weapons are not used anymore. We use thermonuclear fusion weapons which do not irradiate the area as much: Fusion, unlike fission, is relatively “clean”—it releases energy but no harmful radioactive products or large amounts of nuclear fallout. https://en.m.wikipedia.org/wiki/Thermonuclear_weapon#:~:text=Fusion%2C unlike fission%2C is relatively,of fission products and fallout.

Edit: I am a bit wrong, a fusion bomb by itself is relatively clean, but these damn bastards make them with extra fissile material for extra boom. Making it still quite radioactive when exploding