How to survive a nuclear explosion? Yes, there is such a possibility!
In a nuclear explosion, the main danger is the shockwave created by the explosion, not the flash itself and the fireball, which has a relatively small radius. If you are far enough away from the fireball and see it, you may have 8-10 seconds to react correctly. You must quickly lie face down with your fingers over your eyes and ears. You should breathe through your mouth.
If you stay upright, the shockwave will damage your lungs, eardrums, and other organs. As soon as the shockwave passes by, you should immediately find a well-fortified underground shelter and stay there for the next 48 hours. The radioactive material after the explosion diminishes exponentially, and after 48 hours you can already try to find your loved ones. And then you must leave the city and get as far away from the site of the explosion as possible.