Pripyat is not dangerous to visit (you don't need to wear any suit at all, just regular clothes) but is very dangerous to live there for more than a few weeks (as samoselys - local settlers - do). You should stay away from the north block of the power plant of course. And you should have permission to visit it (you can buy a tour in Kyev) because there are many guards on borders of the area and trepassing is punishable.