The setting for my story is a post-post-apocalyptic Earth. There was a nuclear war (and several related nuclear disasters due to power plants being either targeted or neglected), and it's already been almost 300 years since that event.
A small portion of humanity stuck themselves down in bunkers for the better part of this time (kinda like in Fallout) and is only just beginning to re-emerge on the surface. Nature has reclaimed much, if not all, of the world and what's left of cities is pretty much unrecognizable from what they are today.
I was hoping to have minor conflict related to people having to deal with lingering radiation in certain areas, but googling has given me mixed information regarding how long that sort of stuff would actually last and none regarding what areas would be safer or more dangerous over time.
The question: Is is possible for radiation to linger in dangerous quantities after 275+ years? If so, what areas would be more dangerous after this amount of time? Are there any significant affects on the environment that this much lingering radiation would cause?
Nuclear winter is a thing that could have happened for a short period but not to such a degree that it would wipe out all life on the planet (the fallout would ideally be less smoke and ash and more radioactive debris getting as everywhere as it could in populous areas) since things need to be more or less "back to nature". I don't want the radiation to be something that everyone needs to worry about everywhere at all times, but something that should be a concern when going to specific places.
I am perfectly happy if such conditions are impossible to meet, but would appreciate clear answers as to why.
Please make a comment if I need to clarify anything and I'll do my best.