You can absolutely do AA as an atheist, I do, but without a *higher power* of any sort, I don't really see how it works. However I wouldn't let that keep you from going to some meetings and see what you get from it.
Group acceptance is another matter. Some will accept you with open arms. Others won't, they have their own preconceived notions of what kind of people atheists are. *shrug* I have found more acceptance than rejection.