I work with nurses. The vast majority of them are lovely people, but I’ve seen the nurse cliques you are talking about. So has my wife, who also works with nurses. I’ve seen departments of nurses with that “mean girl” vibe that require long-term HR intervention because they are so toxic to one another.
If you see this kind of behavior, run for the hills. However, if you are just talking about normal human interaction to pass the time and socialize, then it is you who are not conforming to normal social expectations. You don’t have to conform, of course, but there are consequences to being anti-social.
The question is, are you an introvert or a misanthrope? An introvert needs alone time to recharge and that’s fine. A misanthrope doesn’t like people, no doubt because of some childhood trauma. If the latter, then therapy might help.
If you truly are an introvert who needs alone time to recharge, I’d suggest “going home to check on the dog” during your break. Even if you don’t have a dog. The point is that you need alone time and that’s perfectly valid.
If you are generally sociable, but simply find their particular conversation boring or insipid, I’d suggest training for something where the work culture is more professional. Regular hospital floor nursing almost always has a “break room culture” and it is easy to get trapped in it, but there are lots of alternatives. Learn surgical assisting, for example, or become a nurse practitioner. Street nursing, public health nursing, and home care nursing are all examples where there is no real break room culture. Or get into management, where there are no breaks.