Only places I've ever been able to count on a break was when I worked in the clinics, and they would
close the clinic for one hour.
BTW, I don't agree with rascal's view that this is somehow acceptable because we "serve others". You can't be an effective caregiver unless you take of yourself, and burning yourself out by not getting a break IS NOT OKAY. Even when I worked a busy high-risk L&D unit, we still covered each other for breaks. The pace was just too fast to go a full 12 hours without some sort of break. If you are working on a unit that isn't supportive of this concept, then LEAVE.