More than that.
Survivable in the sense that the vast majority of humanity would only have to deal with fallout and the social/economic disaster of a major atomic attack.
Not insignificant challenges, to be sure, but essentially if you are ten miles or more away from even a multi-megaton blast, and have the knowledge to deal with fallout, you could survive the effects of the bomb if you knew what you were doing. Other nations dealt with this realistically. We didn't.
The technical details are probably too much for this thread but it wouldn't suck for people to learn how to deal with radiation disasters anyway. Nuclear accidents or dirty bombs are still real dangers.