It's likely to be a 10Kt detonation, which means that anyone within a few miles is toast, anyone outside 10=20 miles will be OK, but the radiation cloud is the long term killer. Mostly anyone outside 30=40 miles from the blast zone should be fairly OK as the cloud would have hopefully dissipated to such an extent that exposure will be minimal and no major upturn in cancer rates will be seen. I'm over 75miles from the blast zone, so will OK to a certain extent. We'll only really be able to tell by how much over a period of decades.