Canticle, like many novels of its era, was set in a new dark age after humans had destroyed so many of their own and so much of their civilization, leaving behind a mutant planet. It didn’t take a lot of smarts to know how they did that either: with the newly discovered power of the atom -- already loosed on the perfectly real cities of Hiroshima and Nagasaki -- aided and abetted by the hubris and bumbling of humanity. (I hope, given the headlines of the moment, you see where I’m heading.)
It's a natural comparison for someone raised in those days to make, although to be fair there's a big difference between a meltdown and the global thermonuclear war depicted in those books. Lester del Rey's Nerves (1956, revised 1976) which involves "atomjacks" fighting to avert a catastrophe at an atomic power plant might be a more apt reference, although it obviously isn't widely known. When it comes to the aftermath of such a crisis, the book that sprang to my mind was Michael Swanwick's In the Drift (1985) which depicts just the kind of irradiated exclusion zone we all fear might result if worse comes to worse.