[PTTG]

I figure that even one super-critical reactor that fails badly with no human supervision will be pretty bad, even if it's just a conventional fire ignited by corium. A long, lingering radioactive fire just is not good.

As for the other plants, grids are pretty fragile, and most plants will enter alarm states soon even if they are still technically functioning. In one interview of a hoover dam tech, he said that the dam would shut down within a day or two just because of deadman's switches.

I assumed that there was a period where technicians shorted out some sensors just too keep the generators working as long as possible without maintenance.