Do keep in mind that even in a worst-case scenario, a light-water reactor can't produce the extreme radiation release that the Chernobyl reactor did. That one was graphite moderated (it was a dual-purpose reactor representing an awkward compromise between weapons production and power generation), and the upshot was that it had a HUGE reactor core moderated with flammable graphite, and no containment vessel to speak of (just a relatively flimsy building surrounding the reactor). When the idiots running the reactor caused the steam explosion that breached the flimsy building, the graphite in the core caught fire (oxygen + superheated carbon = sooty fire), and it was the smoke that caused most of the fallout.
The "ingestion zone" is the area where you might have a problem if you are EATING stuff from your garden or whatever, but I don't think prompt gamma exposure from fallout would be a consideration at all. Might want to look into that a bit further, but your main danger would probably be from people panicking and getting into car accidents, not from radiation issues.
