Yeah, they die after a couple of hours. I tried replanting them over and over but it didn't seem to help.
If all else fails, I plan to build my trade buildings (depot, processors, recycling centers, etc) on top of the radiation because they seem to still function. The problem is I will have a lot of pissed off, sick Sims. Maybe I'll give them a hospital too.
---------- Post added 2013-03-15 at 08:12 PM ----------
Oh, if there is a lesson to be learned from this: don't AFK in a city with a nuclear power plant and medium education Sims.