Don't worry kids, i believe this is supposed to be if there is actual nuclear meltdown... as in the entire core melting and what not.
At the moment the current radiation in the immediate area is 128 mrems per hour which is the equivalent of smoking about 17 cigarettes per hour. This is in the immediate area. The radiation that is being leaked right now doesnt stay radioactive long and turns to no radio active particles.
The people who were exposed initially while waiting were unfortunately exposed to the initial gust of radiation before it had began turning into its non radioactive state.
According to pretty much all the research out there, it will only be days for the surrounding area to go back to normal and they expect the people to be able to go back to their homes sooner than later.
A full dental x-ray causes up to 5000 mrems.... they are being exposed to 128 mrems per hours. So a bit over a day and a half is = to getting a dental x-ray.
As far as people testing positive to radiation... apparently eating a few bananas can do this....
as far as being 1000x above normal, this is because living next to the boundary exposes you to less than an additional 5mrems per year.
Read the radiation stats from here... its pretty interesting
http://www.physics.sfsu.edu/~bland/courses/490/labs/b1/b1.html
USA lost many lives on 9-11-01
Now, Japan has lost more lives on 3-10-11
Add the 2 dates together and you'll get 12-21-12
something to keep in mind...