Here’s a map showing the per capita dose of radiation to thyroids in rads resulting from nuclear weapons testing at the Nevada Test Site from 1951 to 1962. Note that this is above-ground testing. Note also that the activities spewed all kinds of fission products and fuel over a wide area and well up into the atmosphere. Note also that these explosions irradiated all kinds of local materials, flora, and fauna, which was also hurled up into the atmosphere. Note also there were many separate explosions conducted at the NTS (between 200 & 300).

None of these things have the remotest possibility of happening in Japan.

Here’s some help putting this in context. There have been reports of radiation levels near the reactors being 1,000 times normal. Normal is about 5 microrems per hour. 1,000 times that is 5 millirems per hour near the plant. From our map above, we see that the highest dose is about 16 rads over an 11-years period. This is approximately 320 rem or about 30 rem/year. Let’s return to the area immediately surrounding the plant in Japan. If one were to remain in the area where the radiation levels are 1,000 times normal, that person would be receiving a dosage equivalent to about 40-45 rem/year, or about 50% more than the PDB’s immediately downwind of the Nevada Test Site did. Let me restate: They would have to stand there, sufficiently close to the reactors (within a hundred meters or so), for about eight months to receive the same dosage as the people of Southwestern Utah did each years for 11 years.

 (via Surgeon General Regina Benjamin Is An Idiot Open Comments | Hambone)