There is a lack of information coming out of Japan, and America media is failing to cover the news. They have more pressing matters such as what Charlie Sheen is doing.
International news sources cover it much better then MSM does. However reading between the lines, you can find that here the EPA is raising what the "safe" levels of radiation is, half their monitors have been taken down that monitor radiation, and the units being used to measure radiation are being changed or reported in metric values that most Americans cant convert.
This is by far a much worse disaster then Chernobyl was, and the dumping of over 10000 tons of radioactive water into the ocean will have repercussions for years to come. While some of the radiation that was released has only a 8 day half life, some of the other has a half life of upwards of 50 years.
Browse foreign news agencies, read between the lines, and don't be afraid to research on your own what you can find.
The truth is we were told there was initially no chance of radiation reaching the US. Then we were told trace amounts were found, then it appeared in milk, rain water, and the air, and the limits were raised so it was still reported as safe.
I am not advocating running out and building a fallout shelter, but stay as informed as possible.