If you are worried about California radiation, or Radiation Tokyo, then you may want to know that there is over 25 million tons of debris- roughly the size of California that is headed for the US West coast.
This debris is from the destruction of the earthquake that hit Japan in March 2011.US Oceanographers say this debris could include anything from cars, shills, human remains etc.

Already the first pieces hit the US in late 2011.More is expected to arrive over the next two years. However it is hard to pinpoint exactly where it will land.
The EPA and US Coast Guard are organizing a clean up operation. However the agency says they are not sure about the size, whether it will be above or under the surface etc.
There is doubt as to whether they will be any radioactive materials in this debris.
The International Pacific Research Center has developed a computer simulation of how the debris is expected to travel. See the video below.

There is also danger from nuclear plants in the USA.See video below.

One of the best ways to protect themselves from this doomsday scenario is to have a radiation dosimeter handy.That can warn someone when there is high levels of radiation in one’s environment.