Radiation levels in the U.S., particularly on the west coast, will continue to gradually increase so long as the Fukishima plant keeps spewing out radiation.
You would probably get more radiation standing in your basement though. Still, this sucks for the Japanese. and the nuclear power industry.
Anyway, my son (PhD physics), is presently living in the LA area and said that he's not worried about any radiation from this incident but does take comfort in having the potassium iodide. So....