I had heard estimates of 30.
On another note, the plumb of radioactive water that is spilling into the ocean from Japan should reach the north american shores in about 2014. It is good that it happens on the side of Japan that it did, because of the turbulent water diffused it. .. so it might not be as bad as if it wasn't defused. On the other hand.. I am not going to be eating sea food for a while.