thought

I think one- third of Japan is already not suitable for ordinary human life because of the high level of radioation

For example some part of Tokyo, Ayase shows 3.89 micro siebert per hour


I think evacuation or forced evacuation is under realistic agenda


In this case some people are heading for the western part of Japan, though,  others are wanting to go abroad - China

China has 64 million vacant housese

India, Kuril, Siberia, Brazil are likely, though not know to what extent

And contamination of USA, especially west coast and Washington and Oregon state  are real

Jet stream constantly brings radioactive plume from Japan to the USA 

Once Japan start burning radioactive debris, radioactive concentration  proceeds to 33 times and that brings more contamination over the land of USA