I would close my windows, turn the air conditioner on, replace the filters frequently, damp mop, put a HEPA filter in the house and try to avoid as much of the hot particles as possible. You are not going to walk around with a Geiger counter at your side. The issue on the West Coast will be dealing with hot particles. And the solution is HEPA filters to avoid them.
Radiation is concentrated in milk. Therefore, when high doses of radiation are being released into the air, we might want to avoid milk altogether for a couple of weeks or so. (Radioactive iodine concentrates in milk, but it has a half-life of only 8 days. So avoiding local milk for a couple of weeks should help keep you safe.)
A number of scientific studies conclude that Vitamin A helps to protect us from radiation. See this,this and this.