What is the US doing to prepare for a worst case Japanese nuclear meltdown now that it looks likely?

This morning, 3-15-11, a New York nuclear physicist said the additional blasts mean the Daiichi plant may have reached the point of no return, and should immediately be covered with sand and cement like they did to contain Chernobyl. That is not happening, so what steps are being taken by the US(or other countries) to monitor radioactive clouds, radioactive seawater(and the marine life in it that might become food), radioactive fallout on crops so they do not get sold, and make potium iodide pills available BEFORE the potential fallout arrives or give people the information they need to voluntarily evacuate? We have perhaps a 1 to 3 week window of time to be proactive on the west coast of Americas, depending on when the meltdown occurs, and do not want same lack of information, false reurances, and reliance on the nuclear reactor industry that Japan is undergoing in the face of this catastrophe. While we can hope for the best, it is better to be prepared than sorry.