Here's my layman's take: Don't believe a WORD the Japanese authorities say. The most accurate assessment is what was told to the Times by one official, that the nuclear plant operators are in "full panic mode." The latest announcement from the Japanese Prime Minister struck a more somber tone. He urged people within a designated 30-plus kilometer perimeter of the stricken nuclear plants to stay indoors in order to avoid radiation contamination, STRONGLY suggesting there has been a MAJOR release of radiation into the atmosphere.
My advice to Chris Jansing (I like her) is get the HELL OUT OF DODGE. The French and German governments (reportedly) have instructed their citizens to leave the country. The French Embassy in Tokyo said radiation could reach that city in 10 hours. The same advice goes for the rest of the media over there. Radiation is colorless, odorless, invisible, AND LETHAL. Unless they're carrying geiger counters, they would be wise to get away. Anderson Cooper doesn't seem to care, but Dr. Sanjay Gupta, who knows a little more about this kind of stuff, looks grim, and very uneasy being there.
Finally, do not believe much of what you hear on the MSM. Take it all in with a grain of salt. They've probably passed the word out at the production meetings not to alarm the viewers, etc. When it comes to the potential deadly hazards to health from widespread radiation contamination carried in the atmosphere, a little alarmism is a good thing. Government health department assurances from the U.S. and Canada that the radiation gets diffused in the atmosphere are meaningless, considering the worst-case scenario — a "China Syndrome" — without any yardstick as to the maximum levels of radioactivity that can be released into the atmosphere from THREE OR FOUR REACTORS PLUS SPENT FUEL RODS, WHOSE CONTAINMENT BUILDING IS REPORTEDLY ON FIRE.
The truth is, no one can say for sure how much radiation will eventually make its way in the Jet Stream to the United States and Canada, and how concentrated (rather than diffuse) it may be. If the media is going to hang around the area as a meltdown disaster unfolds at those plants, then take Dr. Michio Kaku's advice, and have a geiger counter on hand. As for the rest of us, stateside, is OK TO FREAK OUT! (Even Rachel, after her show is done ...)