Cesium shouldn't be in air unless Meltdown is occuring

Bill Nye-"The Science Guy" said this just recently on CNN. So, it is possible that the Japanese Government is trying to shield the already traumatized public from the possible fact that a full meltdown is presently in progress. So, once again, "Cesium should not be present in any air near the nuclear power plant unless a full meltdown is already in progress and the metal encasement has already been melted through in order for the Cesium to be released into the air."

So, people aren't any more terrified by all this than they might need be here is something I found from wikipedia that more technically explains all this. For those who can grasp what is being said in this excelent wikipedia article I hope this helps.
Wikipedia: Fukushima I nuclear accidents