I don't think we are getting the full story here, but this guy doesn't know what he is talking about. Xenon 133 is not only produced in nuclear explosions but in fission in general, or fusion, etc. Also he refers to radiation levels as "high" and "mid level". All he is going by are colors of intensity on a graph! Let's talk in real quantities. Taking a leisurely stroll to wikipedia and not bothering to even read charts you are referencing closely is not going to inform anyone else.
The presenter cites a nuclear explosion...I think this is irresponsible exaggeration.IMO a more accurate term would be a continued or spontaneous, uncontained release of fission byproducts. We don't know where they are coming from (reactor core breach, or spent fuel pool).There's a group called fairewinds associates whose presentations do a good job of analyzing the situation:http://www.fairewinds.com/updatesThey point out Tellurium-129 and Chlorine 38 levels that would indicate that a core containment has failed and inadvertent criticality *must* have been reached - because Te-129 has a like 70 minute half life and the chlorine isotope could only reasonably have been produced from neutrons hitting chlorine 37 which is present in seawater.http://player.vimeo.com/video/21881702
Everyone is encouraged to participate with civilized comments.