Some reports[1] indicate radioactive iodine and cesium are being detected at monitoring stations. How could that happen if confinement hadn't failed? (fuel ro

Some reports[1] indicate radioactive iodine and cesium are being detected at monitoring stations. How could that happen if confinement hadn't failed? (fuel rods melting, containment failure of the reactor vessel and/or primary coolant loop, and the obvious lack of a containment building at this point) Based on the description of two-stage containment for BWRs at wikipedia[2], and the video, if that's the containment strategy at Fukushima, it seems the drywell containment structure blew up, since steam being vented into a pool of water shouldn't cause a visible breach. [1] http://e.nikkei.com/e/fr/tnks/Nni20110312D12JF520.htm http://e.nikkei.com/e/fr/tnks/Nni20110312D12JF520.htm [2] http://en.wikipedia.org/wiki/Containment_building#Boiling_water_reactors http://en.wikipedia.org/wiki/Containment_building#Boiling_wa...