daini site that are at risk. nothing like this ever happened in the nuclear power industry. we are in unchartered territory. >> in terms of worst case scenario, i don't know much about nuclear disaster, but i think i know chernobyl did not have a containment facility around their reactors and that blew up and these reactors do. does that mean this is a qualitatively different thing? >> most experts are not thinking there's that great risk of explosion at these sites, but it could happen if the containment vessel gets too much pressure built up. as you noted on the show, they now have two times the design pressure building up inside the containment vessels, so it is not out of the question, it is just considered unlikely at this point. and as ed lymon said, it is a high plume of radioactive material. probably nothing like that. it is probably more like three mile island scenario, in the