particles being released by those damaged spent fuel rods. by those uranium pellets in the big now probably damaged metal tubes. this is not a nuclear explosion. there are not nuclear chain reactions going on here, but this is a means by which radioactivity is being released into the atmosphere, and the question is whether or not those fuel rods, even if they're already damaged, whether they can be resubmerged. japanese officials floated the idea of helicopters dropping water on them today. they raised the idea of fire trucks or fire hoses being used to get water on them. we're now going to turn to some expert help in trying to understand what the best hopes are for getting the situation under control. joining us now is nuclear physicist, frank von hippel. he is the co-founder of a program at princeton. mr. von hippel, thanks for being here. >> my pleasure. >> tell me what i got wrong in the explanation. >> it was terrific. i don't thing -- the one thing i