covered, it will heat up, and at some point it will begin to release radioactivity. there is, in fact, some evidence that a small amount of radioactivity released has already occurred. there are reports of iodine being measured both in the reactor and possibly also outside, which suggests that there's been at least some failure of the fuel. but it remains to be seen how long it will take, of course, to get more water in the core. the key thing is to get water in the core. as matt points out, at the moment they're limited in their ability to do that because of the loss of the diesel generators. >> matthew, let me come back to you. if the doomsday scenario does occur and we see a meltdown with radiation, what will that do to the environment in japan and what does it mean for nuclear