and then over that is a concrete dome, a secondary containment, that's supposed to serve as an extra barrier of protection. what we don't really know or completely understand is, in reactor 2, what has been going on here and if there have been explosions and other events that have compromised the primary containment or have cracked or created problems for the secondary containment. so we're still sort of operating in a situation where i'm not sure we have a complete picture. >> right. to your point, we're piecing some of these bits of information we're getting together. >> well, not only that. the people on the site don't necessarily have a complete picture of what's going on. >> you know what? i'm glad you brought that up because i know it's a group of some 50 or so workers. robert alvarez, we're going to continue this conversation in the next hour because i have so many more questions for you,