They have a picture of the crack in this video. Looks like it may be the one they are talking about. Although they claim the crack is in a wall of the pit. That looks to be the ceiling of the pit, assuming the pit is covered.
Radioactive water leaking from No.2 reactor crack
I think they are showing a crack in the ceiling, too, since they can’t show the other one. The one in the video is certainly not 8 inches wide. I wonder how (if) they reinforced that concrete.