TEPCO send the workers to Reactor 2 building on January 27 to drill a hole through the 1st floor to the torus room. The location was carefully chosen so that they would have a clear shot at the water accumulated in the torus room. Through the hole, the workers were to feed the camera, dosimeter, and thermometer.
Surprise! When the workers managed to carefully drill a hole and looked in, huge pipes and gratings were in the way, and there was no way for the workers to do the planned work at that hole.
From TEPCO's Photos and Videos, 1/28/2013, "Drilling Holes for the Investigation of Unit 2 Torus Room at Fukushima Daiichi Nuclear Power Station":
From the handout, this was what TEPCO had planned:
How did this happen? TEPCO chose the location because there wasn't supposed to be anything, according to the original drawings. However, as repairs and renovations were done over the years, the original drawings from the time the reactor was built became obsolete.
Don't they have the drawings of those repairs and renovations? Yes they do. But those drawings were stored in one of the buildings that was devastated by the March 11, 2011 earthquake and declared too dangerous to enter. There is no information as to whether anyone has gone back in to retrieve any document or data from the main building. Probably not, because, as we know well by now, TEPCO carefully abides by the rules and regulations from the authorities:
(Photo of the 2nd floor of the main building, Fukushima I Nuke Plant)
Independent journalist Ryuichi Kino tweeted:
It has been known that it is difficult to completely grasp the condition of Fukushima I Nuke Plant. The basic structures of reactors have been the same since the plans were drawn up, but pipes and other small facilities were added and modified later, making the current condition vastly different from the original condition. Therefore, any work that has to do with the structures have been carried out very carefully.
One such example: TEPCO had a difficult time in confirming which pipe to use for nitrogen gas injection and for cooling water injection, because the pipes had been switched around after repairs and renovations. Nuclear and Industrial Safety Agency knew this, and was aware that it was not easy. I once asked NISA, where, then, are the drawings that will allow us to grasp the current condition?
They answered, all the drawings and documents from construction work are stored in the main building at Fukushima I Nuke Plant, and therefore they couldn't go in and retrieve them. The main building was devastated by the earthquake, and declared off-limits.
That was about one year ago. I have to ask again if someone did go to the main building to retrieve the documents. However, the most recent work [drilling a hole through the floor of Reactor 2] revealed unexpected pipes right there in the middle of where they were not supposed to be. So I wonder.
If they cannot grasp the current condition, the best they can do is to do the work in the areas that they are able to see. That wold affect the work not just in Reactor 2 torus room but everywhere where human workers cannot enter. Robots may be able to enter, but [since no one knows the actual condition of the place] no one can give directions to the robots. It is as if they feel their way in the dark, as they continue the work to end the accident.