It took 51 workers (from TEPCO and Hitachi-GE Nuclear Energy, most likely) 3 hours on October 11, 2012 to probe again the Containment Vessel of Reactor 1 at Fukushima I Nuclear Power Plant.
TEPCO's handout for the press (Japanese, 10/11/2012) says the maximum radiation exposure for the workers was 1.83 millisievert. TEPCO does not say how many groups of workers went in, and how long each group spent inside the reactor building.
Tomorrow (October 12), TEPCO will send in the workers again (no information if they are the same ones who have been going there every day since October 9) to collect water samples. On October 13, the workers will go there again, and install a thermocouple and a water gauge inside the Containment Vessel, again using the same penetration.
This is the abbreviated version of the full video which is nearly 1 hour and 40 minutes long (which you can download for your record, here):
It is simply infuriating to think all this work may not have been needed if enough people at TEPCO had dared to break the rules and social niceties on March 11, 12, 13. Even more infuriating that most Japanese still don't get it.