Human workers (as opposed to robots) were sent to survey the upper floors of Reactor 1 at Fuku-I on October 18. The workers spent most of their time on the 4th floor, checking the integrity of the pipes for Isolation Condenser system. You do get to see the 3rd and 2nd floors toward the end of the video. Robot workers (like Quince and Pacbots) wouldn’t be able to navigate through the debris on the 4th floor.
The radiation level was high on all floors, as they were calling out the numbers at various locations. Warm, orange glow coming from outside through the collapsed ceiling. One worker said “The ceiling looks more collapsed than before.”
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