In a survey using a robot of Fukushima Daiichi Nuclear Power Station Unit 1 that has been conducted since the 8th, it was confirmed in the video that there is a lumpy deposit inside the containment vessel where water has accumulated.
TEPCO has decided to continue the investigation, considering that there is a possibility of "fuel debris" in which the nuclear fuel in which this deposit is melted and the structure are mixed.
TEPCO began a robot-based investigation at Fukushima Daiichi Nuclear Power Station Unit 1 on the 8th, and on the 10th, newly released images and photographs taken inside the containment vessel.
In the video, you can see the massive deposits inside the opening of the structure called "pedestal" that supports the reactor of Fukushima Daiichi Nuclear Power Plant Unit 1.
Regarding this deposit, TEPCO explained, "Because it was found right under the reactor, there is a possibility of'fuel debris'."
In addition, the data of the radiation measuring device built into the robot was also released, and the radiation dose when the robot passed through the storage container of Unit 1 was 1 to 2 Sv per hour.
In the future, TEPCO plans to introduce another robot to measure the thickness and distribution of sediments with ultrasonic waves, and to collect a small amount as a sample for detailed analysis.
The removal of fuel debris is considered to be the biggest difficulty in the decommissioning of the Fukushima Daiichi nuclear power plant, and while deposits that appear to be fuel debris were confirmed at Units 2 and 3, they were not confirmed at Unit 1, and this survey was conducted. It will be noticed if you can get a clue.