On the 12th, TEPCO conducted an internal investigation of the containment vessel of Unit 1 of the Fukushima Daiichi Nuclear Power Station and attempted to collect deposits that were presumed to contain "fuel debris." The robot could not be put in, and the work was stopped.
TEPCO has been conducting an internal investigation of the containment vessel of Fukushima Daiichi Nuclear Power Station Unit 1 since February last year, and last month analyzed the radiation of the deposits around the structure that supports the reactor, and determined that the nuclear fuel had melted down. It was presumed that so-called "fuel debris" mixed with surrounding structures was included.
In the investigation on the 12th, there was a plan to introduce a new underwater robot and collect the surface material of this sediment, but according to TEPCO, there was a problem with the device that sent the robot into the containment vessel, and the work was canceled. It means that
The robot was recovered, but the cause of the trouble is unknown, and there is no prospect of resuming the investigation.
TEPCO plans to collect sediments that are presumed to contain "fuel debris" at four locations in the containment vessel of Unit 1, analyze the types and amounts of elements contained in the sediments, and examine the waste. We would like to collect knowledge for the retrieval of "fuel debris", which is considered to be the biggest difficulty in reactor work.