One of the several brave robots to make one-way trips into Fukushima Daiichi Nuclear Power Plant’s severely damaged reactors has accomplished what its less fortunate compatriots did not, sending back photos of what appears to be melted nuclear fuel from the interior of the ruined facility.
The remotely controlled Toshiba robot, which is similar in design to a submarine, managed to gain some glimpses of “a hardened black, grey and orange substance” pooled below reactor No. 3, Bloomberg reported on Friday. Officials with Tokyo Electric Power Co. Holdings Inc. believe the substance is the remains of atomic fuel rods, which melted through and fused with other structural components of the reactor.
Identifying precisely where the melted-down materials are, and what they are composed of, is critical to the ongoing Tepco cleanup efforts.
“Never before have we taken such clear pictures of what could be melted fuel,” utility official Takahiro Kimoto told reporters, per Bloomberg. “We believe that the fuel melted and mixed with the metal directly underneath it. And it is highly likely that we have filmed that on Friday.”
After the 2011 Tōhoku earthquake and tsunami triggered the plant’s meltdown, over 100,000 people were evacuated from a 30-mile radius around the facility. The reactors at Fukushima remain extremely dangerous: In February 2017, radiation levels inside reactor No. 2 reached at least 650 sieverts per hour, enough to fry a person in seconds and destroying the electronics inside Tepco robots.
While the cleanup is expected to take decades and has an estimated $72 billion price tag, authorities are confident enough the area surrounding the plant is now safe they began the process of resettling evacuees last year.