The Tokyo Electric Power Company in Japan (Tepco) has confirmed the discovery of molten debris suspected to include melted and resolifidied fuel at the bottom of the Unit 3 containment vessel at the Fukushima Daiichi Nuclear Generating Station.
Stabilization and decommissioning efforts at the plant have been slowed by the lack of solid proof of the location of the melted fuel in the three damaged reactors that suffered meltdowns just after a massive tsunami hit the plant, taking out back up power in March 2011. On Friday, it was suspected that the robotic probe called the Little Sunfish – a swimming, underwater probe – had filmed what looked to be melted fuel on the pedestal area of Unit 3.
Previous dry probes sent into the reactor containment vessels 1 and 2 had quickly failed due to the extremely high radiation levels that would kill a human in minutes, if not seconds.
A three-day probe of Unit 3 by the Little Sunfish was concluded Saturday. “From the pictures taken today, it is obvious that some melted objects came out of the reactor. This means something of high temperature melted some structural objects and came out. So it is natural to think that melted fuel rods are mixed with them,” said,” Tepco spokesperson Takahiro Kimoto, who also confirmed that the material would be analyzed for removal on the basis of it being resolidified nuclear fuel.
“That debris has apparently fallen from somewhere higher above. We believe it is likely to be melted fuel or something that has mixed with it,” the spokesperson said.
At the bottom of the reactor is about 20 feet of water. Technicians surmise that the melted fuel also melted its casing and other metal inside the reactor, all of which reformed as solids when it cooled.
The company said it would be analyzing the data for the next year, aiming to design a retrieval system for the toxic material by 2021.
Anonymous comments will be moderated. Join for free and post now!