Seven years after the triple meltdowns at the Fukushima Daiichi nuclear power plant, TEPCO, the company who own and run the plant, have finally managed to locate some of the melted fuel inside one of the three wrecked reactors. By sending a camera robot into reactor 3 they have confirmed that most of the 364 tons of melted nuclear fuel has burnt through the bottom of the reactor pressure vessel (RPV) and has slumped to the concrete floor of the primary containment vessel (PCV) underneath. TEPCO said they think that the molten fuel had escaped through the holes in the RPV, through which the control rods are inserted, by melting the graphite gaskets which sealed the holes. The designers used graphite because they assumed the reactor fuel would never melt down.
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