Fukushima operators send robot into worst-hit nuclear reactor

The damaged Unit 1 reactor at the Fukushima Daiichi nuclear power plant (AP)

A remote-controlled robot has been used to probe the hardest-hit nuclear reactor at Japan’s Fukushima plant, as officials push forward with clean-up operations that have been mired in delays and controversy.

An earthquake and tsunami in 2011 unleashed a disastrous meltdown at Fukushima Daiichi’s three reactors that partly sunk their radioactive cores into the plant’s concrete foundations, making removal extremely difficult.