Cosmic beams reveal melted core inside Fukushima No. 2 reactor

Researchers harnessing

The Nagoya University team "looked into" the interior of the reactor using special equipment to examine subatomic particles known as muons passing through, producing images similar to an X-ray.

The researchers also used the method to study the core of the No. 5 reactor, which did not enter a critical state after the facility was overcome by the tsunami generated by the Great East Japan Earthquake.

As the images showed fewer signs of substances inside the No. 2 reactor compared with the No. 5 reactor, the team concluded that the fuel inside the former had fully melted.