Footage released by Tokyo Electric Power Co. on July 24 shows what is believed to be nuclear fuel debris. The lumps are scattered at the bottom of the containment vessel of the No. 3 reactor at the Fukushima No. 1 nuclear power plant. (Video provided by the International Research Institute for Nuclear Decommissioning)

What is believed to be nuclear fuel debris scattered inside a reactor of the crippled Fukushima No. 1 nuclear power plant can be clearly seen in video footage released by Tokyo Electric Power Co. on July 24.

The four-minute video shows nuclear fuel debris dispersed in an area measuring about 5 meters in diameter directly beneath the No. 3 reactor’s pressure vessel. The video comes from 16 hours’ footage filmed by a remote-controlled submersible robot during a survey by plant operator TEPCO on July 19, 21 and 22.

The released video also shows craggy-shaped material that appears to be nuclear fuel debris hanging like an icicle from equipment at the bottom of the pressure vessel.

As the camera-equipped submersible robot advanced toward the bottom of the containment vessel, it captured how pipes and structures had collapsed in a heap.

Although the company thinks such lumps are highly likely to be nuclear fuel debris due to their shape, it has yet to determine exactly what they are. It is because TEPCO could neither measure radiation levels nor collect material in the probe for analysis.

The operator plans to analyze the collected footage in the days ahead to ascertain the extent of scattered debris.

If, or when, any further robot probe is conducted has yet to be decided.

“We have yet to plan a new survey so far,” a TEPCO official said.