TEPCO restarts removal of radioactive debris from Fukushima

SMALL-SCALE removal of radioactive debris has restarted at the Fukushima Daiichi nuclear site, accelerating the decommissioning of one of the world’s worst nuclear disasters.

In an operation expected to last two weeks, a robot is retrieving a sample of melted fuel debris from one of the site’s three reactors, reports AP News.

More than 13 years ago, a major earthquake and subsequent 15m tsunami disabled the cooling processes for reactor Units 1–3 at Fukushima Daiichi.

This led to a meltdown, with nuclear fuel from the three units overheating and melting the cores of the reactors. Several chemical explosions followed, and radioactive material leaked into the atmosphere, prompting an evacuation and the site being marked off.

Around 880 t of radioactive melted nuclear fuel remains in the reactors, and the plant’s operator, Tokyo Electric Power Company Holdings (TEPCO), says decommissioning of the site could take 30–40 years.

Robotic probes

TEPCO has previously used robots to probe and survey the site, but the debris removal operation is the first time a sample has been taken from one of the reactor units.

Removal works were scheduled to begin on 22 August, but were suspended when TEPCO’s team noticed the pipes pushing the 22 m robot, nicknamed Telesco, were arranged in the wrong order.

With the piping reassembled, Telesco is in the process of collecting a 3 g fragment of debris that will be used to give TEPCO a better sense of the condition of the reactors.

A three-step plan

The debris fuel removal operation is being carried out in three steps, with the first involving probing and collecting research samples from the reactors.

The debris will then be transported to newly designed containers stored at the nuclear site.

TEPCO said: “We will continue to work with a sense of urgency, prioritising safety, towards completing the decommissioning process.”