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Destroyed reactor building in Fukushima

Photo: Kyodo News / IMAGO

The Japanese power plant operator Tepco sent a drone into a damaged reactor at the damaged Fukushima Daiichi nuclear power plant on Wednesday.

It is intended to help examine melted fuel residues in the radioactively contaminated plant that previous robots had not been able to reach.

The drone is part of a fleet of four devices.

They are supposed to fly one after the other into the primary containment container in the most damaged reactor 1.

The first two drones will investigate the situation before the other two, if all goes well, move into areas that have not yet been examined.

TEPCO officials said they want to use the drone data to develop a method to remove the melted fuel from the reactor.

According to the AP news agency, the drones are about the size of your hand and weigh 185 grams each. They are said to be particularly maneuverable, but still hardly stir up any dust.

They are equipped with a high-resolution camera that sends live videos and images to a situation center.

Short battery time

The first flight on Wednesday was preceded by months of preparation and training on a dummy outside the facility.

The examination of the inside of the reactor is limited to around five minutes due to the battery life of the drones.

In the past, TEPCO has sent various probes into the reactors, including a crawling robot and an underwater vehicle.

Although they collected some data, their work was hampered by debris and radiation.

For example, the first robot got stuck on a grid in 2015 and had to be abandoned.

Cleanup work behind schedule

In March 2011, an earthquake and tsunami destroyed the power plant's power and cooling systems, leading to meltdowns in three reactors.

Inside the reactors there are still around 880 tons of highly radioactive melted nuclear fuel.

The Japanese government and Tepco have announced that they will remove the remains of the reactors within 30 to 40 years.

However, the plan continues to be delayed and is viewed by critics as overly optimistic.

TEPCO actually wanted to use a special robot arm to remove a small amount of melted debris from the least damaged reactor 2 as a test by the end of March.

However, the work was postponed for months because an obstacle blocked access to the reactor.