Robotic arm, radioactive debris… what is this exceptional mission carried out in one of the Fukushima reactors ?

The Fukushima nuclear disaster is one of the major events in Japanese history. It comes in the wake of the tsunami of March 11, 2011. The operator of Japan's Fukushima nuclear power plant announced Monday that it would send a probe inside a malfunctioning reactor this week for a test to remove radioactive debris.

Equipped with a robotic arm, it is expected to take about a week to reach the radioactive debris inside the reactor and reappear with the sample next month.

880 tons of radioactive debris

The Tokyo Electric Power Company (Tepco) is aiming to retrieve a tiny sample of the estimated 880 tons of radioactive debris believed to be inside the reactors of the tsunami-hit nuclear power plant. The sample will be studied to obtain clues about the condition of the reactors' interiors and their hazardous contents, a crucial step towards the decommissioning of the plant.

The decommissioning of a plant aims to ensure that the dismantling and the resulting waste management can be carried out safely and efficiently without negative impacts on the environment.“We will proceed cautiously with safety as our top priority,”, a Tepco official said at a news conference on Monday.

Decades of decontamination

The debris has such high levels of radiation that Tepco has had to develop specialized robots that can withstand it to operate inside. Removing it is considered the most daunting challenge in the decommissioning project. The colossal work of decontaminating and dismantling the plant is expected to last several decades.

Three of Fukushima's six reactors were operating when the tsunami struck on March 11, 2011, destroying cooling systems and melting them, causing the worst nuclear disaster since Chernobyl. At three units of the Fukushima plant, fuel and other materials melted and solidified into highly radioactive “fuel debris”

Wastewater from the stricken plant in the Pacific Ocean

The operator of the stricken Fukushima nuclear power plant sent two mini-drones and a snake-shaped mini-robot into one of the three badly damaged reactors in late February, where tons of melted, highly radioactive fuel and debris are stored. The operation had been halted due to technical problems. The snake-shaped robot failed to reach its destination because its cables were not working properly, the Mainichi daily reported.

Japan began dumping wastewater from the stricken plant into the Pacific Ocean nearly a year ago after the International Atomic Energy Agency (IAEA) gave the green light. The move sparked a diplomatic row with China and Russia, both of which have banned seafood imports, though Japan insists the dumping is safe, a view supported by the U.N. atomic agency.