Robot To Retrieve Fuel From Fukushima Nuclear Plant

nuclear, radiation

Two week mission for robot to retrieve sample of melted fuel debris from inside one of three damaged Fukushima nuclear reactors

A new recovery mission involving robots has started this week at the badly damaged Fukushima Daiichi nuclear power plant in Japan.

The Associated Press reported that a robot has begun a 2-week mission to retrieve melted fuel from inside one of three damaged reactors at the Fukushima Daiichi nuclear power plant in Sendai, Japan.

A massive earthquake and tsunami had hit Japan in 2011, and the catastrophic natural disaster resulted in 19,759 deaths, 6,242 injured, and 2,553 people missing on that island nation.

Damaged reactors

The tsunami damaged the plant’s cooling systems and resulted in the Fukushima Daiichi nuclear disaster, after the meltdown of three of its reactors and the discharge of radioactive water in Fukushima.

Japanese authorities were forced to enact evacuation zones that has impacted hundreds of thousands of residents.

Now according to the Associated Press, robots are on a new mission to retrieve fuel samples from the plant.

But this is not the first time Japanese authorities have attempted to use robots to enter the damaged plant.

The plant’s operator, Tokyo Electric Power Company Holdings (TEPCO), in April 2011 had used a pair of 60-pound military robots provided by iRobot, originally designed for such tasks as disarming bombs and combat zone surveillance, to enter reactor buildings at the stricken Fukushima nuclear power plant.

Fuel retrieval

However the new two week mission is the first time that robots will be used to collect a sample of the melted fuel debris, in what will mark the start of the most challenging part of the plant’s decades-long decommissioning.

TEPCO witnessing the work in the remote operations room.
Image credit TEPCO

According to the Associated Press, the new mission to utilise robots was initially scheduled to begin on 22 August but was suspended when workers noticed that five 1.5-meter (5-foot) pipes to be used to push the robot into the reactor had been arranged in the wrong order, TEPCO said.

Connecting push pipe to the guide pipe.
Image credit TEPCO

The equipment was reassembled in the right order for Tuesday’s attempt, the company said.

Once inside the reactor vessel, the robot is operated remotely from a safer location, AP reported.

The robot, nicknamed “telesco,” can reportedly extend up to about 22 meters (72 feet), including the pipes pushing it from behind, to reach the melted fuel mound, where it will use tongs to collect a fragment measuring less than 3 grams (0.1 ounce). It is expected to take about two weeks to obtain the fragment.

An estimated 880 tons of fatally radioactive molten fuel remains in the three reactors, AP reported.

Chief government spokesperson Yoshimasa Hayashi was quoted as saying that the mission marked the start of the most difficult phase of the Fukushima Daiichi cleanup.

“The government will firmly and responsibly tackle the decommissioning until the very end,” he was quoted as saying by the Associated Press.

The Japanese government and TEPCO have set a 30- to 40-year target for the cleanup, despite criticism it is unrealistic. No specific plans for the full removal of the melted fuel debris or its storage have been decided, AP reported.