Robots to clean up stricken Fukushima Daiichi nuclear power plant
Robots are to remove the radioactive debris from the damaged Fukushima Daiichi nuclear power plant. A first test run is to be followed by others.
A view of the inside of reactor 1 at Fukushima Daiichi. A snake-like robot can be seen in the middle, examining the reactor.
(Image: TEPCO)
Tokyo Electric Power Company Holdings (TEPCO), the operator of the Japanese nuclear power plant Fukushima Daiichi, which was destroyed by a seaquake in 2011, intends to send robots to the contaminated plant this year to retrieve melted, highly radioactive material. The company has now carried out initial tests with robots. It was possible to pick up tiny pieces of simulated fuel element fragments using a remote-controlled robot.
The removal of the melted fuel elements in the Daiichi 2 reactor unit was actually supposed to have begun by the end of 2021. However, the clean-up work turned out to be more difficult than expected, resulting in repeated delays. TEPCO has now taken a first step and salvaged granulate from a pile of gravel at the Mitsubishi Heavy Industries shipyard in Kobe, Japan, as a test. Mitsubishi Heavy Industries had developed a robot equipped with a telescopic tube and a gripper for this purpose.
First test extraction planned
TEPCO is now planning to use the robot to carry out an initial test sampling in the contaminated reactor block. The aim is to remove around 3 grams of contaminated material.
Videos by heise
"We believe that the upcoming test removal of fuel debris from Unit 2 is a critical step to continuously carry out future decommissioning work," said Yusuke Nakagawa, a TEPCO group leader for the fuel debris retrieval program. "It is important that we proceed with test removal safely and continuously."
However, the robots still have a lot of work ahead of them. The three damaged reactors in Fukushima are believed to contain around 880 tons of highly radioactive, melted nuclear fuel. At the beginning of the year, four mini-drones inspected the containment of reactor 1, for example, and took pictures of the areas that robots could not reach.
The problem is that the damage to the individual reactors is different, so the salvage operation has to be adapted to the prevailing conditions in each case. Experts therefore doubt TEPCO's stated goal of being able to clean up Fukushima Daiishi within 30 to 40 years.
(olb)
