Riccardo Liguori A specialized robot was used to collect a small sample of radioactive debris inside the nuclear power plant's No. 2 reactor. The operation, although complex, represents a crucial step towards the decommissioning of the plant, seriously damaged by the 2011 tsunami
©Foto Ansa
Thirteen years since the fateful tsunami hit the Fukushima Daiichi nuclear power plant, Tepco resumed efforts to remove radioactive debris from the site, estimated at close to 970 tons.
On Tuesday, September 10, a special robot began the painstaking process of retrieving a small sample of highly hazardous material from inside Reactor No. 2. According to Japanese newspaper The Asahi Shimbun, this restart is three years later than its initial schedule.
A crucial yet complex operation
Tepco called it a “pilot extraction,” a major yet extremely complex milestone toward the decommissioning process. The first step in the process is expected to last about two weeks, during which time the robot will collect three grams of the debris. Several tests are planned for the radioactive and molten material that would be extracted to ascertain the conditions in the reactors, data useful in the planning of further cleanup phases.
The most challenging part is removing debris from the reactors, which, according to the Japanese government and Tepco, is expected to be accomplished in 2051.
The first attempt to remove the debris, originally programmed for August 22, had been postponed because of an error in the installation of five tubes used in the operation. Tepco reported having identified the cause of the mistake and has taken necessary preventive measures against further delay.
Mainly, complexity arises due to the strong levels of radiation emanating from the inside of the damaged reactors. To accomplish that, Tepco has developed a specialized robotic application which can be used inside such a hostile environment. The device utilized for the operation works much like a fishing rod and is designed to catch the debris.
The final stage of operation
The gathering of nuclear debris is the first of the three phases in the decommissioning process. The company intends to analyze the structure and characteristics of a sample of molten fuel captured from the reactor at a research center in Ibaraki Prefecture. By doing so, the company hopes that the results will enable it to come up with specific methods for gathering debris. Still, how much of it can be collected remains unknown.
Against this tremendous challenge, Japan is trying hard, and the world watches with bated breath, knowing full well that any success or failure will have consequences not limited to within its borders.
