Damaged fuel debris from the reactors of the Fukushima Daiichi nuclear power plant will be removed as part of a decades-long effort to clean up the site, but much remains unknown about what is inside.
The head of the cleanup effort has said that his team is battling to extract a sample from the center of the radioactive debris at the site, just as Japan is getting ready to commemorate the 13th anniversary of its worst-ever nuclear accident.
Akira Ono, chief of decommissioning at Tokyo Electric Power Company Holdings, said that a sample of melted fuel from within a reactor is the key to solving that issue and cleaning it up.
According to Ono, they have achieved several things, but they still need to do a lot of thinking to tackle the unprecedented task of removing melted fuel.
Japanese authorities estimate that it would take 30–40 years to remove the 880 tons of melted nuclear fuel from the three damaged reactors. According to experts, such a timeframe is too optimistic. There is ten times as much melted fuel as was evacuated from Three Mile Island after its partial core melt in 1979.
Ono hailed the plant’s August 2016 start of treating water before releasing it into the ocean as a huge victory. He called it a “huge step.”
The fourth 7,800-ton water batch is now being released. Despite daily seawater sample results meeting safety criteria, local fishermen and neighboring nations, particularly China, have protested. China has responded by prohibiting Japanese seafood imports.
By 2014, TEPCO had removed all spent fuel rods from the cooling pool of the No. 4 reactor, and by 2021, they had done the same for the No. 3 reactor. The rods are projected to be entirely removed from the No. 1 and No. 2 pools by 2031.
Although robotic probes have managed to get a glimpse inside all three reactors, their research has been hindered by several issues, including technological problems and high radiation levels.
In February, the facility conducted its first drone trip inside the primary containment vessel to study the melted debris and determine the original method of fuel fall from the core.
Unfortunately, a data transmission robot malfunctioned, forcing the cancellation of the second exploration day.
