For the wrecked Fukushima Daiichi nuclear plant, managing the ever-growing volume of radioactive wastewater held in more than 1,000 tanks has been a safety risk and a burden since the meltdown in March 2011. Its release marks a milestone for the decommissioning, which is expected to take decades.
But it’s just the beginning of the challenges ahead, such as the removal of the fatally radioactive melted fuel debris that remains in the three damaged reactors, a daunting task if ever accomplished.
Here’s a look at what’s going on with the plant’s decommissioning:
WHAT HAPPENED AT FUKUSHIMA DAIICHI?
A magnitude 9.0 quake on March 11, 2011, triggered a massive tsunami that destroyed the plant’s power supply and cooling systems, causing three reactors to melt and spew large amounts of radiation.
Highly contaminated cooling water applied to the damaged reactors has leaked continuously into building basements and mixed with groundwater.
The water is collected and treated. Then, some is recycled as cooling water for melted fuel, while the rest is held in tanks that cover much of the plant.
WHY RELEASE THE WATER?
Fukushima Daiichi has struggled to handle the contaminated water since the 2011 disaster. The government and the plant operator, Tokyo Electric Power Company Holdings (TEPCO), say the tanks must be removed to make way for facilities needed to decommission the plant, such as storage space for melted fuel debris and other highly contaminated waste.
WILL THE WASTEWATER RELEASE PUSH DECOMMISSIONING FORWARD?
Not right away, because the water release is slow and the decommissioning is making little progress. TEPCO says it plans to release 31,200 tonnes of treated water by the end of March 2024, which would empty only 10 tanks out of 1,000 because of the continued production of wastewater at the plant.
The pace will later pick up, and about one-third of the tanks will be removed over the next 10 years, freeing up space for the plant’s decommissioning, said TEPCO executive Junichi Matsumoto, who is in charge of the treated water release.
He says the water would be released gradually over the span of 30 years, but as long as the melted fuel stays in the reactors, it requires cooling water, which creates more wastewater.
Emptied tanks also need to be scrapped for storage. Highly radioactive sludge, a byproduct of filtering at the treatment machine, also is a concern.