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The water tanks in Fukushima are full
Photo: Charly Triballeau / AFP
As of this year, Japan plans to discharge more than a million tons of treated water from the damaged Fukushima nuclear power plant into the sea.
The plan has been approved by the International Atomic Energy Agency (IAEA), senior government secretary Hirokazu Matsuno said.
Still, the government will wait for a "comprehensive report" from the UN before approving it, he said.
The water is to reach the sea over several decades through a kilometer-long underwater pipeline.
The plan has been in place for some time, but it was still unclear when it should start.
"We expect the release to happen sometime this spring or summer," Matsuno said.
First, the corresponding systems would have to be completed and tested.
The government will "make every effort to ensure safety," he said, citing ongoing concerns from neighboring countries and local fishermen.
The fishermen fear damage to the image of seafood from Fukushima.
Worst nuclear accident since Chernobyl
The Fukushima nuclear power plant, located by the sea, was hit by an almost 15 meter high tsunami shortly after a severe earthquake on March 11, 2011.
The power plant's cooling system failed, and core meltdowns occurred in three of the six reactors.
It was the worst nuclear accident since the Chernobyl disaster of 1986. The tsunami killed around 18,500 people.
It is estimated that dismantling the reactors will take up to 40 years.
So far there are 1.3 million tons of water on the site, stored in large tanks.
But space is gradually becoming scarce.
This includes water that was used to cool the damaged nuclear facility after the nuclear accident in 2011, but also rainwater and groundwater from the radioactive site.
The water is filtered to remove radioactive components.
Controversial tritium
The actual danger posed by the contaminated water is controversial.
With the exception of the radioactive hydrogen isotope tritium, the company already filters out many dangerous substances.
However, tritium is considered comparatively harmless and, according to experts, is only harmful to humans in high doses.
Tepco also plans to dilute the water to lower tritium levels.
According to the operator, the treated water complies with national standards.
But the Tokyo-based Citizens' Commission on Nuclear Energy stressed that tritium "is still radioactive material" and should not be released into the environment.
The IAEA said the release was in line with international standards and would "do no harm to the environment."
Regional neighbors, including China and South Korea, have criticized the plan.
The cleanup after the disaster is a complex and lengthy process: In 2014, Tepco completed the recovery of the fuel rods from reactor 4.
Originally, the fuel rods were to be removed from reactor 3 immediately afterwards.
However, the situation there is much more complicated.
In the course of the nuclear accident there was an explosion at the cooling pond with the fuel.
It took four years to clear the rubble out of the way.
In the spring of 2019, Tepco then began to salvage fuel rods from the destroyed reactor 3.
Remote-controlled devices removed the radioactive fuel from the rubble.
koe/dpa/AFP