Resolving the crisis at the Fukushima Daiichi nuclear power plant remains a distant goal a decade after three of its reactors melted.
The most difficult part of the cleanup – removing molten nuclear fuel from each reactor – has not yet begun due to high radiation inside the reactor buildings, calling into question the plant’s targeted decommissioning by 2051.
More than 80% of the Japanese public do not consider that significant progress is being made and are worried about other accidents, according to a survey by the national broadcaster NHK. Two recent incidents help explain why.
On February 13, a large earthquake concentrated near Fukushima, a replica of the one 10 years ago, caused water to come out of a tank containing spent fuel rods, which must be kept submerged to avoid overheating. One week later, it was discovered that a fish caught off the coast of Fukushima contains 10 times the permitted level of radioactive cesium.
The episodes were not the only threats to public health. The fuel rods have not been exposed, and Fukushima food is under intensive safety control. The last fish above the radiation limit were found two years earlier.
Workers of the Onahama Kisen Sokobikiami Fishing Association unload “saba” (horse mackerel), a seasonal migratory fish from the region in the port of Iwaki / Onahama. Fukushima Prefecture, Japan
The fishing boat returns to the port of Onahama. Iwaki, Fukushima Prefecture, Japan
The fishing boat returns to the port of Onahama. Iwaki, Fukushima Prefecture, Japan
“Saba” (mackerel), a seasonal migratory fish, in the port of Onahama. Iwaki, Fukushima, Japan
Buyers bid for the catch of the day at the Onahama Kisen Sokobikiami Fishing Association in Onahama Port.
The fisherman spends a lot of time repairing fish nets. The crew of these fishing vessels repaired the nets after returning to the port of Onahama. The local economy is inextricably linked to the sea and the fishing industry does not depend only on clean water for a good catch, but also on convincing end customers that the fish they catch are free of radioactive contaminants. Iwaki, Fukushima Prefecture, Japan
But the incidents show how the risks posed by the plant continue to weigh on those who live and work nearby. Local fish catches fell by more than 80% in 2019, compared to before the accident.
“We are still fighting the harmful rumors of the nuclear power plant accident,” said Tadaaki Sawada, a spokesman for the Fukushima Federation of Fisheries Cooperatives. “How many years will it continue?”
Buyers bid over the catch of the day.
Through several measures, the worst nuclear disaster since the 1986 Chernobyl accident has been limited. Only about 2% of Fukushima prefecture or state is still a no-go area, down from 12% immediately after the disaster. An extensive decontamination process removed the topsoil from the areas around the plant.
However, thousands of people remain forced to leave the cities closest to the plant.
“There are areas where people cannot return home or have just started to return, as well as the problem of agricultural, forestry and fishing businesses damaged by harmful rumors. It is important to support and calm those affected by the disaster, including the elderly and children, “Emperor Naruhito said at a memorial event in Tokyo on Thursday.
Inside the Fukushima Daiichi nuclear power plant, radiation levels are low enough that protective clothing is only needed for those who are about 100 meters from the buildings that house the damaged reactors. The reactors melted when a tsunami triggered by an earthquake on March 11, 2011, shut down the power plant and the water cooling system in the reactors failed.
Last year, the operator of the Tokyo Electric Power Co. plant, known as Tepco, and the government were close to a decision to start releasing more than a million cubic meters of water from the plant into the sea, but plans were suspended due to opposition from local fishermen and concerns raised by neighboring countries.
Contaminated rain and groundwater are stored in large tanks that dominate part of the plant’s site. Once treated to remove most of the radioactive elements, the water still contains tritium, a form of hydrogen that emits a weak form of radiation. Tritium is regularly released into the sea and air from nuclear power plants around the world after dilution.
Inspectors from the International Atomic Energy Agency visited the Fukushima plant last year and said the disposal of treated water at sea will be in line with international practice. “A decision on the disposal route should be taken urgently” to keep general decommissioning on track, the IAEA said.
The most challenging part of the cleanup – removing molten nuclear fuel from each reactor – has not yet begun.
The government says it is still discussing the issue and that the elimination of treated water will not start for another two years.
Ian Fairlie, the former head of a British government radiation risk group and an opponent of nuclear power, said Japan should add water storage capacity and wait for tritium, which has a half-life of just over 12 years. years, to decompose. .
“Whenever you put a large amount of nuclides in the sea, it goes up in the food chain, whether you like it or not. Any good environmentalist will tell you that we should not use dispersal, “said Dr. Fairlie.
A recently opened shopping street in Futaba, the residential neighborhood closest to the nuclear power plant.
Other cleaning issues have not even begun to be addressed, such as when the reactors are dismantled and where the radioactive fuel is placed once recovered. The contaminated soil near the plant was stored locally, but Fukushima Governor Masao Uchibori said the government had agreed to take it elsewhere.
An initial experimental phase to clean up and remove all molten nuclear fuel from each reactor floor is set to begin in 2022, two years ago. A robotic arm that will be used in this process is under development in the UK, but work to create it has been delayed by a year due to the coronavirus pandemic.
Tepco has not yet obtained a clear picture of the location of the molten fuel in the reactors, as radiation levels are harmful even to robots. Akira Ono, the plant’s decommissioning chief, said there was no need to extend the deadline for the process beyond 2051.
Governor Uchibori said getting an accurate understanding of the melt fuel situation is key to moving forward.
“If you look at the whole process, we are now still around the starting point of decommissioning,” he said.
—Chieko Tsuneoka contributed to this article.
Write to Alastair Gale at [email protected]
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