A solution to the crisis at the Fukushima Daiichi nuclear power plant remains a distant goal a decade after three of its reactors melted.
The most challenging part of the cleanup – removing the melted nuclear fuel from each reactor – has not yet started because of the high radiation inside the reactor buildings, putting into question the planned shutdown of the plant by 2051.
More than 80% of the Japanese public do not feel that significant progress is being made and are concerned about new accidents, according to a survey by the national broadcaster NHK. Two recent incidents help to explain why.
On February 13, a major earthquake near Fukushima, a replica of the earthquake 10 years ago, caused water to spill out of a tank containing used fuel rods, which must be kept submerged to prevent overheating. A week later, a fish caught off the coast of Fukushima was found to contain 10 times the permitted level of radioactive cesium.
The episodes were not threats to public health alone. The fuel bars have not been exposed and Fukushima’s food is subject to an intensive safety assessment. The last fish above the radiation limit was found two years earlier.
Onahama Kisen Sokobikiami Fisheries Association workers unload “saba” (mackerel), a seasonal migratory fish in the Iwaki / Onahama Port region. 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 on the day’s catch at the Onahama Kisen Sokobikiami Fisheries Association in the Port of Onahama.
Much of the fisherman’s time is spent repairing fishing nets. The crew of this fishing boat repairs the nets after returning to the Port of Onahama. The local economy is closely linked to the sea and the fishing industry depends not only on clean water for good fishing, but on the belief of end consumers that the fish they fish are free from radioactive contaminants. Iwaki, Fukushima Prefecture, Japan
But the incidents show how the risks of the factory continue to weigh on those who live and work nearby. Local fish catches fell more than 80% in 2019 compared to before the accident.
“We are still struggling with damaging rumors of the nuclear plant accident,” said Tadaaki Sawada, a spokesman for the Fukushima Federation of Fisheries Cooperatives. “How many more years will this continue?”
Buyers bid on the day’s catch.
By several measures, the worst nuclear disaster since the Chernobyl accident in 1986 was contained. Only about 2% of Fukushima prefecture, or state, is still a prohibited area, compared to 12% immediately after the disaster. An extensive decontamination process removed the topsoil from areas around the plant.
Even so, thousands of people continue to be forced to leave the cities closer to the factory.
“There are areas where people are unable to return home or are just beginning to return, as well as the problem of agricultural, forestry and fishing businesses hampered by harmful rumors. It is important to support and calm people affected by the disaster, including the elderly and children, ”said Emperor Naruhito at a memorial event in Tokyo on Thursday.
Within the grounds of the Fukushima Daiichi nuclear power plant, radiation levels are low enough that protective clothing is needed only for those who go about 100 meters from the buildings housing the damaged reactors. The reactors melted when a tsunami triggered by an earthquake on March 11, 2011 cut power to the plant and the reactors’ water cooling system 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 one million cubic meters of water from the plant into the sea, but plans were suspended in amid opposition from local fishermen and concerns raised by neighboring countries.
Contaminated rain and groundwater are stored in large tanks that dominate one side of the plant site. After being treated to remove most 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 into the air by nuclear power plants worldwide after dilution.
Inspectors from the International Atomic Energy Agency visited the Fukushima plant last year and said the disposal of treated water at sea would be in line with international practice. “A decision on the disposal path must be taken urgently” to keep the general decommissioning going, said the IAEA.
The most challenging part of cleaning – removing the melted nuclear fuel from each reactor – has not yet begun.
The government says it is still discussing the matter and that the disposal of treated water will only begin in about two years.
Ian Fairlie, a former head of a UK government panel on radiation risks and an opponent of nuclear power, said Japan should increase its water storage capacity and expect tritium, which has a little more half-life. 12 years, decompose.
“Whenever you put a large amount of nuclides in the sea, it goes up the food chain, whether you like it or not. Any good environmentalist will say that we shouldn’t use dispersion, ”said Fairlie.
A recently opened shopping street in Futaba, the residential neighborhood closest to the nuclear power plant.
Other cleaning issues have not even started to be addressed, such as when to dismantle the reactors and where to place the radioactive fuel after it has been recovered. Contaminated soil near the plant was stored locally, but the governor of Fukushima, Masao Uchibori, said the government agreed it would be taken elsewhere.
An initial experimental phase to clean and remove all the melted nuclear fuel on each floor of the reactor is expected to begin in 2022, with a two-year delay. A robot arm to be used in the process is under development in the UK, but work on creating it has been delayed for a year because of the coronavirus pandemic.
Tepco has yet to get a clear picture of the location of the molten fuel in the reactors because radiation levels are harmful even to robots. Akira Ono, the plant’s decommissioning chief, said there was no need at the moment to extend the timeline for the process beyond 2051.
Governor Uchibori said that getting an accurate understanding of the melted fuel situation was key to moving forward.
“If you look at the whole process, at this point we are 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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