Tanks containing treated water at the crippled Fukushima nuclear power plant are likely to reach capacity around the fall of 2023, later than the initially predicted spring of next year, as the pace of the accumulation of radioactive water slowed in fiscal 2021.
The slowdown, based on an estimate by operator Tokyo Electric Power Company Holdings Inc., gives some breathing space to Prime Minister Fumio Kishida's government if any roadblocks are thrown up in the plan to discharge the treated water into the sea starting around spring next year.
China and South Korea as well as local fishing communities that fear reputational damage to their products remain concerned and have expressed opposition to the plan.
About 1.30 million tons of treated water has accumulated at the Fukushima Daiichi plant following the 2011 nuclear disaster, and it is inching closer to the capacity of 1.37 million tons.
The water became contaminated after being pumped in to cool melted reactor fuel at the plant and has been accumulating at the complex, also mixing with rainwater and groundwater.
According to the plan, the water -- treated through an advanced liquid processing system, or ALPS, that removes radionuclides except for tritium -- will be released 1-kilometer off the Pacific coast of the plant through an underwater pipe.
The International Atomic Energy Agency has been conducting safety reviews of the discharge plan and Director General Rafael Grossi says the U.N. nuclear watchdog will support Japan before, during and after the release of the water, based on science.
An IAEA task force, established last year, is made up of independent and highly regarded experts with diverse technical backgrounds from various countries including China and South Korea.
Japan's new industry minister Yasutoshi Nishimura says the government and TEPCO will go ahead with the discharge plan around the spring of 2023 and stresses the two parties will strengthen communication with local residents and fishermen, as well as neighboring countries, to win their understanding.
Beijing and Seoul are among the 12 countries and regions that still have restrictions on food imports from Japan imposed in the wake of the massive earthquake and tsunami triggered nuclear meltdowns at the Fukushima plant in March 2011.
"We will improve our communication methods so we can convey information backed by scientific evidence to people both at home and abroad more effectively," Nishimura said after taking up the current post in a Cabinet reshuffle Wednesday.
Kishida instructed Nishimura to focus on the planned discharge of ALPS-treated water that will be diluted with seawater to one-40th of the maximum concentration of tritium permitted under Japanese regulations, according to the chief of the Ministry of Economy, Trade and Industry.
The level is lower than the World Health Organization's recommended maximum tritium limit for drinking water.
TEPCO will cap the total amount of tritium to be released into the sea as well.
Meanwhile, the Kishida government has decided to set up a 30 billion yen ($227 million) fund to support the fisheries industry and said it will buy seafood if demand dries up due to harmful rumors.
Fishing along the coast of Fukushima Prefecture, known for high-quality seafood, has been recovering from the reputational damage caused by the nuclear accident but the catch volume in 2021 was only about 5,000 tons, or about 20 percent of 2010 levels.
Construction of discharge facilities at the Fukushima plant started in August, while work to slow the infiltration of rain and groundwater was also conducted.
TEPCO said it was able to reduce the pace of accumulation of contaminated water by fixing the roof of a reactor building and cementing soil slopes around the facilities, among other measures, to prevent rainwater penetration.
The volume of radioactive water decreased some 20 tons a day from a year earlier to about 130 tons per day in fiscal 2021, according to the ministry.
The projected timeline to reach the tank capacity has been calculated based on the assumption that about 140 tons of contaminated water will be generated per day, according to METI.
However, storage tanks could still reach their capacity around the summer of next year if heavy precipitation or some unexpected events occur, the ministry said.
As part of preparations for the planned discharge, the Environment Ministry has started measuring tritium concentration at 30 locations on the surface of the sea and seabed around the Fukushima plant, four times a year.
Similarly, the Nuclear Regulation Authority has increased the number of locations it monitors tritium levels by eight to 20. The Fisheries Agency has started measuring tritium concentration in marine products caught along the Pacific coast stretching from Hokkaido to Chiba Prefecture.
Given that it is expected to take several decades to complete the release of treated water, NRA and METI officials urged TEPCO to further curb the generation of contaminated water at the plant.
"We want TEPCO to step up efforts so as to lower the volume of the daily generation of contaminated water to about 100 tons or lower by the end of 2025," a METI official said.