Advanced Liquid Processing System (2013–) of water storage facilities at the power plant. ALPS works by first pre-processing the water by iron
coprecipitation (removes
alpha-emitting nuclides and organics) and carbonate coprecipitation (removes
alkali earth metals including
strontium elements). The water is then passed through 16 absorbent columns to remove nuclides. Wastewater is pumped to ALPS along with the concentrated saltwater from desalination. Although carbon-14 is not removed, the content in pre-treatment water is low enough to meet drinkable standards without dilution. Unit "A" started operation in April. In June, unit A was found to be leaking water and shut down. In July, the cause was narrowed down to chloride and
hypochlorite corrosion of water tanks; TEPCO responded by adding a rubber layer into the tanks. By August, all systems were shut down awaiting repair. One unit was expected to come online by September, with full recovery planned by the end of 2013. By September 2018, TEPCO reports that 20% of the water had been treated to the required level. By 2020, the daily buildup of contaminated water was reduced to 170 metric tonnes thanks to groundwater isolation installations. The portion of ready-to-discharge water raised to 34% by 2021, and to 35% by 2023. Some scientists expressed reservations due to potential
bioaccumulation of ruthenium, cobalt, strontium, and plutonium, which sometimes slip through the ALPS process and were present in 71% of the tanks. Since the 2011
Fukushima Daiichi nuclear disaster, the nuclear plant has accumulated 1.25 million
tonnes of waste water, stored in 1,061 tanks on the land of the nuclear plant, as of March 2021. It was projected that the site would run out of land for water tanks by 2022.
Mainichi Shimbun criticized the government for showing "no sincerity" in "unilaterally push[ing] through with the logic that there will no longer be enough storage space". On 13 April 2021, the
Cabinet of Prime Minister
Yoshihide Suga unanimously approved that TEPCO dump the stored water to the Pacific Ocean over a course of 30 years. The Cabinet asserted the dumped water will be treated and
diluted to
drinkable standard. The idea of dumping had been floated by Japanese experts and officials as early as June 2016. In April 2023, Japan's NRA announced a
Comprehensive Radiation Monitoring Plan, in which the concentration of radionuclides in food (land and sea), soil, water, and air will be continually monitored across Japan. NRA also set up a system to monitor the radionuclide concentration in ALPS-processed water in order to verify TEPCO's readings.
International testing An IAEA task force was dispatched to Japan in 2021, and they released their first report in February 2022. Among other findings, TEPCO has demonstrated to IAEA that their pump setup thoroughly mixes waters in tanks. The same sample was tested by Japan's NRA with no disagreements found. The tritium that is not filtered out has a radioactivity of 148,900 Bq/L, compared to 620,000 Bq/L before treatment. TEPCO intends to dilute it down to 1,500 Bq/L or less before release. Japan says the water is safe after the use of Advanced Liquid Processing System (ALPS), which removes nearly all traces of radiation from the wastewater, with tritium being the primary exception to this. As a result, Japan has committed to diluting the water in order to bring levels of tritium below the regulatory standards set by the International Atomic Energy Agency. The International Atomic Energy Agency has stated that the plan meets safety standards, but critics contend that more studies need to be done and the release should be halted. On 24 August, Japan began the discharge of treated waste water into the Pacific Ocean, sparking protests in the region and China to expand its ban to all aquatic imports from Japan. Over 1 million tonnes of treated wastewater will be released by Japan over the next thirty years as per the plan. On August 25, TEPCO reported that the amount of tritium in seawater around Fukushima has remained below the detection limit of 10 Bq/L. The Japanese Fishery Agency reported that fish caught 4 km away from the discharge pipe contained no detectable amounts of tritium. On March 15, 2024, the discharge was suspended temporarily after the Fukushima coastal region experienced another 5.8-magnitude earthquake. No abnormalities were detected with the wastewater treatment. On January 22, 2025, the Global Times, affiliated with the Chinese Communist Party's official newspaper, reported that Chinese experts had completed their own analysis of seawater samples. According to the report, no abnormalities were found in the concentrations of radioactive materials such as cesium and strontium. On July 7, 2025, the China Atomic Energy Authority announced that an analysis by Chinese research institutions of seawater and marine life collected in February near TEPCO's Fukushima Daiichi Nuclear Power Plant confirmed no abnormalities in the concentrations of radioactive materials, including tritium.
Reactions Official nuclear science panels • The Japanese expert panel "ALPS subcommittee", chaired by nuclear scientist Ichiro Yamamoto, released a report in January 2020 which calculated that discharging all the water to the sea in one year would cause a radiation dose of 0.81
microsieverts to the locals, therefore it is negligible as compared to the Japanese'
natural radiation of 2,100 microsieverts per year. Its calculations were verified by
International Atomic Energy Agency to be correct.
Japanese public • A panel of public policy professors argued that there was not enough research on the harmful effects of
tritium, and that the government was being insincere in its consideration of alternative disposal proposals, as the proposals were always shelved after "procedural" discussion. • A survey by
Asahi Shimbun in December 2020 found, among 2,126 respondents, that 55% of Japanese opposed dumping and 86% worried about international reception. Opposition is strongest among fishers and coastal communities. The Cooperatives felt bypassed and betrayed by the government's decision. • In June 2020, Baskut Tuncak,
United Nations's Special
Rapporteur on toxics and human rights, wrote on Japan's
Kyodo News that the communities of Fukushima have the right not to be exposed deliberately to additional
radioactive contamination."
Greenpeace and five other UN Rapporteurs (including
Clément Nyaletsossi Voule) issued condemnation echoing those sentiments. • Various governments have voiced concerns, including the governments of South Korea, North Korea, Taiwan, China, Russia, Germany, the Philippines, New Zealand, Belize, Costa Rica, • In June 2021, at least 70 U.S. civic groups condemned Japan's wastewater discharge plan, and 17 civic organizations from various countries held protests in Berlin. • In January 2023, the U.S.
National Association of Marine Laboratories expressed their opposition to the plan and stated that "there was a lack of adequate and accurate scientific data supporting Japan's assertion of safety". • In June 2023, South Korean shoppers rushed to buy up salt and other items prior to the expected release of the treated discharge. The South Korean government had banned seafood from the waters near Fukushima and says it will closely monitor the radioactivity level of
salt farms. A similar salt rush occurred in China, after the discharge began. • In the months leading up to the start of discharge, over 80 per cent of South Koreans surveyed opposed the dumping, and over 60 per cent indicated intention to avoid seafood products after the release begins. • In August 2023, the
Green Party of the United States issued a press release opposing the discharge. • In the same month, Shaun Burnie, senior nuclear specialist for
Greenpeace, accused the Japanese government and TEPCO of diverting attention away from the radiation levels in the waste water from the nuclear plant by emphasizing
tritium, arguing that various other harmful
radionuclides, including
strontium-90,
iodine,
ruthenium,
rhodium,
antimony,
tellurium,
cobalt, and
carbon-14, will remain present even after filtration. • On 24 August, protests against the discharge erupted in South Korea, Hong Kong and Tokyo. According to the organisers, about 50,000 people gathered in
Seoul. Some attempted to storm the
Japanese embassy there. A man threw stones into a
Japanese school in
Qingdao, and eggs were thrown into one in
Suzhou, with no confirmed damage. Social media campaigns in China called for a boycott of Japanese products. This drove a 14% single-day stock price decline for luxury cosmetics conglomerate
Shiseido. • Chinese
state media outlets ran paid ads denouncing the water release on
Facebook and
Instagram in multiple countries and languages. Analysts labeled it part of a concerted
disinformation campaign. • The Chinese government, Hong Kong, Macau, and the South Korean government have banned aquatic imports from some or all regions of Japan. ;In support of discharge •
U.S. Secretary of State Antony Blinken stated on 13 April 2021, "We thank Japan for its transparent efforts in its decision to dispose of the treated water". • On 14 June 2023,
Palau President Surangel Whipps Jr. expressed understanding of Japan's plan to release the treated waste water into the sea, remarking "The people who would be impacted most are their own people. [...] And if it's acceptable to their people, it should be acceptable to all of us." • On 23 August 2023,
Fijian Prime Minister Sitiveni Rabuka expressed support for the IAEA report, stating that the Japanese plan met international safety standards and most of the waste water would be discharged into Japan's "own backyard". ;Mixed • Micronesia had expressed strong opposition to Japan releasing the water. In February 2023, however,
President of the Federated States of Micronesia David Panuelo said he trusted Japan's intention and capabilities but stopped short of offering full support, saying that he would continue to consult with Japan to ensure the water's safety. ;IAEA report • On 23 March 2021,
Rafael Grossi, director-general of the
International Atomic Energy Agency (IAEA), reached a consensus with the Japanese government three weeks before its announcement of decision to release water from the damaged power plant. • In July 2023, the IAEA released its conclusion that Japan's plans to slowly discharge the treated wastewater are in accordance with the relevant international safety standards but stopped short of endorsing the decision, which is for Japan's government to make. • On 10 July 2023, New Zealand expressed confidence in the IAEA report. • On 9 August 2023, during a
Nuclear Non-Proliferation Treaty (NPT) committee, Australia, France, Italy, Malaysia, United Kingdom, and the United States expressed support for the IAEA report. Australia said it was "independent, impartial and science-based" and trusts it completely, the UK also said it can be trusted, and the US said the report was impartial. ;Pacific Islands Forum • In April 2021, the
Pacific Islands Forum expressed deep concerns and urged Japan to rethink its decision on the discharge of the ALPS Treated Water. • In August 2023, a panel of five independent experts consulting for the Pacific Islands Forum was split on the issue of discharge. Some had no issue with it, saying it would not harm the Pacific. Two of them said trying to obtain information from Japan was difficult and its data had "red flags". The panelists wrote that more study is needed on the contaminants inside the water tanks, that TEPCO only took small samples from a quarter of the tanks, which showed large variations in readings, and used commercial pellets, not tritium-exposed fish, as food source for its experiments.
Ken Buesseler, a scientist at the
Woods Hole Oceanographic Institution (WHOI), does not expect widespread direct health effects across the Pacific but said contaminants missed by ALPS could accumulate near the shore in Japan and ultimately hurt fisheries in local areas. He recommended keeping them on land instead and mixing into concrete, for example, which would have been easier to monitor. ==Environmental effects==