What is the plan and why is it controversial?
Japan has started to release more than one million tonnes of treated radioactive water from the damaged Fukushima Daiichi nuclear power plant into the Pacific Ocean. The plan was approved by the Japanese government two years ago and by the UN’s nuclear watchdog in July, despite strong opposition from local fishing communities and neighboring countries.
The water comes from the cooling of the melted fuel rods in the reactors that were hit by a massive earthquake and tsunami in 2011, causing the worst nuclear disaster since Chernobyl. The water has been stored in more than 1,000 tanks at the site, but space is running out and the government says releasing it is a necessary step in the lengthy and costly process of decommissioning the plant.

The water has been treated to remove most of the radioactive elements, except for tritium, a form of hydrogen that is hard to separate from water. Tritium is considered to be relatively harmless in low doses, but some experts say more studies are needed to assess its long-term impact on marine life and human health.
How is the water being released and monitored?
The first release of about 100,000 litres of water began on Thursday, August 24, 2023, and was expected to last for about two hours. The release will be followed by three more between now and the end of March 2024, with a total amount of 1.34 million tonnes of water to be discharged over 30 years.
The plant operator, Tokyo Electric Power Company (TEPCO), says it has installed a special filtering system called ALPS that can remove more than 60 radioactive substances from the water, leaving only tritium. The water is then diluted with seawater until the tritium concentration is below the operational limit of 1,500 becquerels per litre, which is six times lower than the World Health Organization’s limit for drinking water.
TEPCO says it will monitor the water quality and radiation levels before, during and after each release, and report the results to the public and the International Atomic Energy Agency (IAEA), which has a permanent office at Fukushima. The IAEA says it will conduct independent verification and provide technical support to ensure that the release is carried out safely and transparently.
What are the reactions and concerns?
The plan to release the water has sparked protests and criticism from various groups and countries. Local fishermen say they fear that their products will be shunned by consumers, even though they have passed strict safety tests. They also worry that the water will contaminate the marine environment and affect their livelihoods.
Some environmental groups, such as Greenpeace, have argued that Japan should find alternative ways to store or dispose of the water, such as building more tanks or solidifying it into concrete blocks. They have also questioned the effectiveness and reliability of TEPCO’s filtering system and monitoring methods.
China and South Korea have expressed strong opposition to Japan’s decision, saying it poses a threat to regional peace and security. They have also imposed bans or restrictions on Japanese seafood imports. Japan has defended its plan as being based on scientific evidence and international standards, and has urged other countries to respect its sovereignty and not interfere with its internal affairs.