An aerial view shows the storage tanks for treated water at the tsunami-crippled Fukushima Daiichi nuclear power plant in Okuma town, Fukushima prefecture, Japan August 22, 2023, in this photo taken by Kyodo. (Mandatory credit Kyodo via REUTERS)

The plan, approved two years ago by the Japanese government as crucial to decommissioning the plant operated by Tokyo Electric Power Company (TEPCO), has faced criticism from local fishing groups, who fear reputational damage and a threat to their livelihood.

Prime Minister Fumio Kishida has asked TEPCO to swiftly prepare for the water discharge in accordance with the plan approved by the Nuclear Regulation Authority.

The first batch of water that will be released starting Thursday will total 7,800 cubic meters over about 17 days, according to TEPCO. That water will contain about 190 becquerels of tritium per liter, below the World Health Organization drinking limit of 10,000 becquerels per litre. A becquerel is a unit of radioactivity.

The International Atomic Energy Agency (IAEA) greenlighted the plan in July, saying that it met international standards and that the impact it would have on people and the environment was "negligible".