Japan has begun discharging more than one million tonnes of treated radioactive water from the wrecked Fukushima Daiichi nuclear power plant into the Pacific Ocean, prompting China to announce an immediate blanket ban on all seafood imports from Japan. The release, carried out by plant operator Tokyo Electric Power (Tepco), started on Thursday at 1:03pm local time, with the first discharge of 7,800 cubic metres expected to last about 17 days.
Tepco said it had not identified any abnormalities with the seawater pump or surrounding facilities. Monitors from the UN atomic watchdog, the International Atomic Energy Agency (IAEA), which has endorsed the plan, were on site for the procedure, and Tepco workers were scheduled to take water samples later on Thursday. The water is being diluted with seawater before release to reduce tritium levels to well below the World Health Organization’s drinking water limit of 10,000 becquerels per litre.
China’s customs agency announced the immediate suspension of aquatic product imports from Japan, citing the need to prevent radioactive contamination of food safety. Beijing’s foreign ministry branded the release “extremely selfish and irresponsible”, warning of a potential “man-made secondary disaster”. South Korean police arrested at least 14 protesters who entered the Japanese embassy in Seoul, while Japanese fishing communities expressed anger and concern that the discharge will destroy their industry.
The water became contaminated after the 2011 tsunami caused three nuclear reactors to melt down. On-site technology removes most harmful substances but cannot filter out tritium, a radioactive isotope of hydrogen. Critics, including Greenpeace, argue that long-term data is lacking and that the biological impacts of tritium, carbon-14, strontium-90 and iodine-129 have been ignored. Tepco maintains that tritium emits very weak radiation and does not accumulate in the body.
The discharge is expected to take 30 to 40 years. The first batch contains about 190 becquerels of tritium per litre, with a maximum release rate of 500,000 litres per day. The IAEA has supported Japan’s approach, but the plan has caused diplomatic tension with neighbours and concern among local fishers.
