Japan’s government announced on Tuesday (April 13) that it will dump more than a million tons of contaminated wastewater from the Fukushima nuclear power plant into the Pacific Ocean. The highly contaminated water contains more radioactive material than previously acknowledged.
Roughly 1.25 million tons (1.13 million metric tons) of water have accumulated around the Fukushima Daiichi nuclear power plant in northeastern Japan since 2011, after a magnitude-9.0 earthquake and resulting tsunami devastated the region. The twin disasters killed nearly 20,000 people, according to NPR, and caused meltdowns in three of the plant’s six reactors, triggering the worst nuclear disaster since Chernobyl.
To keep the remaining reactor cores from melting, officials with the Tokyo Electric Power Company (TEPCO) have been pumping nearly 200 tons (180 metric tons) of cooling water through the site every day, according to The New York Times.
The contaminated wastewater is stored in more than 1,000 enormous tanks on site and automatically filtered to remove most of the radioactive material, except for tritium — a radioactive isotope of hydrogen that is considered hazardous to human health in large amounts, according to the nonprofit Health Physics Society.
Now, 10 years after the disaster, TEPCO is running out of room to store the wastewater.
The disposal plan, which was approved in a government cabinet meeting on Tuesday, will see the wastewater gradually discharged into the Pacific Ocean, most likely over the course of several decades.
One large concern is that TEPCO’s claims about the water’s safety may be wrong. A study published in the journal Science in August 2020 found traces of several other radioactive isotopes in the Fukushima wastewater, many of which take much longer to decay than tritium, some with a toxic radioactive half life hundreds of years..
There are now about 1.25 million tons of wastewater stored in more than 1,000 tanks at the plant site. The water continues to accumulate at a rate of about 170 tons a day, and releasing all of it is expected to take decades.
In 2019, the Japanese Ministry of Economy, Trade and Industry proposed disposing of the wastewater either by gradually releasing it into the ocean or by allowing it to evaporate. The International Atomic Energy Agency said last year that both options were “technically feasible.”
Hiroshi Kishi, head of Japan’s National Federation of Fisheries, told reporters that his group was still opposed to the ocean release. Neighboring countries including China and South Korea have also expressed concerns.
Responding to Japan’s decision, the U.S. State Department said in a statement, “In this unique and challenging situation, Japan has weighed the options and effects, has been transparent about its decision, and appears to have adopted an approach in accordance with globally accepted nuclear safety standards.”
The International Atomic Energy Agency welcomed Japan’s announcement and said it would offer technical support. It called the plan to release the water into the sea in line with international practice.
“Today’s decision by the government of Japan is a milestone that will help pave the way for continued progress in the decommissioning of the Fukushima Daiichi nuclear power plant,” the agency said in a statement. The decommissioning process is expected to take decades.