TOKYO Japan released more than 1 million metric tons of treated radioactive water from the Fukushima Daiichi nuclear plant into the Pacific Ocean, a process set to begin this summer and continue for three decades or more.
For years, the contaminated water – equivalent to more than 500 Olympic-size swimming pools – has been stored in large metal tanks near the plant, the site of one of the worst nuclear disasters in history. But Japan is running out of space to build more tanks to accommodate the contaminated groundwater and rainwater that continues to enter the site.
The release has become highly politicized by neighboring countries, including South Korea and China. Fukushima’s fishing and agricultural industries are also worried about potential reputational harm on their products, which still carry the stigma of radioactive exposure.
The International Atomic Energy Agency, the international nuclear watchdog, released its final report giving a stamp of approval for Japan’s plans.
The contaminated water that had been stored was treated to remove most of the radioactive materials except for tritium (more on that below).
The wastewater is diluted to 1,500 becquerels – a unit of radioactivity – of tritium per liter of clean water. For comparison, Japan’s regulatory limit allows a maximum of 60,000 becquerels per liter, while the World Health Organization allows 10,000. That means the concentration of tritium is “far below” international regulatory standards, according to the Japanese government.
The water is then released through an underwater tunnel about 3,280 feet (one kilometer) from the coast of Japan, away from areas where fishing routinely takes place. The process is expected to take 30 years or longer.
Tritium is a form of hydrogen with two extra neutrons and it emits low levels of radiation. Like hydrogen, it combines easily with oxygen to form water, or in this case “tritiated water,” which is difficult to distinguish from ordinary water.
We’re actually exposed to small amounts of tritium every day, because it exists in tap water, in the rain and in the air. In fact, tritium is already being discharged into rivers and oceans from other nuclear facilities around the world at higher concentrations than the treated water that is set to be released from Fukushima.
In 2021, Japan asked the IAEA for an independent assessment of its plan to release the water.
After a two-year review and sampling the treated water, the IAEA found that Japan’s plan is “consistent with relevant international safety standards” and its radiological impact on people and the environment would be “negligible.”
The agency now has an office at the site and monitor the process there, and publish independent data.
Japan’s nuclear regulatory agency gave TEPCO approval to release the water, the final step required to begin the process.
On March 11, 2011, a massive earthquake – the most powerful recorded in the country’s history – struck the northeastern coast of Japan. The 9.0-magnitude earthquake was so strong it shifted the Earth’s axis by 6.5 inches. The earthquake and resulting tsunami, with waves up to 20 feet (over 6 meters) high in some places, led to a surge of seawater that caused three of the four nuclear reactors at the Fukushima Daiichi plant to go into catastrophic meltdown. The triple disasters devastated Japan, killing 16,000 people and displacing more than 165,000 people from their homes.
Some scientists have called on Japan to delay the release, saying the potential long-term impact of the low doses of exposure over a long period of time needs to be studied more. Advocates have also accused Japan and TEPCO of a lack of transparency as they devised their plan for the discharge.
Local fisheries associations are extremely concerned about the damage this process could cause to Fukushima’s reputation, and oppose the release of the water.
Chinese officials oppose the discharge, saying that the IAEA’s review was limited to the option to release the water into the ocean, rather than exploring other potential ways to dispose of it. China has threatened to impose import bans on Japanese food once the water is discharged.
The plan has stirred controversy in South Korea, where polls show the majority of the public is worried about the release. Thousands of people including politicians and fishermen have held protests calling on South Korean President Yoon Suk Yeol to stop Tokyo’s plans.
The Yoon administration has been holding frequent briefings to quell the public’s concerns amid its efforts to mend ties with Japan. A South Korean government panel on Friday backed Japan’s plan to discharge the treated water, calling it safe as long as the water is handled as planned.
Nonetheless, the issue is expected to be a major sticking point ahead of South Korea’s 2024 legislative election, and the opposition Democratic Party slammed the panel and the Yoon government for their “complicity in the ocean dump plan.”