The Japanese government decided Tuesday to release treated radioactive water from the crippled Fukushima Daiichi nuclear power plant into the Pacific Ocean, having determined it poses no safety concerns despite opposition from local fishermen and neighboring countries.

The decision ends years of discussions on how to dispose of water accumulating at the plant after a massive earthquake and tsunami triggered a triple meltdown in March 2011.

The actual release of the water, which will be significantly diluted, will not begin for about two years as the utility, Tokyo Electric Power Company Holdings Inc., requires time to set up facilities and receive approval from nuclear regulators.

Water pumped into the ruined reactors at the Fukushima plant to cool the melted fuel, mixed with rain and groundwater that has also been contaminated, is treated using an advanced liquid processing system, or ALPS.

The process removes most radioactive materials including strontium and cesium but leaves behind tritium, which is related to hydrogen and said to pose little health risk in low concentrations. The water is being kept in tanks on the plant's premises -- more than 1.25 million tons in total.

TEPCO expects to run out of storage capacity as early as fall next year, and the government had been looking for ways to dispose of the water.

"Disposing of the treated water is an unavoidable issue for decommissioning the Fukushima Daiichi plant," Prime Minister Yoshihide Suga said after finalizing the decision in a meeting with members of his Cabinet.

The plan will be implemented "while ensuring that safety standards are cleared by a wide margin and firm steps are taken to prevent reputational damage" for the fishery industry, he said.

The head of the national federation of fisheries cooperatives, Hiroshi Kishi, voiced a strong protest against the decision, calling it "extremely regrettable" and "utterly unacceptable."

China's Foreign Ministry said in a statement the move is "extremely irresponsible" and detrimental for neighboring countries, while Taiwan's Atomic Energy Council also voiced opposition.

The South Korean government held an emergency meeting to discuss its response, with a senior official saying Seoul "firmly opposes" the decision,

China, Taiwan and South Korea are among 15 countries and regions that continue to restrict imports of Japanese agricultural and fishery products following the Fukushima disaster.

Meanwhile, the International Atomic Energy Agency has backed the plan to release the tritiated water, with Director General Rafael Grossi saying it is scientifically sound and in line with standard practice in the nuclear industry around the world.

The U.S. State Department noted following the announcement that Japan has "weighed the options and effects" and maintained transparency about its decision.

According to the government's plan, the tritium will be diluted to less than 1,500 becquerels per liter, one-40th of the concentration permitted under Japanese safety standards and one-seventh of the World Health Organization's guideline for drinking water.

Third parties including the IAEA and the Organization for Economic Cooperation and Development's Nuclear Energy Agency will be involved to ensure the plan is being implemented properly.

A subcommittee of Japan's Ministry of Economy, Trade and Industry concluded in February 2020 that releasing the tritiated water into the sea and evaporating it were both realistic options, with the former being easier for monitoring radiation levels.

The government had initially hoped to finalize the decision last October, viewing it as necessary to clear up space at the Fukushima plant in order to move forward with the decades-long decommissioning process, but decided it needed more time to convince local fishermen.

If the fishing industry is deemed to have suffered reputational damage, TEPCO will be responsible for paying compensation.

==Kyodo

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