The destroyed Fukushima nuclear power plant has come one step closer to releasing radioactive water into the Pacific

The operator of the damaged Fukushima nuclear power plant has come one step closer to releasing treated radioactive water into the Pacific Ocean after filing for permission Tuesday to build a tunnel to the Pacific Ocean to safely dispose of the water.

The nuclear power plant was badly damaged in 2011 after a severe earthquake triggered a tsunami that contaminated its cooling water and then leaked it. The 1,000 tanks holding the contaminated water will reach capacity next year, said the facility’s operator, Tokyo Electric Power Company Holdings (TEPCO).

TEPCO plans to build the marine tunnel so that a huge amount of treated radioactive water can be released into the ocean. The nuclear regulatory agency must approve the plan, including the tunnel design, equipment needed to dilute the water, and other materials.

The contaminated water is treated with seawater to reduce the amount of radioactive material to a safe level that will not harm the environment. According to TEPCO’s plan, the water will be removed approximately half a mile from the facility and released approximately 12 meters below the sea surface.

TEPCO plans to start construction in June so that the release of radioactive water can begin by April 2023.

A protester pauses during a rally against the Japanese government’s decision on Jan.
Yuki Iwamura / AFP / Getty Images

The contaminated water must be diluted in order to reduce the concentration of radioactive substances below the permissible limit values.

About 1,000 storage tanks filled with radioactive water would have to be removed to make room for the facilities needed to shut down the facility, TEPCO says.

More and more radioactive water is being stored in the facility. The storage tanks currently hold about 1.29 million tons of water and will reach their capacity of 1.37 million tons by early 2023, the facility says.

Junichi Matsumoto, an official in charge of the water discharge project, said TEPCO will build the underwater tunnel by drilling through bedrock in the seabed.

The government approved the decision in April to begin discharging the water into the Pacific Ocean in accordance with the safety standards set by regulators, calling this the most realistic option. The idea was vehemently rejected by fishermen, residents and neighboring countries such as China and South Korea.

Japan has sought assistance from the International Atomic Energy Agency to ensure the discharge complies with international safety standards and to gain the understanding of the international community.

The release, with an annual cap on radioactive material, will continue for about 30 years or until the facility is closed, TEPCO said.

Government and TEPCO officials say tritium, which is not harmful in small amounts, cannot be removed from the water, but any other isotopes selected for treatment can be reduced to safe levels before release.

The Associated Press contributed to this report.

The operator of a destroyed nuclear power plant in Fukushima said on December 21, 2021 it had applied for approval from safety authorities to build an underwater tunnel and other facilities required for the planned release of treated radioactive water from the facility into the sea. Above, this aerial photo taken on February 13, 2021, shows the Fukushima Daiichi nuclear power plant in Okuma City, Fukushima Prefecture, north of Tokyo.
Kyodo News / AP Photo