Radioactive Water From Fukushima Plant Would Have Small Environmental Impact: Operator

The operator of the Fukushima nuclear power plant said Wednesday that treated radioactive water released into the sea would have an extremely small impact on the environment, marine life and humans, the Associated Press reported.

A massive earthquake that triggered a tsunami in 2011 severely damaged three reactors at the Fukushima Daiichi plant on Japan's Pacific coast. The damage caused a large amount of contaminated cooling water to leak. The water has been stored in about 1,000 tanks that the operator said will reach their capacity late next year.

The Japanese government and the plant's operator, Tokyo Electric Power Company Holdings (TEPCO), said they will start to gradually release the treated radioactive water in the spring of 2023 so the storage tanks at the plant can be removed to make room for facilities needed for its decommissioning.

The plant's operator said that according to a data simulation, its planned release will cause little impact. TEPCO plans to send the water through an undersea tunnel and discharge it about 0.6 miles from the coastal power plant after treating and diluting it with large amounts of seawater.

According to the simulation, radiation levels of seawater temporarily increased slightly but quickly fell to normal levels, TEPCO said. Exposure to radioactivity was significantly lower than the maximum safe levels set by international organizations, it said.

The plan has been strongly opposed by neighboring China and South Korea and Japan's residents and fishermen.

Some experts said the long-term impact on marine life from low-dose exposure is still unknown.

For more reporting from the Associated Press, see below.

Fukushima, radioactive water, japan
A team from the U.N. nuclear agency arrived in Japan on Monday to assess preparations for the release into the Pacific Ocean of treated radioactive water from the wrecked Fukushima Daiichi nuclear power plant. Above, the Pacific is seen behind nuclear reactor units at the Fukushima plant in Okuma, Fukushima prefecture, northeastern Japan, on February 27, 2021. Hiro Komae/AP Photo

Government and TEPCO officials say tritium, which is not harmful in small amounts, cannot be removed from the contaminated water, but all other isotopes selected for treatment can be reduced to safe levels. Controlled release of tritium from normal nuclear plants is a routine global practice, officials say.

The simulation showed a slight rise in tritium levels within 2-3 kilometers (1.2-1.8 miles) from the plant, TEPCO official Junichi Matsumoto said.

The estimated radiation exposure for local fisherman in coastal areas, and for people who regularly consume seafood from the region was much less than 1 millisievert, an annual dose considered safe, TEPCO said.

Japan has requested help from the U.N. nuclear agency to ensure the discharge meets international safety standards and to gain the understanding of the international community.

A six-member team from the International Atomic Energy Agency, currently in Japan, visited the plant on Tuesday to inspect preparations for the planned discharge.