The operator of the damaged Fukushima Daiichi nuclear power plant says it will start the third round of the treated and diluted water release into the sea on November 2.

Tokyo Electric Power Company, or TEPCO, announced the plan on Thursday.

The utility said it intends to discharge about 7,800 tons of treated water from 10 tanks between November 2 and 20.

TEPCO has said it will carry out four rounds of releases in the current fiscal year ending March 2024.

It carried out the first round from August 24 to September 11, and the second round from October 5 to 23. About 7,800 tons were also released in each round.

The Fukushima Daiichi plant suffered a triple meltdown in the 2011 earthquake and tsunami. Water used to cool molten fuel has been mixing with rain and groundwater.

The accumulated water is being treated to remove most radioactive substances, but still contains tritium. The treated water is stored in more than 1,000 tanks.

Before releasing the treated water into the sea, the plant's operator dilutes it to reduce tritium levels to about one-seventh of the World Health Organization's guidance level for drinking water.