TOKYO: Tokyo Electric Power Company Holdings Inc. said Sunday that its Fukushima No. 1 nuclear power plant has completed its fourth and final round of treated water release into the ocean for the initial year.

The tsunami-crippled nuclear plant discharged about 31,200 tons of treated water, which contains small amounts of radioactive tritium, into the ocean in the initial year as planned.

The discharge of treated water started in August 2023. About 7,800 tons of treated water was diluted with a large amount of seawater each time and discharged offshore from an undersea tunnel over a two-week period four times.

Tritium levels in seawater and fishery products measured by TEPCO and the Japanese governments have been below national standards.

In the fourth round that began on Feb. 28, the discharge was suspended for over 15 hours to confirm safety on Friday when a strong earthquake struck Fukushima Prefecture, home to the nuclear plant.

In fiscal 2024, which starts next month, the nuclear plant plans to discharge a total of about 54,600 tons of treated water into the ocean by increasing the number of releases to seven.

JIJI Press