The release of the fifth batch of treated radioactive water from the crippled Fukushima Daiichi nuclear power plant into the sea concluded Tuesday, its operator said.
In the latest discharge, the first of fiscal 2024 from April, Tokyo Electric Power Company Holdings Inc. released around 7,800 tons of processed water, with a total of about 54,600 tons planned for release over the year.
Abnormal tritium levels have not been detected in nearby waters, TEPCO said. Prior to discharge, water used to cool melted fuel at the plant is passed through an advanced liquid processing system that removes most radionuclides apart from tritium.
The company plans to conduct another six rounds of discharge this fiscal year, with the next likely to start later this month or in June, according to the operator.
During the latest round that began on April 19, water discharge was disrupted for around six and a half hours on April 24 due to a power outage caused by damage to a cable during excavation work at the plant.
The release of wastewater began in August and TEPCO had discharged about 31,200 tons in four batches by the end of fiscal 2023.
Although TEPCO has detected tritium in samples collected near the outlet into the sea, the levels were far below the World Health Organization's limit of 10,000 becquerels for drinking water.
