TEPCO completes fourth round of reclaimed water releases for fiscal year 2024

Tokyo Electric Power Company Holdings (Tepco) said on Sunday it had completed the fourth round of discharging reclaimed water from its disaster-damaged Fukushima No. 1 nuclear power plant in Fukushima Prefecture into the sea, planned for fiscal year 2024.

Since the discharge began on August 24 last year, Tepco has released around 62,400 tonnes of the treated water, which contains small amounts of radioactive tritium, over the course of a total of eight cycles.

In each round, about 7,800 tonnes of treated water were diluted with a large amount of seawater before being released over a period of two weeks through an underwater tunnel offshore to a point about one kilometre from the plant.

The government and TEPCO are monitoring tritium levels in the surrounding waters. The levels are well below the limit set by the government.

Tepco plans three more rounds of relief measures in the current fiscal year, which ends in March 2025.

The company hopes to begin dismantling storage tanks at the damaged power plant, which experienced a triple meltdown in March 2011 and was empty after the water leak, in January next year at the earliest. A total of 21 tanks are to be dismantled by the end of March 2026.