The operator of the crippled Fukushima Daiichi nuclear power plant on Monday discharged groundwater filtered after being pumped up from wells around damaged reactor buildings into the ocean, in an effort to curb the amount of toxic water building up at the complex.
The amount of radioactive water is increasing every day at the plant, as some 300 tons per day of groundwater is seeping into the reactor buildings and mixing with highly toxic water generated in the process of cooling reactors that suffered meltdowns. The problem is hampering efforts to decommission the crippled plant more than four years after the nuclear accident triggered by the 2011 quake and tsunami.
By pumping up groundwater through a total of 41 wells and discharging it into the sea after treatment, the government and Tokyo Electric Power Co expect to halve the amount of groundwater flowing into the reactor buildings.
On Monday, TEPCO released some 850 tons of filtered groundwater, which is part of some 4,000 tons pumped up last year on a trial basis and stored in tanks, after confirming that radiation levels are below measurable limits.
Tritium, which cannot be removed through the existing water processing facilities, measured 330 to 600 becquerels per liter, well below the legally allowable limit of 1,500 bq, the utility said, citing analyses conducted by the company and an outside organization.
The project is one of TEPCO’s key measures to tackle the toxic water buildup.
Fishermen in Fukushima Prefecture had long opposed the plan amid concerns over pollution of the ocean and marine products, but they approved it in August on condition that the government and the utility continue paying compensation to them for as long as the nuclear crisis continues to cause damage to their business, among other requirements.
TEPCO is behind schedule on a project to build a huge underground ice wall at the site—another key measure to prevent radioactive water from further increasing there.