Tokyo Electric Power Company Holdings Inc. said Tuesday it may spend up to 20 to 30 years releasing contaminated water into the surrounding environment from its disaster-crippled Fukushima No. 1 nuclear power plant.
The possible time span was mentioned in draft plans Tepco drew up in line with a government panel’s report in February, calling the release of the water into the ocean or the air in the form of vapor a “realistic option.”
The company currently stores roughly 119 tons of water that still contains tritium and other radioactive substances after passing through a treatment process at the nuclear plant, which suffered a triple meltdown in March 2011 caused by a magnitude 9.0 earthquake and tsunami. The amount of contaminated water stored at the facility is still increasing.
According to the draft plans, Tepco will first conduct secondary treatment work to reduce the amount of radioactive substances in the water other than tritium — which cannot be removed by existing systems — to levels below national standards.
Following the treatment, the water will be released into the ocean, after being diluted with seawater to lower the radiation level to 1,500 becquerels per liter, or emitted into the air from a tall exhaust stack after being vaporized.
Tepco also plans to use social media to counter rumors that exposure to radiation from the released water is harmful.