The operator of Fukushima Daiichi nuclear power plant says it will begin full-fledged construction on Thursday of facilities to release treated water from the crippled plant into the ocean. But it suggested the facilities would not be completed until around next summer, which would be later than when the government plans to start the release.
Reactors at Fukushima Daiichi suffered meltdowns in the March 2011 earthquake and tsunami.
Water used to cool molten fuel mixes with rain and groundwater. The accumulated water is treated to remove most of the radioactive materials and stored in tanks on the plant's premises.
The filtered water still contains tritium.
The Japanese government plans to dilute the water so that the concentration of tritium is well below the percentage permitted by national regulations. The amount of tritium in the diluted water is also expected to be below the guidance levels for drinking water quality established by the World Health Organization.
Plant operator Tokyo Electric Power Company plans to build facilities to release the diluted water about one kilometer offshore, starting around next spring.
On Tuesday, Fukushima Prefecture and the towns of Okuma and Futaba, which host the plant, approved the construction of an underwater tunnel and other facilities.
Specifically, the utility will start constructing a tunnel for operating an underground tunneling machine, and installing pipes to transfer the treated water.
It explained that construction work could be delayed by weather conditions.
Ono Akira, president of Fukushima Daiichi Decontamination and Decommissioning Engineering Company, said there are various opinions such as concerns about reputational damage and safety, so he will continue with his efforts to convince relevant parties.