The session was held at the foreign ministry in Tokyo and offered an update on the planned disposal of more than 1 million tonnes of water that have been treated and kept in tanks at the crippled complex, where storage space is likely to run out by 2022
Japan plans to remove all radioactive particles from the water except tritium, an isotope of hydrogen that is hard to separate and is considered to be relatively harmless.
“Compared to evaporation, ocean release can be done more securely,” the spokesman said, pointing to common practice around the world where normally operating nuclear stations release water that contains tritium into the sea.
The briefing session followed submission on Friday by the industry ministry of a draft report on the disposal methods to a subcommittee considering the issue.
The government is exploring ways to deal with the waste water, which already totals more than 1 million tonnes with the volume increasing by more than 100 tonnes every day.
Releasing treated water into the sea in a controlled manner is common practice at nuclear power plants and was generally considered the most viable option for Fukushima-Daichi because it could be done quickly and would cost the least.