The industry ministry said Monday it would be safe to release water contaminated by the Fukushima nuclear disaster into the ocean, stressing that on an annual basis the amount of radiation measured near the release point would be very small compared to levels to which humans are naturally exposed.

Discharging the water into the Pacific Ocean over the course of a year would amount to between just one-1,600th and one-40,000th of the radiation to which humans are naturally exposed, the Economy, Trade and Industry Ministry, or METI, told a government subcommittee on the issue.

Water used to cool the melted-down cores and groundwater from close to the damaged plant contain some radioactive materials, and are currently being collected and stored in tanks on the plant grounds.

But space is running out fast, and the government is exploring ways to deal with the waste water — which already totals more than 1 million tons with the volume increasing by more than 100 tons every day.

According to an estimate performed by the ministry, annual radiation levels near the release point after a release would be between 0.052 and 0.62 microsievert at sea, and 1.3 microsieverts in the atmosphere, compared with the 2,100 microsieverts that humans come into contact with each year in daily life.