The Japanese government claims it would be safe to release water used to cool the melted reactors at the Fukushima Daiichi Nuclear Plant to the Pacific Ocean, and that the health risk to humans would be "significantly small".

Despite treatment with an advance system, the water does contain some radioactive materials from the cores and the grounds around the plant, which had an unprecedented triple meltdown after the massive earthquake and tsunami on 11 March 2011.  The water is currently being collected and stored in tanks on the plant grounds.  But the tanks are running out of space and are expected to become full by the summer of 2022.  

The Ministry of Economy, Trade, and Industry (METI) told a government committee that water into the Pacific Ocean over the course of a year would have between just one-1,600th and one-40,000th of the radiation to which humans are naturally exposed.  

Japan's northeastern Asian neighbors have expressed concern over plans to release the radioactive water into the Pacific Ocean.  But in 2018, one nuclear expert from the International Atomic Energy Agency (IAEA) said that a controlled discharge of such contaminated water "is something which is applied in many nuclear facilities, so it is not something that is new".