International Atomic Energy Agency (IAEA) chief Rafael Grossi met Fukushima residents on Wednesday to assuage concerns over the safety of Japan's plan to release treated radioactive water from the wrecked Fukushima No. 1 nuclear power plant into the ocean.

In a major milestone for the decommissioning of the power plant, damaged in a massive earthquake and tsunami in 2011, the IAEA on Tuesday said a two-year review showed Japan's plans for the water release would have a negligible impact on the environment.

Japanese fishing unions have long opposed the plan, saying it would undo work to repair reputational damage after several countries banned some Japanese food products for fear of radiation. Japan regularly tests seafood from the Fukushima area and found it to be safe.