The International Atomic Energy Agency and Japan have agreed to begin an onsite safety review of the water release at the Fukushima-Daiichi nuclear power station in September, marking the beginning of a major cleanup project at the nuclear station that could last decades.

The agency said its officials will travel to Japan for meetings to discuss the plans and activities for the water discharge, as agreed on Thursday during a meeting of IAEA director-general Rafael Mariano Grossi and Japan’s minister of economy, trade and industry Hiroshi Kajiyama.

Japan announced in April 2021 that it planned to discharge the treated water into the sea in about two years’ time. Shortly after this announcement, Japan asked for help from the IAEA and the Vienna-based agency agreed. The agency’s visit will be the first in a series of missions over the coming years as it fulfils its commitment to support Japan before, during and after the water disposal. The entire operation is expected to last for decades.