On March 11, 2011, a massive tsunami battered the Fukushima No. 1 nuclear power plant in northeastern Japan, triggering a crisis that unnerved the world.

In the 13 years since, the nation’s efforts to contend with the accident, rebuild the surrounding region and decommission the power plant have steadily progressed, with the generous support and understanding of the international community.

For some, however, concerns about the safety of the Fukushima decommissioning efforts remain. One of the biggest issues involves the discharge of treated water into the sea.