Japan began a controversial discharge of treated tritium-laced water from the Fukushima No. 1 nuclear power plant on Thursday, a major step in the decommissioning process for the reactors hit by a triple meltdown following the March 2011 tsunami.

The solution, hailed as safe by the government, follows a struggle for over a decade to deal with an enormous amount of radioactive water building up in tanks on the premises of the crippled plant.

Tokyo Electric Power Company Holdings (Tepco), the plant’s operator, started releasing the water at 1:03 p.m. after weather and sea conditions were judged favorable. No anomalies were reported in the initial release.