BERLIN (AP) — The U.N.'s nuclear watchdog said Friday that Japan is making “significant progress” on its plans to release treated radioactive wastewater from the wrecked Fukushima nuclear plant next year.

A team of experts from the International Atomic Energy Agency visited the plant in February and met with officials from the operator, Tokyo Electric Power Company Holdings, and the Ministry of Economy, Trade and Industry.

“Japan has made significant progress in its preparations, and the task force is satisfied that TEPCO and METI have identified the appropriate next steps for the water discharge scheduled for 2023,” IAEA Director-General Rafael Mariano Grossi said.

Japan has sought the IAEA’s assistance to ensure the release meets international safety standards and to reassure neighboring countries that have sharply criticized the plan. Grossi said the agency's experts would continue working so the team “can provide its conclusions before the discharge.”

The water is being stored in about 1,000 tanks at the damaged plant which must be removed so that facilities can be built for its decommissioning. The tanks are expected to reach their capacity of 1.37 million tons later this year.

A massive earthquake and tsunami in 2011 destroyed the Fukushima plant’s cooling systems, causing the meltdown of three reactors and the release of large amounts of radiation. Water used since the accident to cool the damaged reactor cores, which remain highly radioactive, has leaked extensively.