The head of the International Atomic Energy Agency on Wednesday toured the Fukushima Daiichi nuclear power plant, which suffered a meltdown when a powerful earthquake and tsunami struck northeastern Japan in 2011.

IAEA Director General Rafael Grossi's visit comes as Japan continues efforts to decommission the crippled facility, a decades-long process fraught with difficulty.

Among the most pressing issues is the fate of more than 1 million tons of water that has been contaminated with radioactive materials after being used to cool the melted fuel cores at the plant.

The water is being treated to remove most, but not all, of the contaminants and stored in tanks on the facility's premises, where space is expected to run out by summer 2022.

The government and Tokyo Electric Power Company Holdings Inc., the plant's operator, are considering ways to safely dispose of the water, including releasing it into the ocean and evaporating it.

But local fishermen have voiced strong opposition to such plans for fear that Japanese consumers would shun seafood caught nearby, as those in neighboring South Korea have already done.

Grossi, an Argentine diplomat who succeeded the late Yukiya Amano as IAEA director general in December, has expressed eagerness to play a "constructive role," telling Foreign Minister Toshimitsu Motegi on Tuesday that the Vienna-based organization will help ensure transparency on the issue.

During his tour of the plant, Grossi is slated to speak in front of TEPCO employees undertaking the decommissioning process, which is scheduled to end 30 to 40 years after the disaster.

The process has been marred with setbacks, with the extensive damage at the Nos. 1 to 3 reactors posing technical challenges.

TEPCO had planned to begin assessing the wreckage inside the No. 1 unit's containment vessel using a drone in the latter half of 2019, but was forced to push back the survey due to a spike in radioactivity during the cutting of an entry point into the vessel.

Grossi, who is on a five-day trip to Japan, also met with Prime Minister Shinzo Abe on Tuesday and is slated to hold talks with Cabinet members including industry minister Hiroshi Kajiyama on Thursday.

==Kyodo

© Kyodo News International, Inc., source Newswire