This photo taken on Feb 22, 2023 shows some of about 1,000 huge tanks holding treated but still radioactive wastewater at the Fukushima Daiichi nuclear power plant, operated by Tokyo Electric Power Company Holdings (TEPCO), in Okuma town, northeastern Japan. (PHOTO / AP)

TOKYO - The operator of the crippled Fukushima Daiichi nuclear power plant has completed the construction of a system to release nuclear-contaminated water from the facility into the sea, local media reported Monday.

The plant's operator Tokyo Electric Power Company on Monayd completed tunnel drilling for the release, and removed heavy machinery from the working site 1 kilometer off the coast, public broadcaster NHK reported.

TEPCO then placed a cover on the tunnel's outlet to prevent the ingress of mud and sand, the final step of the construction, which began last August, said the report.

The Japanese government will decide the time of discharge based on the Nuclear Regulation Authority's inspection on Wednesday and the International Atomic Energy Agency's safety report, according to NHK.

READ MORE: Japan sends seawater into tunnel for Fukushima water discharg

Japan's recent rush in its dumping plan has met with strong opposition from civic groups and fishery industries both at home and abroad.