Full-fledged operation of the advanced liquid processing system (ALPS) will start in about four months after its performance is verified. Tepco said it plans to process 250 tons of irradiated water a day using the new multinuclide removal system, which has the capacity to dispose of up to 500 tons when fully operational.

ALPS has been installed to clean the contaminated water flowing through a 4-km loop and used to cool the crippled reactors. Unlike the existing system that can only remove radioactive cesium, ALPS can extract almost all radioactive substances except for tritium.

The new system is necessary to ensure the safe storage of processed water, according to Tepco.

Although the utility initially planned to start a test run by the end of December, its introduction was delayed after containers used to store processed wastewater were found to lack robustness. As Tepco has enhanced the containers' durability, the Nuclear Regulation Agency approved the start of the trial run.

After the March 11, 2011, tsunami inundated the Fukushima No. 1 nuclear plant, causing three catastrophic meltdowns, Tepco created a system in which water used to cool reactors 1 to 3 passes through the current system that removes radioactive cesium. The processed water is then stored in tanks.