The Advanced Liquid Processing Systems (ALPS) is being used to remove radioactive elements from the cooling water. Officials hope to achieve their daily capacity of 2,000 tonnes when they enter full operation this month.
With 500,000 tonnes of contaminated water on-site and one reactor off-limits until 2025, decommissioning of the tsunami-stricken plant will take 40 years.
The man in charge of cleaning up the wrecked Fukushima Daiichi nuclear power plant has admitted there is little cause for optimism while thousands of workers continue their battle to contain huge quantities of radioactive water.