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Radiation-contaminated water at Fukushima plant on the rise

The Fukushima No. 1 Nuclear Power Plant is pictured in this photo taken from a Mainichi helicopter on Nov. 10, 2014. (Mainichi)

FUKUSHIMA -- Efforts to reduce the amount of radiation-contaminated water at the crippled Fukushima No. 1 Nuclear Power Plant have proven helpless, and the overall amount of such water has actually increased, it has been learned.

Tokyo Electric Power Co. (TEPCO), the operator of the plant, had initially planned to halve the daily amount of contaminated groundwater to 150 metric tons by pumping up groundwater from wells called "groundwater drains" on the ocean side and "subdrains" inland. However, because the pumped water was found to be highly radioactive, the utility was unable to release it into the ocean, resulting in up to around 400 tons a day of tainted water being transferred back to the side of reactor buildings.

TEPCO started pumping up groundwater from the ocean-side drains in October, but gave up on releasing the water into the ocean after detecting a high concentration of radioactive materials and salt content in the water pumped from four of the five wells on the plant premises. Meanwhile, the amount of groundwater increased after its flow was stemmed by the 780-meter-long seaside impermeable wall, which is designed to prevent tainted groundwater from flowing out into the ocean. The resultant high water pressure warped the impermeable wall by about 20 centimeters, prompting TEPCO to reinforce the wall.

While TEPCO had boasted that it was able to significantly reduce risks at the plant thanks to the completion of the impermeable wall, the situation still remains unstable.

"We ended up building extra tanks (due to the increase of overall contaminated water), but we will never leak such water to the outside," Naohiro Masuda, president of TEPCO's Fukushima Daiichi Decommissioning Co., told a press conference.

TEPCO aims to cut the influx of groundwater into reactor buildings to somewhere under 100 tons a day by the end of fiscal 2016, and ultimately make the daily increase of tainted water close to zero by the end of 2020 -- the year of the Tokyo Olympics and Paralympics -- by putting the multi-nuclide removal equipment called ALPS into operation. TEPCO is planning to complete the entire decommissioning process by 2041-2051.

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