Tokyo Electric Power Co. plans to dump contaminated water from its crippled Fukushima No. 1 nuclear plant into the Pacific Ocean after removing radioactive substances to reduce contamination to legally permissible levels.
Tepco said Thursday the measure is necessary because the utility fears it will eventually run out of capacity to store radioactive water that continues to accumulate at the plant due to water being injected to help cool the three reactors that experienced core meltdowns in March 2011.
Despite the plan, the utility acknowledged it needs the approval of local governments and other parties before it actually discharges the water into the ocean. "Nothing specific has been decided at this moment," one Tepco official said.
Water that has been used to cool the damaged reactors is recycled and used as coolant after radioactive levels in it have been lowered in a water-processing facility. But the total amount of contaminated water is increasing because the existing water flow allows an influx of about 400 tons of groundwater a day.
Tepco is increasing the number of storage tanks to deal with the situation, but warns they will eventually reach full capacity.
As a key step in the water release, Tepco will operate a new facility that can remove about different 60 types of radioactive substances, more than the existing water processing facility that has mainly worked to reduce the concentration of cesium. But as the new facility is not capable of removing radioactive tritium, an official said Tepco will consider diluting the processed water before releasing it to the sea.