Behind this is the fact that a way to get rid of treated water, or tritium water, has not been decided yet. The government and TEPCO will have to make a tough decision on disposal of tritium water down the road.
Water volume increasing
At the Fukushima No. 1 nuclear plant, groundwater and other water enters the reactor buildings that suffered meltdowns, where the water becomes contaminated. This produces about 160 tons of contaminated water per day. Purification devices remove many of the radioactive materials, but tritium — a radioactive isotope of hydrogen — cannot be removed for technical reasons. Thus, treated water that includes only tritium continues to increase.
Currently, the storage tanks have a capacity of about 1.13 million tons. About 1.07 million tons of that capacity is now in use, of which about 80 percent is for such treated water.