Nearly two years after the onset of the Fukushima Daiichi nuclear disaster, over 220,000 metric tons of contaminated water have been collected and stored on site, still another 75,000 tons remains in the reactor buildings. Every day at least another 40 tons of contaminated water are created, requiring additional storage tanks to be constructed.
Currently the concentrated saltwater receiving tanks are 95% filled to capacity. Currently 220,761 m3 of contaminated water is being stored, but the total capacity is only 232,000 m3.
The utility has been so far unable to prevent the contaminated water injected into the damaged reactors from flowing out of the buildings into the environment and even escaping directly into the ocean. Accumulated water levels in the Turbine Buildings are assumed to increase daily, some of the accumulation due to the interaction between the groundwater on-site and the water inside of the buildings.
Workers at Fukushima Daiichi use a water treatment system called SARRY to remove cesium prior to storing water in tanks. TEPCO is still working to complete construction of multi-nuclide removal equipment, but it is 4 months behind schedule.
The levels of radioactivity measured near the Unit 2 Sub-Drain have been on the rise since November, and while much focus has been justly applied to the continuous aerial release of radionuclides from the reactors themselves, with storage space running out it is critical to control the seeping of contamination through the local groundwater.
Source: The Denki Shimbun