Tokyo Electric Power Co. on Monday started building a huge underground ice wall around the Fukushima No. 1 nuclear plant to reduce the generation of toxic water at the crippled complex.
Under the government-funded project, 1,550 pipes will be inserted into the ground to circulate coolant and freeze the surrounding soil. The measure is aimed at preventing groundwater from seeping into the plant’s four cracked reactor buildings and mixing with heavily radioactive water leaking out of them.
Tepco, as the beleaguered utility is known, plans to finish the 1.5-km wall and have it up and running by the end of March 2015. It will then take a few months or so to fully freeze the soil, a Tepco official said.
Late last month, nuclear regulators gave the green light to the unprecedented project after the utility succeeded in convincing them that it will not trigger significant subsidence that could further endanger the buildings. Evidence of land subsidence was seen at one of the buildings early in the crisis and more recently under some of the hundreds of water tanks set up on land overlooking the reactor buildings.
On Monday afternoon, plant workers started digging a hole for one of the pipes near the No. 1 reactor building, but the utility said it still needs the Nuclear Regulation Authority’s permission for work that could undermine the plant’s safety.
The buildup of radioactive water generated by the need to cool the damaged reactors is a major problem at the plant, where toxic water is building by around 400 tons a day due to the groundwater from the mountains that is entering reactor buildings 1 to 4.
In an another effort to deal with the toxic water problem, Tepco said Monday it had dumped 833 tons of untainted groundwater into the Pacific Ocean after intercepting it and diverting it through wells. The third release brought the total volume of clean water released under the so-called groundwater bypass system to 2,035 tons.