21 Août 2017
August 21, 2017
Work to finish ice wall at crippled plant to begin
The operator of the crippled Fukushima Daiichi nuclear plant will begin the final phase of creating an underground ice wall on Tuesday.
Tokyo Electric Power Company started the work 17 months ago, with the aim of preventing groundwater from entering reactor buildings and getting contaminated with radioactive substances.
The 1.5-kilometer ice barrier is deemed a key step to curb the buildup of tainted water at the plant.
The soil is frozen by sending liquid at minus 30 degrees Celsius into pipes buried around the buildings. But the utility has left a 7-meter section unfrozen, fearing the sudden fall in groundwater levels around the buildings.
There were concerns that the difference of water levels in and outside the reactor buildings would cause tainted water inside to leak out.
But last Tuesday, the Nuclear Regulation Authority said safety measures are ready and gave its approval to freeze of the final section.
Officials of the utility say they will carefully monitor the freezing process of the remaining section.
They say it may take longer to fully freeze than other areas, because the flow of groundwater has been concentrated in that section.
The officials expect that the wall, when completed, will reduce the inflow of groundwater to the buildings from 140 tons a day to less than 100 tons.