Tokyo Electric Power Co. announced completion Monday of a 780-meter coastal wall along the heavily damaged reactor buildings of the Fukushima No. 1 nuclear power plant.
Tepco hopes the wall will significantly reduce the amount of contaminated water that has continued to flow into the Pacific more than four years after the 2011 meltdown crisis.
The gigantic wall, which the utility describes as impermeable, has an underground section that reaches as deep as 30 meters. It will reduce the amount of tainted water flowing into the sea from 400 tons to 10 tons a day, according to Tepco’s estimate.
Until Monday, about 400 tons of groundwater was draining along the sides of the buildings and into the sea each day, after being contaminated with fallout from the 2011 meltdown crisis, according Tepco.
The utility says an estimated 150 tons of underground water is still flowing into the basements of the damaged reactor buildings each day.
The water, some of which has been circulated to cool melted nuclear fuel, is believed to be kept in place within the buildings by pressure exerted by higher underground water levels outside the buildings.
Last month, Tepco, after finally securing the consent of the local fishing industry, started draining underground water from around the plant buildings and dumping it into the sea after subjecting it to decontamination processes.
The launch of this draining operation put Tepco in a position to close the wall’s last 10-meter opening Monday.
The wall is now expected to reduce the amount of radioactive cesium and strontium entering the sea to one-fortieth of previous levels, and that of tritium to one-fifteenth of the previous levels, Tepco officials claimed.
source by japantimes