Tokyo Electric Power Co. was set to release 850 tons of treated radioactive groundwater into the sea off the Fukushima No. 1 nuclear power plant by sundown on Sept. 14.
Tokyo Electric Power Co. was set to release 850 tons of treated radioactive groundwater into the sea off the Fukushima No. 1 nuclear power plant by sundown on Sept. 14.
The discharge marks the first release under the utility's “
TEPCO began discharging water after a third-party panel confirmed that the radioactive content was below the standard set by the utility.
The plan utilizes subdrains, which are essentially wells set up around the main buildings of the power plant to collect groundwater flowing into the complex. Once the groundwater has been pumped from those wells, it undergoes decontamination in a special facility for release into the ocean after being checked for radioactive content.
The Fukushima Prefectural Federation of Fisheries Cooperative Associations gave the green light to the operation on Aug. 11, and TEPCO began pumping in earnest on Sept. 3.
The release of the first batch of decontaminated groundwater, which had been stored in a tank since last year, started around 10 a.m. The water collected from Sept. 3 will be released in a few days.
TEPCO's standard is set at 1 becquerel of radioactive cesium per liter of decontaminated groundwater, 3 becquerels for elements that emit beta rays and 1,500 becquerels for tritium--a substance which is very hard to treat.
As for now, the utility plans to pump 100 to 200 tons of groundwater daily, but will increase the volume to 500 tons if it does not encounter any problems with the decontamination facilities.
TEPCO believes the subdrains can halve the approximately 300 tons of daily groundwater buildup at the plant. However, the utility is uncertain how many months it will take to see whether this holds true.